Abstract: A SAW filter useful in cellular telephone communications includes SAW resonator elements provided in a series and parallel branches for forming a ladder filter network, and SAW resonator elements connected in parallel and provided in the series branch of the SAW filter for providing improved ESD protection to the SAW filter. The SAW filter is effectively used with an ESD protection circuit and a triplexer for receiving and separating low, high, and bandpass frequencies.

Abstract: A surface acoustic wave (SAW) triplexer receives radio frequency signals in three bands and provides output signal components for PCS, GPS, and cellular signal processing ports. The triplexer includes low pass filter and a high pass network operating with an antenna terminal for reception and separation of an incoming signal in a low and high frequency bands, and a SAW filter connected to the input terminal for reception and separation of the incoming signal within a frequency band located between that of the low and the high bands. A low insertion loss bandpass filter is provided by the SAW filter having a transducer and reflectors fabricated on a piezoelectric substrate.