This paper presents a wideband circularly polarized antenna for small satellites to be used with NASA Near- Earth Networks (NEN). This single-fed stacked antenna utilizes the electromagnetic coupling concept and is usable with a duplex transceiver. The circularly-polarized antenna employs hybrid perturbations on stacked patches and covers NASA NEN’s both uplink and downlink frequencies, thus replacing the conventional requirement of two separate antennas. It provides a notable wide axial ratio (AR) < 3 dB bandwidth of 1.16 GHz from 7.02 GHz to 8.18 GHz (15.3%). The optimized patch dimensions provide 34.6% VSWR ~ 2 bandwidth from 6,525 MHz to 9,253 MHz. The overall antenna size is 17 mm × 17 mm × 6.6 mm, and has a peak gain of 7.9 dBi. This proposed antenna will overcome solar cell space constraint on smallsat’s outer wall by saving at least 50% area required by the conventional two-antenna method.
This content will become publicly available on February 1, 2023
Hybrid Perturbations in Stacked Patch–Ring Circularly Polarized Microstrip Antennas for CubeSat Applications
A hybrid perturbation scheme is used in this article to achieve wide axial ratio (AR) bandwidth and beamwidth from circularly polarized (CP) microstrip patch–ring antennas using a single probe feed. Perturbations in the diagonal corners of a square ring and a square patch arranged in a stacked configuration are introduced to achieve the circular polarization. First, an enhanced AR bandwidth is obtained when a combination of a square ring and a square patch with negative perturbations is used as parasitic and driven elements, respectively. Next, circular polarization with wider AR bandwidth, wider beamwidth, and lower cross-polarization is obtained when a combination of a driven square patch with positive perturbation and a parasitic square ring with negative perturbations, termed as hybrid perturbations, is used. This antenna has a footprint suitable for small satellite applications (e.g., CubeSats) and its operating frequencies cover the allocated S-band downlink frequencies of NASA Deep Space Network and NASA Near Earth Network.
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