A Fully Integrated 20-500-GHz Coherent Detector with 2-Hz Frequency Resolution

Abstract

This paper presents an oscillator-free frequency comb-based coherent detector with an on-chip antenna for sensing and imaging applications in millimeter-wave and terahertz frequencies. This design detects arbitrary signals from 20 GHz up to 500 GHz with 2-Hz frequency resolution. A peak sensitivity of −100 dBm is measured with 1 KHz resolution bandwidth (RBW). The frequency spacing in the frequency comb is tunable and set to 4 GHz in this work. This frequency comb is used as an on-chip reference signal (LO frequency comb). This design also functions as a comb radiator. A chip-to-chip dual-frequency comb is successfully measured and characterized in the 20-220-GHz frequency range by using this chip as a transmitter and receiver. Compared with receivers presented in existing studies, this work has the widest bandwidth among coherent receivers.