Handheld telephone for 800MHz-band cellular radio systems
J. Nakagawa, Mitsutaka HIKITA, Y. Kuwamoto, S. Hagiya, A. Iwama, H. Kimura · 1987
A small handheld telephone with a volume of 400ml for 800MHz-band cellular radio systems has been developed. The use of several miniaturized RF hybrid modules and costom integrated circuits have reduced the size, weight and power consumption of the developed telephone. Especially, an antenna duplexer with SAW 'Surface Acoustic Wave' filters contributes to reducing their size and weight. Intermittent operation of a frequency synthesizer reduces the averaged power drain.