Repeater for a same frequency with spillover measurement

摘要

The system for measuring the spillover signal from a transmitter to a receiver in a same frequency repeater or a booster has a frequency conversion device which slightly offsets the transmission frequency from the reception frequency, and a signal detector which measures the offset frequency component in the reception signal. The offset frequency is around 100 Hz, which is higher than the fading frequency, and low enough not to affect the operation of receivers. The measured spillover level is used to control the gain of the repeater, and/or to cancel the spillover signal, so that the repeater has the maximum gain without suffering from oscillation.