VSWR. 8 is 80%, or -0. A low VSWR will minimize reflections from the antenna. Return Loss is a logarithmic scale, and Voltage Standing Wave Ratio (VSWR) is a linear scale. 3 dB. 12] = 6 dB. Click here for VSWR to RL CalculatorReturn Loss to VSWR Reference/Conversion Table. , an), the wavestravelling away from the n-port are b = (b1, b2,. offices email call. Furthermore, a small VSWR reduces reflections from the antenna. These multiple solutions are possible because each contributor is a vector having both. 8. VSWR can also be complex (Re+jIm, in theory) but most people just use it with "Real" values and is always >= 1. How to improve the Return Loss of an amplifier. A calculator designed to compute the VSWR,return loss and matching loss in a transmission line. Return loss calculation EXAMPLE : VSWR = 1. 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. 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. VSWR Mismatch Errors: Both amplitude and phase errors are introduced when mismatched impedances are present at an electrical interface. The Insertion Loss formula is defined as the loss of signal power resulting from the insertion of a device in a transmission line or optical fiber and is usually expressed in decibels (dB) and is represented as I L = 20* log10 (V t / V in) or Insertion Loss = 20* log10 (Voltage / Input Signal Amplitude). multiplier m=1 RL=50*1 multiplier n=-4 XL=40*-4 multiplier k=2 Z0=50*k Q2: An antenna with a load, ZL=RL+jXL, is connected to a lossless transmission line Z0? What is the phase angle of the reflection coefficient in degrees toRelated Calculators. VSWR can be generated by Network Analysers. The input to the antenna will be 8,511 watts. VSWR Return Loss Calculator. from Forward and Reflected Power: Transmitter Forward Power : Watts: System Reflected Power : Watts: VSWR = Reflection Coefficient = Return Loss = dB: Match Efficiency = % Net. To do so, calculate the desired return loss and subtract the known load return. 5 VSWR = Vmax Vmin ≥ 1 VSWR = 1 ∣ 0∣ 1−∣ 0∣ Voltage Standing Wave Ratio VSWR = Voltage Standing Wave Ratio (sometimes just called SWR)2. 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. This is an online calculator that calculates Return Loss based on Reflection Coefficient. Use the S11 value in the calculator above to find the equivalent VSWR. Milli Watts to dBm Calculator. It is related to return loss as follows. Voltage standing wave ratio (VSWR), or often given as just standing wave ratio (SWR), is the ratio between the transmitted and reflected voltage standing waves at a signal chain element incident node. Using complex impedance is an important technique for handling multi-component AC circuits. Calculates the resistor values, attenuation, minimum attenuation, 'impedance', reflection coefficient, VSWR and return loss of a matching Pi attenuator. Wavelength dBm dBuV W dBuVm mWcm2 pJcm2 V VSWR This RF calculator has been developed by Compliance Engineering as a resource for individuals. Note: The historical definition of return loss results in a negative sign. Return loss and VSWR are two important measures of efficient power transmission and both of them can be interconverted to obtain the value. Most RF Coaxial Cables have an impedance of 50 ohms or 75 ohms. 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. The new calculator remains Excel-based; however, provides an enhanced interface so users can: Add radio/tester as a component as it impacts some calculation. VSWR is commonly expressed as a ratio. If we measure the power of a reflected signal from an antenna near a radio transmitter, the measurement of the reflected signal’s amplitude at this juncture compared to the initially transmitted. Application Note File. Unwrapped phase and reference plane extensions. It varies from 1 to (plus) infinity and is always positive. Moreover, return loss is the relationship between both the reflection coefficient (Γ) and the. The ratio of a sinusoidal signal reflected back from the load to the incident signal is called return loss. 50:1, with a corresponding return loss of 3. VSWR to Return Loss (dB) Calculator. If a complex plane is used with resistance along the real axis then the reactances of the capacitor and inductor are treated as imaginary numbers. How to Use? Using the VSWR to RL Calculator involves the following steps: Enter. **Note: All of our calculators allow SI prefix input. You can use our VSWR calculator to see that 1. Our RF calculators and converters will provide the figures you need for your radio frequency engineering needs. Return Loss is similar to VSWR and is generally preferred in the cable industry to a VSWR specification. 2. These equations can be solved with a personal computer and suitable software, or the parameters may be determined with the Smith Chart. The low-pass filter often is a natural choice for lumped element filters. Conclusion: In summary, RL and VSWR formulas and calculators are valuable tools that enhance the efficiency, accuracy and consistency of RF engineering tasks such as measurement, analysis, troubleshooting and system design. You can also use LTSpice to calculate S-parameters as well, which is a bit of a hidden trick. transmitter) with the load (i. 200mW. The VSWR to RL Calculator employs this formula to convert VSWR values into RL values. Vswr To Rl Formula. Stripline Impedance calculator Smith charts VSWR/Return loss converter Wavelength calculator Wilkinson splitter designer. The low-pass filter often is a natural choice for lumped element filters. VSWR to Return Loss . 5 10. Definition and BackgroundVSWR return loss calculator The voltage standing wave ratio (VSWR), reflection coefficient (Τ), return loss and mismatch loss are all dependant on one or the other, as can be seen by the equations below. This attenuation calculator provides as output to the user the. Reflection Coefficient to Impedance Converter Convert a reflection coefficient in Magnitude Angle format into Impedance and vice versa. coefficient of Port 1 (also called return loss), and. If “V” is used, then the ratio is defined to voltage level of a standing wave at a line. Avg. (1) ea Flex Assy - 1. If there is something in the microwave universe that you need a different calculator for, drop us a note and we'll see what we. Calculate. The result is an antenna VSWR or return loss measurement corrected for cable loss. 5:1 정도로써 입력매칭이 거의 완전하게. Return Loss and Mismatch Loss Calculator Calculates the absolute load impedance, reflection coefficient, VSWR, return loss and mismatch loss of a load. VSWR / Return Loss Calculator: IRA Calculator: Wavelength (TEM) Calculator: Link Budget Calculator **Note: All of our radio frequency calculators allow SI prefix input. A series of RF calculators for radio frequency engineers. Return Loss is the amount of power that is lost in the signal returned/reflected by a discontinuity in a transmission line. Voltage Measured Along a Transmission Line. (under "Support" and "Technical Application Notes" tabs). 41:1 with a return loss of 15. Click here for RL to VSWR CalculatorKnowing Return Loss (RL), calculate voltage reflection coefficient Rho= 10^(-RL/20). This can be built into a FLEXI-BOX and a transmission line (50 Ohm track) PCB is available which easily adapts for this circuit with one simple trimming. 예를 들어 Return loss가 10dB 정도라면, VSWR은 2:1 이하가 되어서 입력매칭이 비교적 잘된 경우로 평가하며, Return loss가 14 dB 정도가. Return Loss (RL) = 10 * log(Pr/Pi) Return Loss (RL) in dB = -20* log(Γ) Lesser value of return loss indicates higher impedance matching and vice versa. VSWR / Return Loss Calculator; IRA Calculator; Wavelength (TEM) Calculator; Link Budget Calculator . e. For example, if you wish to input "25000000", just type "25M" instead. High VSWR values indicate less efficient power transmission and can. Return Loss is a measure of the amount of energy that is reflected back at a discontinuity in a Radio Frequency Circuit . Finally, an antenna VSWR monitoring system is shown. 64% or ±10 x log10 (103. The return loss at the input and output ports can be calculated from the reflection coefficient, S 11 or S 22, as follows: RL IN = 20log10|S 11 | dB. S-parameters, S11 and S21. The load ZL imposes an additional constraint on the relationship of the total voltage and current at z = 0: VL IL = V(z = 0) I(z = 0) = ZL. Return loss = 10 log (Pr / Pi) = 20 log (Er / Ei) For example, if a load has a return loss of -10 dB, then 1/10 of the incident power is reflected. Pout is the output power or signal level. 1) RL dB = 10 log P i P r. SWR Excel SheetMeasured VSWR = ratio: RL dB: VSWR at antenna = ratio: RL dB: Power into/at antenna = watts: Power reflected from/at antenna = watts: Notes: Maximum Power rating for RG213 cable is 250 watts taking into account environmental de-rating. Stripline Calculator. This tutorial defines VSWR and explains how it is calculated. 05 + 1. Please enter your values below. The following formula relates the return loss and VSWR. The calculator can also be used to find the value of VSWR using any of the other values. is of particular concern in the implementation of Gigabit Ethernet (1000BASE-T) The value of impedances at the ends of the link must be equal to the characteristic impedance of the link. 299 0. Calculate the VSWR in another column. In order to improve the VSWR, this calculator also has an extra input for adding an attenuator to improve or reduce the system VSWR. RF Works is unable to take liability for. Then click the "Calculate" button next to the value you just typed to compute the others. From a system VSWR level calculate the following parameters:- Reflection coefficient- Forward and reflected power percentage- Mismatch loss in dB. Custom. 5, the corresponding value of. In terms of the reflection coefficient: If VSWR = 1, G 0 = 0 (no reflection) = vp f, vp= c r 0 100 200 300 400 500 600-1. 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. In Figure 14, the ADL5920 is being used to measure the return loss of the load, also at 1 GHz. Introduction to VSWR. A return loss conversion table is used to quickly convert VSWR values into return loss values. This VSWR calculator will calculate return loss, mismatch loss, loss in percentage and the reflection coefficient. For support with the MatchCalc tool, contact [email protected] 24. Reflection Coef. RF Trap With Attenuator Calculator Calculates the attenuation, 'impedance', reflection coefficient, VSWR and return loss of a circuit that incorporates a RF tank circuit into a Pi attenuator. This impedance mismatch can be with a device inserted in the line or with the terminating load. Our RF calculators and converters will provide the figures you need for your radio frequency engineering needs. g. voltage standing wave ratio. You can use it for free. 8. October 20, 2022. Yoni Calculator Online Test System Configurator ezSample. VSWR is a measure of the reflected power on a transmission line. 5:1 정도로써 입력매칭이 거의 완전하게. Here we will learn more about the meaning of VSWR and the associated VSWR formulas. VSWR / Return Loss Calculator. cdn-anritsu. Calculate VSWR, Return Loss, etc. Summarizing: Directivity is ratio of power density in a specified direction to the power density averaged over all directions at the same distance from the antenna. voltage standing wave ratio 020710. 5:1 VSWR is equivalent to -13. Return loss can be converted to mismatch loss and the calculator also gives an intuitive sense of the impact by providing the forward and reflected power ; Related Posts. 4. VSWR Calculator:(by using RL) return loss(RL)= VSWR = RF Coax Cable Assembly Designer: Most Viewed Companies MegaPhase, LLC. Enter VSWR (a value greater than or equal to 1) S11 to VSWR Formula S11 = (VSWR-1)/ (VSWR+1) S11 (dB) = 20*Log10 (S11) The input reflection coefficient, S11 < 1 Example Calculation For a VSWR of 1. Solved Example. VSWR indicates matching condition of source (i. 259 0. Please note that this. The isolation S23 is exactly -20 dB at the center frequency, while the output match is also degraded to about -13. Once the VSWR is known, return loss can be calculated as follows: Return Loss = 20 ∙ log10 () Generally, a higher return loss value is preferable. long or about 1. Given a return loss (variable = RL ) in dB, the VSWR is calculated as follows: The magnitude of the reflection coefficient is defined as Rho , where Rho = ( 10 ^ (RL/-20)): e. 34:1 or a return loss of 16. 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. Directivity, on the other hand, is the level of the signal which appears at Port 4 and is undesired. Enter the source characteristic impedance and the load impedance then press "Calculate" below. Step 3. As we know that the reflection coefficient defines the amount of the electromagnetic wave is reflected due to the impedance discontinuity in a transmission path. The table below converts between VSWR, return loss, reflection coefficient, mismatch loss, reflected power and through power. Return Loss Vs. Any other value indicates that a portion of the energy is reflected. While return loss analysis can be an ambiguous quality indicator,. In addition, the calculation takes into account the effect of signal attenuation in the transmission line. Calculates the resistor values, attenuation, 'impedance', reflection coefficient, VSWR and return loss of a Pi attenuator. Voltage is the pressure from an electrical circuit's power source. There is also a selection of suitable RF. VSWR to Return Loss Conversion Table. VSWR (Voltage Standing Wave Ratio) = [1+Sqrt (Pr / Pf)] / [1-Sqrt (Pr / Pf)] Pf = Forward Power (Watts); Pr = Reflected Power. From the previous chapter, we already know the impedance of the load as measured by the VNA: R=23. Both decimal point and comma are ok. In contrast to Return Loss, VSWR displays the match of the system linearly. 13 24. 5:1. Matching Pi Attenuator Calculator. A known return loss is applied to the RF OUT port. How to improve the Return. The Antenna Downtilt and Coverage Calculator (aka Antenna Tilt Angle Calculator) is used to determine the approximate downward angle, measured in degrees, which the transmitting antenna is to be positioned for optimal signal strength and coverage. 5 dB, (or a VSWR of 1. If VSWR is known, then the reflection coefficient (Γ), return loss (RL), and. 17. For example, an efficiency of 0. It converts the following units: • VSWR • Reflection • Return Loss • Prefl (Power reflection) • Reflections, Reflectionl to Mismatch Uncertainty Enter a value in any field, and all the other values are calculated and displayed. Conversion Formulas. At 1000 MHz, the S11 (dB) = -RL (dB) = -15 dB. S-parameters, S11 and S21. This general RF calculator provides path loss, VSWR and wavelength as well as conversions between many common. VSWR Calculator. Facebook. 예를 들어 Return loss가 10dB 정도라면, VSWR은 2:1 이하가 되어서 입력매칭이 비교적 잘된 경우로 평가하며, Return loss가 14 dB 정도가 되면 VSWR은 1. Definition of VSWR. Γ = Reflection coefficient. . e. 98 dB. This tool calculates the S11 from the Voltage Standing Wave Ratio (VSWR). The concept behind the Smith Chart is simple. VSWR table of return loss vs. VRMSF and VRMSR are measured and the return loss is back calculated. It's assumed that the source impedance is also complex. A commonly required conversion is between return loss and VSWR, and some values are tabulated in chart, along with a graph of these values for quick reference. 44 . The component is said to have a loss of 25 dB. 8. For example, a VSWR of 1. VSWR Calculator: This is the ratio of maximum voltage to minimum voltage in standing wave pattern. Please Support RF Cafe by purchasing my ridiculously low−priced products, all of which I created. Coaxial Cable Impedance Calculator. Thus with ~ 25% reflected power: Return Loss = -10 x Log [ 100/25. multiplier m=1 RL=50*1 multiplier n=-4 XL=40*-4 multiplier k=2 Z0=50*k Q2: An antenna with a load, ZL=RL+jXL, is connected to a lossless transmission line Z0? What is the phase angle of the reflection coefficient in degrees toRelated Calculators. 0. This is actually a general way to express impedance, but it requires an understanding of complex numbers. 1Return Loss. VSWR calculator: Isolation between circuit stages (mentioned above) is a way to minimize the voltage standing wave ratio (VSWR) and, in this way, improve impedance matching. VSWR & Return Loss Calculator: Enter forward and reflected power or match to determine equivalent values. 3. When creating PCB prototypes that conduct alternating current (AC) at radio frequency, designs must compensate for the effects of the current waves on the prototype material. This application note supplies a free of charge software tool that can e. 600mW. But the meter at the transmitter will show a VSWR of 1. Fill in the input field and select the input type and click the "calculate" button to show the values. S21 is the transmission coefficient of Port 2. The online calculators are usable in pop-up mode for easy desktop. 5 0 0. 2. This antenna tilt angle calculator also provides,. 091) (0. 5 1 1. Elite RF. Lower VSWR is always desirable for a system. 41:1 with a return loss of 15. Calculates the resistor values, attenuation, 'impedance', reflection coefficient, VSWR and return loss of a Pi attenuator. Example 2. Calculate VSWR and Return Loss from Zload (or Yload or S11) and Zo; Calculate Vmax, Vmin, Imax, Imin for lossless line from Zload (or Yload) and Zo; Calculate transmission line Matched Line Loss from Rin of o/c or s/c resonant section; Calculate luminous flux (lm) from luminous intensity (cd) and apex angle (°) Calculate irradiance flux (W/m^2. 7. Do y. Vswr To Rl Formula. There are two S-parameters of interest. This calculator converts between return loss (RL), voltage standing wave ration (VSWR), and reflection coefficient (Γ). In some cases, users require a custom impedance value. Just enter the value and click calculate. In Figure 14, the ADL5920 is being used to measure the return loss of the load, also at 1 GHz. Frequency GHz MHz: Distance:Return Loss is basically ratio between Incident power (Pi) on load to Reflected power (Pr) back to source. 5:1 VSWR that appears on. It also shows the percentage of forward to reflected power. LC Impedance matching network designer Enter the input and output impedances to be matched and the centre frequency. Example 2. YourR 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. Mismatch Loss (dB) 3. Formula is:: reflection coefficient (Γ)=. In this Inside Wireless episode we will look at Voltage Standing Wave Ratio (VSWR), |S11|, and Return Loss. A perfect match would be 1:1, meaning that the peak amplitude of the signal is always the same (i. Definition and Background. 8. LC Impedance matching network designer Enter the input and output impedances to be matched and the centre frequency. Return loss, also known as reflection loss, is a measure of the fraction of power that is not delivered by a source to a load. Convert VSWR to Return Loss and vice versa. Result. Pasternack's RF Calculators and Conversions section provides engineers valuable and easy-to-use tools ranging from complex mathematical formulas to simple conversions. 223:1 VSWR (It is slightly improved because of Component A having more insertion loss than. ,100 % power transferred from a source to a load via a transmission line/cable). Pi Attenuator Calculator. 064 36. 3 dB. RF calculations and conversions include metric-standard, link. Software Calculator VSWR dan Return Loss. 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. To do so, calculate the desired return loss and subtract the known load return. Antenna). Values for L and C will be calculated for the four topologies shown. Calculates the resistor values, attenuation, minimum attenuation, 'impedance', reflection coefficient, VSWR and return loss of a matching Pi attenuator. Figure 1. When a transmitted wave hits a boundary such as the one between the lossless transmission line and load (Figure 1), some energy will be transmitted to the. VSWR to Return Loss . Power measurement. 0 indicates about 75% of the power is delivered to the antenna (1. As an example, input power of 100 W (50 dBm) and output of 50 W (47 dBm) yields a cable. Consumers; Contact Us;Return Loss is a measure of the amount of energy that is reflected back at a discontinuity in a Radio Frequency Circuit . This impedance is the equivalent of a 32. Email. Recall that signs of reactances are missing on the full chart. It measures how much energy is reflected back to the transmitter when a signal is transmitted through an antenna. Example Problem Find the SWR of the transmission line or wave guide whose load or. A low VSWR will minimize reflections from the antenna. Radio Frequency Engineering Calculator. Enter VSWR, Reflection Coefficient, or Return Loss to calculate remaining values. Low-pass lumped element filters. R/F Calculators and Conversion Tools VSWR / Return Loss Calculator Find VSWR (Voltage Standing Wave Ratio), Return Loss, Mismatch Loss, and the Reflection Coefficient given any one of the listed input types. Electric fieldrms 5 conductivity 1 mass density 13E03 13 x 10 3. Calculates the resistor values, attenuation, 'impedance', reflection coefficient, VSWR and return loss of a T attenuator. In some cases, users require a custom impedance value. The ratio of the input to the reflected signal is. Voltage standing wave ratio (VSWR) is a way to measure transmission line imperfections. applied power and return loss of load, measured at 1 GHz. Once the VSWR is known, return loss can be calculated as follows: Return Loss = 20 ∙ log10 () Generally, a higher return loss value is preferable. In fact, striplines often make components such as band-pass filter's more accurately, with more symmetric roll-off and no lower cutoff frequency. Fill in the input field and select the input type and click the "calculate" button to show the values. 8. This mix of web-based tools and downloadable Windows software was developed to help engineers design faster and more accurately. Since directivity is a ratio of power densities, it is unitless. 09 = 1. Return Loss (dB) = 10 x Log ( Pr / Pf ) Match Efficiency (%) = 100% x (1 - Pr / Pf)The VNAs with math modes can also directly calculate and display the resulting VSWR value. This can be built into a FLEXI-BOX and a transmission line PCB is. For S 11 it is also possible to display return loss and (voltage) standing wave ratio [(V)SWR] over frequency range. Use the S11 value in the calculator above to find the equivalent VSWR. The main cause of the mismatch is the deviation in the con-Resonant Frequency Calculator. The return loss is the ratio of the power of the. Clear. It turns out that -13. VSWR. 5:1. If a complex plane is used with resistance along the real axis then the reactances of the capacitor and inductor are treated as imaginary numbers. 9913 and LMR-400 are popular “low-loss” RG-8 types. g. You can use our VSWR calculator to see that 1. SWR / Return Loss Calculator will find VSWR, Return Loss, Mismatch Loss, and the Reflection Coefficient given any one of the listed input types. Z (impedance, complex number, in ohms), here are 2 examples of Z: Zs = Rs + jXs, source impedance. com +1 (718) 934 4500 +1 (800) 654 7949. Return Loss vs VSWR Calculator: The calculator calculates VSWR from return loss and return loss from VSWR. 2 means a peak voltage 1. On the other hand, VSWR and the reflection coefficient are connected by the equation: VSWR = (1+|Γ. The formula and equations used by this calculator are also provided. 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. Formally, S11 is the negative of return loss and. Return loss load -2. Here's the unwrapped phase of S21:by Eamon Nash Download PDF. Because the reflection coefficient Γ < 1, then the return loss will have a positive dB value. com . Moreover, return loss is the relationship between both the reflection coefficient (Γ) and the. net I(RL) V1. But 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. 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. 0708,min,max = =A VSWR value of 2 or under is typically acceptable for antennae in communications systems. Return Loss. But the meter at the transmitter will show a VSWR of 1. 155 dB. applied power and return loss of load, measured at 1 GHz. 44 . 1 Return loss in dB = 26. So a perfect match can be represented by the range 0. 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. be used to add or subtract an arbitrary number of power, to convert power and voltage units from the linear to the logarithmic. VSWR | Return Loss | Reflection Coefficient Conversion Calculator: This Javascript calculator converts between return loss (RL), voltage standing wave ration (VSWR),. To use the calculator, enter the VSWR value for each of the assembly components being added, as exampled below. 15 + 1. 25mW. Calculate! Where do these calculations come from? Well, start with the formula for VSWR: If we invert this formula, we can calculate the reflection coefficient (, or the return loss. This calculator converts Return loss (RL) to Voltage Standing Wave Ratio (VSWR). It is often expressed in terms of a percentage, or in dB. S11 then would be the reflected power radio 1 is trying to deliver to antenna 1. Let’s start by looking at a 2-port device illustrated in Figure 1. 12 VSWR max. A 2-port device has two distinctly interesting. We have designed a special VSWR and Return Loss Calculator. Like insertion loss, return loss is also generally described in decibels of power. The VNAs with math modes can also directly calculate and display the resulting VSWR value. 205 11. Useful converters and calculatorsVSWR & Return Loss Calculator: Enter forward and reflected power or match to determine equivalent values. Values for L and C will be calculated for the four topologies shown. The ideal condition, whereYou can assume power dissipation to be uniform, provided the assembly does not operate in high VSWR/return-loss conditions. VSWR & RL Power Home Enter Calculates VSWR Return Loss Match Efficiency Rho Forward Power Reflected Power dB % Input Power Watts Power Attenuation dBm Output Power Output Power (dBm) = Input Power (dBm) - Attenuation (dB) VSWR = Voltage Standing Wave Ratio Power (dBm) = 10 x Log [ Power (Watts) ] + 30 dB Attenuation. (3) ea 90°E-Bend - 1. Next, plug in the calculated return loss value into the formula VSWR = (1 + 10^ (RL/20))/ (1 - 10^ (RL/20)). S11 is the reflection. Subscribe to receive Mini-Circuits News. Forward Power (W) Reverse Power (W) VSWR. The Reflection Coefficient can be calculated from return loss by using the following formula. 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. 000:Calculate SWR and return loss from impedance values. This VSWR calculator will calculate return loss, mismatch loss, loss in percentage and the reflection coefficient.