Distributed balanced duplexer

TL;DR: In this article, a distributed balanced duplexer that can be utilized to facilitate concurrent signal transmission and reception is presented, where the couplers interface the filters to front/back ends such as signal processors, transmitters, and receivers.

Abstract: The present invention relates to a system and a method that employs a distributed balanced duplexer that can be utilized to facilitate concurrent signal transmission and reception. The system and method can be employed within mobile devices such as cell phones and utilize two-filters (e.g., acoustic) with substantially similar input/output impedances interfaced with two couplers (e.g., 3 dB hybrid), and a third filter in series with a receiver filter, which provide isolation and maintain the duplexer's input/output impedance. The couplers interface the filters to front/back ends such as signal processors, transmitters and receivers. The novel aspects of the present invention mitigate the need to employ external directional couplers between the duplexer and front/back ends. The system and method further provides for separation and isolation of transmitters and receivers, which reduces noise coupling and enables the transmitter and receiver to be placed within close proximity.