A Stopband and Passband Switchable Microwave Photonic Filter Based on Integrated Dual Ring Coupled Mach–Zehnder Interferometer

A stopband and passband switchable microwave photonic filter based on the integrated tunable dual ring coupled Mach–Zehnder interferometer has been demonstrated. By using the optical single sideband modulation, the switchable stopband and passband optical responses of the optical filter are one-to-one mapping to the RF spectra. The center frequency and bandwidth of the switchable microwave photonic filter are both reconfigurable. A frequency tuning range of 4–25 GHz is obtained, and the bandwidth tuning ranges of the passband and stopband MPFs are 4.54–9.72 GHz and 3.65–6.35 GHz, respectively. In addition, a RF rejection ratio about 20 dB is achieved. Compared with the switchable MPFs implemented by nonintegrated devices, the proposed switchable MPF provides a simple and low cost method to process radiofrequency signals.