Calculating voltage wave ratio

When the antenna input impedance and the characteristic impedance of the feeder are inconsistent, the generated reflected wave and the incident wave are superimposed on the feed line, and the ratio of the maximum value to the minimum value of the adjacent voltage is the voltage standing wave ratio, which is to check the transmission efficiency of the feeder basis.

The voltage standing wave ratio is less than 1.5, and the voltage standing wave ratio at the operating frequency is less than 1.2.

If the voltage standing wave ratio is too large, the communication distance will be shortened, and the reflected power will return to the power amplifier part of the transmitter, which will easily burn out the power amplifier tube and affect the normal operation of the communication system.