On-Chip Miniaturized Cavity V-Band Coplanar Folded Slot Array With High Efficiency and Reduced Mutual Coupling

Abstract

We present a V-band <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1\times 8$ </tex-math></inline-formula> on-chip miniaturized cavity coplanar folded slot antenna (CFSA) array with high efficiency and reduced mutual coupling. Substrate-integrated air cavities (SICs) are used to enhance efficiency and gain, diminish element-to-element coupling, and counter parasitic parallel-plate modes to improve CFSA efficiency. We developed CPW corporate feeds using SiO2 bridges and rounded bends to demonstrate beamsteering. The E- and H-planes of the radiation pattern were measured with a custom robotic setup. The measured CFSA single element -10-dB bandwidth is 55.4–60.3 GHz (8.5%) with an efficiency of 93%. The measured broadside array’s bandwidth spans 52–60.2 GHz (14.6%), with a total efficiency of 67% and 11.0-dBi gain. This study marks the first demonstration of beamsteering using on-chip antennas (OCAs) with SICs, steering up to 45°, and corresponding gains of 8.1, 8.9, and 9.2 dBi.