Miniaturized near-field-focused antenna array

Abstract

This paper presents a microstrip planar antenna array designed for near-field focusing operating at 10 GHz. It is a challenge to reach the phase and amplitude distribution of near-field-focused antenna arrays with small focal spots. The antenna elements of this array are arranged radially on the aperture of only 5.6λ₀× 5.6λ₀, which reduces the focal spot diameter. We designed an unequal-amplitude unequal-phase power divider to reach phase distribution and binomial taper distribution. The proposed array suppresses the sidelobes on the focal plane. It increases the electric field intensity by 11.46 dB compared with the horn with the same aperture size and increases 9.42 dB compared with the equal-phase array. The focus spot diameter is only 0.33λ₀. The simulated and measured results are in good agreement, which verifies the high performance of the array. This miniaturized high-focus array has a good prospect in near-field applications like wireless energy transmission and industrial detection.

KEYWORDS:

• Microstrip array
• planar array
• near-field-focused
• miniaturization

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the National Natural Science Foundations of China [grant numbers 61971340 and 62122061]; the National Key Research and Development Program of China [grant number 2020YFA0709800]; and the Technology Program of Shenzhen [grant number JCYJ20180508152233431].