Research On Broadband Dual-band Dual-polarized Aperture-coupled Microstrip Antenna Technology

The dual-band dual-polarized aperture-coupled microstrip antenna is greatsignificance for the synthetic aperture radar(SAR), and it has become research focusesof microstrip antenna.Firstly, basic concept of microstrip antenna is described. The radiated mechanism，sortation and cavity method, bandwidth of the microstrip antenna are presented. Theadvantages and disadvantages of all the feeding methods of the microstrip antenna areanalyzed and compared. Then microstrip antenna array, feeding network, basic formand common technology are discussed.Secondly, the structures of broadband dual-polarized aperture-coupled microstripantenna elements in P-band and S-band are proposed. The impact of geometricparameters which are most critical in the design of element on the antenna inputresistance is analyzed, followed by discussion of the anti-phase feeding technique,short-circuited coupled-line technique is considered in design of anti-phase feedingnetwork of the horizontal polarized port and both of the polarization ports are fed with acoplanar microstrip line, the simulated results show that the relative impedancebandwidth，the isolation between the dual polarization ports and the cross polarizationof the microstrip antenna performs very well.The design scheme of the broadband dual-band dual-polarized aperture-coupledmicrostrip patch antenna array is presented in chapter4. The dual-band is implementedthrough mutual of the medium and earth-plate of4element linear array in P-band and8element linear array in S-band. The simulated results show that either P-band or S-bandarray performs broad band, high isolation and low cross polarization.The design method of the dual-band coplanar aperture-coupled microstrip patchantenna array is presented in chapter5.The schemes of2element linear array in P-bandand4×4element array in X-band are designed. The coplanarity for the dual-band isrealized through windowing on the earth-plate of the array in P-band which is therouteway for the electromagnetic wave in X-band. The simulated results of thedual-band coplanar aperture-coupled microstrip patch antenna array are presented at theend of this thesis.