Design of a 18 GHZ divide-by-4 prescaler using 1µM GaAs HBT technology

This paper describes the design of a 18 GHz high frequency divide-by-4 prescaler using WIN Foundry 1 μm GaAs HBT technology. The prescaler was designed with differential operation on the base of two master-slave D-latches with the input signal on the clock terminals of the latches. Parasitic effects of the circuit layout, which would reduce the prescaler´s maximum working frequency, are taken into considerations during the post co-simulation of the circuit layout at high frequency range. Modifications to the layout, based on the EM simulation results, are made to restore the designed the high frequency performance. The designed prescaler operates at 5.0 V supply, consumes about 400 mW power and its phase noise is -151.67 dBm at 100 KHz. The divide-by-4 prescaler is suitable for RF and microwave applications between S and Ku bands.