Search

The current worldwide energy and economical crisis has triggered the need for more sustainable technological solutions to implement energy-efficient next generation communication systems, which should also be commercially viable and cost-effective. Moreover, future terrestrial and satellite communications will bring a wide range of use cases, services, and environments with very different requirements and specifications to ful-fill in order to generate a smart digital, fully connected society. Designing new antennas for each single application is not feasible since it is very complex to meet the customer's demand in the short run, and antenna system solutions that are easily re-configurable to be re-used in diverse scenarios are needed. The combination of lenses with traditional phased array antennas (also known as dome antennas) is a promising way of mixing the advantages of both antenna technologies and optimizing the performance of our systems depending on the use case scenario. This article discusses the industrial and technical potential of using dome antennas implemented in different technologies for expected use cases and applications of future terrestrial and satellite communication systems.

A modeling methodology to obtain the dispersion characteristics of mirror- and glide-symmetric structures is presented. A novel Green’s function is proposed as the integration kernel of the electric-field integral equation solved by the method of moments (MoM). Key aspects of implementation, such as adapting the Ewald acceleration, accurate computation of singular integrals, and a zero-search algorithm to obtain solutions, are presented. The proposed methodology is applied to fully metallic 2-D periodic unit cells with arbitrary geometries. The results of the method are found to be in very good agreement with reference results from the literature. Compared to the conventional MoM analysis, the proposed approach obtains results in half the time and gives additional information about the modal properties.

This article applies an in-house generalized ray-tracing (RT) model to efficiently compute both the radiation pattern and the efficiency of geodesic lenses with nonrotationally symmetric shapes. Losses due to ohmic effects and surface roughness are included in the model. These losses are very relevant for monolithic geodesic lens antennas as postprocessing techniques cannot be applied to reduce the surface roughness of internal part of the metallic plates. The model is validated by comparison with full-wave simulations for three different lenses: a circular flat parallel-plate waveguide (PPW), an elliptically compressed geodesic lens, and a water-drop lens. These results show a reduction in computational time by a factor of 600 using the RT model. A non-rotationally symmetric water drop lens has been manufactured in a monolithic piece using the laser powder-bed fusion (LPBF) technique with successful experimental results.

We propose and study a new type of double-layer holey structure with a wide bandgap. The structure can have glide symmetry in two orthogonal directions but not 2-D glide symmetry. We report results in terms of dispersion diagrams calculated with the eigensolver of a commercial solver, as well as with a multimode transfer matrix approach that permits an accurate calculation of the attenuation constant. The results demonstrate that the bandgap of the proposed structure can provide a wider fractional bandwidth and a larger attenuation constant than those of a 2-D glide-symmetric holey configuration. Therefore, this new type of periodic structure can be advantageous in preventing leakage in gap waveguide technology or, in general, parallel plate configurations and filters. The operation of this new unit cell is experimentally demonstrated with a double-flange configuration between 40–60 GHz.

The Luneburg lens is of significant interest for microwave and optical devices due to its wide-angle focusing properties. However, the inhomogeneous refractive index of the lens is restrictive and can be difficult to realize, especially at high frequency (typically millimeter-waves and above). Here, we present an inhomogeneous lens referred to as the collimating truncated virtual image lens, which is derived as a combination of the recently proposed virtual image lens and a conventional extended hemispherical lens. We investigate the operation of the proposed lens and we demonstrate that it provides similar focusing properties as the Luneburg lens, but with a flexible refractive index profile. This flexibility can be used to alleviate the strict manufacturing constraints typically associated with the Luneburg lens. We validate the properties of the proposed lens with a demonstrator at millimeter-wave frequencies showing that an antenna based on the proposed lens can obtain similar directivity and sidelobe levels to those obtained in an ideal Luneburg lens antenna, while the proposed lens is easier to realize. The collimating truncated virtual image lens is attractive for instruments and antennas at high frequency.