CMOS FM Receivers.

Experimental results of two narrowband CMOS FM receivers based on two distinct architectures are presented. One receiver is a double heterodyne receiver with a 3MHz switched-capacitor IF filter while the other is a pseudo double heterodyne receiver with a switched-capacitor baseband filter. The integration covers all the filtering and demodulation circuits from RF frequencies to the audio output. FM receivers exhibiting a 5mV sensitivity with a -30dB quieting level without considering the gain of a front-end RF amplifier are implemented on the Si area less than 10mm(2) using 1.75mu CMOS technology. Achieved performances are not yet comparable to the specifications of commercial FM broadcast receivers at this time, however, the integration approaches will surely be a winner in competing with receivers made conventionally, particularly for narrowband applications as progress continues in the future.