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1. A Dual-Band circularly polarized printed antenna for deep space CubeSat communication

   Mubashir, Muhammed; Hossain, Mohammad; Maula, Qudrat; Latif, Saeed; Spencer, E. (August 2020, Small Satellite Conference, Logan, Utah)

   null (Ed.)

   This paper presents the design of a dual-band printed planar antenna for deep space CubeSat communications. The antenna system will be used with a radio for duplex operation in a CubeSat, which can be used for a lunar mission or any deep space mission. While a high-gain CubeSat planar antenna/array is always desired for a deep space mission, high-performance ground stations are also required for robust communication links. For such a mission, the X-band is the appropriate frequency for the downlink communication, which is very challenging in the case of deep space communication compared to the uplink communication. At this frequency, the antenna size can have small enough dimension to form an array to obtain high-gain directional radiations for the successful communication, including telemetry and data download. NASA’s Deep Space Network (DSN) has the largest and most sensitive 70 meterdiameter antenna that can be considered for this type of mission for reliability. DSN has uplink and downlink frequency of operations in 7.1-GHz and 8.4-GHz bands, respectively, which are separated by approximately 1.3 GHz. A straight forward approach is to use two antennas to cover uplink and downlink frequencies. However, CubeSats have huge space constraints to accommodate science instruments and other subsystems and commonly utilize outside faces for solar cells. Therefore, in this paper, we have proposed a planar directional circularly polarized antenna with a single feed that operates at both uplink and downlink DSN frequencies. Simulated 3-dB axial ratio bandwidth of 165 MHz, from 7064 MHz to 7229 MHz for uplink, and that of 183 MHz, from 8325 MHz to 8508 MHz for downlink, are achieved. Also, a wide impedance bandwidth of 23.86% (VSWR < 2) is obtained. From this single probe-fed stacked patch antenna, peak RHCP gain of 9.24 dBic can be achieved. 

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2. Dual-Port Butterfly Slot Antenna for Biosensing Applications

   https://doi.org/10.3390/s25164980  

   Milijic, Marija; Jokanovic, Branka; Tasic, Miodrag; Jovanovic, Sinisa; Boric-Lubecke, Olga; Lubecke, Victor (August 2025, Sensors)

   This paper presents the novel design of a printed, low-cost, dual-port, and dual-polarized slot antenna for microwave biomedical radars. The butterfly shape of the radiating element, with orthogonally positioned arms, enables simultaneous radiation of both vertically and horizontally polarized waves. The antenna is intended for full-duplex in-band applications using two mutually isolated antenna ports, with the CPW port on the same side of the substrate as the slot antenna and the microstrip port positioned orthogonally on the other side of the substrate. Those two ports can be used as transmit and receive ports in a radar transceiver, with a port isolation of 25 dB. Thanks to the bow-tie shape of the slots and an additional coupling region between the butterfly arms, there is more flexibility in simultaneous optimization of the resonant frequency and input impedance at both ports, avoiding the need for a complicated matching network that introduces the attenuation and increases antenna dimensions. The advantage of this design is demonstrated through the modeling of an eight-element dual-port linear array with an extremely simple feed network for high-gain biosensing applications. To validate the simulation results, prototypes of the proposed antenna were fabricated and tested. The measured operating band of the antennas spans from 2.35 GHz to 2.55 GHz, with reflection coefficients of less than—10 dB, a maximum gain of 8.5 dBi, and a front-to-back gain ratio that is greater than 15 dB, which is comparable with other published single dual-port slot antennas. This is the simplest proposed dual-port, dual-polarization antenna that enables straightforward scaling to other frequency bands. 

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3. A shared-aperture pentaband antenna with high impedance surface for CubeSat application

   https://doi.org/10.1038/s41598-024-66632-7  

   Uddin, Md Nazim; Alwan, Elias A (December 2024, Scientific Reports)

   A circular polarized (CP) pentaband antenna based on the aperture-in-aperture (AIA) concept is presented for CubeSat applications. This AIA consists of five different bands ranging from L-band to Ka-band. Four different antennas, each operating at a specific frequency band, namely 12 GHz, 18.5 GHz, 26 GHz, and 32 GHz, were incorporated into an L-band (viz. 1.5 GHz) antenna. Notably, the five antennas can operate simultaneously for a CubeSat downlink operation with a frequency ratio of 21.3:1. The antenna structure shows a realized gain of 5–10 dBi with good CP bandwidth (< 3 dB) across the overall operational frequency range. That is, the realized gain of L-band (1.5 GHz), X-band (12.5 GHz), K-band1 (18.5 GHz), K-band2 (26 GHz), and Ka-bands (32 GHz) are 5.05 dBi, 8.21 dBi, 7.33 dBi, 7.97 dBi, and 8.56 dBi. A high impedance surface (HIS) is incorporated with the Ka-band antenna to mitigate the ripples in the radiation pattern created by the interference of surface waves. A prototype was fabricated and tested. The measurement data agrees well with the simulation. 

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4. Modified U Slot Patch Antenna with Large Frequency Ratio for Vehicle-to-Vehicle Communication

   https://doi.org/10.3390/s23136108  

   Govindarajulu, Sandhiya Reddy; Tarek, Md Nurul; Guerra, Marisol Roman; Hassan, Asif; Alwan, Elias (July 2023, Sensors)

   This paper presents a single-fed, single-layer, dual-band antenna with a large frequency ratio of 4.74:1 for vehicle-to-vehicle communication. The antenna consists of a 28 GHz inset-fed rectangular patch embedded into a 5.9 GHz patch antenna for dual-band operation. The designed dual-band antenna operates from 5.81 to 5.99 GHz (Dedicated Short Range Communications, DSRC) and 27.9 to 30.1 GHz (5G millimeter-wave (mm-wave) band). Furthermore, the upper band patch was modified by inserting slots near the inset feed line to achieve an instantaneous bandwidth of 4.5 GHz. The antenna was fabricated and measured. The manufactured prototype operates simultaneously from 5.8 to 6.05 GHz and from 26.8 to 31.3 GHz. Notably, the designed dual-band antenna offers a high peak gain of 7.7 dBi in the DSRC band and 6.38 dBi in the 5G mm-wave band. 

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5. Broadband Dual-Polarized Planar Antennas for Radar With Printed Circuit Balun

   https://doi.org/10.1109/ICRAMET53537.2021.9650456  

   Mai, Hoang Trong; Rodriguez-Morales, Fernando (November 2021, 2021 International Conference on Radar, Antenna, Microwave, Electronics, and Telecommunications (ICRAMET))

   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. 

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