Hung, K. F.K. F.HungYI-CHENG LIN2018-09-102018-09-1020100018926Xhttp://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000273331800005&KeyUID=WOS:000273331800005http://scholars.lib.ntu.edu.tw/handle/123456789/358510https://www.scopus.com/inward/record.uri?eid=2-s2.0-73949154322&doi=10.1109%2fTAP.2009.2036187&partnerID=40&md5=4810beefb325bceac353c997f1413168A novel broadband circularly polarized aperture antenna is presented that uses traveling-wave excitation as the design concept. The antenna configuration consists of a circular radiating aperture, a backed cavity, and an equiangular tapered strip outer-fed by a microstrip transmission line. Operating with a traveling wave excitation, the proposed antenna contains inherent broadband characteristics in terms of the impedance, axial ratio, and gain performances. The presented antenna is comprehensively investigated, including the working principles, design consideration, and parametric studies. In addition, the research interests are extended to a 2 × 2 antenna array. Promising results from the experimental 2 × 2 array are achieved, including the 10-Db return loss bandwidth of 70%, the 3-dB axial ratio bandwidth of 50%, and the half-power (3-dB) gain bandwidth of 40% with a maximum gain about 11 dBi. The measured and simulated results are well complied with each other. © 2009 IEEE.Aperture antennas; Broadband antennas; Cavity-backed antennas; Circularly polarized antennas; Microstrip-line-fed antennasAperture antennas; Broad-band antenna; Cavity backed antenna; Circularly polarized antennas; Microstrip-line-fed antennas; Antenna arrays; Bandpass filters; Bandwidth; Traveling wave antennasjournal article10.1109/TAP.2009.20361872-s2.0-73949154322