Design And Analysis Of Several Microwave Passive Components Based On Substrate Integrated Waveguide

Substrate Integrated Waveguide(SIW) is a new kind of transmission line in waveguide type, which can form similar guided wave structure with traditional dielectric filled waveguide. The present theory has proved that the transmission characteristics are also similar. Therefore, SIW possesses the advantages of traditional waveguide such as low insertion loss, high power capacity, low radiation. Meanwhile, it possesses advantages of micro strip such as low profile, small dimension, easily processed, easily integrated with other planar structures.In this thesis, four types of microwave passive components based on SIW are proposed:(1) Vanishing mode filter based on three-dimensional folded SIW is proposed, with operation band of 2.04-3.28 GHz, with relative bandwidth of 46.61%. Out-of-band rejection is better than 25 d B.(2) Full-mode power divider based on SIW is proposed, which can achieve power splitting within band of 9.4-11 GHz. Besides, a half mode SIW(HMSIW) power divider with two out-ports are proposed. Such structure is applied in the former one. It can obtain a power divider with four out-ports based on HMSIW. The new power divider can achieve power splitting within band of 7.79-9.86 GHz.(3) Phase shifter based on SIW is proposed. Equivalent circuit of waveguide inserted with cylindrical inductance posts is analyzed. A SIW phase shifter loaded with four pairs posts is proposed. A phase shifter of 90°±5° can be obtained within band of 9.32-9.68 GHz, with relative bandwidth of 3.79%.(4) A SIW directional coupler with several slots is proposed. Its working band is 5.52-6.58 GHz. Besides, a new one based on HMSIW is proposed. Its working band is 5.03-8.51 GHz. For coupling ports, the transmission coefficient is around-6d B. Compared with the one based on SIW, the one based on HMSIW has better performance. The characteristic of miniaturization is well with 51.9% reduction in lateral dimensions, 48.7% reduction in longitudinal dimension.All the microwave passive component models above are built in CST Microwave Studio? with plenty optimization work. Optimized dimensions are obtained to process prototypes. All the prototypes have been tested by Agilent N5227 A Vector Network Analyzer. The results agree well with the simulated ones, which proves correctness of design ideas. All the microwave passive components can achieve characteristics of low profile and light weight which can be used in corresponding communication and electronic systems.