Investigations On Microwave And Millimeter Wave Integrated Components And Circuits

Investigations on the integrated design of microwave and millimeter-wave antennas,circuits and systems plays an important role in the development of wireless communication systems,navigation systems and radar systems.Integrated design of integrated passive components and microwave and millimeter-wave monolithic integrated circuits with high performance is the mainstream direction of microwave and millimeter-wave system integration research in the present stage.Based on the above discussion,the passive circuits such as antennas,filters and highperformance microwave and millimeter-wave monolithic integrated circuits which are easy to be planar integrated are studied in this paper.The main contributions of this dissertation are as follows:The introduction briefly reviews the backgrounds of the microwave and millimeter wave circuits and systems at first.Then,the research status of topic on microwave and millimeter wave circuits is introduced.Finally,the research objectives and main contents of the dissertation are elaborated.Chapter One focuses on the studies of quasi-planar Ortho-mode transducer(OMT)and quasiplanar dual-polarized antenna array which are easy to be planar integrated.Firstly,a quasi-planar OMT is proposed,which is fed by a substrate integrated waveguide(SIW)structure to ensure that the OMT can be integrated with planar circuits.Two ports of OMT's four ports are synthesized into one port by using microstrip line and the other two ports are synthesized into one port by SIW combiner.Thus the original four ports are simplified into two ports.This design reduces the size and also ensures the performance.Although the OMT has a part of metal structure,it can be integrated with planar circuits directly.So it is called quasi-planar OMT in this paper.Based on this quasi-planar OMT,a quasi-planar 1×8 dualpolized array is proposed in this chapter.One polarization of the dual-polarized array is fed by dual-terminal series feeding and the other is fed by parallel feeding,which reduces the complexity of the feeding network and can be realized on a single-layer PCB.In addition,the dual-terminal series-fed can provide stable radiation for the array and also improve the bandwidth performance.OMT and antenna array are fabricated and tested,and the experimental results are consistent with the simulation results.The studies of this chapter has been applied for a patent.Chapter Two focuses on a novel dual-polarized planar lens which is based on the results of the previous chapter.The lens uses a modified double rectangular ring unit-cell,which only affects the phase of one polarization and hardly affects the other polarization.Therefore,this planar lens has the priority of polarization selective that only takes effect on one polarization,without affecting the other orthogonal polarization.In this way,the dual-polarized lens can achieve both wide coverage and long detection distance,which has high engineering application value.The studies of this chapter has been published in IEEE Transactions on Antennas and Propagation.Chapter Three focuses on miniaturized filters.Firstly,a miniaturized quarter-mode substrate integrated waveguide(QMSIW)filter is proposed.The size of QMSIW filter is reduced by more than 50% by loading comb-line structure,and finally realized a QMSIW filter with high out-ofband rejection.Then,two microstrip resonators are added to this fourth-order filter,and a sixthorder filter is implemented.Secondly,in this chapter,a multi-band filter based on SIW resonator and microstrip resonator is proposed.By loading microstrip band-stop resonators with SIW bandpass resonators,two dual-band filters and one quad-band filters are proposed.The studies of this chapter has been published in Electronics Letters.Chapter Four focuses on the miniaturized feeding network and antenna arrays.Firstly,a miniaturized and broadband ring coupler is proposed in this chapter.This ring coupler combines three existing miniaturization technologies,which reduces the size by more than 90% and has a relative bandwidth of up to 80%.Then,a dual-band filtering antenna array is designed.The feed network of the filtering antenna array integrates the dualband filter,power divider and balun.The whole filtering antenna has good return loss and out-of-band suppression.The above design has been fabricated and measured,and the measured results are consistent with the simulation results.The studies of this chapter has been published in IET Microwaves,Antennas & Propagation,and has been applied for a patent.Chapter five focuses on GaAs microwave and millimeter wave chips and GaN microwave and millimeter wave chips.Firstly,a multi-functional millimeter-wave chip based on GaAs technology is proposed in this chapter.This chip integrates multiplier,driver amplifier,and mixer and filter circuits.The mixer adopts passive structure,which can be used for both up-conversion and downconversion.Therefore,the chip can be used for both transmitting and receiving components.The working frequency of the chip is 37-43.5GHz,which meets the application of 5G communication system.In addition,the possibility of applying SIW structure to silicon-based GaN process is verified,and according to the characteristics of silicon-based GaN process,a V-band on-chip HMSIW filter is realized.Then a wideband switch chips based on silicon-based GaN technology is also designed,and the experimental results are basically consistent with the simulation results.