2 means a peak voltage 1. Poor VSWR can cause shadowing in a TV broadcast system as the signal reflected off the antenna reflects again off the power amplifier and is then rebroadcast. A calculator designed to compute and calculate the VSWR, return Loss of a circuit and matching loss in a transmission line based on the parameters you enter. Avg. In summary, return loss is the loss of signal power due to signal reflection or return by a discontinuity in a fiber-optic link or transmission line. vary with frequency). 8. This means return loss will always be positive. Return Loss in decibels (RLdb): Definition: Return loss is the ratio between Forward and Reflected Power in decibels. Please enter your values below. . Return Loss Vs. 02 (51/50) which produces a return loss of 39 dB, an improvement of 13 dB over the 55-ohm termination. 01. However, each field, when changed will allow. Load serial resistance and reactance ohm. 0:1,. 39 0. Suppose the wave is not matched with load and signal there is some unwanted signals are interrupted or signal loss is occurred. 12] = 6 dB. VSWR is referring to the maximum and minimum voltage values that is being transmitted and reflected by the component. dB (S 21) SWR = to 1: Insertion Loss = dB (S 21) Return Loss = dB (S 11) Return Loss = dB (S 11) NOTE: NOTE: Introduction to scattering parameters (S 11 and S 21): SWR is always greater than 1 to 1. If problems show up during this test, there is a very good. Calculations Pathloss / RSSI; Missmatch Loss; IP3 / SFDR Calculator; IP3, IP2, 1dB Comp. This is a measurement of how much energy is either radiated or is dissipated in heat, due to resistive or dielectric losses. A01TKL_ RF Inductor by Coilcraft →. Consumers; Contact Us;866. VSWR (voltage standing wave ratio, sometimes pronounced "viswar"), is the ratio of the maximum standing wave amplitude at one node to the minimum. VSWR - Return Loss - Γ Conversions These are the standard set of equations for converting between VSWR, return loss, and reflection coefficient (Γ). S-parameters are a valuable tool for calculating reflection coefficients and transmission gains for a two-port network's input and output sides. Just enter one value and snap calculate. applied return loss and RF power, measured at 1 GHz. When you look at a graph of a return loss formula, the negative sign is often omitted and is sometimes used interchangeably with the S11 parameter. com Reflections propagate back and forth in a line, but most assessments only consider the effects of the initial reflection because the back and forth energy attenuates until it is untraceable. VSWR and impedance, Part 2: Reflected power. The VSWR calculator helps in finding the reflection coefficient, return loss, and mismatch loss from the VSWR value. VSWR to Return Loss. Put a decent isolator in your signal chain (typically ~1 dB insertion loss, >10 dB return loss and > 20 dB reverse isolation over relevant bandwidth) and subsequent VSWRs won't matter either. Calculate. The graph below shows input return loss for an amplifier. everything RF has the largest selection of online calculators for the RF and Microwave Industry. 1 and VSWR = 5, which yields the required value p = (1 – 5q)/5 = 0. But, for a practical system, there will be a small impedance. narrowband components) should provide a system worst case of 18dB return loss. Both decimal point and comma are ok. If we look at the Return Loss chart for this. 9. 8. This impedance mismatch can be with a device inserted in the line or with the terminating load. Reflection Coef. For five t-line sections each having a VSWR of 1. Measure S11 across the desired frequency range. It tells the severity of standing waves in a transmission line. This VSWR / Return Loss calculator allows you to compute corresponding VSWR, Return Loss, Reflection coefficient and Mismatch Loss values for the entered input value and input type. 64% or ±10 x log10 (103. Assuming that the source and load are perfect then when the signal from the source arrives at the switch some of that signal is reflected. Return Loss or a VSWR: return loss (dB) (evaluated as neg. Return loss is related to both standing wave ratio (SWR) and reflection coef-ficient (Γ). 5. Z L = Ω. 2. Home Return Loss to VSWR Conversion Chart Due to mismatches in impedance within the connector, some of the signal is reflected. 05:1 it calculates a VSWR of 1. Use the S11 value in the calculator above to find the equivalent VSWR. To generate the table, engineers must measure the VSWR for a range of frequencies and then calculate the return loss. Measuring Insertion Loss using RETURN LOSS MODE. reflection coefficient definition. SFDR VisualizerVSWR & Return Loss Calculator Enter forward and reflected power or match to determine equivalent values. This calculator computes the VSWR, reflection coefficient, return loss and matching loss in a transmission line. Conclusion : In summary, RL and VSWR formulas and calculators are valuable tools that enhance the efficiency. VSWR/Return Loss Calculator will find VSWR, Return Loss, Mismatch Loss, and the Reflection Coefficient given any one of the listed input types. This calculator shows how return loss (VSWR) affects forward power and calculates the power loss difference caused by two different return loss paths. 0. Increasing return loss corresponds to lower SWR. This calculator converts values between VSWR, Return loss, Reflection Coefficient and Mis-Match Loss. VSWR is defined as the ratio of the maximum voltage to the minimum voltage in standing wave pattern along the length of a transmission line structure. The input to the antenna will be 8,511 watts. Step 2. Γ = (VSWR – 1)/(VSWR + 1) Return Loss (dB) = -20*Log 10 (|Γ|) Mismatch Loss (dB) = -10*Log 10 (1. The calculator is designed to be fine tuned after the initial input. 1, for system 2 is 0. There is an equivalent definition for VSWR, which can also be expressed in terms of the Return Loss (RL). The isolation S23 is exactly -20 dB at the center frequency, while the output match is also degraded to about -13. 2 8. Consider the antenna being used in transmit mode. What is the VSWR ratio to return loss? There is an inverse relationship between Voltage Standing Wave Ratio (VSWR) and Return Loss. 62 GHz, and the measured return loss for the fabricated antenna was −19. 99 $ = 1-\Gamma^2$ Convert VSWR to Return Loss, Reflection Coefficient, and Mismatch Loss with our easy conversion calculator. termination would give a VSWR of 1. sales@minicircuits. Enter a value for VSWR (remember: VSWR should be a number larger than 1. Γ = Reflection coefficient. Return loss and VSWR are two important measures of efficient power transmission and both of them can be interconverted to obtain the value of one another. To do so, calculate the desired return loss and subtract the known load return. RETURN RETURN RETURN RETURN RETURN LOSS VSWR LOSS VSWR LOSS VSWR LOSS VSWR LOSS VSWR (dB) (dB) (dB) (dB) (dB) return loss Vs. The return loss scale is normally set up from 0 to 60 dB with 0 being an open or a short and 60 dB would be close to a perfect match. com. A high return loss is desirable and results in a lower insertion loss . USA CHINA MALAYSIA INDIA ISRAEL UNITED KINGDOM. 54 dB (11% of your transmitter power is reflected back). The path loss that might be measured in a system however will not be this. Convert the VSWR value to a ratio by subtracting 1 from the VSWR value. Electrical waves reflect when they encounter a change in the impedance of the medium they are traveling in. The calculator is a spreadsheet that accepts VSWR specifications for all the components in your RF Path—tower mounted amplifiers, diplexers, bias tees, etc. They are related but measure different aspects of signal performance. Calculate Effective Radiated Power (ERP) With Known Transmission Variables: Transmitter Output Power :. The low-pass filter often is a natural choice for lumped element filters. To calculate the Return Loss, add 1 to the VSWR and divide the result. dB Path Loss with respect to dipole or isotropic antenna: Watts: dBw or dBm: microVolts: dBm: pforward (Watts) pref (Watts) Return Loss or a VSWR: return loss (dB) (evaluated as neg. It's located in our download area . 8 is 80%, or -0. Definition of VSWR. When you look at a graph of a return loss formula, the negative sign is often omitted and is sometimes used interchangeably with the S11 parameter. The concept of loss factor is discussed on this page. Reflection Coefficient to Impedance Converter Convert a reflection coefficient in Magnitude Angle format into Impedance and vice versa. Hence, the return loss is always lower than the ideal system (i. VSWR. Forward. everything RF has this largest selection about online calculators for the RF and Cooking Industry. 64/100) = ±0. R = 10log 10 (P incident /P reflected) and. 0 15. This can be built into a FLEXI-BOX and a transmission line PCB is available which easily adapts for this circuit with a simple trimming operation. The load can be an antenna, filter or other equipment connected to a transmission line. It is a natural phenomenon that occurs for any type of transmission—whether it's electricity or data. 1. Mismatch Loss: Reflected Power Through Power (dB) Coefficient, Γ (dB) (%) (%) 1 17. Calculate FAQs How do you calculate insertion loss? Insertion loss can be calculated by measuring the power or signal level before and after a component, device,. 0708,min,max = =This is an online calculator that calculates Return Loss based on VSWR. Thus with ~ 25% reflected power: Return Loss = -10 x Log [ 100/25. 57. VSWR to Return Loss (dB) Converter; Return Loss (dB) to VSWR Converter; Power Conversion : dBm - volts - watts; Phase Noise to Phase Jitter Converter; Phase Jitter to Phase Noise Converter; ppm to Hz Converter; misc. Note that we have a VSWR calculator that will allow you to convert between VSWR, mismatch loss and return loss!. Next, plug in the calculated return loss value into the formula VSWR = (1 + 10^ (RL/20))/ (1 - 10^ (RL/20)). As an example, input power of 100 W (50 dBm) and output of 50 W (47 dBm) yields a cable. They are related but measure different aspects of signal performance. 98 dB return loss. The days of searching through desk drawers for your old HP Slide-chart tool are finally a thing of the past with the launch of MDL’s newest tool online – the Reflectometer Calculator(as shown. VSWR is the voltage standing wave ratio it used to measure the all-types waves (example: antenna waves) during transmission. The return loss at that point has degraded by approximately 5 dB. The losses are due to copper losses/skin loss and for more esoteric antennas (planar types) it's usually dielectric loss. Just enter the value real click calculate. This is the amount of power that is lost due to impedance mismatch, and. 30 MB. Loss (dB) Volt. Products. RF Trap With Attenuators Computes attenuation, return loss, reflection coefficient and VSWR . VSWR is a measure of the reflected power on a transmission line. Our RF and microwave calculators and converters will provide the figures you need for your radio frequency engineering needs. Here Click here to learn more about VSWR. Moreover, return loss is the relationship between both the reflection coefficient (Γ) and the. com1) VSWR Calculation. Thus, the 55-ohm termination contributed 26 dB loss to the inherent 6 dB loss of a two-way splitter. This general RF calculator provides path loss, VSWR and wavelength as well as conversions between many common measurements used in the wireless industry. Calculates the resistor values, attenuation, 'impedance', reflection coefficient, VSWR and return loss of a T attenuator. For example, quickly compute the effect of VSWR or return loss on transmitted power; cascaded gain and noise figure for up to five amplifier stages; and power-to-voltage conversion. 45 dB at 1. To use this calculator to determine the effective VSWR/Return Loss of an attenuator/device combination, enter the attenuation, VSWR or Return Loss, and Gain of the device, then press the [Calculate] button. Example 1: Cable Loss of 3 dB Cable loss: 3. Note: impedance is a complex quantity, it has real and imaginary parts or magnitude and phase; instruments are almost always calibrated for Zo being some nominal real value, is Xo=0 (eg when people speak of a 50Ω instrument, that means 50+j0Ω even if they don't. complimentary copy of the "RF Calculator" at . A match is good if the return loss is high. 794But for a practical transmission system with load, there will be a small impedance mismatch that will lead to a small amount of incident power reflected back to the source. Since the signal velocity through the network is a known constant, like the sound velocity in our analogy above, the time it takes for the reflections or echoes to return can be converted to distance. Return loss (RL) is the ratio of the reflected power to the incident power, in decibels (dB). 5:1 VSWR is equivalent to -13. The return loss vs. dBm To Watt Calculator; Noise Factor to Noise Figure Calculator; Noise Temperature to Noise Figure Converter;where RL(dB) is the return loss in dB, Pi is the incident power and Pr is the reflected power. Return Loss. Just enter the value additionally mouse calculate. Mismatch Loss (dB) 3. In no event will Qorvo be liable to any user of these tools for any loss or damages, including without limitation, indirect or consequential damages arising out of or associated with the use of these tools. How to fill out return loss to VSWR: First, calculate the return loss (RL) value using the formula RL = -20*log (VSWR+1). 00Watts Enter 1. 02 dB. A Forward and Reflected Power to VSWR Calculator is a tool that helps to determine the Voltage Standing Wave Ratio (VSWR) of a transmission line by using measurements of the forward and reflected power. R is the symbol for return loss, which as previously discussed is the ratio, in decibels, of incident power P incident to reflected power P reflected, or incident voltage to reflected voltage, described in the following two formulas. The voltage standing wave ratio (VSWR) is defined. 5. Reflection Coefficient to Impedance Converter Convert a reflection coefficient in Magnitude Angle format into Impedance and vice versa. In some systems this is not a trivial amount and points to the need for components with low VSWR. VSWR to Return Loss Calculator RF Transformer CalculatorLike insertion loss, return loss is also generally described in decibels of power. Let’s calculate Voltage standing. Return Loss is a measure of the amount of energy that is reflected back at a discontinuity in a Radio Frequency Circuit . The following formula relates the return loss and VSWR. It including shows one percentage from forward to reflected power. It varies from 1 to (plus) infinity. Return loss vs. The component is said to have a loss of 25 dB. 3333. " – Dr. This calculator converts between return loss (RL), voltage standing wave ration (VSWR), and reflection coefficient (Γ). Return loss and VSWR are two important measures of efficient power transmission and both of them can be interconverted to obtain the value. This tool calculates the Return loss in dB. 000Match Efficiency (%) Calculates Match Efficiency. In order to improve the VSWR, this calculator also has an extra input for adding an attenuator to improve or reduce the system VSWR. 1. One is tempted to seek the maximum value and make a “pass / fail” decision based on this value. Dieser is an online calculator that calculates Return Hurt based on VSWR. voltage standing wave ratio 020710. 1 Return Loss. Subscribe to receive Mini-Circuits News. If the power incident on a load is Pi P i and the power reflected by the load is Pr P r, then the return loss in decibels is [6, 7] RLdB = 10 log Pi Pr (2. If the antenna reflects 250 watts the VSWR at the antenna will be 1. Solution: From eqn. The VSWR value should be close to 1. This VSWR / Return Loss calculator allows you to compute corresponding VSWR, Return Loss, Reflection coefficient and Mismatch Loss values for the entered input. In practice, the generally accepted frequency band limits for rectangular waveguide are between 125% and 189% of the lower cutoff frequency, in this case 8. 1) (2. Moreover, return loss is the relationship between both the reflection coefficient (Γ) and the. ZoReturn Loss = incident power/ reflected power. Increasing return loss corresponds to lower SWR. Reflection Coef. But the meter at the transmitter will show a VSWR of 1. To help the engineers conducting VSWR sweeps, Lou developed the PIM and. Step 1. Equitable enter the value and click calculate. Application Note File. VSWR Return Loss Calculator. Due to mismatches in impedance within the connector, some of the signal is reflected. Now, let us investigate the physical meaning of return loss. 54. In general, a lower VSWR means a system and load is well matched with most of the power being radiated by the antenna and a relatively small amount reflected back. VSWR and Return Loss RF Calculator VSWR (Voltage Standing Wave Ratio) is a measurement of how well matched a radio transmitter and transmission line is to a load such as an antenna. VSWR & Return Loss Calculator: Enter forward and reflected power or match to determine equivalent values. With this calculator, you can calculate the final improved VSWR value when attenuation is inserted between the source and the load impedance that initially do not have a 50 Ohm match. Enter the source characteristic impedance and the load impedance then press "Calculate" below. Convert VSWR to Return Loss, Reflection Coefficient, and Mismatch Loss with our easy conversion calculator. Learn about voltage standing wave ratio (VSWR), return loss, and mismatch loss, which helps characterize the wave reflections in a radio frequency (RF) design. 5:1. To do this, I start at the input port and re-calculate the return loss for each component, factoring in the insertion loss of the previous components in the chain, as they will help improve the component's VSWR further down the chain:. 50:1, the resulting maximum VSWR will be 4. 1) (7. 98dB = 96. The ratio of the input to the reflected signal is. The simulated return loss was −20. REGISTER. 1. Lower VSWR means lower reflection power (good impedance matching); thus, power transfers to load will be high. Always expressed as a ratio to unity, a VSWR of 1. The table below converts between VSWR, return loss, reflection coefficient, mismatch loss, reflected power and through power. Installer for the Windows version of dB Calculator. 5:1 VSWR that appears on. How to Calculate VSWR . 4. Note: The historical definition of return loss results in a negative sign. Reflection. Just by entering the. Select the FREQ-RETURN LOSS using the Up/Down arrow key and press ENTER. However, if the parasitics differ much from 0. They will show SWR and Return Loss (RL). Usually this is the threshold when most devices are considered. Return Loss (dB) VSWR. Just enter the value and click calculate. 0. With the initial values in place, you need only click on Calculate. The graph below shows input return loss for an amplifier. entirety RF has the largest selection of online calculators for the RF and Microwave Industry. Calculates the absolute load impedance, reflection coefficient, VSWR, return loss and mismatch loss of a load. The Reflection Coefficient can be calculated from return loss by using the following formula. 1) RL dB = 10 log P i P r. These multiple solutions are possible because each contributor is a vector having both. To use this calculator, enter one of the following data: the voltage standing waves ratio VSWR, the return loss RL, the reflection coefficient ρ, the power ratio ρ 2, the forward and reflected power P fwd and P ref; or the impedances Z c and Z l. g. , some amount of incident power will reflect the source in a practical system). e. 4200 | Fax 408. 02 VSWR (i. To use this calculator, enter one of the following data: the voltage standing waves ratio VSWR, the return loss RL, the reflection coefficient ρ, the power ratio ρ 2, the forward and reflected power P fwd and P ref; or the impedances Z c and Z l. To do so, calculate the desired return loss and subtract the known load return. 0:1, 2. 3) RLOUT = 20log10|S22| dB (Eq. Because the reflection coefficient Γ < 1, then the return loss will have a positive dB value. Return loss is a meas-ure of how well devices or lines are matched. 32 dB and 1. Formula is:: reflection coefficient(Γ)= VSWR = VSWR Calculator:(by using RL)From the table we can understand that when the return loss is <10dB, the antenna will be at VSWR >2, indicating the system will reflect >30% power and the performance of the antenna will be <70%. everything RF has and larges selection from online calculators for an RF plus Microwave Industry. The voltage standing wave ratio (VSWR) calculator determines reflection coefficient (GAMMA), VSWR, and return loss (dB) for a mismatched line. This is an online calculator that calculates VSWR based on Get Loss. number) VSWR or % Reflected Power: MHz: a wavelength in inches or feet This VSWR calculator will calculate return loss, mismatch loss, loss in percentage and the reflection coefficient. 0:1). A series of RF calculators for radio frequency engineers. 4. Return Loss. VSWR =. ,100 % power transferred from a source to a load via a transmission line/cable). Reflection Calculator: RL = dB: VSWR = Γ = VSWR = RL = dB: Γ = Zo . Conversion Tables. VSWR to Return Loss (dB) Calculator. Value dB. 93 dB. R = 20log 10 (E incident /E reflected)This can an online calculator that estimates VSWR based on Return Loss. 1 Return loss in dB = 26. This is an online calculator that calculated Returned Loss based on VSWR. By converting between VSWR and RL, this calculator aids in assessing signal quality, minimizing signal loss, and ensuring efficient RF system. VSWR to Return Loss Calculator; Cavity Resonance Frequency Calculator; Circular Waveguide Calculator; Rectangular Waveguide Cut-off Frequency Calculator; All Conversion Calculators . Just enter an value and click calculate. Here is the problem. Effective Radiated Power and Coax Loss Calculator. 57. Return loss (RL) is the ratio of the reflected power to the incident power, in decibels (dB). Just entered the value or click calculation. A calculator designed to compute the VSWR, reflection coefficient, return loss and matching loss in a transmission line2. Input Value: Calculate Reset Definition of VSWR "Understanding VSWR isn't just about crunching numbers; it's about shaping the future of efficient wireless communication. Enter the Noise Figure and gain for each stage. Γ = Reflection coefficient. Calculates the resistor values, attenuation, minimum attenuation, impedance, reflection coefficient, VSWR and return loss of a resistive matching Pi attenuator. Isolation Var6. 58 dB in return loss. This indicates the effectiveness of the coupling, and that a large part of the energy is transmitted to the antenna with very little reflection. These calculators help with unit conversions, VSWR calculations, attenuator design, antenna design, radars, and various other basic calculations that are often required. frequency graph of the above assembly is shown in figure 5. Return Loss to VSWR Calculator. return loss Calculator. The Voltage Standing Wave Ratio (VSWR) is defined as the ratio of the maximum amplitude to the minimum magnitude of the voltage standing wave at an input port of an antenna. VSWR ( VSWR meaning Voltage Standing Wave Ratio) is an important concept in radio frequency (RF) engineering. Mismatch loss. This is an online numeric that calculates VSWR based on Return Loss. Γ is then used to calculate the return loss. Dual Dielectric Coax Calculator. With the initial values in place, you need only click on Calculate. It also indicates the in of forward to reflected power. Some are based on look-up tables, some completely hide their algorithms. See the vswr table below to see a numerical mapping between reflected power, s11 and VSWR. N = current stage. This is an ideal open or short circuit, equivalent to VSWR=infinite. Convert S11 to return loss; Compute Voltage Standing Wave Ratio (VSWR) from Return Loss; References [1] Return Loss on Wikipedia Conversion Tables. Upon arriving back at the source, part of the reflected wave. Convert the load VSWR to load return loss per the following equation: RL Improved = 2*Attenuator + RL Load [dB] (where RL=Return Loss) Of course, the method can be reversed to predict the attenuator required to improve a load VSWR by a predetermined amount. Input Return Loss Var2. Return Loss (dB) VSWR:An online calculator for converting between VSWR and Return Loss, Reflection Coefficient, Mismatch Loss, and Reflected Power. Calculates will find VSWR, Return Loss, Mismatch Loss, and the Reflection Coefficient given any one of the listed input types. . 51 dB, and a return loss of 9. 707. Convert VSWR to Return Loss and vice versa. 780-444-6767A calculator designed to compute the VSWR, reflection coefficient, return loss and matching loss in a transmission line T-Pad Attenuator Calculator This calculator helps you determine the values of the resistors R1 and R2 to be used for a T-pad attenuator. 1Thus, for this system, VSWR = 1:1 (i. 0 Frequency (GHz) Return Loss (dB) Return Loss (dB) Figure 5 A VSWR plot, to the uninitiated, can be a very confusing plot. 6 Adding VSWR to the MixT Attenuator Calculator. every RF has one largest selection of online calculators for the RF and Microwave Industry. The return loss is the ratio of the power of the. When an ideal match is not encountered by the incident (forward) wave, part of it is coupled to the load and part is reflected back to the source. Calculate SWR and return loss from impedance values. everything RF has the largest selection of buy calculators for the RF and Stove Industry. Return loss is the ratio between the reflected power and input power: $$ mathrm{RL}=frac{P_{ref}}{P_{in}} $$ If the input signal is 0 dBm and there is 25 dB return loss, then the component will create a reflected wave of -25 dBm back toward the. This calculator converts between return loss (RL), voltage standing wave ration (VSWR), and reflection coefficient (Γ). Unless you have a piece of slotted line-test equipment this is a hard definition to use, especially since the concept of voltage. At small VSWRs, the plus and minus. These measurements show the user the match of the system and if it conforms to system engineering specifications. 3 dB. Therefore, the return loss parameter RL can only be used to express the mismatch of R L to Z 0. VSWR to Return Loss Formula VSWR = (1 + 10-RL/20)/ (1 - 10-RL/20) Example Calculation A Return. If you don't want to go through complicated equations to understand the relationship between VSWR, mismatch loss, s11/gamma and would like a calculator to do it for you, check out our VSWR. VSWR specs (specifications) are introduced, along with formulas for mismatch loss and return loss in relationship to VSWR. With this equation, you can plug in the value of D and the measured voltages, and finally solve the above. Choose Conversion Calculator or Table: Convert µV to dBm Convert dBm to µV Convert Watts to dBW Convert dBW to Watts Convert Return Loss dB to VSWR Convert VSWR to Return Loss dB Convert Reflected and Forward Power to VSWR Calculate Effective Radiated Power Calculate Effective Receiver PerformanceFigure 5 shows return loss data plotted in time-domain. 891: 6. At 1000 MHz, the S11 (dB) = -RL (dB) = -15 dB. For example, a VSWR of 1. Low-pass lumped element filters. The VSWR can easily be converted into Return Loss ( RL R L ) using the following formula: RL = 20log10(VSWR + 1 VSWR − 1) R L = 20 log 10 ( V S W R + 1 V S W R − 1) Directional power meter. This calculator converts Return loss (RL) to Voltage Standing Wave Ratio (VSWR). This calculator is designed to give the efficiency loss of a given antenna, based on the input of VSWR (voltage standing wave ratio) and other subsequent factors. The calculated value is MUCH worse. Then click the "Calculate" button next to the value you just typed to compute the others. 2 8. Use at your risk. VSWR (Voltage Standing Wave Ratio) is a measurement of how well matched a radio transmitter and transmission line is to a load such as an antenna. Return loss is always expressed in dB, which is a logarithmic scale. A match is good if the return loss is high. total RF has the largest selection of online calculators for the RF and Micro Industry.