Microwave Coaxial Waveguide Space Power Synthesis Technology Research

With the rapid development of microwave radio technique, the demand for high-efficiency and high-power devices is steadily on the increase. However, the output power from a single device is limited.With the idea of power dividing, magnifying and combining, the output power can be improved significantly, which has motivated the development of power synthesis technology. Based on coaxial waveguide, three types of novel spatial power combining circuts have been presented in this dissertation, and detailed theoretical study, circuit design, electromagnetic simulation and experiment study have been made. The major work and achievements are as follow:1. Square coaxial chain structured power divider/combiner has been given a further study. The dominant mode of square coaxial transmission line is TEM mode, simulated and measured results show that the quasi-planar structured power Splitter has low radiation loss, and can be easily designed, fabricated and integrated with microstrip circuts. It has a broad application prospect in microwave and millimeterwave system.2. An oversized coaxial waveguide power dividing circuit using ridge waveguide to microstrip transitions is presented. Analysis and design on four way and sixteen way dividers have been carried out. This coaxial power divider/combiner has broad bandwidth, multi way output ports, and can be used in wireless communication and arrayantennas area.3. Power dividing/combining circuit based on coaxial waveguide and substrate integrated waveguide (SIW) have been proposed. With the advantages of wideband, low insertion loss, compact and easy to be integrated with micorsttrip ciucuts, an eight way divider based on the structure has been designed and simulated. It is easier to divide the input power equally and to receive a uniform phase response at output ports because of the symmetrical EM field.