A novel dual-band planar microstrip filter using parallel coupled microstrip lines and open-loop stepped-impedance resonators（SIRs）loaded with two shunt open stubs is presented.By tuning the physical lengths of open...A novel dual-band planar microstrip filter using parallel coupled microstrip lines and open-loop stepped-impedance resonators（SIRs）loaded with two shunt open stubs is presented.By tuning the physical lengths of open-loop SIRs,parallel coupled microstrip lines and two stubs,the bandpass filter has good dual-passband performance at 2.55 and 5.35 GHz and high isolation between the two passbands.The relative bandwidths of the two passbands are 11.8% and 16.8%,respectively.Compared with the conventional open-loop SIR filters,the designed filter has a comparatively broader fractional bandwidth at the second passband.So it can cover all the wireless LAN（local area network）bands.In addition,the filter has the features of low loss,high rejection and low ripple.The measured results are in good agreement with the simulated responses by HFSS software.展开更多
This article presents a technical review of circularly polarized(CP) dielectric resonator antennas(DRA) for wideband applications.The primary objective of this review is,to highlight the techniques used by different r...This article presents a technical review of circularly polarized(CP) dielectric resonator antennas(DRA) for wideband applications.The primary objective of this review is,to highlight the techniques used by different researchers for generating circular polarization in DRA.First,a general idea of circular polarization and it advantages over linear polarization is presented,and then all the major developments made in the CP DRA are highlighted.The emphasis of the paper is on the wideband circularly polarized dielectric resonator antenna.The current state of the art and all the realizable features of the CP DRA are addressed comprehensively.Finally,some recommendations for future CP DRAs are given and the paper ends with concluding remarks.展开更多
基金The National Natural Science Foundation of China(No.60621002,60702027,60921063)the National Basic Research Program of China(973Program)(No.2010CB327400)the National High Technology Research and Development Program of China(863Program)(No.2008ZX03005-001,2008AA01Z223,2009AA011503)
文摘A novel dual-band planar microstrip filter using parallel coupled microstrip lines and open-loop stepped-impedance resonators（SIRs）loaded with two shunt open stubs is presented.By tuning the physical lengths of open-loop SIRs,parallel coupled microstrip lines and two stubs,the bandpass filter has good dual-passband performance at 2.55 and 5.35 GHz and high isolation between the two passbands.The relative bandwidths of the two passbands are 11.8% and 16.8%,respectively.Compared with the conventional open-loop SIR filters,the designed filter has a comparatively broader fractional bandwidth at the second passband.So it can cover all the wireless LAN（local area network）bands.In addition,the filter has the features of low loss,high rejection and low ripple.The measured results are in good agreement with the simulated responses by HFSS software.
基金Global Fellowship Scheme of Universiti Sains Malaysia,research grant number USM RUT 1001/PELECT/854004
文摘This article presents a technical review of circularly polarized(CP) dielectric resonator antennas(DRA) for wideband applications.The primary objective of this review is,to highlight the techniques used by different researchers for generating circular polarization in DRA.First,a general idea of circular polarization and it advantages over linear polarization is presented,and then all the major developments made in the CP DRA are highlighted.The emphasis of the paper is on the wideband circularly polarized dielectric resonator antenna.The current state of the art and all the realizable features of the CP DRA are addressed comprehensively.Finally,some recommendations for future CP DRAs are given and the paper ends with concluding remarks.
