8mm Radial Solid-state Power Combining Technology Research

In the millimeter-wave band, the electronic vacuum power amplifier has been replaced by solid-state power amplifiers due to advantages of high reliability, low DC supply voltage, lightweight and easy to modularize. The use of power combining and amplifying technology is the most effective way when the requirements can not be satisfied with output power of MMIC amplifier.The combining efficiency reduced following multi-stage concatenation of 3dB waveguide bridge.In order to overcome the barrier, the method of radial waveguide spatial power combining was taken to seek a breakthrough in the multi-way and high-power situations in this issue.To the general power combining amplifiers, this paper analyzed the state of power combining amplifier with the method of Parameterization of combining network, 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. I designed of two 8mm band radial waveguide power combiner on this basis.Based on the dominant mode of coaxial line, designed the 8 way power combiner network excited by coaxial. Test result show that: within the frequency range 29 GHz to 31 GHz, the insertion loss is about 2.7dB. Based on the feature of the fifth high-order mode of circular waveguide, Designed and simulated the sixteen-way power combiner excited by circular waveguide, designed the marine-type mode converter on the basis of gradual change of mode. The simulation results show that the power combiner meet the requirements of low loss and wide band.Based on the idea of modular design and 8-way power combiner excited by coaxial, I produced the8-way radial power combining amplifier of 8mm band.Test results show that: in the frequency range 29GHz-31 GHz, the saturated output power achieve the maximum of 31.72 dBm at 30 GHz, the 1dB compression point output power achieve the maximum of 31.04 dBm at 30 GHz, the peak of combining efficiency is 83% at 30 GHz.The successful development of waveguide power combining amplifier revealed that: the structure based on the idea of spatial power combining Technology of one divided directly multiple can be applied to multi-way and high power applications and as a effective expansion and breakthrough has the value of research and reference.