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1. A 38° Wide Beam-Steerable Compact and Highly Efficient V-band Leaky Wave Antenna with Surface Integrated Waveguide for Vehicle-to-Vehicle Communication

   https://doi.org/10.1109/WMCS58822.2023.10194262  

   Sah, Pallav ; Mahbub, Ifana ( April 2023 , 2023 IEEE Texas Symposium on Wireless and Microwave Circuits and Systems (WMCS))

   This paper presents a highly efficient single-layer substrate-integrated waveguide (SIW) based leaky-wave antenna (LWA) for the millimeter-wave unmanned aerial vehicle (UAV) communication system. The leaky wave-based radiating part of the unit cell includes a combination of two Y-shaped slots with 46° stretched V etched on the top SIW, resulting in a W-shaped structure. The proposed array achieves a high gain of 13.47 dBi for the frequency range of 56.3 GHz to 63.4 GHz covering the unlicensed band, with a fine matching level below -21 dB. Using the leaky wave antenna's frequency scanning capability, the proposed antenna exhibits a scanning range of 38°. The designed antenna shows a promising solution for the UAV-to-UAV applications due to its low profile and compactness and is well-suited for the single-layer low-cost printed circuit board fabrication process using Rogers RT 5880 as substrate. The radiation pattern for the achieved bandwidth shows an average half-power angular beamwidth of 12.1°, resulting in a radiation efficiency of more than 62% for the elements arranged uniformly at a distance of 0.456λ . Following an overall low-profile compact size of 6.48×4 λ corresponding to 3.24×0.2 cm and improved performance, the antenna achieves an elliptical polarization at 60 GHz for an axial ratio equal to 3.5 dBi. 

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2. Metamaterial-Based LTCC Compressed Luneburg Lens Antenna at 60 GHz for Wireless Communications

   https://doi.org/10.3390/electronics12112354  

   Zelenchuk, Dmitry ; Kirillov, Vitalii ; Kärnfelt, Camilla ; Gallée, Francois ; Munina, Irina ( June 2023 , Electronics)

   In this study, a metamaterial-based LTCC compressed Luneburg lens was designed, manufactured and measured. The lens was designed at 60 GHz to utilize the unlicensed mm-wave spectrum available for short-range high-capacity wireless communication networks. The transformation optics method was applied to ensure the compression of the Luneburg lens antenna and thus maintain a low-profile structure. The two different types of unit cells for low and high permittivity regions were considered. The parametric study of the effect of compression on lens performance was presented. The antenna is implemented with a standard high-permittivity LTCC process, and details of the manufacturing process for the metamaterial lens are discussed. The low-profile lens is thinner than 2 mm and measures 19 mm in diameter. A size reduction of 63.6% in comparison with a spherical lens was achieved. The near-field to far-field mm-wave measurement technique is presented, and the measurement results show a peak antenna gain of 16 dBi at 60 GHz and a beam-scanning capacity with 1 dB scan loss within a 50° field of view. 

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3. A Single Antenna Full-Duplex Radio Using a Non-Magnetic, CMOS Circulator with In-built Isolation Tuning

   Aravind Nagulu, Tingjun Chen ( January 2019 , IEEE ICC'19 Workshop on Full-Duplex Communications for Future Wireless Networks)

   Wireless systems which can simultaneously transmit and receive (STAR) are gaining significant academic and commercial interest due to their wide range of applications such as full-duplex (FD) wireless communication and FMCW radar. FD radios, where the transmitter (TX) and the receiver (RX) operate simultaneously at the same frequency, can potentially double the data rate at the physical layer and can provide many other advantages in the higher layers. The antenna interface of an FD radio is typically built using a multi-antenna system, or a single antenna through a bulky magnetic circulator or a lossy reciprocal hybrid. However, recent advances in CMOS-integrated circulators through spatio-temporal conductivity modulation have shown promise and potential to replace traditional bulky magnetic circulators. However, unlike magnetic circulators, CMOS-integrated non-magnetic circulators will introduce some nonlinear distortion and spurious tones arising from their clock circuitry. In this work, we present an FD radio using a highly linear CMOS integrable circulator, a frequency-flat RF canceler, and a USRP software-defined radio (SDR). At TX power level of +15 dBm, the implemented FD radio achieves a self-interference cancellation (SIC) of +55 dB from the circulator and RF canceler in the RF domain, and an overall SIC of +95 dB together with SIC in the digital domain. To analyze the non-linear phenomena of the CMOS circulator, we calculated the link level data-rate gain in an FD system with imperfect SIC and then extended this calculation to count the effect of TX-RX non-linearity of the circulator. In addition, we provide a qualitative discussion on the spurious tone responses of the circulator due to the clocking imperfections and non-linearity. Index Terms—Circulator, CMOS, conductivity modulation, full-duplex, non-reciprocity, self-interference cancellation. 

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4. 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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5. Dual-Band Antenna Array for 5.9 GHz DSRC and 28 GHz 5G Vehicle to Vehicle communication

   https://doi.org/10.1109/IEEECONF35879.2020.9330220  

   Govindarajulu, Sandhiya Reddy ; Hokayem, Rimon ; Alwan, Elias A. ( July 2020 , 2020 IEEE International Symposium on Antennas and Propagation and North American Radio Science Meeting)

   null (Ed.)

   The Dedicated Short Range Communications (DSRC) band (5.85-5.925 GHz) allocated for vehicle-to-vehicle (V2V) communication provides limited opportunities for high speed data transfer. Alternatively, FCC plans to allocate millimeter-wave spectrum for 5G V2V communication. In this paper, we present a novel dual-band dual linearly-polarized antenna array for both DSRC and 28 GHz communications. For each band, we optimized antenna gain and number of elements to maximize range and data rate. The designed array has dual linear polarization and is fed with a simple quarter wave transformer. Due to large available connector’s size, a Wilkinson power divider is designed to combine adjacent elements. Infinite array simulation show that the array is well matched (S11 < -10 dB) from 5.85 to 6.48 GHz, and from 17.29 to 29 GHz. The realized gain at both frequency bands is neartheoretical. 

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