W-band flat lens antenna with compact size and broadband performance

• Published in: IET microwaves, antennas & propagation Vol. 14; no. 10; pp. 1047 - 1052
• Main Authors: Liu, Shi Lin, Lin, Xian Qi, Lan, Jian Yu, He, Xiao Bin
• Format: Journal Article
• Language: English
• Published: The Institution of Engineering and Technology 12.08.2020
• Subjects: antenna radiation patterns; antenna radiation performances; broad frequency band; broadband performance; broadband short‐length lens antenna; compact lens antenna; compact size; dielectric host material; dielectric unit‐cell; frequency 94.0 GHz; gain bandwidths; gain enhancement; gain performance; horn antennas; length‐shortened horn antenna; lens antennas; lens height; lens profile; lenses; microwave photonics; millimetre wave antennas; performance deterioration; Research Article; three‐dimensional printing method; total lens antenna; variable square holes; W‐band flat lens antenna; antenna radiation performances; gain performance; variable square holes; compact size; microwave photonics; broadband performance; lens height; lens antennas; dielectric unit-cell; broadband short-length lens antenna; antenna radiation patterns; performance deterioration; millimetre wave antennas; gain bandwidths; lenses; length-shortened horn antenna; horn antennas; frequency 94.0 GHz; dielectric host material; lens profile; W-band flat lens antenna; total lens antenna; broad frequency band; compact lens antenna; three-dimensional printing method; gain enhancement
• ISSN: 1751-8725; 1751-8733; 1751-8733
• DOI: 10.1049/iet-map.2019.0654

A broadband short-length lens antenna operating in W band is presented in this study. The lens is composed of a dielectric host material with numerous variable square holes drilling on it, which is fabricated using the three-dimensional printing method with high accuracy and low cost. Then, the lens is mounted directly on the end of a length-shortened horn antenna, obtaining a compact lens antenna. Phase variations of the dielectric unit-cell under different oblique incidences are taken into consideration while constructing the lens. Simulation results reveal that gain enhancement of about 1 dB is achieved compared with the designs using the conventional method. Effects of lens height on antenna radiation performances are also studied and the lens profile is reduced to half with little performances deterioration. For the total lens antenna, a maximum gain of 23.2 dBi is measured at 94 GHz, which reveals 7.4 dB gain enhancement compared with the feed source. The measured 1 and 3 dB gain bandwidths are 13.8 and 37.8%, respectively. The proposed lens antenna shows a profile reduction of 42.3% with respect to the optimum horn while exhibiting comparable gain performance within a broad frequency band.