Dual-Band Focused Transmitarray Antenna for Microwave Measurements

Abstract

A dual-band focused transmitarray antenna designed by using frequency selective surfaces (FSS) technique is proposed in this paper. Compared with the traditional transmitarray antenna, the proposed antenna has advantages of good ability to focus electromagnetic wave in the dual-band, high resistant of poor measurement environment and easy to process. The transmitarray consists of four identical metal phase shift layers, each of which is separated by an air gap. The elements distributed on metal layer are composed of a I-shaped slot at the center and four L-shaped slots with central symmetry. The change of I-shaped slot length affects the change of phase in low frequency band and the change of L-shaped slot length affects the change of phase in high frequency band. The mutual coupling between the two kinds of slots can be neglected. The proposed antenna consisting of a transmitarray and a feed has been analysed, simulated, and measured. The results show that the average focal spot diameter (SD) is 35.2 mm at 12 GHz and 24.5 mm at 18 GHz, and the dual-band focused transmitarray antenna can operate in two frequency bands 11.8-12.2 and 17.8-18.1 GHz. Simulated and measured results show that the proposed antenna has good concordance, making it possible for various microwave measurements. INDEX TERMS Focused; all metal elements; dual-band; transmitarray antenna; frequency selective surfaces (FSS).

An Integrated Dual-Band Dual-Circularly Polarized Shared-Aperture Transmit-Array Antenna for K-/Ka-Band Applications Enabled by Polarization Twisting Elements

“…TA cells can be realized based on AFA structures [6-9, 16-18, 21-22], multi-layered PSSs [10][11][12][13][14][15]19], and metamaterials [34,35]. In this design, the AFA structure is adopted for designing the TA cells due to its inherent low panel thickness.…”

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.…”

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

“…However, the focusing performance in some region is influenced by the block effect of the reflection mode. 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 .…”

“…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.…”