Design study on a compact, high performance SAW duplexer

Abstract

-In this paper various design aspects concerning SAW duplexers are presented. Special focus is placed on an integrated lumped matching network, which allows to save space within the LTCC package. This corresponds with the trend of miniaturization of RF front-end components for cellular phones. To show the feasibility of this approach a SAW duplexer has been designed accordingly. In the design process two different modelling techniques for the electromagnetic computation of the package are compared in terms of their accuracies. Simulation and measurement of the device agree very well.

A Design Method of Compact Lumped-Element Matching Circuits for Diplexers Using SAW Filters

“…[1,2] In order to achieve a compact size and high attenuation, duplexers that use surface acoustic wave (SAW) resonators have been developed. [3][4][5][6] Diplexers based on low temperature co-fired ceramic (LTCC) technology are useful for a compact size and low insertion losses. [7,8] Many planar diplexers use transmission lines for the matching circuits.…”

“…A SAW duplexer which uses the matching circuits based on lumped elements was developed. [3] In [4] and [5], the SAW duplexers' filters included a part of the function of the matching circuits. However, the bands of these SAW duplexers require a relatively narrow gap, due to the separation of the transmitted and received signals.…”