Research On Compact Bandpass Filters And Multiplexers Using Different Transmission Line Types And Fabricated Technologies

Nowadays,the wireless communication system is becoming more and more important in our daily life.People's requirement for the performances of microwave devices has gradually developed toward miniaturization,multiple passbands,low loss,and high selectivity.Especially,the miniaturized components have become an irresistible trend.To further develop the performances of microwave devices,more and more structures and processes are applied to the design and research of microwave devices.The first chapter of this paper briefly introduces the planar microstrip line structure,the composite right-left handed transmission line(CRLH-TL)structure and the 0.13-?m SiGe(Bi)-CMOS process that can be used to realize radio frequency integrated circuits(RFIC).The prior two structures are PCB planar structures,and the third one is a multilayer-board process.These structures and processes all promote the miniaturization of microwave devices.The second,third and fourth chapters of this paper illustrate the research and design of passive devices based on these different structures and processes we introduced earlier.In the second chapter,multimode filters and multiband filters are studied.Two planar microwave bandpass filters,a three-mode filter and a second-order dual-mode dual pass filter,are designed on the PCB by loading stubs on half-wavelength and quarter-wavelength resonators,respectively.Spiral structure and folded structure are utilized to realize the miniaturization of the filter.In chapter 3,compact diplexer and triplexer based on stub-loaded CRLH-TL resonators are presented.The multimode resonator is constructed by adding stubs to CRLH-TL unit cells to obtain extra resonant mode and the expressions of resonant frequencies are deduced in this chapter.In addition,matching circuits are also used to connect different stub-loaded composite right-left handed resonators to gain the proposed miniaturized diplexer and triplexer with good selectivity and isolation characteristics.The fourth chapter presents a bandpass filter implemented and fabricated in a commercial 0.13-?m SiGe(Bi)-CMOS technology using hybrid coupling.In this chapter,the size of BPF is reduced to a large extent.Moreover,a novel method to solve the zero-pole position by calculating the transfer function of LC-equivalent circuit is proposed.The final calculated results agree well with the simulated results of the proposed BPF.