6J-3 Design of Test Modules for the Characterization of SAW Duplexer Inserts by Measurement

Due to the growing demand for miniaturization and functionality of modern mobile W-CDMA terminals, current developments for integrating SAW or FBAR duplexers into subsystems such as LTCC front-end modules by means of duplexer inserts have been reported recently. We will present the first approach to our knowledge to design test modules for the characterization of SAW duplexer inserts by measurement. The main goal is to characterize the duplexer insert in the environment of an LTCC module without the influence of the other active or passive, mounted or integrated components of the module. This can be achieved by replacing all components, including all metal structures of the LTCC module, with the exception of the duplexer insert, by electrically neutral connections. They have to be well designed for high isolation between the signal paths and have to be optimized for good matching between the PCB and the module. This was realized by using a modified stripline with a slotted ground, which offers both the required high isolation and the required impedance of 50 Omega. Additionally, the PCB-module transition was designed carefully for low reflections. We call the combination of duplexer inserts and neutral connections a test module. By focusing on the design approach of the neutral connection, we will present first samples of test modules with duplexer inserts for W-CDMA 1900