Photonic processing of ultra-broadband radio frequency waveforms.

摘要

Photonic processing has been significantly explored in the past few decades to process electrical signals; however, photonic processing of ultra-broadband signals with bandwidths in excess of multi GHz and large fractional bandwidth has been less investigated with minimal attention given to time domain aspects. Moreover photonic processing benefits from properties such as large bandwidth, immunity to electromagnetic interference, tunability, and programmability compared to electrical processing. Therefore radio frequency photonic techniques can be utilized to enhance the performance of analog radio frequency systems in detection and filtering of ultra-broadband signals.;We present the first implementation of radio frequency photonic matched filter based on hyperfine optical pulse shaping to compress ultra-broadband arbitrary radio frequency waveforms to their bandwidth limited duration. This filter which has a programmable arbitrary frequency response enables real-time fast processing of ultra-broadband signals. Further more the application of this technique to post-compensate broadband antenna's dispersion will be demonstrated which potentially pushes ultra-broadband radio frequency systems and radars toward dispersion free performance. Finally for the first time tunable programmable microwave photonic filters based on optical frequency combs are implemented. These filters have finite impulse response with tap weights programmed by arbitrary complex coefficients. The large number of comb lines provides more freedom to shape the bandpass filter while tunability is achieved using an interferometric scheme.