  We demonstrate a multipurpose microwave frequency identification solution
that is implemented based on a photonic integrated chip and is able to identify
different types of microwave signals, including single-frequency,
multiple-frequency, chirped and frequency-hopping microwave signals. The key
component is a thermally-tunable high-Q-factor silicon microring resonator
which is used to implement the frequency-to-time mapping. The frequency
measurement range is ultra-wide, from 1 to 30 GHz, with a high resolution of
375 MHz and a low measurement error of 237.3 MHz. This demonstration opens the
door for future fully integrated solution for high speed, wideband and
multipurpose signal identification with high resolution.
