Research Of Miniaturized Ultra-Wideband Power Dividers Based On Planar/Quasi-planar Structures

Nowadays,research on wideband,miniaturized passive components has become one of the main trend to adapt to the background of rapidly developing microwave/millimeter-wave communication systems.Based on parallel-coupled microstrip line,DSPSL,and SICL,several ultra-wideband power dividers with different performance are proposed.The main research works of this dissertation are arranged as follows:1.Based on parallel-coupled lines,several planar ultra-wideband filtering power dividers have been manufactured.Firstly,based on multi-section impedance matching,stepped-impedance open-circuited stubs,the prototype of ultra-wideband filtering power divider is obtained.By using the nested structure,one can reduce the circuit size on a great scale,the isolation between output ports is achieved by applying the air-bridged isolation resistor.Secondly,a planar four-way ultra-wideband filtering power divider has been developed based on parallel-coupled three-lines,the air-bridged isolation resistors are adopted similarly to realize the isolations between the ports on the same side of symmetrical plane.Finally,based on Marchand balun,out-of-phase isolation technique and DGS,the two-way and four-way ultra-wideband filtering out-ofphase power dividers have been designed separately.2.Based on DSPSL-slotline coupled structure,by applying the differential signal propagated on DSPSL with inserted ground plane,an ultra-wideband reconfigurable power divider with variable ways and switchable output ports has been proposed.This structure only adopts two PIN diodes separately located on top and bottom layer,the ultra-wideband performance is achieved under both working status without extra matching circuits,by installing isolation resistors on the open ends of coupled microstrip lines,the output ports matching and isolations are achieved,meanwhile,the isolation resistors between the layers are reused.Secondly,from the perspective of millimeter-wave design theory,we improve the bias circuit,which ameliorates the bandwidth and magnitude balances.3.Based on SICL,coupled capacitive window structure,two quasi-planar ultrawideband miniaturized power dividers have been proposed.Firstly,by using two-section impedance matching,the ultra-wideband performance of SICL power divider is realized,and the loading of isolation resistors is achieved by applying capacitive slot technique.The measured results of the fabricated circuit verify its favorable performance.Secondly,based on SICL radial structure,by using the coupled capacitive structures located on the input and output ports,and combining the isolation stub technique,an ultra-wideband six-way power divider with bandpass response has been proposed,which expands the application of SICL in multi-way power dividers.