A compact high-isolation parallel coupler with π-shaped structure

Abstract

A compact microstrip parallel coupler with high isolation is presented in this article. Adopting reflected power canceller (RPC) approach, the developed coupler with π-shaped structure not only effectively enhance the directivity of the coupler but also compact size. For verification purposes, a proposed parallel coupler is fabricated and measured at 915 MHz. The proposed couplers achieve a physical size reduction of almost 35% with the performance competed with the conventional one. Moreover, the proposed parallel coupler can obtain excellent isolation of −58.4 dB and directivity of −40.4 dB at 915 MHz. Simulated results are in good agreement with the measured results, which verified the reliability of the designed coupler. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 663–666, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24115