A 2 to 20 GHz Resolution-Enhanced RF Spectrum Sensor Using a Looped Phase-Time Array

This paper presents a 2-to-20 GHz RF signal processor based on a looped phase–time array that significantly enhances frequency resolution for ultra-broadband spectrum sensing. In prior phased-array-inspired RF signal processors, the achievable resolution bandwidth scales inversely with the number of array elements, leading to fundamental trade-offs among frequency resolution, chip area, and power consumption. By looping the phase-time array, the proposed architecture emulates the response of an infinite-element array, effectively overcoming these trade-offs. The signal processor is fabricated in a 22-nm FD-SOI process and achieves an average resolution bandwidth of 1.6 GHz (3.3 GHz for loop off), a frequency step of 0.8 GHz, and a scanning range from 2 to 20 GHz, while consuming 122 mW of power and occupying a chip area of 5 mm^2.