Optimization of a very low-size, planar UMTS duplexer, using new miniaturized open-loop resonator filters

An optimized topology of planar UMTS duplexer has been developed in this work. This circuit is based on both the use of novel ultra-compact open-loop resonator filters and a well-suited T/sub x/ and R/sub x/ filter combination. With this solution, all the required specifications for a high-level, low-cost integration have been encountered. The design methodology of the new miniaturized filters and the description of the filters combination into a very low-size duplexer configuration are successively given. Finally, measurements for a UMTS device are presented.