Frequency Tunable, Single Passband, Photonic Microwave Transversal Filter Incorporating Differential Group Delay Device-Based Comb Filter

A single passband, photonic microwave finite impulse response filter, whose passband frequency can be dynamically tuned with a high frequency resolution, is experimentally demonstrated. A computer-controlled, differential group delay (DGD) device-based comb filter is used to produce flexible wavelength-spacing tunable, multi-wavelength filter taps with a sinusoidal and continuous spectral shape. An RF frequency tuning resolution as low as similar to 1.16 MHz is demonstrated. (c) 2009 The Japan Society of Applied Physics