Reflection Coefficient to VSWR Calculator

Reflection Coefficient to VSWR Calculator

Voltage Standing Wave Ratio (VSWR) measures the efficiency of power transferred from a source to a load via a transmission line/cable. VSWR means the ratio of the maximum voltage to the minimum voltage in the standing wave pattern along the transmission line. The standing wave pattern present along a transmission line is due to the impedance mismatch between the transmission line and the connected load.  Lower VSWR is always desirable for a system. Lower VSWR means lower reflection power (good impedance matching); thus, power transfers to load will be high.

This online reflection coefficient to VSWR calculator calculates the VSWR by entering the reflection efficient Γ (= value between 0 & 1).

What is VSWR?

VSWR (Voltage Standing Wave Ratio) measures the efficiency of power transferred from a source to a load via a transmission line/cable. 

Impedance mismatch/discontinuity between the transmission line/cable to the connected load leads to a small amount of incident signal power reflected back to the source. The reflected wave interferes with the forward wave resulting in standing waves. This leads to peaks and valleys in the voltage at various times and distances along the line. VSWR measures this voltage variation. VSWR can be defined as the ratio of the maximum voltage to the minimum voltage in the standing wave pattern along the transmission line.

For an ideal system, there is no mismatch between the line and load impedance; thus, no reflection results in no voltage variation along the line. Thus, VSWR is 1:1 for an ideal system. But for a practical system, there will be a small impedance mismatch always; hence, VSWR is like 3.0:1, 2.0:1. Higher VSWR implies a higher mismatch.    

How to find the VSWR of a reflection coefficient?

The following formula is used to calculate the VSWR of a reflection coefficient. 

Where,

VSWR = Voltage standing wave ratio

Γ = Reflection coefficient