Rectangular Waveguide Cavity Matched Load Design And Research

The matched load is one of many terminal devices in the microwave system. Looked from the energy angle, it can absorb all the incident energy without any reflection on the ideal condition. The matched load has only one scattering matrix parameter whose reflection coefficient S₁₁ amounts to zero on the ideal condition, when seemed as a one-port network from the perspective of network. In reality, however, it may have a little reflection at the input-port of the matched load, which may lead to the S₁₁ larger than zero. At the same time, in the high-power microwave system, another fairly important problem for the matched load is the heat dispersing. At present, the matched load used in industry should be adjusted along with the increasement of microwave power synchronously, which largely limits its flexible application in industry.On the basis of the basic rectangular resonator cavity theory, in this dissertation, I detailedly researched into the change of the distribution of the electric field that results from the perturbation been introduced into the resonator cavity, such as water and the posts. Then, I analyzed the difference of the reflection coefficient at the input port which was affected by different kinds of coupling structures in the resonator cavity. Based on the above research, a rectangular resonator cavity matched load model with three posts has been founded in this dissertation, which could be applied to the high-power microwave system. The HFSS (high frequency simulator software) can help us to optimize the parameters in the resonator cavity matched load so that the reflection coefficient at the input port could meet the demand of the standard in industry.Based on the accomplishment of the rectangular waveguide resonator cavity matched load research and the relationship between the selection of rectangular waveguide and the corresponding frequency band, in this dissertation, I have studied two types of rectangular waveguide, one is on the same frequency band and the other is on the different one. Also the simulation results at the input port of the matched loads are well. The frequency band (wavelength) about the rectangular waveguide and the distance between the posts in the matched load have a relationship, which is also been researched in the dissertation.