High frequency and low power 128/129 dual modulus prescaler ICs are developed for mobile communication applications, using 0.5 µm GaAs MESFET technology. Provided with an on-chip voltage regulator, a prescaler IC with an input amplifier operates in a wide frequency range from 200 MHz to 1,500 MHz at input power from -15 dBm to +17 dBm at the temperature of -30 to +120 with supply voltage of 2.7 V, 3.0 V and 5.0 V. At the same time, it demonstrated its low power characteristics consuming 3.68 mA with 3.0 V at +30 in operation, 0.16 mA while powered-off. Another prescaler IC without an input amplifier operates up to 1,650 MHz with Vdd=2.7 V, 3.0 V and 5.0 V at +30, dissipating 2.74 mA/3.0 V.