Compact Diode Connected MOSFET Detector for On-Chip Millimeter-Wave Voltage Measurements

A root-mean-square diode connected MOSFET detector for estimating the signal voltage of internal nodes of millimeter-wave circuits is demonstrated. These detectors fabricated in a foundry 65 nm CMOS process provide an affordable means for RF testing, built-in self-test as well as debugging of mm-wave circuits. This broadband detector operates from 80–110 GHz with detector gain of 8.5
${\mathrm V}^{-1}$
at 60 nA bias. This in combination with high input impedance that results in less than 0.15 dB insertion loss relative to a thru structure, and a small area of 20
$\mu\text{m}^{2}$
makes the detector non-invasive.