Kyocera Corp. has announced that its lightweight surface acoustic wave (SAW) duplexer with a built-in matching circuit featuring improved attenuation and isolation characteristics. Used in an antenna circuit, it enables duplex and simultaneous conversation by discriminating transmitting and receiving signals. It is mainly used in the circuits of a CDMA system where it determines telephone speech quality. The SD25 series chip size package (CSP) mounts a minimized SAW element directly onto a ceramic substrate, seals it and coats it with resin. Optimizing the combination of the SAW element and the substrate enables the duplexer to be as small as 2.5 mm × 2.0 mm × 0.8 mm (typical value).