Millimeter Wave Band Based On The Te <sub> 21 </ Sub> Mode Poor Web Design

In this thesis, the "tight" and "loose" coupling wave theory are elaborated first as the foundation of the coupler design, via the application of coupling wave formula, the basic design principle for TE21-mode coupler is outlined, at the same time, the technical diffculty for classic principle application is forwarded. To counter the technical diffculty, in the process of millimeter-wave TE21-mode coupler design, the voltage coupling formula of small hole is introduced, which take shell thickness effect into account. Given the hole coupling function, the diameter of each hole is re-calculated. On this basis, the performances of TE21-mode coupler dimension parameters are analyzed via numeric simulation of CST, the results demonstrate that the sensitive parameters are circular waveguide diameter, the wide edge of rectangular waveguide and coupling holes diameter. After accomplishment of manual parameter adjustment, the average coupling coefficient of coupler is chosen as the target function, GA and CST macro function are utilized to concrete the optimization strategy, and the optimization enhance the hole coupling obviously. On the basis of coupler design, two kinds of sketch configuration of differential network are forwarded, and its each corresponding part design is elaborated. At last, the prototype of differential feed is fabricated and verified via test, the results show result data confirms well with simulation, and performances satisfy requirements.