New miniature SAW antenna duplexer used in GHz-band digital mobile cellular radios

New filters used in an antenna duplexer which is applied to GHz-band digital cellular radios were developed. Taking 1.5 GHz PDC, we have achieved low insertion losses of 0.8 and 1.6 dB for T1 and R1 filters, respectively. The developed duplexer is 1.4/spl times/0.6/spl times/0.2 cm/sup 3/, several-time smaller than a conventional dielectric-filter duplexer. It also satisfied all required specifications and provided sufficient power-handling capabilities.