Microwave GaN MMIC High Efficiency High Power Amplifier

Over the past decade, high electron mobility transistor(HEMT) based on the third generation of semiconductor material gallium nitride(GaN) has a distinct advantage in the microwave high power amplifier. With domestic and foreign GaN HEMT technology matures and related products come out, microwave GaN power amplifier has shown a good market prospects. Microwave monolithic integrated circuit(MMIC) has a smaller size, better repeat performance and more design flexibility than hybrid integrated circuit(HIC). The design of MMIC high efficiency high power amplifier based on GaN HEMT is a hot research field of microwave amplifier.The efficiency of Amplifier is important to enhance the performance of the communication system. Compared with Class E, F power amplifier, harmonic control structure is relatively easy to achieve because it only needs to consider the second harmonic, especially in the relatively narrow space MMIC circuit Thus, harmonic control applications in MMIC have been widespread concern in recent years. But for high-gain, high-power multi-stage MMIC amplifier limited by technology, size and other factors, harmonic control technology still faces enormous challenges Therefore, this paper carries out researches on the application theory and technology of harmonic control in the microwave high power amplifier The main works are as follows:Based on domestic technology and harmonic control technology, a C-band GaN MMIC power amplifier with high gain is presented in this paper. The amplifier uses a three-stage structure with the final stage amplifier optimized by the second harmonic control technology. The inputs of the final stage amplifier are matched by open stubs on the basis of the fundamental matching and the outputs of the final stage amplifier meet the high efficiency working conditions by adjusting component values. Calculation results show, at the bias point VGS=-2.5V, VDS=28V, the GaN PA MMIC achieves more than 48.3dBm output power, over 25.3dB gain and over 40% PAE within 5.0~6.0GHz.To further improve the efficiency of the power amplifier, this paper tries multi-stage circuit harmonic control in GaN MMIC power amplifier design. In other words, this paper tries to apply the harmonic control technology to all driver stages of the amplifier. The overall efficiency of the power amplifier effectively improves since the harmonic control technology increases the gain and efficiency of every stage amplifier. Calculation and simulation results show, with multi-stage circuit harmonic control technology, the GaN PA MMIC with the same HEMT achieves more than 49 dBm output power, over 26.8dB gain and over 52% PAE within 5.0~6.0GHz. Power added efficiency(PAE) of the latter amplifier lifts over 6% on the basis of the former amplifier. The amplifier has been taped out and tested.This paper has a reference value to improve the efficiency of MMIC GaN power amplifier.