Researches On Design And Simulation Technology Of Waveguide-to-Microstrip Transitions

In the technology of microwave and millimeter wave, microstrip is a very important transmission form in the microwave circuits, but many millimeter wave test systems and interface of apparatus are using waveguide. To make the two transmission lines have good matching transition, a waveguide-to-microstrip transition is widely used to test millimeter wave hybrid circuits and MMIC and also to interconnect waveguide and planar circuits. So the waveguide-to-microstrip transition technology becomes one of the key technologies of system implementation.The well-known waveguide-to-microstrip transitions are probe type, the ridged waveguide type and the slot coupled type. This thesis analysis and design the probe transition and ridged waveguide transition on the basis of researching the theory of transmission line and impedance transformation.The ridged waveguide transition consists of a ridge-to-microstrip junction and a ridge to rectangular waveguide impedance transformer. By reducing the depth of the ridge, the transition converts the dominant mode in the microstrip line to that in the rectangular waveguide. We achieve wideband transition in the design process through using Chebyshev impedance transformer.The probe transition couples the electric field to the microstrip through the effect of probe. This thesis introduces the microstrip-probe and coaxial-probe transition according to the different structures of probes. They all have low insertion loss and wideband. Based on the impedance matching, the optimized data is presented through using HFSS software.