Photonic generation of pulsed microwave signals with tunable frequency and phase based on spectral-shaping and frequency-to-time mapping.

A scheme for photonic generation of pulsed microwave signals with tunable frequency and phase based on optical spectral-shaping and frequency-to-time mapping is proposed and experimentally demonstrated. The spectral shaping is realized by a tunable optical comb filter consisting of a differential group delay (DGD) element, a polarization modulator (PolM), and a polarizer. By passing a short optical pulse through the tunable comb filter and a dispersive element (DE), a pulsed microwave signal is generated after optical-to-electrical conversion. The phase of the generated microwave signal can be continuously tuned by tuning the voltage applied to the PolM. The frequency of the microwave signal can be tuned by changing the DGD and/or the dispersion of the DE. An experiment is performed. The generation of a pulsed microwave signal with tunable frequency and phase is demonstrated.