Open AccessCompact monopulse sum‐difference comparator based on double‐layer substrateintegrated waveguide
Author(s) -
Liu Yi,
Yang Hu,
He Yan,
Zhu Jiang
Publication year - 2017
Publication title -
electronics letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.375
H-Index - 146
eISSN - 1350-911X
pISSN - 0013-5194
DOI - 10.1049/el.2017.2647
Subject(s) - comparator , monopulse radar , bandwidth (computing) , magic tee , phase shift module , optics , amplitude , frequency band , physics , power dividers and directional couplers , materials science , optoelectronics , insertion loss , hybrid coupler , computer science , telecommunications , radar , quantum mechanics , voltage , radar imaging , continuous wave radar
A monopulse sum‐difference comparator based on double‐layer substrate integrated waveguide (SIW) for X‐band applications is investigated and experimentally validated. A 90° 3‐dB directional coupler with a double‐stepped coupling slot in the common broad side between a pair of folded parallel SIWs and an equal‐length unequal‐width 90° phase shifter are adopted to form a magic tee. The four magic tees are elegantly interconnected to design a highly compact comparator. Experimental results show the bandwidth (reflection coefficient < −10 dB) of the comparator can achieve 10% with an operating frequency range of 9.5–10.5 GHz, in which the output amplitude and phase imbalance are within 0.75 dB and 14° (RMS), respectively. The insertion losses are about 1.5–2.5 dB and the isolations between the three channels are all better than 20 dB. In particular, the double‐layer configuration of the comparator network reduces the occupied area with the potential for high integration and makes it to be a good candidate for miniaturised and compact monopulse antenna systems.