New high-performance and low-loss SAW filters used in ultra-wideband cellular radio systems

Several new technologies are reported for the design of high-performance and low-loss surface acoustic wave (SAW) filters used in ultra-wideband cellular radios. Among them, new configurations for wideband bandpass filters applicable as receiver filters have been developed. These configurations allow 3- or 4-dB insertion loss and sharp-cutoff frequency responses. New structures for wideband band-rejection filters applicable as transmitter final stage filters have also been developed. Their use results in loss as low as 1.4 dB as well as high-power characteristics. A SAW front-end module constructed with SAW filters, with a low-noise amplifier, and with a single balanced mixer is described.<
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