Fully integrated 38 GHz transmitter and receiver MMICs for communications applications

In this paper the design of resistive PHEMT mixers and their applications in fully integrated millimetre-wave monolithic transmitter and receiver chips are described. In particular, techniques for obtaining low conversion loss of the resistive mixer in single-chip transmitters and receivers, in which the LO power available is limited, are described. The design method has been verified with excellent measured performances over the RF frequency range of 36.5~40 GHz for designs implemented using a commercial AlGaAs/InGaAs PHEMT process. The main feature of the design approach is that low conversion loss of the resistive mixer can be obtained even at very low pump power by using an alternative optimum gate bias point, and good linearity of the mixer is still achieved at this alternative optimum gate bias voltage