Compact tunable microwave filter using retroreflective acousto-optic filtering and delay controls

Programmable broadband rf filters are demonstrated using a compact retroreflective optical design with an acousto-optic tunable filter and a chirped fiber Bragg grating. This design enables fast 34 mu s domain analog-mode control of rf filter time delays and weights. Two proof-of-concept filters are demonstrated including a two-tap notch filter with \u3e 35 dB notch depth and a four-tap bandpass filter. Both filters have 2-8 GHz tunability and a 34 mu s reset time