A 1-GHz band low-power dissipation GaAs prescaler IC

It is important that the power consumption by mobile communication equipment be reduced as much as possible from the viewpoint of miniaturization, weight reduction and battery operation. One approach to this problem has been the development of a dual modulus prescaler IC for 1/128 and 1/129 division in the 1-GHz band with GaAs FET's capable of high-speed operation and low power consumption. Since nonuniformity of device characteristics is still substantial in GaAs FET's, an optimization in the circuit design is needed whereby the characteristics of the FET are given sufficient consideration. In the design of the prescaler, the SCFL is used as a logic gate which has a broad tolerance in characteristic fluctuations of the FET. In addition to consideration of the operating margin and fan-out characteristics, such design optimizations as the pattern orientation of the IC and the current distribution to each part have been carried out. With only one 5-V power supply, the power supply current required has been less than 5 mA in the 1-GHz band. This power consumption is less than half that used by the conventional SiECL IC. The design procedure and the results of the test fabrication are reported.