Coaxial cable, or coax (pronounced /ˈkoʊ.æks/) is a type of electrical cable that has an inner conductor surrounded by a tubular insulating layer, surrounded by a tubular conducting shield. Many coaxial cables also have an insulating outer sheath or jacket. The term coaxial comes from the inner conductor and the outer shield sharing a geometric axis. Coaxial cable was invented by English physicist, engineer, and mathematician Oliver Heaviside, who patented the design in 1880.
Coaxial cable is a type of transmission line, used to carry high frequency electrical signals with low losses. It is used in such applications as telephone trunklines, broadband internet networking cables, high speed computer data busses, carrying cable television signals, and connecting radio transmitters and receivers to their antennas. It differs from other shielded cables because the dimensions of the cable and connectors are controlled to give a precise, constant conductor spacing, which is needed for it to function efficiently as a transmission line.
Coaxial cable is used as a transmission line for radio frequency signals. Its applications include feedlines connecting radio transmitters and receivers to their antennas, computer network (e.g., Ethernet) connections, digital audio (S/PDIF), and distribution of cable television signals. One advantage of coaxial over other types of radio transmission line is that in an ideal coaxial cable the electromagnetic field carrying the signal exists only in the space between the inner and outer conductors. This allows coaxial cable runs to be installed next to metal objects such as gutters without the power losses that occur in other types of transmission lines. Coaxial cable also provides protection of the signal from external electromagnetic interference.
Coaxial cable conducts electrical signal using an inner conductor (usually a solid copper, stranded copper or copper plated steel wire) surrounded by an insulating layer and all enclosed by a shield, typically one to four layers of woven metallic braid and metallic tape. The cable is protected by an outer insulating jacket. Normally, the shield is kept at ground potential and a signal carrying voltage is applied to the center conductor. The advantage of coaxial design is that electric and magnetic fields are restricted to the dielectric with little leakage outside the shield. Conversely, electric and magnetic fields outside the cable are largely kept from interfering with signals inside the cable. Larger diameter cables and cables with multiple shields have less leakage. This property makes coaxial cable a good choice for carrying weak signals that cannot tolerate interference from the environment or for stronger electrical signals that must not be allowed to radiate or couple into adjacent structures or circuits.
The characteristic impedance of the cable () is determined by the dielectric constant of the inner insulator and the radii of the inner and outer conductors. In radio frequency systems, where the cable length is comparable to the wavelength of the signals transmitted, a uniform cable characteristic impedance is important to minimize loss. The source and load impedances are chosen to match the impedance of the cable to ensure maximum power transfer and minimum standing wave ratio. Other important properties of coaxial cable include attenuation as a function of frequency, voltage handling capability, and shield quality.
Coaxial cable design choices affect physical size, frequency performance, attenuation, power handling capabilities, flexibility, strength, and cost. The inner conductor might be solid or stranded; stranded is more flexible. To get better high-frequency performance, the inner conductor may be silver-plated. Copper-plated steel wire is often used as an inner conductor for cable used in the cable TV industry.
The insulator surrounding the inner conductor may be solid plastic, a foam plastic, or air with spacers supporting the inner wire. The properties of the dielectric insulator determine some of the electrical properties of the cable. A common choice is a solid polyethylene (PE) insulator, used in lower-loss cables. Solid Teflon (PTFE) is also used as an insulator. Some coaxial lines use air (or some other gas) and have spacers to keep the inner conductor from touching the shield.
Many conventional coaxial cables use braided copper wire forming the shield. This allows the cable to be flexible, but it also means there are gaps in the shield layer, and the inner dimension of the shield varies slightly because the braid cannot be flat. Sometimes the braid is silver-plated. For better shield performance, some cables have a double-layer shield. The shield might be just two braids, but it is more common now to have a thin foil shield covered by a wire braid. Some cables may invest in more than two shield layers, such as "quad-shield", which uses four alternating layers of foil and braid. Other shield designs sacrifice flexibility for better performance; some shields are a solid metal tube. Those cables cannot be bent sharply, as the shield will kink, causing losses in the cable. When a foil shield is used a small wire conductor incorporated into the foil makes soldering the shield termination easier.
For high-power radio-frequency transmission up to about 1 GHz, coaxial cable with a solid copper outer conductor is available in sizes of 0.25 inch upward. The outer conductor is corrugated like a bellows to permit flexibility and the inner conductor is held in position by a plastic spiral to approximate an air dielectric. One brand name for such cable is Heliax.
Coaxial cables require an internal structure of an insulating (dielectric) material to maintain the spacing between the center conductor and shield. The dielectric losses increase in this order: Ideal dielectric (no loss), vacuum, air, polytetrafluoroethylene (PTFE), polyethylene foam, and solid polyethylene. A low relative permittivity allows for higher-frequency usage. An inhomogeneous dielectric needs to be compensated by a non-circular conductor to avoid current hot-spots.
While many cables have a solid dielectric, many others have a foam dielectric that contains as much air or other gas as possible to reduce the losses by allowing the use of a larger diameter center conductor. Foam coax will have about 15% less attenuation but some types of foam dielectric can absorb moisture—especially at its many surfaces — in humid environments, significantly increasing the loss. Supports shaped like stars or spokes are even better but more expensive and very susceptible to moisture infiltration. Still more expensive were the air-spaced coaxials used for some inter-city communications in the mid-20th century. The center conductor was suspended by polyethylene discs every few centimeters. In some low-loss coaxial cables such as the RG-62 type, the inner conductor is supported by a spiral strand of polyethylene, so that an air space exists between most of the conductor and the inside of the jacket. The lower dielectric constant of air allows for a greater inner diameter at the same impedance and a greater outer diameter at the same cutoff frequency, lowering ohmic losses. Inner conductors are sometimes silver-plated to smooth the surface and reduce losses due to skin effect. A rough surface extends the current path and concentrates the current at peaks, thus increasing ohmic loss.
The insulating jacket can be made from many materials. A common choice is PVC, but some applications may require fire-resistant materials. Outdoor applications may require the jacket to resist ultraviolet light, oxidation, rodent damage, or direct burial. Flooded coaxial cables use a water blocking gel to protect the cable from water infiltration through minor cuts in the jacket. For internal chassis connections the insulating jacket may be omitted.
Twin-lead transmission lines have the property that the electromagnetic wave propagating down the line extends into the space surrounding the parallel wires. These lines have low loss, but also have undesirable characteristics. They cannot be bent, tightly twisted, or otherwise shaped without changing their characteristic impedance, causing reflection of the signal back toward the source. They also cannot be buried or run along or attached to anything conductive, as the extended fields will induce currents in the nearby conductors causing unwanted radiation and detuning of the line. Coaxial lines largely solve this problem by confining virtually all of the electromagnetic wave to the area inside the cable. Coaxial lines can therefore be bent and moderately twisted without negative effects, and they can be strapped to conductive supports without inducing unwanted currents in them.
In radio-frequency applications up to a few gigahertz, the wave propagates primarily in the transverse electric magnetic (TEM) mode, which means that the electric and magnetic fields are both perpendicular to the direction of propagation. However, above a certain cutoff frequency, transverse electric (TE) or transverse magnetic (TM) modes can also propagate, as they do in a waveguide. It is usually undesirable to transmit signals above the cutoff frequency, since it may cause multiple modes with different phase velocities to propagate, interfering with each other. The outer diameter is roughly inversely proportional to the cutoff frequency. A propagating surface-wave mode that does not involve or require the outer shield but only a single central conductor also exists in coax but this mode is effectively suppressed in coax of conventional geometry and common impedance. Electric field lines for this [TM] mode have a longitudinal component and require line lengths of a half-wavelength or longer.
Coaxial cable may be viewed as a type of waveguide. Power is transmitted through the radial electric field and the circumferential magnetic field in the TEM00 transverse mode. This is the dominant mode from zero frequency (DC) to an upper limit determined by the electrical dimensions of the cable.
The ends of coaxial cables usually terminate with connectors. Coaxial connectors are designed to maintain a coaxial form across the connection and have the same impedance as the attached cable. Connectors are usually plated with high-conductivity metals such as silver or tarnish-resistant gold. Due to the skin effect, the RF signal is only carried by the plating at higher frequencies and does not penetrate to the connector body. Silver however tarnishes quickly and the silver sulfide that is produced is poorly conductive, degrading connector performance, making silver a poor choice for this application.
In the following section, these symbols are used:
The best coaxial cable impedances in high-power, high-voltage, and low-attenuation applications were experimentally determined at Bell Laboratories in 1929 to be 30, 60, and 77 Ω, respectively. For a coaxial cable with air dielectric and a shield of a given inner diameter, the attenuation is minimized by choosing the diameter of the inner conductor to give a characteristic impedance of 76.7 Ω. When more common dielectrics are considered, the best-loss impedance drops down to a value between 52–64 Ω. Maximum power handling is achieved at 30 Ω.
The approximate impedance required to match a centre-fed dipole antenna in free space (i.e., a dipole without ground reflections) is 73 Ω, so 75 Ω coax was commonly used for connecting shortwave antennas to receivers. These typically involve such low levels of RF power that power-handling and high-voltage breakdown characteristics are unimportant when compared to attenuation. Likewise with CATV, although many broadcast TV installations and CATV headends use 300 Ω folded dipole antennas to receive off-the-air signals, 75 Ω coax makes a convenient 4:1 balun transformer for these as well as possessing low attenuation.
The arithmetic mean between 30 Ω and 77 Ω is 53.5 Ω; the geometric mean is 48 Ω. The selection of 50 Ω as a compromise between power-handling capability and attenuation is in general cited as the reason for the number. 50 Ω also works out tolerably well because it corresponds approximately to the drive impedance (ideally 36 ohms) of a quarter-wave monopole, mounted on a less than optimum ground plane such as a vehicle roof. The match is better at low frequencies, such as for CB Radio around 27 MHz, where the roof dimensions are much less than a quarter wavelength, and relatively poor at higher frequencies, VHF and UHF, where the roof dimensions may be several wavelengths. The match is at best poor, because the antenna drive impedance, due to the imperfect ground plane, is reactive rather than purely resistive, and so a 36 ohm coaxial cable would not match properly either. Installations which need exact matching will use some kind of matching circuit at the base of the antenna, or elsewhere, in conjunction with a carefully chosen (in terms of wavelength) length of coaxial, such that a proper match is achieved, which will be only over a fairly narrow frequency range.
RG-62 is a 93 Ω coaxial cable originally used in mainframe computer networks in the 1970s and early 1980s (it was the cable used to connect IBM 3270 terminals to IBM 3274/3174 terminal cluster controllers). Later, some manufacturers of LAN equipment, such as Datapoint for ARCNET, adopted RG-62 as their coaxial cable standard. The cable has the lowest capacitance per unit-length when compared to other coaxial cables of similar size.
All of the components of a coaxial system should have the same impedance to avoid internal reflections at connections between components. Such reflections may cause signal attenuation and ghosting TV picture display; multiple reflections may cause the original signal to be followed by more than one echo. In analog video or TV systems, this causes ghosting in the image. Reflections also introduce standing waves, which cause increased losses and can even result in cable dielectric breakdown with high-power transmission (see Impedance matching). Briefly, if a coaxial cable is open, the termination has nearly infinite resistance, this causes reflections; if the coaxial cable is short-circuited, the termination resistance is nearly zero, there will be reflections with the opposite polarity. Reflection will be nearly eliminated if the coaxial cable is terminated in a pure resistance equal to its impedance.
Taking the characteristic impedance at high frequencies,
One should also know the inductance and capacitance of the two concentric cylindrical conductors which is the coaxial cable. By definition and getting the electric field by the formula of electric field of an infinite line,
where is the diameter of the bigger conductor and is the diameter of the smaller conductor. The capacitance can then be solved by substitution,
Substituting the derived capacitance and inductance,
Signal leakage is the passage of electromagnetic fields through the shield of a cable and occurs in both directions. Ingress is the passage of an outside signal into the cable and can result in noise and disruption of the desired signal. Egress is the passage of signal intended to remain within the cable into the outside world and can result in a weaker signal at the end of the cable and radio frequency interference to nearby devices. Severe leakage usually results from improperly installed connectors or faults in the cable shield.
For example, in the United States, signal leakage from cable television systems is regulated by the FCC, since cable signals use the same frequencies as aeronautical and radionavigation bands. CATV operators may also choose to monitor their networks for leakage to prevent ingress. Outside signals entering the cable can cause unwanted noise and picture ghosting. Excessive noise can overwhelm the signal, making it useless.
An ideal shield would be a perfect conductor with no holes, gaps, or bumps connected to a perfect ground. However, a smooth solid highly conductive shield would be heavy, inflexible, and expensive. Such coax is used for straight line feeds to commercial radio broadcast towers. More economical cables must make compromises between shield efficacy, flexibility, and cost, such as the corrugated surface of flexible hardline, flexible braid, or foil shields. Since shields cannot be perfect conductors, current flowing on the inside of the shield produces an electromagnetic field on the outer surface of the shield.
Consider the skin effect. The magnitude of an alternating current in a conductor decays exponentially with distance beneath the surface, with the depth of penetration being proportional to the square root of the resistivity. This means that, in a shield of finite thickness, some small amount of current will still be flowing on the opposite surface of the conductor. With a perfect conductor (i.e., zero resistivity), all of the current would flow at the surface, with no penetration into and through the conductor. Real cables have a shield made of an imperfect, although usually very good, conductor, so there must always be some leakage.
The gaps or holes, allow some of the electromagnetic field to penetrate to the other side. For example, braided shields have many small gaps. The gaps are smaller when using a foil (solid metal) shield, but there is still a seam running the length of the cable. Foil becomes increasingly rigid with increasing thickness, so a thin foil layer is often surrounded by a layer of braided metal, which offers greater flexibility for a given cross-section.
Signal leakage can be severe if there is poor contact at the interface to connectors at either end of the cable or if there is a break in the shield.
To greatly reduce signal leakage into or out of the cable, by a factor of 1000, or even 10,000, superscreened cables are often used in critical applications, such as for neutron flux counters in nuclear reactors.
Superscreened cables for nuclear use are defined in IEC 96-4-1, 1990, however as there have been long gaps in the construction of nuclear power stations in Europe, many existing installations are using superscreened cables to the UK standard AESS(TRG) 71181 which is referenced in IEC 61917.
A continuous current, even if small, along the imperfect shield of a coaxial cable can cause visible or audible interference. In CATV systems distributing analog signals the potential difference between the coaxial network and the electrical grounding system of a house can cause a visible "hum bar" in the picture. This appears as a wide horizontal distortion bar in the picture that scrolls slowly upward. Such differences in potential can be reduced by proper bonding to a common ground at the house. See ground loop.
External fields create a voltage across the inductance of the outside of the outer conductor between sender and receiver. The effect is less when there are several parallel cables, as this reduces the inductance and, therefore, the voltage. Because the outer conductor carries the reference potential for the signal on the inner conductor, the receiving circuit measures the wrong voltage.
The transformer effect is sometimes used to mitigate the effect of currents induced in the shield. The inner and outer conductors form the primary and secondary winding of the transformer, and the effect is enhanced in some high-quality cables that have an outer layer of mu-metal. Because of this 1:1 transformer, the aforementioned voltage across the outer conductor is transformed onto the inner conductor so that the two voltages can be cancelled by the receiver. Many sender and receivers have means to reduce the leakage even further. They increase the transformer effect by passing the whole cable through a ferrite core one or more times.
Common mode current occurs when stray currents in the shield flow in the same direction as the current in the center conductor, causing the coax to radiate.
Most of the shield effect in coax results from opposing currents in the center conductor and shield creating opposite magnetic fields that cancel, and thus do not radiate. The same effect helps ladder line. However, ladder line is extremely sensitive to surrounding metal objects, which can enter the fields before they completely cancel. Coax does not have this problem, since the field is enclosed in the shield. However, it is still possible for a field to form between the shield and other connected objects, such as the antenna the coax feeds. The current formed by the field between the antenna and the coax shield would flow in the same direction as the current in the center conductor, and thus not be canceled. Energy would radiate from the coax itself, affecting the radiation pattern of the antenna. With sufficient power this could be a hazard to people near the cable. A properly placed and properly sized balun can prevent common mode radiation in coax. An isolating transformer or blocking capacitor can be used to couple a coaxial cable to equipment, where it is desirable to pass radio-frequency signals but to block direct current or low-frequency power.
Most coaxial cables have a characteristic impedance of either 50, 52, 75, or 93 Ω. The RF industry uses standard type-names for coaxial cables. Thanks to television, RG-6 is the most commonly used coaxial cable for home use, and the majority of connections outside Europe are by F connectors.
A series of standard types of coaxial cable were specified for military uses, in the form "RG-#" or "RG-#/U". They date from World War II and were listed in MIL-HDBK-216 published in 1962. These designations are now obsolete. The RG designation stands for Radio Guide; the U designation stands for Universal. The current military standard is MIL-SPEC MIL-C-17. MIL-C-17 numbers, such as "M17/75-RG214", are given for military cables and manufacturer's catalog numbers for civilian applications. However, the RG-series designations were so common for generations that they are still used, although critical users should be aware that since the handbook is withdrawn there is no standard to guarantee the electrical and physical characteristics of a cable described as "RG-# type". The RG designators are mostly used to identify compatible connectors that fit the inner conductor, dielectric, and jacket dimensions of the old RG-series cables.
|Core (mm)||Dielectric||Outside diameter||Shields||Remarks||Max. attenuation, 750 MHz |
|RG-6/U||75||1.024||PF||0.75||0.185||4.7||0.270||6.86||Double||Low loss at high frequency for cable television, satellite television and cable modems||5.650|
|RG-6/UQ||75||1.024||PF||0.75||0.185||4.7||0.298||7.57||Quad||This is "quad shield RG-6". It has four layers of shielding; regular RG-6 has only one or two||5.650|
|RG-7||75||1.30||PF||0.225||5.72||0.320||8.13||Double||Low loss at high frequency for cable television, satellite television and cable modems||4.570|
|RG-8/U||50||2.17||PE||0.285||7.2||0.405||10.3||Amateur radio; Thicknet (10BASE5) is similar||5.967|
|RG-8X||50||1.0||PF||0.75||0.185||4.7||0.242||6.1||Double||A thinner version, with the electrical characteristics of RG-8U in a diameter similar to RG-6.||10.946|
|RG-11/U||75||1.63||PE||0.66-.85||0.285||7.2||0.412||10.5||Dual/triple/quad||Low loss at high frequency for cable and satellite television. Used for long drops and underground conduit, similar to RG7 but generally lower loss.||3.650|
|RG-56/U||48||1.4859||0.308||7.82||Dual braid shielded||Rated to 8000 volts, rubber dielectric|
|RG-58/U||50||0.81||PE||0.66||0.116||2.9||0.195||5.0||Single||Used for radiocommunication and amateur radio, thin Ethernet (10BASE2) and NIM electronics, Loss 1.056 dB/m @ 2.4 GHz. Common.||13.104|
|RG-59/U||75||0.64||PE||0.66||0.146||3.7||0.242||6.1||Single||Used to carry baseband video in closed-circuit television, previously used for cable television. In general, it has poor shielding but will carry an HQ HD signal or video over short distances.||9.708|
|RG-59A/U||75||0.762||PF||0.78||0.146||3.7||0.242||6.1||Single||Similar physical characteristics as RG-59 and RG-59/U, but with a higher velocity factor. 8.9@700 MHz||8.900|
|3C-2V||75||0.50||PE||0.85||3.0||5.4||Single||Used to carry television, video observation systems, and other. PVC jacket.|
|5C-2V||75||0.80||PE||0.82±0.02||0.181||4.6||0.256||6.5||Double||Used for interior lines for monitoring system, CCTV feeder lines, wiring between the camera and control unit and video signal transmission. PVC jacket.|
|RG-60/U||50||1.024||PE||0.425||10.8||Single||Used for high-definition cable TV and high-speed cable Internet.|
|RG-62/U||92||PF||0.84||0.242||6.1||Single||Used for ARCNET and automotive radio antennas.|
|RG-62A||93||ASP||0.242||6.1||Single||Used for NIM electronics|
|RG-63||125||1.2||PE||0.405||10.29||Double braid||Used for aerospace||4.6|
|RG-142/U||50||0.94||PTFE||0.116||2.95||0.195||4.95||Double braid||Used for test equipment||9.600|
|RG-174/U||50||7x0.16||PE||0.66||0.059||1.5||0.100||2.55||Single||Common for Wi-Fi pigtails: more flexible but higher loss than RG58; used with LEMO 00 connectors in NIM electronics.||23.565|
|RG-178/U||50||7×0.1||PTFE||0.69||0.033||0.84||0.071||1.8||Single||Used for high-frequency signal transmission. 42.7 @ 900 MHz, Core material: Ag-plated Cu-clad Steel||42.700|
|RG-179/U||75||7×0.1||PTFE||0.67||0.063||1.6||0.098||2.5||Single||VGA RGBHV, Core material: Ag-plated Cu|
|RG-180B/U||95||0.31||PTFE||0.102||2.59||0.145||3.68||Single silver-covered copper||VGA RGBHV, Core material: Ag-plated Cu-clad steel|
|RG-188A/U||50||7×0.16||PTFE||0.70||0.06||1.52||0.1||2.54||Single||26.2 @ 1000 MHz, Core material: Ag-plated Cu-clad steel||26.200|
|RG-195||95||0.305||PTFE||0.102||2.59||0.145||3.68||Single||PTFE jacket suitable for direct burial, Core material: Ag-plated Cu-clad steel|||
|RG-213/U||50||7×0.75||PE||0.66||0.285||7.2||0.405||10.3||Single||For radiocommunication and amateur radio, EMC test antenna cables. Typically lower loss than RG58. Common.||5.967|
|RG-214/U||50||7×0.75||PE||0.66||0.285||7.2||0.425||10.8||Double||Used for high-frequency signal transmission.||6.702|
|RG-218||50||4.963||PE||0.66||0.660 (0.680?)||16.76 (17.27?)||0.870||22||Single||Large diameter, not very flexible, low-loss (2.5 dB/100 ft @ 400 MHz), 11 kV dielectric withstand.||2.834|
|RG-223/U||50||0.88||PE||0.66||0.0815||2.07||0.212||5.4||Double||Silver-plated shields. Sample RG-223 Datasheet||11.461|
|RG-316/U||50||7×0.17||PTFE||0.695||0.060||1.5||0.098||2.6||Single||Used with LEMO 00 connectors in NIM electronics||22.452|
|RG-402/U||50||0.93||PTFE||3.0||0.1409||3.58||Single silver-plated copper||Semi-rigid, 0.91 dB/m@5 GHz||27.700|
|RG-405/U||50||0.51||PTFE||1.68||0.0865||2.20||Single silver-plated copper-clad steel||Semi-rigid, 1.51 dB/m@5 GHz||46.000|
|H155||50||19 × 0.28||PF||0.79||0.0984||2.5||0.2126||5.4||Double||Lower loss at high frequency for radiocommunication and amateur radio|
|H500||50||2.5||PF||0.81||0.1772||4.5||0.386||9.8||Double||Low loss at high frequency for radiocommunication and amateur radio, 4.45 @ 1000 MHz||4.450|
|LMR-100||50||0.46||PE||0.66||0.0417||1.06||0.110||2.79||Double||Low loss communications, 1.36 dB/meter @ 2.4 GHz||20.725|
|LMR-195||50||0.94||PF||0.80||0.073||1.85||0.195||4.95||Double||Low loss communications, 0.620 dB/meter @ 2.4 GHz||10.125|
|50||1.12||PF||0.83||0.116||2.95||0.195||4.95||Double||Low-loss communications, 0.554 dB/meter @ 2.4 GHz||9.035|
|50||1.42||PF||0.84||0.150||3.81||0.240||6.1||Double||Amateur radio, low-loss replacement for RG-8X||6.877|
|50||2.74||PF||0.85||0.285||7.24||0.405||10.29||Double||Low-loss communications, 0.223 dB/meter @ 2.4 GHz, Core material: Cu-clad Al||3.544|
|LMR-500||50||3.61||PF||0.86||0.370||9.4||0.500||12.7||Double||Low-loss communications, Core material: Cu-clad Al||2.800|
|LMR-600||50||4.47||PF||0.87||0.455||11.56||0.590||14.99||Double||Low-loss communications, 0.144 dB/meter @ 2.4 GHz, Core material: Cu-clad Al||2.264|
|LMR-900||50||6.65||PF||0.87||0.680||17.27||0.870||22.10||Double||Low-loss communications, 0.098 dB/meter @ 2.4 GHz, Core material: BC tube||1.537|
|LMR-1200||50||8.86||PF||0.88||0.920||23.37||1.200||30.48||Double||Low-loss communications, 0.075 dB/meter @ 2.4 GHz, Core material: BC tube||1.143|
|LMR-1700||50||13.39||PF||0.89||1.350||34.29||1.670||42.42||Double||Low-loss communications, 0.056 dB/meter @ 2.4 GHz, Core material: BC tube||0.844|
|QR-320||75||1.80||PF||0.395||10.03||Single||Low-loss line, which replaced RG-11 in most applications||3.340|
|QR-540||75||3.15||PF||0.610||15.49||Single||Low-loss hard line||1.850|
|QR-715||75||4.22||PF||0.785||19.94||Single||Low-loss hard line||1.490|
|QR-860||75||5.16||PF||0.960||24.38||Single||Low-loss hard line||1.240|
|QR-1125||75||6.68||PF||1.225||31.12||Single||Low-loss hard line||1.010|
Dielectric material codes
VF is the Velocity Factor; it is determined by the effective and 
There are also other designation schemes for coaxial cables such as the URM, CT, BT, RA, PSF and WF series.
Short coaxial cables are commonly used to connect home video equipment, in ham radio setups, and in measurement electronics. While formerly common for implementing computer networks, in particular Ethernet ("thick" 10BASE5 and "thin" 10BASE2), twisted pair cables have replaced them in most applications except in the growing consumer cable modem market for broadband Internet access.
Long distance coaxial cable was used in the 20th century to connect radio networks, television networks, and Long Distance telephone networks though this has largely been superseded by later methods (fibre optics, T1/E1, satellite).
Shorter coaxials still carry cable television signals to the majority of television receivers, and this purpose consumes the majority of coaxial cable production. In 1980s and early 1990s coaxial cable was also used in computer networking, most prominently in Ethernet networks, where it was later in late 1990s to early 2000s replaced by UTP cables in North America and STP cables in Western Europe, both with 8P8C modular connectors.
Micro coaxial cables are used in a range of consumer devices, military equipment, and also in ultra-sound scanning equipment.
The most common impedances that are widely used are 50 or 52 ohms, and 75 ohms, although other impedances are available for specific applications. The 50 / 52 ohm cables are widely used for industrial and commercial two-way radio frequency applications (including radio, and telecommunications), although 75 ohms is commonly used for broadcast television and radio.
Coax cable is often used to carry data/signals from an antenna to a receiver—from a satellite dish to a satellite receiver, from a television antenna to a television receiver, from a radio mast to a radio receiver, etc. In many cases, the same single coax cable carries power in the opposite direction, to the antenna, to power the low-noise amplifier. In some cases a single coax cable carries (unidirectional) power and bidirectional data/signals, as in DiSEqC.
Hard line is used in broadcasting as well as many other forms of radio communication. It is a coaxial cable constructed using round copper, silver or gold tubing or a combination of such metals as a shield. Some lower-quality hard line may use aluminum shielding, aluminum however is easily oxidized and unlike silver oxide, aluminum oxide drastically loses effective conductivity. Therefore, all connections must be air and water tight. The center conductor may consist of solid copper, or copper-plated aluminum. Since skin effect is an issue with RF, copper plating provides sufficient surface for an effective conductor. Most varieties of hardline used for external chassis or when exposed to the elements have a PVC jacket; however, some internal applications may omit the insulation jacket. Hard line can be very thick, typically at least a half inch or 13 mm and up to several times that, and has low loss even at high power. These large-scale hard lines are almost always used in the connection between a transmitter on the ground and the antenna or aerial on a tower. Hard line may also be known by trademarked names such as Heliax (CommScope), or Cablewave (RFS/Cablewave). Larger varieties of hardline may have a center conductor that is constructed from either rigid or corrugated copper tubing. The dielectric in hard line may consist of polyethylene foam, air, or a pressurized gas such as nitrogen or desiccated air (dried air). In gas-charged lines, hard plastics such as nylon are used as spacers to separate the inner and outer conductors. The addition of these gases into the dielectric space reduces moisture contamination, provides a stable dielectric constant, and provides a reduced risk of internal arcing. Gas-filled hardlines are usually used on high-power RF transmitters such as television or radio broadcasting, military transmitters, and high-power amateur radio applications but may also be used on some critical lower-power applications such as those in the microwave bands. However, in the microwave region, waveguide is more often used than hard line for transmitter-to-antenna, or antenna-to-receiver applications. The various shields used in hardline also differ; some forms use rigid tubing, or pipe, while others may use a corrugated tubing, which makes bending easier, as well as reduces kinking when the cable is bent to conform. Smaller varieties of hard line may be used internally in some high-frequency applications, in particular in equipment within the microwave range, to reduce interference between stages of the device.
Radiating or leaky cable is another form of coaxial cable which is constructed in a similar fashion to hard line, however it is constructed with tuned slots cut into the shield. These slots are tuned to the specific RF wavelength of operation or tuned to a specific radio frequency band. This type of cable is to provide a tuned bi-directional "desired" leakage effect between transmitter and receiver. It is often used in elevator shafts, US Navy Ships, underground transportation tunnels and in other areas where an antenna is not feasible. One example of this type of cable is Radiax (CommScope).
RG-6 is available in four different types designed for various applications. In addition, the core may be copper clad steel (CCS) or bare solid copper (BC). "Plain" or "house" RG-6 is designed for indoor or external house wiring. "Flooded" cable is infused with waterblocking gel for use in underground conduit or direct burial. "Messenger" may contain some waterproofing but is distinguished by the addition of a steel messenger wire along its length to carry the tension involved in an aerial drop from a utility pole. "Plenum" cabling is expensive and comes with a special Teflon-based outer jacket designed for use in ventilation ducts to meet fire codes. It was developed since the plastics used as the outer jacket and inner insulation in many "Plain" or "house" cabling gives off poison gas when burned.
Triaxial cable or triax is coaxial cable with a third layer of shielding, insulation and sheathing. The outer shield, which is earthed (grounded), protects the inner shield from electromagnetic interference from outside sources.
Twin-axial cable or twinax is a balanced, twisted pair within a cylindrical shield. It allows a nearly perfect differential signal which is both shielded and balanced to pass through. Multi-conductor coaxial cable is also sometimes used.
Semi-rigid cable is a coaxial form using a solid copper outer sheath. This type of coax offers superior screening compared to cables with a braided outer conductor, especially at higher frequencies. The major disadvantage is that the cable, as its name implies, is not very flexible, and is not intended to be flexed after initial forming. (See "hard line")
Conformable cable is a flexible reformable alternative to semi-rigid coaxial cable used where flexibility is required. Conformable cable can be stripped and formed by hand without the need for specialized tools, similar to standard coaxial cable.
Rigid line is a coaxial line formed by two copper tubes maintained concentric every other meter using PTFE-supports. Rigid lines cannot be bent, so they often need elbows. Interconnection with rigid line is done with an inner bullet/inner support and a flange or connection kit. Typically, rigid lines are connected using standardised EIA RF Connectors whose bullet and flange sizes match the standard line diameters. For each outer diameter, either 75 or 50 ohm inner tubes can be obtained. Rigid line is commonly used indoors for interconnection between high power transmitters and other RF-components, but more rugged rigid line with weatherproof flanges is used outdoors on antenna masts, etc. In the interests of saving weight and costs, on masts and similar structures the outer line is often aluminium, and special care must be taken to prevent corrosion. With a flange connector, it is also possible to go from rigid line to hard line. Many broadcasting antennas and antenna splitters use the flanged rigid line interface even when connecting to flexible coaxial cables and hard line. Rigid line is produced in a number of different sizes:
|Size||Outer conductor||Inner conductor|
|Outer diameter (not flanged)||Inner diameter||Outer diameter||Inner diameter|
|7/8"||22.2 mm||20 mm||8.7 mm||7.4 mm|
|1 5/8"||41.3 mm||38.8 mm||16.9 mm||15.0 mm|
|3 1/8"||79.4 mm||76.9 mm||33.4 mm||31.3 mm|
|4 1/2"||106 mm||103 mm||44.8 mm||42.8 mm|
|6 1/8"||155.6 mm||151.9 mm||66.0 mm||64.0 mm|
At the start of analogue satellite TV broadcasts in the UK by BskyB, a 75 ohm cable referred to as RG6 was used. This cable had a 1 mm copper core, air-spaced polyethylene dielectric and copper braid on an aluminium foil shield. When installed outdoors without protection, the cable was affected by UV radiation, which cracked the PVC outer sheath and allowed moisture ingress. The combination of copper, aluminium, moisture and air caused rapid corrosion, sometimes resulting in a 'snake swallowed an egg' appearance. Consequently, despite the higher cost, the RG6 cable was dropped in favour of CT100 when BSKYB launched its digital broadcasts.
From around 1999 to 2005 (when CT100 manufacturer Raydex went out of business), CT100 remained the 75 ohm cable of choice for satellite TV and especially BskyB. It had an air-spaced polyethylene dielectric, a 1 mm solid copper core and copper braid on copper foil shield. CT63 was a thinner cable in 'shotgun' style, meaning that it was two cables moulded together and was used mainly by BskyB for the twin connection required by the Sky+ satellite TV receiver, which incorporated a hard drive recording system and a second, independent tuner.
In 2005, these cables were replaced by WF100 and WF65, respectively, manufactured by Webro and having a similar construction but a foam dielectric that provided the same electrical performance as air-spaced but was more robust and less likely to be crushed.
At the same time, with the price of copper steadily rising, the original RG6 was dropped in favour of a construction that used a copper-clad steel core and aluminium braid on aluminium foil. Its lower price made it attractive to aerial installers looking for a replacement for the so-called low-loss cable traditionally used for UK terrestrial aerial installations. This cable had been manufactured with a decreasing number of strands of braid, as the price of copper increased, such that the shielding performance of cheaper brands had fallen to as low as 40 percent. With the advent of digital terrestrial transmissions in the UK, this low-loss cable was no longer suitable.
The new RG6 still performed well at high frequencies because of the skin effect in the copper cladding. However, the aluminium shield had a high DC resistance and the steel core an even higher one. The result is that this type of cable could not reliably be used in satellite TV installations, where it was required to carry a significant amount of current, because the voltage drop affected the operation of the low noise block downconverter (LNB) on the dish.
A problem with all the aforementioned cables, when passing current, is that electrolytic corrosion can occur in the connections unless moisture and air are excluded. Consequently, various solutions to exclude moisture have been proposed. The first was to seal the connection by wrapping it with self-amalgamating rubberised tape, which bonds to itself when activated by stretching. The second proposal, by the American Channel Master company (now owned by Andrews corp.) at least as early as 1999, was to apply silicone grease to the wires making connection. The third proposal was to fit a self-sealing plug to the cable. All of these methods are reasonably successful if implemented correctly.
Coaxial cable insulation may degrade, requiring replacement of the cable, especially if it has been exposed to the elements on a continuous basis. The shield is normally grounded, and if even a single thread of the braid or filament of foil touches the center conductor, the signal will be shorted causing significant or total signal loss. This most often occurs at improperly installed end connectors and splices. Also, the connector or splice must be properly attached to the shield, as this provides the path to ground for the interfering signal.
Despite being shielded, interference can occur on coaxial cable lines. Susceptibility to interference has little relationship to broad cable type designations (e.g. RG-59, RG-6) but is strongly related to the composition and configuration of the cable's shielding. For cable television, with frequencies extending well into the UHF range, a foil shield is normally provided, and will provide total coverage as well as high effectiveness against high-frequency interference. Foil shielding is ordinarily accompanied by a tinned copper or aluminum braid shield, with anywhere from 60 to 95% coverage. The braid is important to shield effectiveness because (1) it is more effective than foil at preventing low-frequency interference, (2) it provides higher conductivity to ground than foil, and (3) it makes attaching a connector easier and more reliable. "Quad-shield" cable, using two low-coverage aluminum braid shields and two layers of foil, is often used in situations involving troublesome interference, but is less effective than a single layer of foil and single high-coverage copper braid shield such as is found on broadcast-quality precision video cable.
In the United States and some other countries, cable television distribution systems use extensive networks of outdoor coaxial cable, often with in-line distribution amplifiers. Leakage of signals into and out of cable TV systems can cause interference to cable subscribers and to over-the-air radio services using the same frequencies as those of the cable system.
10BASE2 (also known as cheapernet, thin Ethernet, thinnet, and thinwire) is a variant of Ethernet that uses thin coaxial cable terminated with BNC connectors. During the mid to late 1980s this was the dominant 10 Mbit/s Ethernet standard, but due to the immense demand for high speed networking, the low cost of Category 5 cable, and the popularity of 802.11 wireless networks, both 10BASE2 and 10BASE5 have become increasingly obsolete, though devices still exist in some locations. As of 2011, IEEE 802.3 has deprecated this standard for new installations.10BASE5
10BASE5 (also known as thick Ethernet or thicknet) was the first commercially available variant of Ethernet. 10BASE5 uses a thick and stiff coaxial cable up to 500 metres (1,600 ft) in length. Up to 100 stations can be connected to the cable using vampire taps and share a single collision domain with 10 Mbit/s of bandwidth shared among them. The system is difficult to install and maintain.
10BASE5 was superseded by much cheaper and more convenient alternatives: first by 10BASE2 based on a thinner coaxial cable, and then once Ethernet over twisted pair was developed, by 10BASE-T and its successors 100BASE-TX and 1000BASE-T. As of 2003, IEEE 802.3 has deprecated this standard for new installations.Balun
A balun (for balanced to unbalanced) is an electrical device that converts between a balanced signal and an unbalanced signal. A balun can take many forms and may include devices that also transform impedances but need not do so. Transformer baluns can also be used to connect lines of differing impedance. Sometimes, in the case of transformer baluns, they use magnetic coupling but need not do so. Common-mode chokes are also used as baluns and work by eliminating, rather than ignoring, common mode signals.
There are two variations of this device - they are:
the unun, which transfers signal from one unbalanced line to another.
the balbal, which transfers signal from one balanced line to another.Cable television
Cable television is a system of delivering television programming to consumers via radio frequency (RF) signals transmitted through coaxial cables, or in more recent systems, light pulses through fiber-optic cables. This contrasts with broadcast television (also known as terrestrial television), in which the television signal is transmitted over the air by radio waves and received by a television antenna attached to the television; or satellite television, in which the television signal is transmitted by a communications satellite orbiting the Earth and received by a satellite dish on the roof. FM radio programming, high-speed Internet, telephone services, and similar non-television services may also be provided through these cables. Analog television was standard in the 20th century, but since the 2000s, cable systems have been upgraded to digital cable operation.
A "cable channel" (sometimes known as a "cable network") is a television network available via cable television. When available through satellite television, including direct broadcast satellite providers such as DirecTV, Dish Network and Sky, as well as via IPTV providers such as Verizon FIOS and AT&T U-verse is referred to as a "satellite channel". Alternative terms include "non-broadcast channel" or "programming service", the latter being mainly used in legal contexts. Examples of cable/satellite channels/cable networks available in many countries are HBO, Cinemax, MTV, Cartoon Network, AXN, E!, FX, Discovery Channel, Canal+, Eurosport, Fox Sports, Disney Channel, Nickelodeon, CNN International, and ESPN.
The abbreviation CATV is often used for cable television. It originally stood for Community Access Television or Community Antenna Television, from cable television's origins in 1948. In areas where over-the-air TV reception was limited by distance from transmitters or mountainous terrain, large "community antennas" were constructed, and cable was run from them to individual homes. The origins of cable broadcasting for radio are even older as radio programming was distributed by cable in some European cities as far back as 1924.Coaxial
In geometry, coaxial means that two or more three-dimensional linear forms share a common axis. Thus, it is concentric in three-dimensional, linear forms.
A coaxial cable, as a common example, is a three-dimensional linear structure. It has a wire conductor in the centre (D), a circumferential outer conductor (B), and an insulating medium called the dielectric (C) separating these two conductors. The outer conductor is usually sheathed in a protective PVC outer jacket (A). All these have a common axis.
The dimension and material of the conductors and insulation determine the cable's characteristic impedance and attenuation at various frequencies.
In loudspeaker design, coaxial speakers are a loudspeaker system in which the individual driver units radiate sound from the same point or axis.
A coaxial weapon mount places two weapons on [roughly] the same axis – as the weapons are usually side-by-side or one on top of the other, they are technically par-axial rather than coaxial, however the distances involved mean that they are effectively coaxial as far as the operator is concerned.Digital Signal 3
A Digital Signal 3 (DS3) is a digital signal level 3 T-carrier. It may also be referred to as a T3 line.
The data rate for this type of signal is 44.736 Mbit/s (45 Mb).
DS3 uses 75ohm coaxial cable and BNC connectors.
This level of carrier can transport 28 DS1 level signals within its payload.
This level of carrier can transport 672 DS0 level channels within its payload.
Such circuits are the usual kind between telephony carriers, both wired and wireless, and typically by OC1 optical connections.Ethernet over coax
Ethernet over Coax (EoC) is a family of technologies that supports the transmission of Ethernet frames over coaxial cable.Feed line
In a radio antenna, the feed line (feedline), or feeder, is the cable or other transmission line that connects the antenna with the radio transmitter or receiver. In a transmitting antenna, it feeds the radio frequency (RF) current from the transmitter to the antenna, where it is radiated as radio waves. In a receiving antenna it transfers the tiny RF voltage induced in the antenna by the radio wave to the receiver. In order to carry RF current efficiently, feed lines are made of specialized types of cable called transmission line. The most widely used types of feed line are coaxial cable, twin-lead, ladder line, and at microwave frequencies, waveguide.
Particularly with a transmitting antenna, the feed line is a critical component that must be adjusted to work correctly with the antenna and transmitter. Each type of transmission line has a specific characteristic impedance. This must be matched to the impedance of the antenna and the transmitter, to transfer power efficiently to the antenna. If these impedances are not matched it can cause a condition called standing waves on the feed line, in which the RF energy is reflected back toward the transmitter, wasting energy and possibly overheating the transmitter. This adjustment is done with a device called an antenna tuner in the transmitter, and sometimes a matching network at the antenna. The degree of mismatch between the feedline and the antenna is measured by an instrument called an SWR meter (standing wave ratio meter), which measures the standing wave ratio (SWR) on the line.Hybrid fibre-coaxial
Hybrid fiber-coaxial (HFC) is a telecommunications industry term for a broadband network that combines optical fiber and coaxial cable. It has been commonly employed globally by cable television operators since the early 1990s.
In a hybrid fiber-coaxial cable system, the television channels are sent from the cable system's distribution facility, the headend, to local communities through optical fiber subscriber lines. At the local community, a box called an optical node translates the signal from a light beam to radio frequency (RF), and sends it over coaxial cable lines for distribution to subscriber residences. The fiberoptic trunk lines provide adequate bandwidth to allow future expansion and new bandwidth-intensive services.Leaky feeder
A leaky feeder is a communications system used in underground mining and other tunnel environments. Manufacturers and cabling professionals use the term "radiating cable" as this implies that the cable is designed to radiate: something that coaxial cable is not generally supposed to do.Motorola connector
A Motorola connector also known as a motorola antenna plug, a male DIN 41585, or simply a DIN connector, is a common coaxial cable RF connector used primarily in the automotive industry for connecting the coaxial feedline from the antenna to the radio receiver. It is also sometimes used for connecting scanner antennas to scanners. The male plug somewhat resembles an RCA connector in size and shape, but instead of surrounding the pin, the sleeve is "folded" back over the coax.The pin is soldered to the center conductor of the coaxial cable coming from the antenna, and the grounded side forms a 1.5 inch (38 mm) long sleeve around the coax. The sleeve usually contains one or more longitudinal spring surfaces, which provide reliable electrical contact by wiping against the mating female socket.Networking cables
Networking cables are networking hardware used to connect one network device to other network devices or to connect two or more computers to share printers, scanners etc. Different types of network cables, such as coaxial cable, optical fiber cable, and twisted pair cables, are used depending on the network's physical layer, topology, and size. The devices can be separated by a few meters (e.g. via Ethernet) or nearly unlimited distances (e.g. via the interconnections of the Internet).
There are several technologies used for network connections. Patch cables are used for short distances in offices and wiring closets. Electrical connections using twisted pair or coaxial cable are used within a building. Optical fiber cable is used for long distances or for applications requiring high bandwidth or electrical isolation. Many installations use structured cabling practices to improve reliability and maintainability. In some home and industrial applications power lines are used as network cabling.RG-6
RG-6/U is a common type of coaxial cable used in a wide variety of residential and commercial applications. An RG-6/U coaxial cable has a characteristic impedance of 75 ohms. The term, RG-6, is generic and is applied to a wide variety of cable designs, which differ from one another in shielding characteristics, center conductor composition, dielectric type and jacket type. RG was originally a unit indicator for bulk radio frequency (RF) cable in the U.S. military's Joint Electronics Type Designation System. The suffix /U means for general utility use. The number was assigned sequentially. The RG unit indicator is no longer part of the JETDS system (MIL-STD-196E) and cable sold today under the RG-6 label is unlikely to meet military specifications. In practice, the term RG-6 is generally used to refer to coaxial cables with an 18 AWG (1.024 mm) center conductor and 75 ohm characteristic impedance.Star network
A star network is an implementation of a spoke–hub distribution paradigm in computer networks. In a star network, every host is connected to a central hub. In its simplest form, one central hub acts as a conduit to transmit messages. The star network is one of the most common computer network topologies.
The hub and hosts, and the transmission lines between them, form a graph with the topology of a star. Data on a star network passes through the hub before continuing to its destination. The hub manages and controls all functions of the network. It also acts as a repeater for the data flow.
The star topology reduces the impact of a transmission line failure by independently connecting each host to the hub. Each host may thus communicate with all others by transmitting to, and receiving from, the hub. The failure of a transmission line linking any host to the hub will result in the isolation of that host from all others, but the rest of the network will be unaffected.The star configuration is commonly used with twisted pair cable and optical fibre cable. However, it can also be used with coaxial cable.TAT-7
TAT-7 was the seventh transatlantic telephone cable, in operation from 1983 to 1994, initially carrying 4,000 3 kHz telephone circuits between New Jersey, Unites States and Porthcurno in southwest England. It was owned by AT&T, British Telecom and France Telecom.Although optical fiber had been invented in 1970, this cable was still using coaxial cable technology.Transmission line
In radio-frequency engineering, a transmission line is a specialized cable or other structure designed to conduct alternating current of radio frequency, that is, currents with a frequency high enough that their wave nature must be taken into account. Transmission lines are used for purposes such as connecting radio transmitters and receivers with their antennas (they are then called feed lines or feeders), distributing cable television signals, trunklines routing calls between telephone switching centres, computer network connections and high speed computer data buses.
This article covers two-conductor transmission line such as parallel line (ladder line), coaxial cable, stripline, and microstrip. Some sources also refer to waveguide, dielectric waveguide, and even optical fibre as transmission line, however these lines require different analytical techniques and so are not covered by this article; see Waveguide (electromagnetism).Triaxial cable
Triaxial cable, often referred to as triax for short, is a type of electrical cable similar to coaxial cable, but with the addition of an extra layer of insulation and a second conducting sheath. It provides greater bandwidth and rejection of interference than coax, but is more expensive.Twin-lead
Twin-lead cable is a two-conductor flat cable used as a balanced transmission line to carry radio frequency (RF) signals. It is constructed of two stranded copper or copper-clad steel wires, held a precise distance apart by a plastic (usually polyethylene) ribbon. The uniform spacing of the wires is the key to the cable's function as a transmission line; any abrupt changes in spacing would reflect some of the signal back toward the source. The plastic also covers and insulates the wires.
Twin lead can have significantly lower signal loss than miniature flexible coaxial cable at shortwave and VHF radio frequencies; for example, type RG-58 coaxial cable loses 6.6 dB per 100 m at 30 MHz, while 300 ohm twin-lead loses only 0.55 dB. However, twin-lead is more vulnerable to interference. Proximity to metal objects will inject signals into twin-lead that would be blocked out by coaxial cable. Twin lead therefore requires careful installation around rain gutters, and standoffs from metal support masts. Twin-lead is also susceptible to significant degradation when wet or ice covered, whereas coax is less or not affected in these conditions. For these reasons, coax has largely replaced twin-lead in most uses, except where maximum signal is required.Vivaldi antenna
A Vivaldi antenna or Vivaldi aerial or tapered slot antenna is a co-planar broadband-antenna, which can be made from a solid piece of sheet metal, a printed circuit board, or from a dielectric plate metalized on one or both sides.
The feeding line excites an open space via a microstrip line or coaxial cable, and may be terminated with a sector-shaped area or a direct coaxial connection. From the open space area the energy reaches an exponentially tapered pattern via a symmetrical slot line.
Vivaldi antennas can be made for linear polarized waves or – using two devices arranged in orthogonal direction – for transmitting / receiving both polarization orientations.
If fed with 90-degree phase-shifted signals, orthogonal devices can transmit/receive circular-oriented electromagnetic waves.
Vivaldi antennas are useful for any frequency, as all antennas are scalable in size for use at any frequency. Printed circuit technology makes this type antenna cost effective at microwave frequencies exceeding 1 GHz.
Advantages of Vivaldi antennas are their broadband characteristics (suitable for ultra-wideband signals ), their easy manufacturing process using common methods for PCB production, and their easy impedance matching to the feeding line using microstrip line modeling methods .
The MWEE collection of EM simulation benchmarks includes a Vivaldi antenna.
RF connectors (coaxial)