A W-band integrated silicon-germanium loop-back and front-end transmit-receive switch for Built-in-self-test

This paper presents a front-end switch that integrates the ability to provide both loop-back testing and transmit-receive operation. In addition, power detectors are integrated with capacitive couplers to sense the power levels at the transmitter output and the receiver input. The measured results show the power detectors have constant responsivity and can predict the power level within 0.5 dB. These capabilities are added to the front-end switch while maintaining an insertion loss of 2.3-2.5 dB and an isolation of 19.5 dB at 94 GHz.