학술논문
Spot Focusing Coma Correction by Linearly Polarized Dual-Transmitarray Antenna in the Terahertz Region
Document Type
Periodical
Author
Source
IEEE Transactions on Terahertz Science and Technology IEEE Trans. THz Sci. Technol. Terahertz Science and Technology, IEEE Transactions on. 13(5):493-502 Sep, 2023
Subject
Language
ISSN
2156-342X
2156-3446
2156-3446
Abstract
Focus scanning is critically important in many terahertz (THz) imaging and sensing applications. A traditional single focusing transmitarray can achieve a good focus when the source is on-axis, but moving the source off-axis produces a significant aberration. This article presents a novel approach to reducing coma for transmitarray off-axis scanning in the THz region. Here, a dual transmitarray solution is proposed, in which a transmitarray with an optimized phase profile is placed behind a regular phase profile transmitarray. A linearly polarized, dual-transmitarray antenna was fabricated for validation, and the focusing performances were experimentally characterized. The measured results are in good agreement with the theoretical ones. The generated spot of the dual-transmitarray antenna remains focused on an angle up to 50°, with a −3 dB spot size of less than 4 mm at 290 GHz. The measured near-field sidelobes are all below −10 dB within the whole scanning range.