A Simple Model for Analyzing Transmitarray Lenses

Abstract

A new model for characterizing a complex system formed by a feeding horn and a transmitarray lens is presented in this paper. This model characterizes the spillover radiation and is capable of analyzing its effect on the radiation pattern. Both the contribution of the lens and the spillover radiation are modeled as planar arrays. The proposed model shows good agreement with the results obtained in simulations using a commercial full-wave software. In addition, some features, such as the characterization of the feeding element, are included in this model, in order to improve its accuracy. Finally, the limits of applicability are also discussed throughout this paper. Thus, it is possible to set up the boundaries, in terms of F=D ratio and number of elements, within which the model is reliable.

Analysis and Design of a Metamaterial Lens Antenna Using the Theory of Characteristic Modes

“…Metal lenses have attracted an increasing interest during the last decade due to their multiple applications [1][2][3][4][5][6][7][8][9]. In this context, different lenses have been recently proposed aimed at maximizing the gain and the efficiency of the radiating structures.…”

“…Periodic structures are also used to design transmitarrays [4,5] and reflectarrays [6] by means of an intensive study of the physical model of the feed element and the unit cell. Additionally, the compactness of metamaterial lens antennas makes them very attractive for the low-cost development of metal lenses at terahertz frequencies [7], thin planar lenses for massive MIMO applications in the millimeter-wave band [8], or ultrathin planar lens antennas based on gradient metasurfaces [9].…”

A High-Performance Transmitarray Antenna with Thin Metasurface for 5G Communication Based on PSO (Particle Swarm Optimization)

“…The patch antenna was chosen because of its easy manufacturing and small transmission direction size, which shows the inherent advantage of the low-profile property, but the patch antenna is often limited by the narrow bandwidth, in general, the −10 dB bandwidth of patch antenna is less than 10%. Another shortcoming of the patch antenna is that it is difficult to keep the symmetric radiation pattern in the azimuthal direction because the asymmetrical radiation will bring the distortion to the radiation when the TA or RA is feed by off-set source or in the situation of beam steering [18,19].…”

“…To overcome these shortages, the TA is developed to overcome the shortcoming of the RA and has greater tolerance to the surface errors [18]. Unlike the incident wave and reflected wave at the same side of the RA, the incident wave illuminates on the TA and passes through the array becoming the transmitted wave, so the blocking effect could be avoided largely.…”

“…[ 23 ], while the two-layer structures are exploited, respectively. The other is based on the various working principles, TA could be further categorized into four different types, namely, frequency selective surfaces (FSS) [ 15 , 18 , 19 , 20 , 22 , 24 ], metasurface (MS) [ 21 , 23 , 25 , 26 ], the spatial bandpass-filter based structure [ 27 ], receive/transmit-mode structure, and so on [ 16 , 28 , 29 ]. Owing to the transmission, amplitude and phase should be taken into consideration at the same time, how to simply the TA while keeping the specific properties of lower SLL as well as greater surface tolerance for the application in 5G communication has become an urgent research hotpot.…”