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.
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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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- Award ID(s):
- 1936665
- PAR ID:
- 10354208
- Date Published:
- Journal Name:
- IEEE aerospace and electronic systems magazine
- Volume:
- 37
- Issue:
- 3
- ISSN:
- 1557-959X
- Page Range / eLocation ID:
- 24-31
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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In this article, a compact multiband antenna design and analysis is presented with a view of ensuring efficient uplink/downlink communications at the same time from a single antenna for CubeSat applications. This design shares the aperture of an S-band slot antenna to accommodate a square patch antenna operating in the X-band. Shared aperture antennas, along with an air gap and dielectric loading, provided good gain in both frequency bands. The S-band patch had an S11 = −10 dB bandwidth of 30 MHz (2013–2043 MHz, 1.5%), and the X-band antenna demonstrated a bandwidth of 210 MHz (8320–8530 MHz, 2.5%). The Axial Ratio (<3 dB) bandwidth of the slot antenna in the S-band is 7 MHz (2013–2020 MHz, 0.35%), and it is 67 MHz (8433–8500 MHz, 0.8%) in the case of patch antenna in the X-band. While the maximum gain in the S-band reached 7.7 dBic, in the X-band, the peak gain was 12.8 dBic. This performance comparison study shows that the antenna is advantageous in terms of high gain, maintains circular polarization over a wideband, and can replace two antennas needed in CubeSats for uplink/downlink, which essentially saves space.
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Abstract The Event Horizon Telescope observed the horizon-scale synchrotron emission region around the Galactic center supermassive black hole, Sagittarius A* (Sgr A*), in 2017. These observations revealed a bright, thick ring morphology with a diameter of 51.8 ± 2.3
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This paper demonstrates the design and implementation of two dual-polarized ultra-wideband antennas for radar ice sounding. The first antenna operates at UHF (600– 900 MHz). The second antenna operates at VHF (140–215 MHz). Each antenna element is composed of two orthogonal octagon-shaped dipoles, two inter-locked printed circuit baluns and an impedance matching network for each polarization. We built and tested one prototype antenna for each band and showed a VSWR of less than 2:1 at both polarizations over a fractional bandwidth exceeding 40 %. Our antennas display cross-polarization isolation larger than 30 dB, an E-plane 3-dB beamwidth of 69 degrees, and a gain of at least 4 dBi with a variation of ± 1 dB across the bandwidth. We demonstrate peak power handling capabilities of 400-W and 1000-W for the UHF and VHF bands, respectively. Our design flow allows for straightforward adjustment of the antenna dimensions to meet other bandwidth constraints.more » « less
- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1109/MAES.2022.3141436.
