.2 W-class Broadband Ka-band Millimeter-wave Power Amplifier Design

In the communication system,power ampliers are the key components at the transmitting end.This paper mainly introduce the circuit design of Ka band PHEMT transistor MMIC power amplifier, which applys to Ka band local multipoint distribution services(LMDS).A Ka-band MMIC power amplifier based on 0.13μm GaAs PHEMT proeess is designed. The amplifier is composed of three-stage asgain-stage, that PHEMT with gate wide of 8×30μm is used of the first stage, and the second stage has the same gate width and numbers; The third stage PHEMT with gate width is 12×40μm.The design employs the internally matched achieve optimum power match; the chip size is 3.07mm×2.71mm. With Vds=5V and Vgs=-0.4V double DC power supply for the every stage. The amplify works at class-A operation. At the design and implementation of 27～39GHz,the power amplifier has 18±dB small-signal gain with input and output VSWR less than 2, The output power at 1dB gain compression is more than 31dBm and the saturation output power is more than 33dBm. Inconclusion, then the paper designs the millimeter power amplifier and simulates that the design is satisfied with the all requirements.