Research On Microwave/Millimeter-wave Planar/Quasi-planar Power Combining Tehnologies

Since the concept of power combining technology being put forwarded,many kinds of power-combining network structures have been proposed after decades of development,such as the planar structure,waveguide-based structure and quasi-optical structure.The planar power combining network has the advantages of simple structure,low cost and easily to integrate with other circuit components.It could be widely used in the microwave and millimeter wave communication systems.However,it is difficult to imply the isolation network in the planar/quasi-planar multi-way(N?4)power dividers,only two-or three-way power dividers can be implemented due to structural limitation,which will greatly limit their application in practical systems.Therefore,the study of the multi-way high isolation power divider based on the planar/quasi-planar structure has a great significance to this field.The main research of this dissertation includes the following aspects:Firstly,the technical parameters of the power-combining amplifier are analyzed.The influence factors of these key parameters and their mutual relation are analyzed.According to the S matrix of the power-combining network,the factors that impact the power-combining efficiency are also given.Then,detail analyses and comparison of these factors,such as amplitude,phase,insertion loss and the number of the input port are also given.The equations of the power-combining efficiency of different kind of power-combining networks are developed.At last,the design principles of the power-diving/combining network are provided.Secondly,the planar wideband/ultra-wideband multi-way power dividers were studied.The performances of different kind of impedance matching networks which are usually used in the design of power divider are analyzed and compared in detail,which provides the selective basis of the impedance matching network in different conditions.Basing on some high isolation power dividers,the isolation and output impedance matching performance of these isolation networks used in these power dividers are analyzed.And the strengths and weaknesses of these isolation networks are also compared.According to these analyses and comparison,the theoretical basis of designing the isolation network is given.Basing on these impedance matching networks and isolation networks,some wideband/ultra-wideband multi-way high isolation power dividers/combiners are developed,which provided the method of designing different kind of wideband/ultra-wideband power divider/combiner.Meanwhile,the transition from coaxial waveguide to microstrip line is analyzed,which provides the design method of realizing high performance transition.Thirdly,basing on the double layer substrate structure,the quasi-planar multi-way high isolation power dividers were developed.By implying the coplanar waveguide to microstrip line electromagnetic coupling transition structure,a quasi-planar four-way high isolation power divider is proposed.Basing on the equivalent circuits,two improved performance four-way power dividers are developed by introducing the capacitance compensation technique,of which the performance of isolation and output return loss are improved.By implying the coplanar waveguide to microstrip line via transition structure,another quasi-planar four-way high isolation power divider is proposed.Basing on the multi-way power dividing ability of the via transition structure,a quasi-planar six-way high isolation power divider using ring-type isolation network is proposed.At last,a wideband quasi-planar multi-way high isolation Gysel power divider is proposed,of which the isolation network and the power dividing network lies on different layers.The realization of the wideband performance after introducing the transmission line and isolated resistor combined isolation network is also analyzed.Fourthly,the wideband multi-way waveguide-based quasi-planar power combining circuits are studied.A novel H-T junction structure is proposed.Basing on this H-T junction,a W-band wideband rectangular waveguide four-way power divider is developed.And the realization of the wideband performance after introducing the interconnecting line is also analyzed.Meanwhile,a Ka-band wideband rectangular waveguide Gysel power divider is proposed basing on this novel H-T junction.Then,by introducing the tapered impedance transfer and one-step impedance transfer,an ultra-wideband eight-way ring-cavity power divider is developed.Basing on the electromagnetic field in ring-cavity,a quasi-planar rectangular ring-cavity structure is proposed to realize the planarizartion of the ring-cavity.In order to improve the processing and assembly tolerances,a novel inserted ground waveguide probe is developed.Moreover,the performance of the rectangular coaxial waveguide is analyzed and the equations of the characteristic impedance and the first high order mode is given.Baseing on this rectangular ring-cavity and the rectangular coaxial waveguide,a wideband power-combining amplifier is developed.The passive power combining efficiency of this power combining network is studied.Then,the wideband high efficiency power combining amplifier is realized.Finally,the research of the entire dissertation was summarized,and future work was suggested.