A Quadrature Phase Detector in 28nm CMOS for Differential mm-Wave Sensing Applications Using Dielectric Waveguides

This paper presents a quadrature phase detector in 28nm CMOS, which is used to perform a differential phase measurement between two dielectric waveguides at 120 GHz. The phase detector has on-chip quadrature generation with a measured maximum quadrature error of 2° over a 20 GHz bandwidth. The quadrature phase detector achieves a maximum uncalibrated phase error of 11 °. The proposed waveguide sensing system allows for both intrinsic measurements, in which the dielectric waveguide acts as a sensor, and extrinsic measurements, where the dielectric waveguide acts as a guided channel and antenna. Intrinsic sensing is demonstrated by a temperature measurement and extrinsic with a non-destructive test of a 3D-printed polymer sample.