Application Study Of Substrate Integrated Waveguides In Some Novel Microwave Passive Components And Antennas

As a novel guide wave structure, substrate integrated waveguide (SIW) is asynthetic rectangular waveguide formed by the top and bottom metal plates of a lowloss tangent dielectric slab and two sidewalls of period metallic via-holes. It hasadvantages such as high Q factor, low profile, low cost and easily being integrated onplanar circuits. This dissertation is mainly concerned with the design of various SIWfilters and SIW power dividers, as well as the implementation of SIW antennas andarrays. The author’s major contributions are outlined as follows:1. Miniaturized dual-mode substrate integrated waveguide filters have beenstudied. The impact of a series of cross-slot structures, such as cross-slot structure,T-shaped loaded cross-slot structure and H-shaped loaded cross-slot structure ondual-mode SIW filter is studied. Cross-slot structure, T-shaped loaded cross-slotstructure and H-shaped cross-slot structure has22.15%,30.56%and56.25%sizereduction compared with conventional dual-mode SIW filter. Measured results illustratethat the series of cross-slot structures are effective in size reduction for longer effectivelength while two controllable transmission zeros can be obtained.2. Wideband filters which are composed of SIW and defected ground structures(DGS) have been studied. Firstly, by using high-pass characteristics of SIW andlow-pass characteristics of double-U shaped cascaded DGS, a wideband filter has beendeveloped. Secondly, by using size reduction of half-mode substrate integratedwaveguide (HMSIW), a compact UWB filter is implemented, which is composite ofHMSIW and interdigital DGS. Finally, by introducing high Q factor bended U-shapedDGS in UWB filter, a band-notched UWB filter has been developed.3. SIW unequal power dividers have been studied. Firstly, a microstrip dual-bandunequal power divider was developed, which has relatively complicated designprocedure though high power split ratio. Commonly used T-shaped, Y-shaped SIW andWilkinson HMSIW power divider have been studied. Corresponding SIW unequalpower dividers have been designed at the same time. The series of unequal powerdividers demonstrated that SIW unequal power divider can be easily designed by anasymmetry structure, which distributes electromagnetic energy into different outputports with required ratio.4. SIW cavity backed antenna, filter antenna and8-element linear array have beenstudied. Firstly, a novel dual-mode dual-band SIW cavity backed antenna has been designed. Then, UWB filter antenna with dual narrow band-notched characteristics hasbeen developed. Conceptual equivalent circuit models are given through the analysis ofinput impedance. Finally, compact SIW filter antenna has been presented throughintegrative design of filter and antenna. An8-element SIW filter antenna linear array hasbeen designed. The array prototype with the feeding network is constructed at the sametime.