Silicon integrated frequency-tunable microwave photonic bandpass filter

Microwave photonic filters have been regarded as an alternative to traditional radio-frequency filters because of their wide bandwidth and large tunability. Integrated microwave photonic filters can integrate all necessary components into a single chip and are highly demanded for future radio-frequency applications. Here, a highly integrated frequency-tunable microwave photonic bandpass filter based on a silicon platform is proposed and demonstrated. The integrated filter consists of a phase modulator, four cascaded microring resonators and a photodetector. The frequency-tunable range of the integrated filter is from 6.1 to 35.9 GHz, and the reconfigurable bandwidth is from 0.22 to 0.54 GHz. A large spurious free dynamic range of 102.1 dB Hz^2/3 is obtained. This highly integrated approach holds great promise for miniaturised, flexible, and high-performance microwave signal processing in modern radar and communication systems.