Wide Band Gap Solid-state Power Amplifier

In recent years, with the development of communications and microelectronic technologies, modern military radar system is developing towards miniaturization, high-power, high efficiency, wide bandwidth and suitable for working in harsh environments. As the core of the system, the characteristic of RF power amplifier has played a key role in the performance and technology level of the whole system. And the power amplifier is also the main energy-consuming modules in the system. Therefore the research of improving the efficiency of power amplifier is essential to the whole system.The third-generation semiconductor materials have wide band gap such as GaN, SiC, etc. These materials have a better performance on breakdown electric field, high heat conduction rate, high power density capability, high electron mobility and the better ability of anti-radiation. They are very suitable for high-frequency, high-efficiency and high power electronic devices. So the investigation on wide-band power amplifiers becomes a research hotspot.In this thesis, a class E power amplifier and a class F power amplifier have been designed using WBG devices. The peak current and peak voltage of Class E and class F power amplifier do not occur at the same time, so the device is similar to a "switch" with the characteristics of the lowest power consumption and theoretical efficiency of 100%. The basic principle and design method of class E and class F power amplifiers were described in detail in this thesis. The high efficiency of the power amplifiers has been achieved with the matching circuits formed by micro strip branch lines. The power amplifiers were simulated and optimized by using load-pull technology and harmonic balance technology in ADS 2008. At last, the debug and test of the power amplifier have been done and the test results meet the design requirements.The test results are shown in the following. The class E power amplifier works in the 1.8GHz ~ 2.0GHz frequency band. When the input power equals to 30dBm, the gain is more than 10dB and power-added efficiency (PAE) reaches more than 50%, even 60% in 1.95GHz. The class F power amplifier works in the 2.2GHz ~ 2.4GHz frequency band. When the input power equals to 28dBm, the output power reaches 41dBm and the PAE is more than 50%. The test results of two power amplifiers meet the design requirements and have the value in engineering project.