Example 2. S-parameters, S11 and S21. A 2-port device has two distinctly interesting. VSWR = Voltage standing wave ratio. 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. 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. 0 indicates 44% of the power is delivered to the antenna (3. It also shows the percentage of forward to reflected power. The VSWR is a measure of the matching of the antenna to the source and feeder cables. By Marki Microwave, Posted Wed May 19 2010. to a calculator or computer program that will handle it. VSWR Calculator: This is the ratio of maximum voltage to minimum voltage in standing wave pattern. Return loss can be measured by using microwave and RF test equipment such as a signal generator, directional coupler along with a spectrum analyser or power meter, or alternatively by using a. Wavelength Calculator. The following formula is used to calculate the Return Loss (RL) from Voltage Standing Wave Ratio (VSWR). Just enter the forward and reflected power in watts. Vswr To Rl Formula. VSWR: RL (dB) 1. Voltage standing wave ratio (VSWR) is a way to measure transmission line imperfections. It measures how much of the signal sent from the antenna is reflected back to the source. By Marki Microwave, Posted Wed May 19 2010. Step 3. 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. Calculate impedance from resistance and reactance in parallel. 8. Solution: First the VSWR figures are converted to reflection coefficient magnitudes: Then the mismatch uncertainty is: M u = ±200 (0. VSWR Calculator. Wavelength dBm dBuV W dBuVm mWcm2 pJcm2 V VSWR This RF calculator has been developed by Compliance Engineering as a resource for individuals. VSWR / Return Loss Calculator. As an added bonus, the results are modifiable and can calculate. g. The load can be an antenna, filter or other equipment connected to a transmission line. 2. 8. October 20, 2022. Convert S11 to return loss; Compute Voltage Standing Wave Ratio (VSWR) from Return Loss; References [1] Return Loss on Wikipedia The formula for insertion loss in decibels (dB) is: Insertion Loss (dB) = 10 * log10 (Pin / Pout) Where: Pin is the input power or signal level. Reflection Coef. VSWR - Return Loss - Γ Conversions These are the standard set of equations for converting between VSWR, return loss, and reflection coefficient (Γ). Example 2. 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. The online calculators are usable in pop-up mode for easy. 3 800–960 MHz 1. number) VSWR or % Reflected Power: MHz: a wavelength in inches or feet: Get Help. 16-Feb-2022. A low VSWR will minimize reflections from the antenna. 7145 VSWR 6 Directivit y of directiona l coupler 23 dB 0. 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. The return loss & VSWR is related by the following formula, from which we can calculate return loss for a given VSWR. S-parameters, S11 and S21. These are the standard set of equations for converting between VSWR, return loss, and reflection coefficient (Γ). VSWR. Calculates the resistor values, attenuation, 'impedance', reflection coefficient, VSWR and return loss of a Pi attenuator. This is an online calculator that calculates Return Loss based on VSWR. VSWR/Return Loss Frequency Band VSWR Return Loss (dB) 680–800 MHz 1. The input to the antenna will be 8,511 watts. RG-8 and RG-213 (50 ohm); and RG-11 (75 ohm) are about 0. 405 inch. 많은 초심자들이 대체 왜 return loss란 지표와 VSWR이란 지표가 혼용되는지 이해하기 어려워 하는 경향이 있다. VRMSF and VRMSR are measured and the return loss is back calculated. 13 24. 695. 009. Determine how to calculate the effect of VSWR on Return Loss. Radio Frequency Engineering Calculator. VRMSF and VRMSR are measured and the return loss is back calculated. The VNAs with math modes can also directly calculate and display the resulting VSWR value. DASAR TEORI. 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. Convert VSWR to Return Loss and vice versa. VSWR and Return Loss RF Calculator. The table below converts between VSWR, return loss, reflection coefficient, mismatch loss, reflected power and through power. 35. At 100 MHz, the loss is 0. **Note: Like our stripline impedance calculator, all of our RF calculators allow SI prefix input. After using our pi pad calculator and installing your attenuator, you can use our VSWR calculator to know how your VSWR has improved. The return loss and VSWR measurements are key measurements for anyone making cable and antenna measurements in the field. But, for a practical system, there will be a small impedance. 259 0. They are related but measure different aspects of signal performance. 7. Calculates the absolute load impedance, reflection coefficient, VSWR, return loss and mismatch loss of a load. comThere are many antenna parameters out there. Here's a simple VSWR calculator. Return Loss (dB) VSWR. Skin Depth Calculator. The return loss of a system is defined as the ratio of incident power to reflected power and is measured in dB. Suppose the wave is not matched with load and signal there is some unwanted signals are interrupted or signal loss is occurred. Note that in general S-parameters are a function of frequency (i. , thereby assisting engineers to detect system problems and avoid costly, time-consuming system failures. Once the VSWR is known, return loss can be calculated as follows: Return Loss = 20 ∙ log10 () Generally, a higher return loss value is preferable. 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. Click here to use the VSWR Calculator . Directivity, on the other hand, is the level of the signal which appears at Port 4 and is undesired. Since it is a logarithmic measurement, it is very useful when displaying very small reflections. Solved Example. Return loss vs. While we’re at it, the reflection coefficient is: Γ=(75-50)/(75+50)=0. These multiple solutions are possible because each contributor is a vector having both. The voltage standing wave ratio (VSWR) is defined. 15 + 1. If the antenna reflects 250 watts the VSWR at the antenna will be 1. Return Loss VSWR Reflection. The corresponding value in the right column is the VSWR value. Note: If you select a waveguide size from the dropdown below, the broad wall width will be automatically calculated along with the other results. Clear. 특히 Return loss와 VSWR의 대략적 값의 관계정도는 암기해두는게 편리할 때가 많다. In this case, you may also need to calculate localized heating due to a current standing wave. VSWR - Return Loss - Γ Conversions These are the standard set of equations for converting between VSWR, return loss, and reflection coefficient (Γ). Now, let us investigate the physical meaning of return loss. Please Support RF Cafe by purchasing my ridiculously low−priced products, all of which I created. 3 2300–2700 MHz 1. But the meter at the transmitter will show a VSWR of 1. The relationship between composite return loss and individual return loss in the constructive condition of identical mismatches is that the composite VSWR is the the square of the individual VSWRs. VSWR measures the ratio of voltage peaks and valleys. 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. Visit Return Loss to VSWR converter>> RF Calculator #5 :Effects of Cable Loss in VSWR and Return Loss Measurements By Jim Norton Bird Technologies Group Applications Engineer 1 | Bird Technologies Group 866. This antenna tilt angle calculator also provides,. Voltage standing wave ratio (VSWR) is a way to measure transmission line imperfections. 155 dB. Measure the power levels at the input and output of your cable, convert to units of dBm, and calculate the difference. Home Return Loss to VSWR Conversion Chart Due to mismatches in impedance within the connector, some of the signal is reflected. Two years ago, one of our most respected RF experts, Lou Meyer, wrote a blog post describing the technicalities of return loss and voltage standing wave ratio (VSWR) and how the multiple components at a cell site tower make the calculations more complex. VSWR is the voltage standing wave ratio it used to measure the all-types waves (example: antenna waves) during transmission. The voltage standing wave ratio (VSWR) at a port, represented by the lower case 's', is a similar measure of port match to return loss but is a scalar linear quantity, the ratio of the standing wave maximum voltage to the standing wave minimum voltage. The result is an antenna VSWR or return loss measurement corrected for cable loss. comThe antenna accepts a certain amount of energy delivered to it by the transmission line (characterized by S11, VSWR, or return loss), and Antenna Efficiency characterizes the amount of energy lost ‘in’ the antenna after this. Usually this is the threshold when most devices are considered. p65 Author: barbara Created Date:Pi Attenuator Calculator. VSWR is the ratio of the peak amplitude of a standing wave to the minimum amplitude of a standing wave, as seen in the following Figure: Figure 1. VSWR & Return Loss Calculator: Enter forward and reflected power or match to determine equivalent values. VSWR / Return Loss Calculator; IRA Calculator; Wavelength (TEM) Calculator; Link Budget Calculator . For transmission lines to have the highest quality, it is necessary to have impedance matching. Unless you have a piece of slotted line-test equipment this is a hard definition to use, especially since the concept of voltage. At 1000 MHz, the S11 (dB) = -RL (dB) = -15 dB. VSWR / Return Loss Calculator VSWR / Return Loss Calculator Introduction Input Type: Input Value: Calculate Reset Definition of VSWR "Understanding VSWR isn't just about. The VSWR is a measure of the efficiency of a transmission line and is used to determine how well the line is matched to the impedance of the. 7. 7. VSWR is a measure of the reflected power on a transmission line. 특히 Return loss와 VSWR의 대략적 값의 관계정도는 암기해두는게 편리할 때가 많다. Return loss is when the transmitted signal is not completely. VSWR. RG-8 and RG-213 (50 ohm); and RG-11 (75 ohm) are about 0. VSWR table of return loss vs. Example 2. Figure 2: VSWR Measurement Principle The return loss at the input and output ports can be calculated from the respective reflection coefficients as follows: Input return loss (RL IN) is a scalar measure of how close the actual input impedance of the network is to theReturn Loss (RL) is a measure of all reflections that are caused by the impedance mismatches at all locations along the link and is expressed in decibel (dB). ZL = RL + jXL, load impedance. 091) (0. Enter Input Value Output. November 2023. Conversion Formulas. But the meter at the transmitter will show a VSWR of 1. 0 indicates about 75% of the power is delivered to the antenna (1. flectioncoefficientΓ,voltagestandingwaveratio(VSWR) and return loss (RL) and these quantities are interre-lated. 17. How to Calculate VSWR . 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. Formulas used: s r r. 41:1 with a return loss of 15. At 100 MHz, the loss is 0. 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. e. This is because the parasitics of lumped elements tend to kill the frequency response as you go higher in frequency. Calculate VSWR, Return Loss, etc. 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. 8. 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. 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. Preferred resistor values are entered into the text boxes, similar to the way that values for a prototype may be selected. A power meter may also be used to calculate cable loss. Matching Pi Attenuator Calculator. Then click the "Calculate" button next to the value you just typed to compute the others. 1. Return Loss is a measure of the amount of energy that is reflected back at a discontinuity in a Radio Frequency Circuit . The flexible types (9913F and LMR-400UF) are preferred, particularly for rotatable antennas. A similar version of this article appeared in the October 2012 issue of Power Systems Design magazine. VSWR is a function of the characteristic impedance of the transmission line and the impedance of the antenna. 2. 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. Calculates the resistor values, attenuation, minimum attenuation, 'impedance', reflection coefficient, VSWR and return loss of a matching Pi attenuator. 707. The image below shows what your completed Excel sheet might look like. (1) ea Flex Assy - 1. Yes, we did that without a calculator. This is an online conversion tool for converting between VSWR, return loss and reflection coefficient, which are different ways to express how well a load is matched to a source. Return loss calculation EXAMPLE : VSWR = 1. This ratio can also be measured in dB, and expressed as Return Loss. Directivity and VSWR Measurements. These are considered to be standardized impedance values with cables readily available. 8. Voltage Measured Along a Transmission Line. VSWR to Return Loss Formula VSWR = (1 + 10-RL/20)/ (1 - 10-RL/20) Example Calculation A Return. Calculate the VSWR in another column. Click here for RL to VSWR CalculatorKnowing Return Loss (RL), calculate voltage reflection coefficient Rho= 10^(-RL/20). A series of RF calculators for radio frequency engineers. The ratio of the input to the reflected signal is called the Voltage Standing Wave Ratio (VSWR). The graph below shows input return loss for an amplifier. $\begingroup$ If that was the only information you were given, you would first find the return loss looking at the load, then use system 2's S matrix to find the RL looking into it, then do the same with system 1 until you finally have the RL looking into the entire network. But, for a practical system, there will be a small impedance. 6 dB of mismatch loss). It varies from 1 to (plus) infinity and is always positive. Stripline Impedance calculator Smith charts VSWR/Return loss converter Wavelength calculator Wilkinson splitter designer. Complex Impedance for RL and RC. Return loss is when the transmitted signal is not completely. Reactance Calculator. Given a certain level of heat generation within an assembly, thermal dissipation occurs through three primary mechanisms. 3 dB. The Tee attenuator consists of one series resistor at the input and two parallel, one of which is grounded while the other goes to output. Most RF Coaxial Cables have an impedance of 50 ohms or 75 ohms. 1, directivity does not depend on the distance from the antenna. There is also a selection of suitable RF. p65 Author: barbara Created Date: 5/6/2003 8:50:18 AMThe voltage standing wave ratio (VSWR) at a port, represented by the lower case 's', is a similar measure of port match to return loss but is a scalar linear quantity, the ratio of the standing wave maximum voltage to the standing wave minimum voltage. Return Loss. Power on the Site Master and press the MODE key. Calculate the VSWR to 1 decimal place. VSWR Return Loss Calculator. 54 dB (11% of your transmitter power is reflected back). This calculator computes the VSWR, reflection coefficient, return loss and matching loss in a transmission line. The component is said to have a loss of 25 dB. The isolation S23 is exactly -20 dB at the center frequency, while the output match is also degraded to about -13. Just enter the value and click calculate. g. An equation for the prediction of the Return Loss of cascaded systems has been previously presented and validated. A table of convenient values are presented at the bottom. This VSWR calculator will calculate return loss, mismatch loss, loss in percentage and the reflection coefficient. The term ‘forward power is synonymous with powered deliver to the load, or thru power. $\endgroup$ – 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. S11 is the reflection. What is the VSWR ratio to return loss? There is an inverse relationship between Voltage Standing Wave Ratio (VSWR) and Return Loss. VSWR. 0 indicates 44% of the power is delivered to the antenna (3. 4 centimeters. Upon arriving back at the source, part of the reflected wave is coupled back. transmitter) with the load (i. This calculator computes the VSWR, reflection coefficient, return loss and matching loss in a transmission line. VSWR to Return Loss Conversion Table. It is often expressed in terms of a percentage, or in dB. Forward Power vs Return Loss Calculator RF calculators and converters. For example, an antenna with a VSWR of 2:1 would have a reflection coefficient of 0. A low VSWR will minimize reflections from the antenna. 0. 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 . A VSWR of 6 or more is pretty high and will generally need to be improved. 5:1. These calculators help with unit conversions, VSWR calculations, attenuator design, antenna design, radars, and various other basic calculations that are often required. Online SWR Calculator. 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. The corresponding value in the right column is the return loss value. Forward Power (W) Reverse Power (W) VSWR. A calculator designed to compute the VSWR, reflection coefficient, return loss and matching loss in a transmission lineThis VSWR calculator will calculate return loss, mismatch loss, loss in percentage and the reflection coefficient. 92 dB 0. SWR / Return Loss Calculator will find VSWR, Return Loss, Mismatch Loss, and the Reflection Coefficient given any one of the listed input types. 1 3. Return loss can be measured by using microwave and RF test. Cable and antenna analyzers allow operators to measure return loss/VSWR, cable loss, distance-to-fault (DTF) measurements, reflection measurement, antenna isolation measurement, impedance, etc. 25 dB of mismatch loss); a VSWR of 7. 8. 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. In some cases, users require a custom impedance value. The reader is encouraged to do this with the full impedance Smith chart as shown in Figure 3. Measure the power levels at the input and output of your cable, convert to units of dBm, and calculate the difference. Thus, for this system, VSWR = 1:1 (i. Cable impedance ohm. reflection coefficient definition. 1) (2. As an example, F1=750 MHz and F2=850 MHz for a typical cellular frequency band. While return loss analysis can be an ambiguous quality indicator,. The return loss & VSWR is related by the following formula, from which we can calculate return loss for a given VSWR. 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. Fill in the input field and select the input type and click the "calculate" button to show the values. Software Calculator VSWR dan Return Loss. Since directivity is a ratio of power densities, it is unitless. It is related to return loss as follows. Suitable for VHF (~1. VSWR to Return Loss (dB) Calculator. 5 0 0. To convert from Return Loss to VSWR, find the return loss value in the left column. So Return Loss is positive quantity RL (dB)= Incident power ( Pi)/Reflected power (Pr. This online reflection coefficient to VSWR calculator calculates the VSWR by entering the reflection efficient Γ (= value between 0 & 1). The Reflection Coefficient can be calculated from return loss by using the following formula. This site comprises a comprehensive array of tutorials and related tools, including explanations, examples, references and charting. 0 0. e. From a system VSWR level calculate the following parameters:- Reflection coefficient- Forward and reflected power percentage- Mismatch loss in dB. In one typical RF application, VSWR is used to measure the amount of reflection due to impedance mismatch. Mismatch Loss: Reflected Power Through Power (dB) Coefficient,VSWR is defined as the maximum voltage of the standing wave (E max) to the minimum voltage of the standing wave (E min ). The ratio of the input to the reflected signal is. 938 dB ==> 1. VSWR (pronounced "viswar"), or the Voltage Standing Wave Ratio, is the ratio of the maximum standing wave amplitude at one node to the minimum amplitude at another node in a system. The equivalent VSWR is 1. dl. 224 X=-14. Vswr To Rl Formula. 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. If our directional coupler had perfect isolation, the return loss of the load would equal the difference between the reflected and forward measurements:. 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. Figure 14. Return loss can be measured by using microwave and RF test equipment such as a signal generator, directional coupler along with a spectrum analyser or power meter, or alternatively by using a. There is an equivalent definition for VSWR, which can also be expressed in terms of the Return Loss (RL). As an added bonus, the results are modifiable and can calculate the other values. R = 20log 10 (E incident /E reflected)Pasternack's RF Calculators and Conversions section provides engineers valuable and easy-to-use tools ranging from complex mathematical formulas to simple conversions. VSWR table of return loss vs. 2. VSWR to Return Loss . This impedance is the equivalent of a 32. This can be achieved by regulating the inner and outer diameter of the coaxial cable, along with the. This is an ideal open or short circuit, equivalent to VSWR=infinite. Just enter the value and click calculate. , if RL = 20dB, then calculate Rho = (10 ^ (20/-20)) = 10 ^ (-1) = 0. 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. VSWR table of return loss vs. The lower the VSWR is, the better the antenna is impedance-matched to the transmission line and the higher the power delivered to the antenna. Understanding VSWR and Return Loss. Please Support RF Cafe by purchasing my ridiculously low−priced products, all of which I created. [email protected] insertion loss, return loss is also generally described in decibels of power. Our RF calculators and converters will provide the figures you need for your radio frequency engineering needs. 05 VSWR max. Introduction to VSWR. VSWR (voltage standing wave ratio, sometimes pronounced "viswar"), is the ratio of the maximum standing wave amplitude at one node to the minimum amplitude at another node in a system. Noise Conversion Calculator. Advanced Control Components. com +1 (718) 934 4500 +1 (800) 654 7949. Enter VSWR, Reflection Coefficient, or Return Loss to calculate remaining values. Lower VSWR means lower reflection power (good impedance matching); thus, power transfers to load will be high. 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. 25mW. The calculated value is MUCH worse. 223:1 VSWR (It is slightly improved because of Component A having more insertion loss than. LOSS VSWR LOSS VSWR LOSS VSWR LOSS VSWR LOSS VSWR (dB) (dB) (dB) (dB) (dB) return loss Vs. Lower VSWR is always desirable for a system. 예를 들어 Return loss가 10dB 정도라면, VSWR은 2:1 이하가 되어서 입력매칭이 비교적 잘된 경우로 평가하며, Return loss가 14 dB 정도가 되면 VSWR은 1. You can use it for free. S21 is the transmission coefficient of Port 2. VSWR Calculator. In order to get the best power transfer from a source to a load, the source impedance must equal the complex conjugate of the load impedance: Rs + jXs =RL −. Forward Power Watts ? Reflected Power Watts ? VSWR → RL (Return Loss). S11 is the reflection. This VSWR calculator will calculate return loss, mismatch loss, loss in percentage and the reflection coefficient. This general RF calculator includes calculations of path loss, VSWR and wavelength as well as conversions between many common terms used in the wireless industry. Power Density Calculator . 672 0. It varies from 1 to (plus) infinity. A known return loss is applied to the RF OUT port. 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. The calculator is a spreadsheet that accepts VSWR specifications for all the components in your RF Path—tower mounted amplifiers, diplexers, bias tees, etc. Reflections are measured using either VSWR or Return Loss. Return loss load -2. Email. Unwrapped phase and reference plane extensions. 2 times the minimum voltage along that line, if the line is at least one half wavelength long. Return loss and insertion loss are both measurements of how a component or device affects the transmission of signals in a system. 8. A VSWR of 6 or more is pretty high and will generally need to be improved. 05 + 1. 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. 091) (0. VSWR Calculator:(by using RL) return loss(RL)= VSWR = RF Coax Cable Assembly Designer: Most Viewed Companies MegaPhase, LLC. reflection coefficient Calculator. VSWR is determined from the voltage measured along a transmission line leading to an antenna. Convert VSWR to Return Loss, Reflection Coefficient, and Mismatch Loss with our easy conversion calculator. RF engineers often measure return loss on a “dB. By entering the values given above into the VSWR calculator, we see that the probable assembly-chain VSWR of: 1. These are considered to be standardized impedance values with cables readily available. 2%) = ±3. Return Loss and Mismatch Loss Calculator. LC Impedance matching network designer Enter the input and output impedances to be matched and the centre frequency. Formula is:: reflection coefficient (Γ)=. 19. As an example of common VSWR values, a VSWR of 3. Stripline Calculator. Voltage Measured Along a Transmission Line. This can be built into a FLEXI-BOX and a transmission line PCB is available which easily adapts for this circuit with one simple trimming operation. Figure 14. The Smith Chart achieves this by superimposing a grid on S11 that maps load impedance. 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. In industry, VSWR is sometimes pronounced "viz-wer". In order to improve the VSWR, this calculator also has an extra input for adding an attenuator to improve or reduce the system VSWR. Return Loss Vs. Voltage is the pressure from an electrical circuit's power source. 000:Calculate SWR and return loss from impedance values. The below step by step solved example problem may helpful for users to understand how the input values are being used in such calculations to find the ratio of load impedance matching to the transmission line or wave guide characteristic impedance (Z 0). This formula is used to calculate the VSWR from the given return loss. Any other value indicates that a portion of the energy is reflected. 7145 VSWR 6 Directivit y of directiona l coupler 23 dB 0.