Design of directional coupler based on micro-coaxial transmission line

In this paper, a new type of directional coupler is designed by using the advanced micro-coaxial technology to solve the problem of insufficient power capacity of the feed network. Compared with the traditional microstrip line coupler, this coupler can realize dual-circular polarization feed, and has the advantages of lower loss and greater power capacity. Through design and simulation, it has good performance index. In the range of 12.4~15.9GHz, the reflection coefficient of each port is less than - 15dB, the amplitude difference of the two output ports is controlled within ± 0.5dB, and the phase difference is also kept around 90 °, which meets the design requirements of the branch line directional coupler. While realizing the dual-circular polarization feed, its loss is lower and its power capacity is larger, which has important reference significance for the application of the feed network.