Multifunctional near field focusing transmission metasurface based on polarization sensitivity

Abstract

In this paper, a near field focusing transmission metasurface (MS) based on polarization sensitivity is developed at microwave frequency. The MS unit cell has only three metal layers, which is less than the published dualpolarized transmission structure. And the phase shifting range can cover 320 for x-and y-polarized waves. The biggest bright spot of the focusing MS made of the proposed units is its changeable focus point by rotating the horn 0 -90 round its central axis: focusing switching between one and two focusing points. In addition, the developed MS has the following advantages: multifunctional, low sidelobe, high focusing efficiency, small size, wideband, and less layer number. The focusing relative bandwidth is 9.7%, and the maximum focusing efficiency is 30% at center frequency 15.5 GHz. The efficiency is higher than that of published results in transmission orthogonal polarization mode. The proposed MS has potential applications in medical treatment, noncontact sensing system.

A single‐layer dual‐polarization transmission metasurface for multi‐feeds and multi‐focus

“…The mainly reason is as follows: (1) moving the probe and f A comparison has been made between the proposed design and the recently published metasurface antenna as listed in Table 1. Compared with reflectarray, our transmission metasurface can overcome the block effect of the reflection mode in Zhang et al 23 Compared with published multilayer transmission metasurfaces, 18 the proposed structure is a single layer substrate. Compared with far field single layer substrate transmission metasurfaces, 19 our structure has dual polarization, multi-focus, and multi-feeds multifunctions.…”

“…For transmitarray, the focal point and the feed source are located on each side of the MS. A dual‐band focused transmitarray consisting of four identical metal layers separated by an air gap operates in two frequency bands 11.8–12.2 and 17.8–18.1 GHz 17 . A near field focusing transmission MS consisting of three metal layers has focusing relative bandwidth 9.7% and maximum focusing efficiency 30% at center frequency 15.5 GHz 18 . However, for the near field focusing MSs, the single layer reflectarray has block effect of the reflection mode, and the transmitarrays are commonly above three metal layers to get high transmission amplitude and wide phase change range.…”

“…17 A near field focusing transmission MS consisting of three metal layers has focusing relative bandwidth 9.7% and maximum focusing efficiency 30% at center frequency 15.5 GHz. 18 However, for the near field focusing MSs, the single layer reflectarray has block effect of the reflection mode, and the transmitarrays are commonly above three metal layers to get high transmission amplitude and wide phase change range.…”

Near-field focused planar transmitarray with low profile design for microwave power transmission

“…For transmitarray antennas operating at C-band, a challenge is to use unit cells with lower profiles to achieve a full transmissive phase range of 360° while avoiding a reduction in unit cell transmission amplitude. Furthermore, existing studies of NFF transmitarray antennas [26,27,28] have not considered how to achieve the best focusing performance with known unit cell characteristics.…”