To Siw Six-port Circuit Optimization Of Design And Applied Research

In this dissertation,a research has been made on the design and applications of substrate integrated waveguide(SIW) and half mode substrate integrated waveguide(HMSIW) six-port junction.First,this dissertation researched the principle and characteristic of SIW and HMSIW structure.The SIW is a type of rectangular dielectric-filled waveguide that is synthesized in a planar substrate with arrays of metallic vias to realize bilateral edge walls.Benefiting from the properties of moderate profile,low insertion loss,high quality factor(Q-factor) and insensitive to outside interference,etc.,it is easily to be integrated in microwave and miliimetre-wave integrated circuits.The HMSIW,which is developed from the SIW,keeps the advantages of SIW but have a smaller size(half reduced) and also a lower cost.Nowadays, the SIW and HMSIW have been widely used in the design of microwave passive elements, such as filters,couplers etc.Second,this dissertation researched the mechanism and applications of the six-port technology.The six-port junction circuitry usually consists of passive combiners like power dividers and couplers,it can directly demodulate the RF signals to the baseband signals,and take place of the expensive active elements in application of receiver systems,then make the A/D device working only under the baseband frequency,so it is effectively reduce the complexity and cost of the circuit.Anyway,the six-port junction provides an excellent RF front-end for the software defined radio receiver systems.At last,some dividers and couplers etc.,based on the SIW and HMSIW technology have been designed in this dissertation,then two six-port junction circuits operating at 10GHz have been simulated and measured using the SIW and HMSIW structure respectively.From the date analyzing,good agreement between simulated and measured results is found for the proposed six-port junctions.