High-Resolution Single Bandpass Microwave Photonic Filter With Shape-Invariant Tunability

A novel high-resolution microwave photonic signal processor is presented, which can realize single bandpass response, narrow passband characteristic, and widely tuned center frequency with shape-invariance. It realizes the single passband signal processing function within the optical link via shifting the dispersion induced RF fading of the modulated bipolar optical broadband source. The configuration can overcome the distortion in shifted dispersion induced RF fading caused by the non-uniformity in the group delay slope of dispersive delay lines. Therefore, a wider spectrum source can be used to improve the selectivity of the passband response. Experimental results verify the new proposed structure and demonstrate a shape-invariant tunable bandpass filter with a 3 dB bandwidth of 157 MHz over 0-20 GHz range.