X Band Monolithic Microwave Integrated Circuits Power Amplifier Based On GaN HEMT

GaN high electron mobility transistor (HEMT) has advantages of high breakdown voltage, high power density, high output power, high working efficiency, wide instantaneous bandwidth, suitable for high temperature environments and anti-radiation. Its performance is far superior to today's mainstream GaAs HEMT, and become the third generation of wide-band gap semiconductor power devices. Based on GaN HEMT the monolithic microwave power amplifier with great advantages of high operating voltage, high output power, wide frequency bandwidth and small features loss has been widely used in phased-array radar, aerospace, missile interception system. When the developed countries have developed high-performance GaN HEMT monolithic microwave integrated power amplifiers, our country just begun to independent research and develop. This article is based on GaN HEMT to design MMIC power amplifier by two different methods of matching.Based on the analysis of the working mechanism of GaN HEMT and the basic working principles of monolithic microwave integrated power amplifier, the two kinds of circuits using different matching networks are analyzed and used to realize the power amplifier, at last good results are obtained. The main work is as follows.Completing the design of monolithic microwave integrated power amplifier. The power matching method is used to design the matching network with discrete and lumped components respectively.In order to improve the accuracy of circuit design, full-wave Method of Moments (MOMENTUM) is used to simulating the matching network. MOMENTUM method with advantages of producing accurate electromagnetic model and considering the coupling and parasitic effects can obtain MOMENTUM components which are more accurate than the matching network. Putting the MOMENTUM components into the corresponding circuits, Using ADS software, under the same bias and input power, the circuits are simulated respectively, then the circuit whose matching network is used lumped components got power gain of 5.8dB,the out power>37dBm,PAE reach to 14.2%,and the circuit whose matching network is used discrete components got in-band gain of 5.59 dB, the out power>36.8dBm,PAE reach to19%.Both results are fit for the design specifications. And then the advantages and disadvantages of the two methods of matching network is discussed. Finally the layout is made out respectively, and recording to the level of our lab's technology, the process of realizing MMIC power amplifier is proposed and the key points of the process are analyzing.