Study Of Ridged Waveguide Passband Characteristics

Ridged waveguide is one deformation type of rectangular waveguide. In recent years, due to its high frequence working band, wide·bandwidth and the steady structure etc, ridged waveguide device is gradually used for military, satellite communications, and other important fields in national defense, national production. Based on the advantages of ridged waveguide beside adding a tapered impedance line, two type of ultra wide band (UWB) waveguide device are designed, and software simulation results are given. Specific research contents include:First, the history, research significance of ultra wide band filter, and some basic type of filter are introduced in this thesis. A new type waveguide device is designed, and the HFSS simulation results are also given. This device works at 12～21GHz, has wider bandwidth, disadvantage is return loss bigger than goal.Then, the basic principle and characteristics of ridged waveguide are introduced, and three popular tapered impedance lines are also introduced. Double ridged waveguide structure and index tapered line are used to propose a new structure of waveguide to coaxial-cable conversion device. Double ridged millimeter waveguide mode Collaborative simulation results by HFSS and CST show validation of this device. It work at 22-40GHz, compared to rectangular waveguide device have wider bandwidth and lower return loss, higher working frequency.Finally, a new ultra wide band waveguide device is designed using the three ridged waveguide structure, its effective bandwidth wider than double ridged waveguide device. And frequency offset phenomenon of the three ridged waveguide device are discussed in design process. This device works at 21.4-45GHz, have bandwidth advantages when compared with double ridged waveguide device. But vice ridge height have certain influence at three ridged waveguide device cutoff frequency, more attention should be paied in design process.