Ka-band Solid State Power Synthesis Technology Research

Millimeter-wave band is a main band of radar, navigation and satellite communication technology development. In order to achieve a higher information transmission rates, longer communication distance and a stronger anti-jamming capability, millimeter-wave power resources remains a key issue. With the rapid development of space technology, transmission power required in the communications increases, a single solid-state MMIC chip hard to meet the requirement, which requires use of power combining technology.This dissertation studies the Ka-band waveguide-based binary tree circuit power combining technology. First take the theoretical analysis in E-T waveguide junction, branch waveguide, H surface slot coupler and three-port power divider / combiner network, and use the electromagnetic simulation software CST and HFSS for a few kinds of networks of field analysis. On this basis, made the waveguide - microstrip transition and several power divider / combiner, then tested. Test results show that the studied waveguide - microstrip transition structure and power divider / combiner network can meet the practical engineering applications.The insertion loss of a waveguide-to-microstrip transition structure is less than 0.4dB, the return loss is lower than -12 dB; H plane slot coupler loss is less than 0.5 dB, return loss is less than -18 dB. Also discussed the a variety of factors affected the efficiency of power combining and several millimeter-wave technics.Firstly,After the previous work, the 4-way T junction waveguide binary tree form of power divider / combiner networks was studied.In the basics of the 4-way power divider / combiner network, based on the use of CHA5294 medium-power MMIC chip, we developed into a high-efficiency power amplifie(rthe largest combining efficiency in frequency band is 91%). Put the power chip inside the single cavity in order to form a power amplifier module, then a number of separate power amplifier modules side by side, superimposed on the power divider / combiner network, complete the production of combining amplifier. This increases the flexibility of PA production. This can also provide the product maintainability: Each individual power amplifier modules are standard parts, when the work of a few broken one or some, you can easily put on standby module, so that the replacement process will not affect the combining of other units; Since each single individual to do in a cavity inside, with a separate space for heat dissipation, the inherent heat capacity of a product is strong that can improve product reliability.Secondly,According to this idea, this dissertation has continued to study the form of branching waveguide 8-way power divider / combiner, Then we use CHA5294 developed into two 8-way power combining amplifiers; using of H plane waveguide slot coupler combine the two above-mentioned power amplifiers back-to-back, a 16-way power combiner amplifier was developed and tested. Test results shows the largest combining efficiency in frequency band is 88% and 95% respectively.