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

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