Photonic Generation of Microwave Phase-Coded Signals Based on Frequency-to-Time Conversion

An all-fiber approach to generate phase-coded microwave signals, based on spectral shaping and a frequency-to-time conversion, is proposed and experimentally demonstrated. A phase modulator cascaded by a filter module that has a sinusoidal spectral response is used to create a frequency-shifted optical spectrum. Microwave pulses with the same shape as the optical spectrum are obtained through frequency-to-time conversion in a dispersive fiber. The phase of the generated radio frequency signals can be continuously shifted by tuning the applied voltage on the optical phase modulator.