TRANSMISSION POWER DETECTION CIRCUIT FOR RELAY AMPLIFIER

摘要

PURPOSE:To reduce a ternary distortion component superimposed in a transmission output leaked from the transmission power detection circuit in the transmission output of a radio repeater arranged distributingly in a stereoscopic parking place and an underground shop street or the like as a countermeasure of a dead band of a cellular telephone system or a portable telephone system. CONSTITUTION:A power corresponding to a transmission output P1 of an amplifier 2 is extracted by a directional coupler 3 and a signal P2 obtained from the power amplified forward by an isolation amplifier 13 via an attenuator 12 is rectified by a rectifier circuit 11 to obtain a desired detection voltage VD1.