A 6.5/11/17.5/30-GHz high throughput interferometer-based reactance sensors using injection-locked oscillators and ping-pong nested chopping

Abstract

A series of high-sensitivity reactance sensors at 6.5/11/17.5/30-GHz is demonstrated for dielectric spectroscopy sensing on a single micron-size biological specimen. SNR is enhanced with the combination of interferometry and injection-locked oscillator sensors while the offset incurred by chopping-ripple is reduced through ping-pong nested chopping. The sensors achieve a sensitivity of less than 1.25 aF at 100-kHz, enabling label-free cellular detection as a new analytical tool.