A Circularly Polarized Spaceborne Antenna With Shaped Beam for Earth Coverage Applications

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalNot applicablepeer-review

2 Scopus Citations
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Detail(s)

Original languageEnglish
Pages (from-to)2235-2242
Journal / PublicationIEEE Transactions on Antennas and Propagation
Volume67
Issue number4
Online published21 Dec 2018
Publication statusPublished - Apr 2019

Abstract

Since the earth is spherical in shape, the paths from the satellite to various points on the earth are different in both the distance and atmospheric attenuation. In order to maintain approximately uniform effective signal strength on the surface of the earth, the radiation pattern of the antenna should be formed according to the shape of the earth. Former antennas for earth coverage are either bulky or hard to realize the desired beam pattern within a wide angle range, thus are not suitable for small satellite. To solve this problem, this paper presents a novel circularly polarized earth coverage antenna for spaceborne applications. The proposed antenna consists of a specially designed dielectric cylinder, in which a cavity backed patch antenna is embedded. With the help of the concave structure at the top of the dielectric cylinder, the refraction of electromagnetic wave can be controlled, and then the radiation pattern is shaped. A sequentially feeding network is designed to drive the antenna. To verify our concept, a prototype is fabricated and experiments are carried out. The simulation agrees well with the measurement. The earth coverage radiation pattern is obtained within the beamwidth of θ in the range of ±50° with the measured space axial ratio is better than 3 dB from 4.9 GHz to 5.2 GHz. The measured peak gain is about 3.45 dBic at the elevation angle of ±50°.

Research Area(s)

  • antenna, Antenna radiation patterns, Cavity resonators, Circular polarization, Dielectrics, Earth, earth coverage, Loaded antennas, Patch antennas, shaped beam, spaceborne antenna