High Performance WCDMA1900 Combined LTCC/SAW/BAW Duplexer for Mobile Phones

In this paper are presented a design and a performance of a duplexer for WCDMA systems combined of a low temperature co-fired ceramic (LTCC) substrate, a surface acoustic wave (SAW) filter and a bulk acoustic resonance (BAW) filter. The designed duplexer provides enhanced stopband characteristics and occupies a small volume. The insertion losses are better than -3.8 dB in the 1850-1910 MHz and 1930-1990 MHz bands and the rejection of the out-of-band frequencies till 2.5 GHz is higher than -38 dB.