A Planar Wideband Millimeter-Wave Antenna Array With Low Sidelobe Using '±1' Excitations

• Published in: IEEE transactions on antennas and propagation Vol. 69; no. 10; pp. 6999 - 7004
• Main Authors: Dai, Xin, Li, Xun, Luk, Kwai-Man
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.10.2021; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Algorithms; Antenna arrays; Antennas; Bandwidth; Dipole antennas; Dipoles; Excitation; Feeds; Low sidelobe; magnetoelectric (ME) dipole; Microstrip; microstrip line; Microstrip transmission lines; Millimeter waves; millimeter-wave (mmW); Particle swarm optimization; Planar arrays; Power dividers; Sidelobe reduction; Sidelobes; Substrates; wideband
• ISSN: 0018-926X; 1558-2221
• DOI: 10.1109/TAP.2021.3076217

A new method is proposed to suppress the sidelobe level (SLL) of antenna array. Different from the conventional amplitude-tapered excitation method, '±1' excitations are used to feed the antenna array and achieve low SLL. The SLL is first optimized by using a modified binary particle swarm optimization algorithm with ideal '±1' excitations. Then, the ideal '±1' excitations are replaced with microstrip line feed and aperture-coupled magnetoelectric (ME) dipoles. The '+1' excited ME dipoles are fed from the default direction, while the '−1' excited ME dipoles are fed from the direction physically reversed. According to the optimized array configuration, combining the ME dipole elements with a 256-way parallel power divider, a planar <inline-formula> <tex-math notation="LaTeX">16\times16 </tex-math></inline-formula> millimeter-wave antenna array is designed, fabricated, and measured. An overlapped working bandwidth of 38% (24.1-35.4 GHz) is obtained with an SWR less than 2.4 and SLL lower than −17.2 dB. The gain is up to 26.3 dBi. The new binary concept paves a new way for SLL suppressing.