8 Mm Waveguide Spatial Power Combining Amplifier Technology Research

Millimeter-wave is the main frequency band in military electronic technology at the present. High-power amplifier is a necessary component of wireless transmitters at millimeter-wave. The approach of power combining is an effective solution for greater output power. The advantage of spatial combination structure, which is one of the combining methods, is that combining efficiency is high. This paper emphasizes this method, including the design, emluation, fabrication and measurement of the circuit.This paper has discussed complication which can affect the combining efficiency. And it researches four ways of spatial combination structure, which are analyzed, simulated and optimized respective.By deeply researching branched-waveguide, waveguide-T-junction and microstrip double probe, as well as particularly discussing of the characteristic of three-port-network, this paper proposals a structure including the branched-waveguide and microstrip double probe. The structure is symmetrical, and the amplitudes in four way power divider are consistent. This structure has solved two difficult problems of spatial power combining: how to place many accessories in finity room and how to improve the phase difference and amplitude difference in combination structure. The results of emulation show that this structure has low insert loss.At last, the improved T-junction-waveguide-microstrip-double-probe network has been machininged. Based on the researching and experimenting, the high-power amplifier that can provide output power more than 7W, the small signal gain is more than 40dB and the combining efficiency is over 80% in the 31-37GHz and 10W in the 31-34GHz, has been completed. From 31 to 34GHz.The highest output Psat is 41.19dBm (13.15W), the highest combining efficiency is 87.4%.