Study Of Miniaturized,Reconfigurable Circuits And Networks On Substrate Integrated Waveguide

Substrate Integrated Waveguide(SIW)is a transmission line implemented into dielectric substrate by using metallized posts or slots.It takes the features of low profile,low loss,low radiation,high power capacity and high Q,while it can be easily integrated into a single substrate with microstrip,coplanar waveguide and some other planar transmission lines.Since it was firstly proposed by Prof.Ke Wu from the University of Montreal in 2002,large numbers of theoretical and engineering researches have been carried out in many countries.In 2011,SIW was selected by IEEE Microwave Magzines and ranked No.1 of the top ten extraordinary inventions of passive and control devices,which would change the world in the near future.In this way,we may see that further researches of SIW technology,especially those aiming at engineering applications,are quite important.In this thesis,based on the current theoretical and engineering researches of SIW,some key technologies,such as precision measurement,device miniaturization,high power,switchable\reconfiguration and system-level electric-large-size circuit design are studied emphatically.The main innovative work in this thesis can be summarized as follows:1.Accurate measurement Method of SIW circuits.TRL(Thru-Reflect-Line)Calibration method has been investigated.(a)The design criteria of the TRL calibrator for SIW are proposed and validated by experimental comparison,(b)TRL calibration kits with normalized SIW/microstrip line adaptor is proposed to reduce the measurement error caused by the inconsistency of the adaptor,(c)Both narrow band and broadband SIW-based matching loads are proposed by embedding absorbing material in the substrate medium method,which take the features of easy processing and practicality.2.Miniturized and high-power SIW devices.Based on the low temperature cofired ceramics(LTCC)process,multilayer folding method is used to realize miniarized design,(a)Novel SIW two-bit dispersion-type delay line is proposed and developed.(b)Planar Gysel high power deviders based on integrated waveguides are proposed and implemented using LTCC process,quite compact design is achieved.(C)An ultra-compact SIW stereoscopic Gysel power divider is proposed.Based on the LTCC technology,the miniarized SIW circuits are further investigated,indicating the advantages of the LTCC process for implementation of SIW circuits and provides some helpful guidance for the design of the miniaturized circuit.3.Switchable and reconfigurable circuit based on the(half-mode)substrate integrated waveguide.(a)A method of controlling the circuit by loading a switchable microstrip open circuit is proposed,and frequency bandwidth enhancement is studied.(b)HMSIW circuits with loaded open and shorted microstrips arestudied and compared,while series of single-pole-single-throw(SPST)and single-pole-double,throw(SPDT)switches are proposed;(c)Based on the study of the electric field distribution and impedance characteristics of the HMSIW,a functional reconfigurable circuit,between the power divider and the SPDT switch,is proposed.The research of switches and reconfigurable circuit based on HMSIW solves the problem of designing switchable circuit on single-conductor circuit.4.Design method of electrically large SIW network.Aiming at the practical engineering requirement,the design method of large-scale SIW network is investigated.Based on the system configuration and material selection,a compact electrically large monopulse feeding network is studied and co-simulation technique is proposed.Core devices in the network system are optimized and a miniaturization method is proposed.The resulting large-scale monopulse network demonstrates compact structure,stable performance and good enectromagnetic compatiability,which indicates the advantages of the substrate integrated waveguide like low profile,low loss,high power etc.