Synthesis And High Power Solid State Power Amplifier Technology Research

With the development of solid-state devices in microwave and millimeter wave systems, the requirements of high output power solid-state devices are increasing rapidly. Power combining is a very effective way to improve the system’s output power. In recent years, power combining technology developed to three directions:high frequency and power, broadband and more combine ways. In this paper, broadband, high power, more combine ways have been researched.Starting from the basic theory of the microwave network, the affect of imbalance of power and phase of N-way power combining structure is analysis in this paper.Wilkinson power combiner’s power capacity is small. Bandwidth of branch line coupler and rat-race is narrow. Lange coupler is not easy to process. According to broadside-coupled theory, use GDS technology, design a6-18GHz Wilkinson power combiner. From6to18GHz the difference of phase is less than2degree, the difference of amplitude is less than1.5dB, the path attenuation is less than0.1dB, all ports return loss are better than20dB.One of the directions of multiple ways power combiner is radial line waveguide power combiner structure. There are two problems of it, one is coaxial line’s power capacity is limited. The other is that, if branch ports are coaxial line, they can not be used in millimeter-wave band, if branch ports are rectangular waveguide, more combining ways gets more resonances. This article was first proposed that using bold coaxial line with lager inner and outer conductor to overcome the first defect. A Ku-band8-way radial power combiner has been designed. Coaxial inner conductor is connect to the cavity wall, so it is easy to processing and locating. Measure result has good agreement with the simulation result, from13.7GHz to19.3GHz, return loss is better than15dB, transmission coefficient is better than9.9dB, the phase error is less than5degrees and bandwidth is about35%.Using bold coaxial line is just overcome the first defect. In order to solve those two problems, combine port change to circular waveguide working in TE01mode and let rectangle waveguide’s narrow side array around axis. Circular waveguide has large power capacity and input port can use reduce high rectangular waveguide. Marie transducer has designed to transform rectangular waveguide’s TE10mode to circular waveguide’s TE01mode. Marie transducer and Ka-band32way radial power combiner cascade’s simulation result shows that, from27.5GHz to37.5GHz, combiner port’s return loss is better than19dB, the transmission coefficient is better than15.4dB, the bandwidth is about30.3%.Power combining technology usually use in high power situation and it is no easy. In this paper, a power amplifier has been designed, using two TIM5359-80SLDS, which has biggest output power in the public market. From5.1-6.1GHz, output power is130W by two way combing.