Design Of X-band GaN Microwave Monolithic Low-noise Amplifier

An X-band microwave monolithic low noise amplifier based on GaN HEMT is designed in this paper. First, the advantages of GaN materials and GaN HEMT and the development status of GaN MMICs are introduced briefly. Then the fundamental principle of the microwave circuit design, including the description of two-port network, the noise theory, the main characteristic indicators of LNA are given, and a variety of matching network are described in detail. The working principle, structures, small-signal equivalent circuit model of active devices and lumped components are analyzed, and then the characters of passive components are simulated by HFSS software. Combining the broadband amplifier, low noise amplifier and design technology, the two stages LNA is designed by ADS software.Finally the two stages low-noise amplifier with the Gain> 19 dB, NF<2.7dB, input and output VSWR<2.5, in X-band is achieved. At last, the layout is made by using L-edit software. Combining the existing technology, the GaN HEMT MMICs process is introduced, and the main process steps are analyzed.