Millimeter Band Solid-state Power Combining

Solid-state power devices are more widely used in millimeter-wave systems, it replaces of the electronic vacuum power amplifier due to advantages of high reliability, low DC supply voltage, lightweight and easy to modularize in gradually. The output power of a single solid state power amplifier is still low, in order to achieving the requirements of high-power millimeter-wave systems, The use of power combining technology is the most effective way.This article is based on methods of waveguide power combining to analysis and design the millimeter-wave waveguide power solid state power combining technology, and discussed the related invalid issues of combining power amplifier, deduced the influence of combining efficiency caused by circuit losses and amplitude and phase imbalance, elaborated the principles of radial waveguide power combining technology. On the basis of waveguide power combining principles,it has been designed the Sixteenth road of Ka-band solid state power amplifier, and 12 road of W-band radial waveguide power distribute network.Based on the theory of waveguide branch hybrid, designed and developed the five holes waveguide branch hybrid and seven holes waveguide branch hybrid has been designed and developed.the E-plane five holes waveguide branch hybrid has been studied and developed in 32-40 GHz, S21,S31 are about-3.1d B~-3.4d B. Same work is been done on E-plane seven holes waveguide branch hybrid,it is expanding the bandwidth,but the losses has been increased. Based on the five holes waveguide branch hybrid, the 4 roads three-dimensional combining network has been designed,the amplitude and phase is measured in consistency. And also designed a 4 roads combining network of the five holes waveguide branch hybrid with the microstrip double-probe,the insertion losses is about 1d B in 32-40 GHz, it has high isolation, low losses, wide bandwidth.Based on the principles of radial waveguide, designed and manufactured a 12 roads of circular waveguide excited space radial space power distribution network in the W –band due to circular waveguide TE01 mode features. Been designed the flower-type mode converters,been used in the circular waveguide to effective inhibit the transmission of the others low- order modes.In 88GHz-96 GHz, the insertion loss of output port is about 11.1~11.7d B, Returned losses had better than 15 d B. It shows the characteristics of broadband and low losses, so that it can be applied to W-band power combining technology.Designed a 16 roads of the Ka-band waveguide spatial power combining amplifier, the results show that Psat is 35.11 d Bm at 36 GHz, the P-1d B is 34.51 d Bm.The combining efficiency is greater than 75% in 32 ~ 40 GHz,the maximum point reached 84.3% at 36 GHz.