This calculator converts values between VSWR, Return loss, Reflection Coefficient and Mis-Match Loss. View VSWR Table
What is VSWR calculator?
VSWR calculator is an online calculator is used to convert the values between the VSWR, return loss, reflection coefficient, and mismatch loss.
What is VSWR?
VSWR (Voltage Standing Wave Ratio) is the measure of how efficiently RF power is transmitted in to a load. For example, if a power amplifier is connected to an antenna through a transmission line - ideally there will be no reflections and all the signal from the power amplifier will be transmitted to the antenna. However in the real world, there will be some mismatches which will cause some of the signal to get reflected back in to the transmission line. VSWR is the measure of how much signal get reflected back in to the system. It is the ratio between transmitted and reflected waves. A high VSWR indicates poor transmission-line efficiency and reflected energy.
What is return loss (RL)?
Return Loss is a amount of power that is lost to the load and does not return in to the system as a reflection. It is expressed in dB - A high return loss means more power is lost at the load.
What is reflection coefficient (Γ)?
Reflection Coefficient indicates how much of an electromagnetic wave is reflected by an impedance discontinuity in the transmission medium. It is a ratio of the amplitude of the reflected wave to the wave incident at the junction. The reflection coefficient is denoted by the symbol gamma. The magnitude of the reflection coefficient does not depend on the length of the line, only the load impedance and the impedance of the transmission line.
What is mismatch loss (ML)?
Impedance mismatch/discontinuity between the transmission line/cable to the connected load/component leads to a small amount of incident signal power reflect back to the source. In transmission line theory, the mismatch loss (ML) is the ratio of incident power (Pi) to the difference between incident and reflected power (Pr). High mismatch loss means high reflected power, so high mismatch loss is not good for a system. The mismatch loss is expressed in dB as follows.
For an ideal system, there is no impedance mismatch between the transmission line & load, hence no reflection, so no reflected power. Hence, the mismatch loss is zero. So, the all the incident power is delivered to the load. But, for a practical system, there will be a small impedance mismatch always; hence, significant reflection will be there, so the significant reflected power will be there. Hence, for a practical system, the mismatch loss is higher than the ideal system.
This calculator uses the following formulas for converting the values between the VSWR, return loss, reflection coefficient, and mismatch loss.
- If VSWR is known, then the reflection coefficient (Γ), return loss (RL), and mismatch loss (ML) is calculated by using following formulas.
- If the reflection coefficient (Γ) is known, then the VSWR, return loss (RL), and mismatch loss (ML) is calculated by using following formulas.
- If the return loss (RL) is known, then the VSWR, reflection coefficient (Γ), and mismatch loss (ML) is calculated by using following formulas.
- Where:
- VSWR = Voltage standing wave ratio
- Γ - Reflection coefficient
- RL = Return loss in dB
- ML = mismatch loss in dB