A Multifunctional Full-Polarization Reconfigurable 28 GHz Staggered Butterfly 1-D-Beam Steering Antenna

• Published in: IEEE transactions on antennas and propagation 2021-10, Vol.69 (10), p.6468-6479
• Main Authors: Mishra, Ghanshyam, Sharma, Satish Kumar
• Format: Article
• Language: English
• Subjects: Antenna arrays; Antenna radiation patterns; Antennas; Beam steering; Butterfly antenna; Circular polarization; flexible radiation pattern; full-polarization reconfiguration; Leaky waves; leaky-wave antennas (LWAs); Linear antenna arrays; Linear arrays; Mathematical model; Microstrip antennas; Patch antennas; Phased arrays; Planar arrays; Radiation; Reconfiguration; series-fed traveling-wave antenna; Sidelobe reduction; Sidelobes; staggered array; Unit cell
• ISSN: 0018-926X; 1558-2221
• DOI: 10.1109/TAP.2021.3070226

A novel multifunctional staggered 8\,\,\times12 Butterfly phased array antenna is proposed at Ka -band (28 GHz) for 5G communications with key features of full-polarization reconfigurability, flexible radiation pattern, and wide-angle 1-D-beam steering performance. The unit cell of the proposed array is a two Butterfly radiating antennas separated by 2\lambda \text{g} ( \lambda \text{g}\,\,= effective wavelength) with two ports, where each Butterfly is a sequentially rotated series-fed microstrip patch antennas. Full-polarization reconfiguration (right-hand circular polarization (RHCP), left-hand circular polarization (LHCP), Linear-X, and Linear-Y polarization) is achieved by suitable excitation of the ports to realize increased system capacity. Flexible radiation pattern with dynamic 3 dB gain-beamwidth from 16° to 90° is achieved to realize a variable cellular range, angle, and gain requirements. The proposed staggered planar array configuration reduces the spacing between the adjacent series-fed linear array to 0.45\lambda _{0} , where \lambda _{0} is the free-space wavelength at 28 GHz. The proposed array size of 8\,\,\times12 Butterfly provides beam steering up to ±63° without any grating lobes. Analytical study using a periodic leaky-wave antenna (LWA) theory is included to provide insights into the radiation characteristics of the Butterfly series-fed linear array antenna. The beam steering characteristics were verified by using measured patterns of the individual branches and by applying the computed array factor. The full-polarization reconfiguration and flexible radiation patterns with sidelobe reduction are implemented and experimentally verified with a 16-channel Analog Devices ADMV4821 RFIC Ka -band beamformer.