Design of dual-band circular polarization for the monopole antenna by utilizing triple-strip topology

• Published in: Microwave and optical technology letters Vol. 58; no. 3; pp. 514 - 521
• Main Authors: Wang, Chien-Jen, Shih, Meng-Hong
• Format: Journal Article
• Language: English
• Published: New York Blackwell Publishing Ltd 01.03.2016; Wiley Subscription Services, Inc
• Subjects: Antennas; axial ratio; Bandwidth; circular polarization; Circularity; current distribution; Design engineering; Excitation; Impedance; Microwaves; Monopole antennas; triple-strip topology
• ISSN: 0895-2477; 1098-2760
• DOI: 10.1002/mop.29603

ABSTRACT The design and performance of a dual‐band circularly polarized monopole antenna for multisystem integration are shown in this paper. A triple‐strip monopole structure, which is fed at the microstrip line, is designed and fabricated to excite several resonances. After optimization of the geometrical parameters of the antenna, the resonances are merged, and thus a wide impedance bandwidth is obtained. The measured impedance bandwidth of a S11 < −10 dB ranges from 1.43 to 3.29 GHz, and covers most of commercial wireless communication systems. A right‐hand circularly polarized wave at 1.57 GHz for the global positioning system is not only excited, but a left‐hand circularly polarized wave at 2.33 GHz for satellite digital audio radio service system is also generated. The 3‐dB axial ratio bandwidths are about 70 MHz at the lower band (1.57 GHz) and 60 MHz at the upper band (2.33 GHz). Both of simulated and measured results are shown to validate the impedance and CP characteristics of the proposed monopole antenna. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:514–521, 2016