Continuously Tunable Microwave Photonic Notch Filter With a Complex Coefficient

This paper presents a continuously tunable microwave photonic notch filter with a complex coefficient. The complex coefficient is generated using a radio-frequency (RF) phase shifter that consists of a dual-parallel Mach-Zehnder modulator (DPMZM) and a tunable optical bandpass filter (TBPF). By simply controlling the bias voltage of the DPMZM, the frequency response of the filter can be continuously tuned over a full free spectral range (FSR) without changing the shape of the frequency response.