Taking a 1.5-GHz SAW antenna duplexer for PDC, we have developed a new
configuration for the transmitter final stage Biter and a new weighti
ng technique for the receiver top filter. These transmitter and receiv
er filters provide insertion losses as low as 0.8 and 1.6 dB, respecti
vely. Combining the filters, we have developed a miniature antenna dup
lexer of which size is 1.4 X 0.6 X 0.2 cm(3), several-time smaller tha
n that of a conventional dielectric-filter duplexer. It also ensures s
ufficient power-handling capabilities.