A miniaturized broadband monopulse comparator with all DELTA channels nulling in Ku band

Abstract

A compact monopulse comparator with complete nulling in all DELTA channels is designed and fabricated. The proposed comparator has small dimension and consists of interconnections of four broadband branch-line couplers and several 90° phase shifters with multistage Schiffman coupled-lines. This comparator has been characterized by its eight-portS-parameters to generate the SUM and DELTA channel frequency responses. Over 30-dB null depth was achieved in DELTA channels across the SUM channels in pass band from 14.8 to 18.2 GHz frequency range.

A Compact Monopulse Antenna Array With Suppressed Mutual Coupling Using Broadband Schiffman Phase Shifters

“…8. In this particular design, the monopulse comparator reported in [15] was used. It is composed of four branchline 90°3dB hybrid couplers and four wideband Schiffman 90°phase shifters.…”

“…9. The design procedure for this monopulse comparator is described in detail in [15]. The characteristics of the monopulse comparator were measured using a vector network analyzer(VNA).…”

“…As a result, we achieved a 20% 30 dB null bandwidth in both DELTA channels within the monopulse comparator and a 15% 30 dB null bandwidth when integrated with the antenna array. This study employs an innovative design that incorporates four broadband branchline couplers and multiple 90°phase shifters using multistage Schiffman coupled-lines [15]. This approach achieves both compact size and wideband capability.…”