Implementation of a Highly-Sensitive and Wide-Range Frequency Measurement Using a Si3N4 MDR-Based Optoelectronic Oscillator

Microwave photonic technologies have been introduced for achieving broadband radio-frequency signal measurement. However, few of the proposed schemes mention the low-power radio-frequency signal detection, which stringently limits their practical applications in certain areas. In this paper, we designed and demonstrated a wideband low-power radio-frequency signal measurement system with optoelectronic oscillator. Here, the unknown radio-frequency signal matched the potential oscillation mode is allowable to be detected, amplified and estimated. The key component in the tunable optoelectronic oscillator is a silicon nitride micro-disk resonator with a very high Q-factor, which is utilized to achieve frequency selection as a microwave filter. A frequency measurement system range from 1 ~ 20 GHz with radio frequency power as low as -105 dBm, measurement errors of ±375 MHz and the maximum gain of 61.7 dB were realized experimentally.