A Novel Wideband GaAs FET Source Injected Distributed Mixer

In this paper, the design and measured results of a novel wideband distributed architecture GaAs FET mixer in which the LO signal is injected into the mixer through the source terminals of FETs are presented. The prototype MESFET source injected distributed mixer has a conversion gain (without IF signal amplification) varying from -8 to -3.5 dB in the range 1 to 3 GHz. It has good return losses at all ports, and excellent isolation between the three ports, in the range 1 to 3 GHz. The mixer requires a DC voltage of only 1.5 V and operates with less than 12 mA current. The topology of this mixer is suitable for monolithic implementation.