This article presents a new design of an ultra-wideband conformal antenna for Unmanned Aerial Vehicle (UAV) applications. The antenna is a low-profile structure which is very suitable to diminish aerial vehicle drag problem. The design utilizes Rogers Duroid 5880LZ material with dimensions of 29 mm W 39 mm. The measurement results show an ultrawideband performance of the S11<-10dB from 2.9 GHz to 15.9 GHz. A Y-rounded shape achieves this frequency range with a parasitic circular element at the center of the structure. The acceptable radiation pattern performance is until 10.1 GHz, and the system fidelity factor is SFF>0.9 in the maximum radiation. The proposed antenna was simulated and measured to test its performance when it is mounted on an UAV model.

This paper presents a design of UAVs-based 3D antenna arrays for a maximum performance in terms of directivity and side lobe level (SLL). This paper illustrates how to model the UAVs formation flight using 3D nonuniform antenna arrays. This design of 3D antenna arrays considers the optimization of the positions of the antenna elements to model the UAVs formation flight. In this case, a disk patch antenna is chosen to be used as element in each UAV. The disk patch antenna is formulated by the well-known cavity model. The synthesis process is carried out by the method of Differential Evolution for Multiobjective Optimization (DEMO). Furthermore, a comparison of the performance of 3D nonuniform antenna arrays is provided with respect to the most conventional arrays (circular, planar, linear, and the cubic) for UAVs formation flight.

This article presents an innovative design technique for feeding phase antenna arrays using coherently radiating periodic structure (CORPS) technology for reducing the number of phase shifters (PSs) in limited-scan applications with low sidelobe level (SLL). The proposed configuration is implemented taking advantage of the phase interpolation property of a CORPS network of one layer. This configuration is built by interconnecting $2\times 3$ CORPS networks in a strategic way in order to provide a reduction in the number of PSs while maintaining the scanning capability. Experimental results and full-wave simulations based on CST Microwave Studio reveal that the proposed design technique reduces the recombination losses and generates a better phase slope with respect to the basic CORPS network providing a reduction in the number of PSs. As a novel contribution, this article provides the full antenna system design in order to analyze and study the PSs reduction performance and scanning capabilities of the proposed technique to feed linear antenna arrays. The proposed design technique provides a reduction in the number of PSs for a scanning range of ±25° in linear arrays. The array design model includes the application of the raised cosine amplitude distribution to generate a radiation pattern with minimum SLL. The linear array system was validated by experimental measurements of the full system prototype and full-wave simulations results are provided to verify the accuracy of the array model and to take mutual coupling into account. The proposed case provides a good design compromise with respect to other cases in the state of the art.

The design of concentric rings arrays for isoflux radiation is reported in this paper. This design considers the reduction of the side lobe level and the isoflux radiation requirements for Geostationary Earth Orbit (GEO) satellites. The optimization problem considers the spacing between rings and the levels of amplitude excitations. The well-known method of Particle Swarm Optimization (PSO) is utilized for the optimization. The obtained results could lead the satellite hardware to be reduced significantly even more than results presented previously in the literature

A comparison between different modern multi-objective optimization methods applied to the design of concentric rings antenna arrays is presented in this paper. This design of concentric rings antenna arrays considers the optimization of the amplitude and phase excitations across the antenna elements in order to generate the trade-off curves between side lobe level and directivity for a scannable pattern with optimal performance in the whole azimuth plane. Simulation results by using evolutionary multi-objective optimization methods, such as: NSGA-II, DEMO, and EM-MOPSO are provided in this document. Furthermore, a comparative analysis of the performance between these algorithms is presented.

This paper introduces the design of sparse concentric rings array for isoflux coverage to Earth surface over a visibility cone of more than 100°. This design of concentric rings antenna array considers the optimization of the angular separation between the antenna elements and the amplitude excitation across the array in order to generate the characteristics of the desired isoflux radiation. Simulation results using an evolutionary multi-objective optimization method are provided in this document. Furthermore, an analysis of several design cases of sparse concentric rings array for wide isoflux patterns considering a different number of antenna elements for Low Earth Orbit satellites is achieved.