This article presents low-profile configurations of the Fresnel zone plate antenna at Ka-band. The investigation involved progressively reducing the focal distance of the antenna through simulations and observing the effect on the directivity, radiation patterns, and aperture efficiency. The number of metal zones was also varied in the simulations. It was found that focal distances below 0.75λ yielded little more directivity than the feed itself. With a single zone, the 1.25λ focal distance achieved the highest overall aperture efficiency of 24%, which was a significant improvement over the larger focal distance cases. Measurements were performed to verify the simulated results.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics
- Electrical and Electronic Engineering