66–76 GHz High-Isolation 1-D Wide-Angle Scanning Phased Array Antenna With Bent-Wall Structures

In this letter, a millimeter-wave wide-angle scanning phased array antenna based on low-temperature co-fired ceramics is proposed. First, metal grounded vias and metal plates are introduced around the patch antenna to form a bent wall, which can broaden the E-plane beamwidth from 100° to 118° at 66 GHz to 76 GHz. Based on the wide-beam element, a 4 × 4 array is constructed with a spacing of only 0.38λ0, and a Π-shaped decoupling structure is introduced between adjacent elements to construct a planar coupling cancelation path with equal magnitude and opposite phase, which can increase the isolation from 15 dB to 20 dB. In addition, two rows of dummy elements are loaded along the E-plane on both sides of the array to improve the maximum scanning angle to ±71°, with the gain attenuation within 2 dB. The antenna prototypes are fabricated and the measured and simulated results are highly consistent, indicating the proposed phased array antenna is a favorable candidate for 6G applications.