Microwave Photonic Crystal Video Receiver for Radar Interception

Abstract

This article introduces an approach of a crystal video receiver (CVR) based on microwave photonics (MWP) to detect pulsed radar signals. The pulsed radiofrequency (RF) envelope detection is achieved using the optical self-homodyne technique on the photodetection process. The proposed architecture uses a phase modulator (PM) to modulate the optical carrier and a fiber Bragg grating (FBG) to filter the spectrum to convert phase to intensity modulation. The self-homodyne technique eliminates the optical carrier at photodetector to reduce the shot noise and saturation on it. Moreover, the photodetection is performed at the radar pulse baseband, allowing to obtain transimpedance gain. The theoretical principle and an experimental demonstration are presented. A CVR sensitivity of 53 V/mW and a tangential signal sensitivity (TSS) equal to −40 dBm is achieved for a pulsed radar operating at 17 GHz.