In this work, we examine the methodology for numerically computing the dispersion diagram of three-dimensional periodic structures using commercial electromagnetic simulators. Examples of periodic structures based on body-centered cubic, face-centered cubic, and monoclinic lattices are used to illustrate this methodology. We first outline the characteristics of these structures in both physical and reciprocal spaces from a theoretical point of view. On this basis, we provide a comprehensive explanation of how to adjust the setting in simulation software commonly used in microwave engineering to generate the dispersion diagrams of these structures. The appropriate simulation conditions are tabulated to serve as a further guide for other researchers. This study also explores the influence of the elements of the unit cell on the dispersion characteristics. Additionally, we evaluate and contrast the dispersion properties of identical periodic elements when having simple cubic, body-centered cubic, and face-centered cubic arrangements. We found that symmetries, such as those seen in body-centered cubic and face-centered cubic arrangements, can improve the isotropy and maintain low-dispersion characteristics over a wider frequency range. The monoclinic structure is also taken as an example to demonstrate that the reported analysis method can be applied to the dispersion analysis of other more complex noncubic lattices. Our findings offer useful information for the examination and engineering of three-dimensional periodic structures, which can be used to design microwave and antenna devices.

Lenses are used for multiple applications, including communications, surveillance and security, and medical instruments. In homogeneous lenses, the contour is used to control the electromagnetic propagation. Differently, graded-index lenses make use of inhomogeneous materials, which is an extra degree of freedom. This extra degree of freedom enables the design of devices with a high performance. For instance, rotationally symmetric lenses without spherical aberrations, e.g., the Luneburg lens, can be designed. However, the manufacturing of such lenses is more complex. One possible approach to implement these lenses is using metamaterials, which are able to produce equivalent refractive indices. Here, we propose a new type of three-dimensional metamaterial formed with two independent sets of wires. The double-mesh twin-wire structure permits the propagation of a first mode without cut-off frequency and with low dispersion and high isotropy. These properties are similar to periodic structures with higher symmetries, such as glide symmetry. The variations of the equivalent refractive index are achieved with the dimension of the meandered wires. The potential of this new metamaterial is demonstrated with simulated results of a Luneburg meta-lens.

It is demonstrated that combining phased array antennas with dielectric lenses constitutes a suitable solution to increase the energy efficiency in next-generation communication systems. A dielectric lens is designed to increase the gain of an array antenna working in the 3GPP n257 band (26.5–29.5 GHz). The simulated results demonstrate that the dielectric lens increases the gain between 0.4 and 1.3 dB in a large scanning range from 0° to 60° at 28 GHz; meaning that the output RF power can be decreased by up to 26% for a same equivalent isotropic radiated power required from the base station.

This letter presents the analysis, design, and experimental validation of a dielectric dome aimed at extending the scanning range of a realistic 8 × 8 phased array antenna (PAA) in the Ka-band. The dome profile is defined using spline functions and determined through an efficient two-dimensional (2-D) ray-tracing (RT) model. Compared to full-wave simulations in commercial software CST, the 2-D RT methodology accelerates the design process by more than 8000 times while maintaining good agreement in radiation pattern calculation. The proposed dome is fabricated using fused deposition modeling technology. Experimental results show that the dome effectively increases PAA gain at large scanning angles, providing measured gain improvements of approximately 0.5 dB and 2 dB at 50° and 60°, respectively, compared to the standalone array. In addition, the integrated dome provides a more accurate beam pointing at these large scanning angles. These results validate the effectiveness of the RT-based methodology for the design of wide-angle scanning dome-array systems.

It is demonstrated that combining phased array antennas with dielectric lenses constitutes a suitable solution to increase the energy efficiency in next-generation communication systems. A dielectric lens is designed to increase the gain of an array antenna working in the 3GPP n257 band (26.5–29.5 GHz). The simulated results demonstrate that the dielectric lens increases the gain between 0.4 and 1.3 dB in a large scanning range from 0° to 60° at 28 GHz; meaning that the output RF power can be decreased by up to 26% for a same equivalent isotropic radiated power required from the base station.

This paper presents a ray-tracing and physicaloptics (RT-PO) model for the analysis and design of hybrid domes that enable steerable flat-top beams in phased array antennas (PAAs). The hybrid dome combines a dielectric lens (DL) and a metadome (MD), leveraging their complementary advantages to extend the PAA scanning range while reducing DL volume and enabling a broader frequency range in the MD design. The proposed RT-PO model efficiently and accurately predicts farfield radiation patterns and determines the predistorted array excitations required to generate a flat-top beam at different scanning angles. Using this approach, a hybrid dome is designed to achieve steerable flat-top beams up to approximately 80°, with directivity variation below 1 dB in most directions. The RT-PO model's computed radiation patterns show excellent agreement with CST full-wave simulations. Furthermore, the model increases the computation speed by several hundred times, confirming its effectiveness for the efficient analysis and design of hybrid domes for steerable flat-top PAAs.