This is a required field. ε = dielectric constant = ε0 * εr. Coaxial cable combiners with ferrite cores are often used to combine the output powers of power amplifiers intended for wideband applica-tions. The width of the conducting layer is important to calculate the radiation intensity since it directly affects. Then use the LCR Meter and measure the inductance at the open end of the cable. 6/1. Coaxial Cable: A common type of coaxial cable has a characteristic impedance of 50 ohms. EXAMPLE: INPUTS: Outer diameter = 36 , Inner diameter = 10 , Relative permittivity =2. Scroll down to find formulas for determining attenuation, wavelength, characteristic impedance, time delay, and more. A Rectangular Waveguide is a conducting cylinder of rectangular cross-section used to guide the propagation of waves. c is the speed of light 299,792,458 m⋅s −1,. COAXIAL CABLE IMPEDANCE CALCULATOR Calculates the characteristic impedance of a coaxial cable given its dimensions. √ 50*12. This works from DC to 1. By understanding the formula and utilizing the calculator, professionals can determine the characteristic impedance of coaxial lines, ensuring proper impedance matching and efficient signal transmission. 35dB. Engineers were designing air-filled coaxial cables for radio transmitters designed to output kW worth of power. 345 IMT Conduit 1. Coaxial Cable Attenuation. More consistent results will usually be obtained by using a dedicated cable joiner or a plug and socket with the same impedance as the cable. where. The functionality of a coax loss calculator is straightforward, yet it provides critical information for ensuring optimal performance. RG316 coaxial cable is a low-loss, high-frequency cable with a characteristic impedance of 50 ohms. The entry unit of frequency can be modified, the output wavelength is calculated in meters. This will also provide the time delay the cable provides for a signal and also the capacitan…Coax Cable Transmission Line Models. Since we might as well find the impedance per length, we can study the expression: Rl = 1 σA R l = 1 σ A. Identify as much information as you can about your piece of cable prior to discussion: Characteristic impedance. It is widely used for data communications and telecommunications applications in structured cabling systems. 15 mm (0. Calculation Dielectric Outer Diameter: Inner Conductor Diameter: Result: Pasternack carries hundreds of coaxial RF cables all in-stock and available for same-day shipping worldwide. 25 inches. The inner and outer. d is the diameter of the inner conductor of the coax cable; units of D and d must be the same,. 150 MHz start by calculating the freespace wavelength… Wavelength(Freespace-7. The Coaxial Line Impedance (Z0) Calculator is a valuable tool for engineers working with RF and telecommunications systems. 1. 854187817620. Geometriy is not that critical. Sensor Fusion Comes to RetailNext: Interview with Alexei Agretchev . com If it. The return loss of a system is defined as the ratio of incident power to reflected power and is measured in dB. 6 dB/100 m yields 1 dB. Example: Calculate the distributed capacitance and inductance, impedance and a cutoff frequency of a coaxial cable RG-58 with the following characteristics: inner conductor diameter 0. Any coaxial cable filled with air has a wave impedance of ~377 Ω, but this does not at all help to make the open piece of coaxial cable a good antenna. × 10 −12 F/m is the. If a short section of a 50 ohm cable has a 75 ohm impedance, then 33% of the voltage signal will be reflected at each end of the 75. × 10 −12 F/m is the. Fiber calculators and tools. To use the calculator you first need to measure the impedance (resistance + reactance(j)) of your antenna, this can be done with an antenna analyzer (i. coaxial cable. Find a length of coaxial cable and bring it with you to class for discussion. This coaxial cable calculator determines the distributed capacitance and inductance of a coaxial cable, its impedance and cutoff frequency for a given cable geometry, and relative permittivity or velocity factor. Permeability (µ) is assumed to be 1. 3. a = r = 0. The coaxial cable (coax) is one of the most ubiquitous transmission line structures. Co-axial cable. 9 mm (0. Telegram. ) using the high and low frequency approximations. This calculator is able to calculate the impedance, delay, inductance, and capacitance of a coaxial cable. Commercial Electric 25 ft. RF calculations and RF conversions include metric-standard, link budget, coax cable, power, attenuation, frequency and many more. Along the slot line, the electromagnetic wave encounters the substrate and the air, which serve as its transmission medium. for chosen frequency. Cable Capacitance (pF/ft) 23. Output values are rounded to the second decimal place. 4w. Email. In most test instruments, the signal outputs present a 50-O output impedance while the instrument inputs present a 50-O. In a nut shell the characteristic impedance of a coax cable is the square root of (the per unit length inductance divide by the per unit length capacitance). 557 GHz. Coaxial Impedance Calculator. The Coaxial Line Impedance (Z0) Calculator is a valuable tool for engineers working with RF and telecommunications systems. Show Me Cables' high quality RG6 quad shield coaxial cable consists of an 18 AWG solid bare copper. RG-58/U, Belden 8240: RG-58C/U, Belden 8259: MHz: dB/50 ft:The square root of 15 (feed point) times 50 (normal coax cable) is 27. 80 for typical two-wire lines and coaxial cables. This formula is from the following reference. Distributed Inductance (L') For a coaxial cable, the inductance per unit length L' in henries per meter (H/m) is defined as. The following formula is used to calculate the impedance of a coaxial cable. The choke balun usually does the same thing as a regular 1:1 current balun but adds the high impedance path to the common mode currents too. Length of the three-quarter-wave section 3λ g /4: mm. 66 and 0. When the load impedance is mismatched to the source in a 1 : N imped-The calculator now shows that for the length of coax the loss is 0. Gamma matching allows you to match such a dipole with a 50-ohm coaxial feeder. . Characteristic Impedance Calculation For Typical RG58U Coaxial Cable The plots below show the characteristic impedance Zo for a coaxial cable with typical RG58U characteristics (cables from different manufacturers differ somewhat in the exact physical dimensions, dielectric constants etc. All signals that travel on a transmission line are waves, whether they are harmonic analog. The following formula relates the return loss and VSWR. 2. Pasternack RG178 flexible coax cable is 50 Ohm and has a PTFE dielectric. In-Ear Sensors Record Health Metrics From Brain Activity and SweatDistributed Inductance (L') For a coaxial cable, the inductance per unit length L' in henries per meter (H/m) is defined as. Model # Y278784 SKU # 1000724874. 66 kW Black TPE Jacket (. 9 mm (0. Calculation Dielectric Outer Diameter: Inner Conductor Diameter: Result: Pasternack carries hundreds of coaxial RF cables all in-stock and available for same-day shipping worldwide. Simply put, the coax is losing 8. In the limiting case of infinite load impedance, theBecause a coax operates in TEM mode — with the electric and magnetic fields normal to the direction of propagation along the cable — modeling a 2D cross section suffices to compute the fields and the impedance. But it is not applicable to large and non-symmetrical cable-connector system as. On Figure 5, the. Coaxial cables are commonly used for transmitting electrical signals, including RF (radio frequency) signals. The epsilon_r of the cable isolation is 2 so total electric permittivity is 2 * 8. Now, let us investigate the physical meaning of return loss. Looking at the datapoints and moving back from the antenna (75. com Coax Cable Impedance Calculator Where, d = The outside diameter of the inner or center conductor. This calculator calculates the impedance of a coaxial cable. The impedance of the coax is a relationship of the capacitance per unit length and the inductance per unit length. For any cable type, it is equal to the reciprocal (1/x) of the square root of the relative permittivity of the cable’s insulation. SMA connectors are one of the most used RF connectors. 5dB loss per 100 feet at 146 MHz). Attenuation (dB/100 ft, @. Where we basically use the effective area instead. 1. Image 1, "matched") : Cable is impedance matched with 50 Ohm. Injecting a current transient into one side of a microstrip or coax transmission line causes a voltage to appear across only one of the two conductors. Figure 3. In the limiting case of infinite load impedance, the Because a coax operates in TEM mode — with the electric and magnetic fields normal to the direction of propagation along the cable — modeling a 2D cross section suffices to compute the fields and the impedance. Generally, a wave is reflected back. 6 . 56 X 10-7 H/m, Capacitance =. ,100 % power transferred from a source to a load via a transmission line/cable). Twisted pairs are used with balanced signals. 81, giving an impedance of 120. d is the diameter of the inner conductor of the coax cable; units of D and d must be the same,. In summary, the design process for the coaxial probe placement is simple: Select an operating frequency and stackup. , the signal reflected back in a transmission line. Use RG 58 cable (or any 50 ohm cable) You will ear the. . 5 mm Coaxial Connector is a widely used standardized coaxial connector type with some interesting features. Use the above equation to calculate the x-coordinate for the probe location. 4. 9 mm (0. Since we might as well find the impedance per length, we can study the expression: Rl = 1 σA R l = 1 σ A. LOGIN. The Velocity of propagation (Vp) of a cable is the speed at which an electrical signal can propagate through the cable in comparison to the speed of light. Provides an impedance matched 50 ohm coaxial connection for two receivers when feeding signal from one active antenna, or when combining two different antennas (L. A coax loss calculator is an essential tool for network planning that helps in calculating attenuation and choosing the right coaxial cable for your network. 36Ω), the impedance is: Transformed through 25 feet of RG-8 coaxial cable to 111. e. 1. Twisted-Pair Impedance Calculator; Embedded Microstrip Impedance Calculator; Microstrip Impedance Calculator;A twisted-pair cable is simply two wires that are twisted together so as to reduce radiated EMI (electromagnetic interference) and mitigate the effects of received EMI. More. ε 0 = 8. 10. where. R ≈ l σ(δs2πa) (δs ≪ a) The impedance of a wire of length l and radius a ≫ δs is given by Equation 4. Brown part is the copper itself. Capacitance of Cables, Charging Current, and Charging Reactive Power. . The cable dictates how much current initially flows based (mainly) on its inductance, capacitance and resistance. For coaxial cables the characteristic impedance will be typically between 20 and 150 ohms. 40 GHz. RF Coax Cable Assembly Designer Fairview Microwave's Coaxial Cable Impedance Calculator allows you to enter the Outer Diameter Dielectric width, Inner conductor Diameter width and either the Dielectric Constant or Velocity of Propagation (VoP) values in order to calculate the impedance of the coax. Hence, the return loss is always lower than the ideal system (i. Transmission line impedance is an important aspect of RF electronics, as it greatly influences the quality of a signal. When the bend radius is exceeded it alters the characteristic impedance of the cable. RELATED WORKSHEETS: Characteristic Impedance Worksheet A twisted-pair cable is simply two wires that are twisted together so as to reduce radiated EMI (electromagnetic interference) and mitigate the effects of received EMI. On the shield is written COAXIAL CABLE 5C-2V 75 ohm. I used 100m for l. where. D is the inside diameter of the coax cable shield,. Outer Shield DCR Nom. You can use either a 1:1 balun or a choke balun at the feed point of the antenna or where the balanced part of the system meets the unbalanced part. To find the termination resistance that matches the characteristic cable impedance, connect a 200Ω potentiometer at the cable end and tune it until no reflections occur. The characteristic impedance of a coaxial cable with a dielectric is then and the propagation velocity of a wave is, where c is the speed of light In free space, the wavelength of a wave with frequency f is For a polyethylene-insulated coaxial cable, the propagation velocity is roughly 2/3 the speed. This will also provide the time delay the cable provides for a signal and also the capacitance and inductance per. Recommended Frequency Band: 8. . × 10 −12 F/m is the. As we know that the definition of the return loss of a system is the ratio of incident power to. For example, connecting coax cable to a dipole antenna. D is the inside diameter of the coax cable shield,. You can calculate it with the following equation: Z (z) = V (z)/I (z). Example: Calculate the distributed capacitance and inductance, impedance and a cutoff frequency of a coaxial cable RG-58 with the following characteristics: inner. RG-8 and RG-213 (50 ohm); and RG-11 (75 ohm) are about 0. Maximum Operating Voltage (Vrms) 4000. Γ = Reflection coefficient. . Coaxial Cable Impedance Calculator. These calculations for Pout (Power out in watts) are for an input of 50 watts. 5dB loss per 100 feet at 146 MHz). While commonly constructed using printed circuit boards, this structure can also be built using other materials as long as there is a conductor separated from. It has an inner copper weld wire (CW) or copper-clad steel (CCS) conductor (carrying the electrical signal), which is enclosed by an insulation layer typically made of air space Polyethylene (ASP). Early in my explorations of electricity, I came across a length of coaxial cable with a label of “50 ohms” printed along its outer sheath (Figure below). If it's safe to assume that both drivers have an output of the same amplitude, we can even calculate the loss introduced by the cable: 20×log(1. εr = Dielectric constant of the insulator. cally short cables, these answers can be very different. A length of 13. Same-day shipping if you order in the next hours!. Input. . 2. Short the cable ends and measure the ZSC (cable short circuited). The history of 50 Ohm impedance goes back to the late 1920s/early 1930s, when the telecom industry was in its infancy. Therefore, in this case, one cannot do without measurements, the calculator shows a certain average value. From my measurement I got data as below: From that table, we can see that there is significant impedance of the cable. 16 mm]The loss tangent introduces a "real" conductance which is calculated from the susceptance by multiplying by loss tangent. The distance between the first two dips (deltaF) is 99 MHz. 66 and 0. The measure of this reflected power is called as return loss. D (inches) d (inches) for a typical polyethylene-insulated cable. Quite often, it is desirable to verify your calculations of the charac-The characteristic impedance of a coaxial cable is determined by the inductance and the capacitance per unit length; Zo = √(L/C). We have a conflict in statements here where formula 6. A coaxial cable is designedCoaxial cable, or coax (pronounced / ˈ k oʊ. 20 to 12. Sep 3, 2018. To calculate the impedance of a coaxial cable with a diameter of 0. While commonly constructed using printed circuit boards, this structure can also be built using other materials as long as there is a conductor separated from. Ze is the external earth loop impedance. #2. The use of a standardized impedance makes RF design much more practical and efficient. DS3 & DS4 Cable. This calculator is able to calculate the impedance, delay, inductance, and capacitance of a coaxial cable. Cutoff wavelength and frequency. Free Windows program for calculating the loss and impedance transformation. e. 5 mm Coaxial Connector is designed to be relatively rugged. We recently corrected a problem with the cut-off frequency calculation for single dielectric, which was pointed out by Andrew (thanks!) It will calculate characteristic impedance of coax that contains up to five concentric dielectrics!You can find online coaxial cable impedance calculators that accept inputs of outer diameter dielectric width, inner conductor diameter width and either the dielectric constant or velocity of propagation (VoP, the speed at which RF propagates through the cable conductors) values to calculate the intrinsic impedance of the coax. 3pF) in the tuner to 111. Here, you can utilize the online calculator to ascertain the impedance of a coaxial cable in ohms for a specific circuit. Brown part is the copper itself. the combined velocity factor will be around 0. Note that the very first dip is where the cable is less than 1/4 wavelength. 2. 4w to achieve 100w at the aerial. 718. is required to do the impedance transformation from 50 ohms to 292 ohms at 146 MHz. Among the commonly used connectors for 50 Ω coaxial cable is the venerable PL-259, available from Amphenol RF as the 83-1SP-1050 (Figure 5), as well as the wideband Type N, such as the VNS30-2051. Np = Number of turns in the primary coil. R is resistance per metre, L is inductance per metre, C is parallel capacitance per metre and G is parallel. For the air-filled cables typically used in high-power applications, this corresponds to a characteristic impedance of about 30 Ω. The length of the dipole is usually one-half of the wavelength of the RF signals. Unlike cable used for mains or other power transfer, the impedance of a coaxial cable is not affected by its length. This frequency to wavelength calculator helps you determine the wavelength of a waveform based on the frequency. which can be algebraically solved for Z 0 as: Z 0 = Z a Z b. Someone once asked us for an equation for calculating the characteristic impedance of off-center coax. f if the frequency of the RF signals. Use the frequency and layer thickness/Dk value to determine the antenna size. U. When a balanced source is to be isolated from an un-balanced load, the impedance matching transformer is referred to as a balun. coaxial cable. Quarter Wave Transformer Impedance Calculator. 854187817620. The twisted pair helps create a more uniform inductance and capacitance per unit length of wire to ensure a constant impedance, by keeping the return path as close to the signal as possible. If there is an insulator around the wire then this. Calculate the impedanceThe correct way to consider impedance matching in transmission lines is to look at the load end of the interconnect and work backwards to the source. A typical coax cable has 50 ohm characteristic impedance above about 1 MHz but that doesn't mean that's the impedance that the source sees because, if the load isn't 50 ohm then the "seen" impedance isn't 50 ohms and reflections will be present. High return loss means low reflected power, so high return loss is good for a system. 66) / 10. For my loop, the length of the matching section worked out to: 16. coax cross section. Triax Cable. Coax Impedance Calculator. The coaxial cable is so fundamental that Oliver Heaviside patented it in 1880, just a few years after Maxwell published his famous equations. Find a length of coaxial cable and bring it with you to class for discussion. EEWeb offers a free online twisted pair impedance (transmission line) calculator. This ratio represented in dB is called as Return Loss. An example follows. The characteristic impedance of a coaxial cable with a dielectric is then and the propagation velocity of a wave is, where c is the speed of light In free space, the wavelength of a wave with frequency f is For a polyethylene-insulated coaxial cable, the propagation velocity is roughly 2/3 the speed. d is the diameter of the inner conductor of the coax cable; units of D and d must be the same,. The coax is a good way to create a transmission line. Figure [Math Processing Error] 7. Coaxial Cable Impedance Calculator allows you to enter the Outer Diameter Dielectric width, Inner onductor Diameter width and either the Dielectric Constant or Velocity of Propagation (VoP) values in order to calculate the impedance of the coax. This tool will help you find the inductance for a given length of coax cable. Coaxial Cable Calculator. If the source is a DC source, a current, I, flows down the center conductor, through the load, and back to the source via the outer conductor. This online reflection coefficient to return loss calculator calculates the return loss (dB) by entering the reflection efficient Γ (= value. a = outside radius of inner conductor (inches) b = inside radius of outer conductor (inches) c = speed of light in a vacuum = 299,792 km/s = 186,282 mi/s. ε0 = permittivity of free space = 8. Values range between 0. Location. Resistance in this calculator formula for pi attenuator is measured in Ohms. So 50 ohm cables are intended to be used to carry power and voltage, like the. 850c-0. The waveguide width determines the lower cutoff frequency and is equal (ideally) to ½ wavelength of the lower cutoff frequency. The cutoff frequency is the frequency up to which the system functions efficiently. 2. Surge Impedance Calculation 35 100 0. ε = dielectric constant = ε0 * εr. This is actually a general way to express impedance, but it requires an understanding of complex numbers. 7mm. If we look again at the example of the coaxial cable and leave it open at the end, achieving a characteristic impedance of ~377 Ω does not relate to anything about the fields. When a coaxial cable is constructed using two concentric dielectrics as shown above, the wave propagation is no longer purely transverse-electromagnetic (TEM), as in the single-dielectric coax, but. Below the cutoff frequency, power flow will be reduced. Cable Capacitance (pF/ft) 20. Here it is: For outer diameter D, inner diameter d, and eccentricity c: Z0= [60/sqrt (ER)] x acosh [ (1/2)x (D/d+d/D-4c^2/ (dxD)] We entered the equation into Excel, and sure enough, if c=0 you get the same exact impedance you get from the. The calculator allows you to automate the calculation of losses in a coaxial cable. Attenuation (dB/100 ft , @ 400 MHz). fc = Cutoff frequency. Coax impedance is the square-root of the ratio of inductance/length divided by capacitance/length: Note that because the ln (D/d) term is a ratio, you can just as well use ln (R/r), and in either case the dimensional units don't matter. Also known as RG-400 or RG400 cable, this premium coaxial cable is designed to meet the demanding requirements of high-frequency applications. Over time properties of standard coaxial type cables have been standardized. The cutoff frequency is the frequency up to which the system functions efficiently. L = Series inductance per unit length. 2022. Z = 138 * log (D/d) / Sqrt (pr) Z = 138 ∗ log(D/d)/Sqrt(pr) Where Z is the impedance. Click on any RF calculator below to get started. 49 m. 124 in), type of insulation is polyethylene with the relative permittivity of 2. 854187817620. Insulation service (cable tray, conduit, direct burial, etc. ) and i notice that a lot of people use RG 6 or tv cable, all 75 ohm impedance, causing a mismatch and a loss of +/- 15 @ 25 % reception. . You have to remove some of the insulation on the other side of the cable and short out the center pin to the shield. The capacitance of a one conductor shielded cable is given by the formula below: Where: C = Total capacitance of the cable (microfarads) I charge = Charging current of the cable. The input impedance of such a dipole is typically less than 50 ohms and may have a reactance. Although widely applied to. c is the speed of light 299,792,458 m⋅s −1,. in both cases, the speed and the Characteristic Impedance depend upon logarithms of the ratio of two distances in the cross. G = 2πσ ln(b / a) Figure 2. The 3. For practical applications, please visit manufacturers’ websites and consult their data. The VSWR/return loss calculator from Pasternack will find VSWR, return Loss, mismatch loss, and the reflection coefficient given any one of the listed input types. This is actually a general way to express impedance, but it requires an understanding of complex numbers. Eq 1 assumes that the reference impedance of the mea-suring instrument equals the com-plex characteristic impedance of the cable. Example 25. 4. This configurator will generate a bill of materials for a Constellation power delivery system. The most common values of coaxial cable impedance are 50 and 75 ohms. The impedance of a coaxial cable is a critical parameter that characterizes its electrical properties. MiniVNA or MFJ-269 or similar). a = outside radius of inner conductor (inches) b = inside radius of outer conductor (inches) c = speed of light in a vacuum = 299,792 km/s = 186,282 mi/s. where. Linkedin. A 50Ω coax has an impedance of 50Ω whether it's one metre or one kilometre long. 4w to achieve 100w at the aerial. The capacitance value varies with the spacing of the conductors, the dielectric constant, and the impedance of the cable. 405 inches and a voltage rating of up to 1000 Vrms. Semi-rigid coax (new for June 2021!) Triax (new for August 2023!) Coax cable vendors . This calculator calculates the impedance of a coaxial cable. where. 3. This is the online directional coupler calculator that calculates the coupling (dB), coupling loss(dB), insertion loss (dB), and directivity (dB) of a directional coupler by entering the value of input power P1 (dBm/Watt(s)), output power. 7mm. Characteristic Impedance (Zo) 50 (±2) ohms. If you want to put this thing outdoors, do not use brass, as it gets brittle. I rounded the numbers after the. 9 mm (0. I've added the formulae to my answer. Transmission lines Transmission line concepts and an online transmission line calculator by Owen Duffy, VK1OD. 50 Ohm coaxial cables are used in microwave transmitters, translators, FM low power systems, ham frequency systems, and two-way radios. D is the inside diameter of the coax cable shield,. æ k s /), is a type of electrical cable consisting of an inner conductor surrounded by a concentric conducting shield, with the two separated by a dielectric (insulating material); many coaxial cables also have a protective outer sheath or jacket. The fabrication procedure for slot lines is the same as that for microstrip lines. × 10 −12 F/m is the. D = Inside diameter of the shield. 1. . The twisted pair helps create a more uniform inductance and capacitance per unit length of wire to ensure a constant impedance, by keeping the return path as close to the signal as possible. Cutoff Frequency of Lowest Order Mode: 6. Distributed Inductance (L') For a coaxial cable, the inductance per unit length L' in henries per meter (H/m) is defined as. Gamma matching is the most commonly used matching device used for a planar dipole in the Yagi-Uda antenna. 85, and using a speed-of-light figure of 186,000 miles per second, the velocity of propagation will be 158,100 miles per second. 15 mm (0. Maximum Voltage Rating (RMS) 4000 V. REGISTER. WR90 Specifications. This may not seem much of a loss but look at the Power Compensator again and you will see that 100w from your transmitter would have to be increased to 108. EEWeb offers a free online twisted pair impedance (transmission line) calculator. To understand how a coax loss calculator works, you. Coax Impedance (Transmission Line) Calculator. c is the speed of light 299,792,458 m⋅s −1,. Check the velocity factor for bare copper, which is 0. If you are interested in how to build a copper J-pole antenna, follow these instructions: Choose 145 MHz from the 2-meter frequency band, note the speed of light c, and calculate the wavelength λ from the formula λ = c/f = (299,792,458 m/s) / (145,000,000 1/s) = 2. This calculator helps you calculate the characteristic impedance of a coaxial cable given its dimensions. A slot or gap with a conducting coating on a dielectric substrate makes up a slot line, a form of transmission line comparable to CPW. 5 to 21. Characteristic Impedance Calculator. These are considered to be standardized impedance values with cables readily available. After all, if there is a mismatch of the antenna with this cable, the signal will be reflected before it enters to the cable. My thoughts: The source sees from DC to approximately 300 kHz 117 Ohm Real Component (as 2x50 Ohm + 10*1. The formula defining characteristic impedance may be written as follows : Theoretical formula in the case of a perfect line. The reason for this approach is due to the behavior of real electrical signals on a transmission line. It supports both balanced and unbalanced lines.