Photonics Generation of Pulsed Arbitrary-Phase-Coded Microwave Signals Based on the Conversion Between Intensity Modulation and Phase Modulation

This article proposes a pulsed arbitrary-phase-coded microwave signals (APCMSs) photonics generation system. The key to this scheme is to achieve the single-sideband modulated (SSBM) optical signal with the conversion capability between intensity modulation and phase modulation by utilizing dual-parallel Mach-Zehnder modulator (DPMZM) and optical bandpass filter (OBPF). Through heterodyne detection of the SSBM optical signal, pulsed APCMSs can be generated. Unlike previous continuous-wave (CW) APCMSs and pulsed binary phase-coded microwave signals (PCMSs) photonics generation schemes, our scheme provides a pulsed APCMSs generation scheme. The scheme realizes the generation of APCMSs without CW background signals, and the scheme is not only suitable for binary phase codes but also suitable for arbitrary phase codes. The useless CW background signals are effectively suppressed without cascading an intensity modulator for gating operation and the coded phases are linear with the input pre-encoding signals amplitudes, leading to great improvement of practical application values. A theory analysis, a system simulation, and a proof-of-concept experiment are provided. Simulation demonstrates the generations of 2-Gbps 14-GHz and 1-Gbps 16-GHz pulsed APCMSs. The generations of 2-Gbps 14-GHz and 1-Gbps 16-GHz pulsed PCMSs with a 13-bit binary Barker-code and a 16-bit quaternary Frank-code are verified in experiment.