Delay compensation of stretching signal in OTHR

Abstract

In the stretch processing system of linear FM (chirp modulation), the time delay of the return is converted into frequency. The frequency and time delay are proportional to the target range. Each intermediate frequency (IF) pulse occupies a different time interval, indicating the variation in time delay as a function of range. It results in a high sidelobe when proceeding with a uniform weight in the whole time width. The paper describes the delay compensation technology by a subband filter group which can reduce the sidelobe level of the weighted signal greatly after the synthesis of multiple channels.