A 60GHz 65nm CMOS RMS power detector for antenna impedance mismatch detection

Abstract

This paper presents a 60GHz 65nm CMOS RMS power detector to be used in a Power Amplifier regulation loop. The presented test-chip integrates also a differential capacitive coupler sensing the RF voltage on a differential transmission line. The circuit shows 25dB of linear detection range at 60GHz, well enough to cover a VSWR of up to 7∶1 caused by antenna impedance mismatch while still having 10dB margin for output power regulation. The detector consumes only 50µA from a 1.2V power supply and occupies an active area of 80×80µm2.