A new wiggly technique for ultra‐wideband two‐line directional couplers

Abstract

In this letter, a new wiggly structure of two-line directional couplers is presented in which the coupling part of the coupler has a saw-tooth with rectangular edges. It has been shown that this method can offer advantages of both saw-tooth and rectangular counterparts with phase velocity compensation over a wider frequency range and a lower possibility of deformations. To evaluate the proposed approach, a 21 dB directional coupler at the frequency range of 4-8 GHz is designed and fabricated on a RO4003C board.