Substrate-Integrated-Waveguide-Based Complementary Source Array With Enhanced Beamwidth

• Published in: IEEE transactions on antennas and propagation Vol. 69; no. 8; pp. 5136 - 5141
• Main Authors: Sun, Kai, Chen, Yongpin, Liu, Sihao, Zhao, Yanwen, Yang, Deqiang
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.08.2021; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Antenna arrays; Antenna radiation patterns; Arrays; Complementary sources; Current; Excitation; linear array; Magnetic resonance imaging; Magnetosphere; Monopoles; Radiation; Slot antennas; Substrate integrated waveguides; substrate-integrated waveguide (SIW); Substrates; wide beamwidth
• ISSN: 0018-926X; 1558-2221
• DOI: 10.1109/TAP.2021.3060058

A complementary source array with enhanced beamwidth is presented based on the substrate-integrated waveguide (SIW) in this communication. The orthogonal complementary source consists of a SIW slot and a vertical monopole, of which the radiation pattern is heart-shaped, pointing to the direction perpendicular to both slot and monopole. To achieve an enhanced beamwidth from the heart-shaped pattern, the complementary sources are cascaded to form an array. In particular, the slots are etched alternately on both sides of the central axis to achieve an in-phase excitation, while the monopoles are uniformly loaded with an alternate antiphase excitation. This arrangement makes the heart-shaped pattern of each complementary source element alternately point to either side of the array axis, so that the synthesized radiation beamwidth is enhanced in the E-plane. Based on the proposed idea, a nine-element line array is designed, fabricated, and tested. Compared with the same-sized referenced SIW slot array with an E-plane half-power beamwidth (HPBW) of only 80°, the proposed complementary source array extends the HPBW to 180°.