The performance of petal antennas is often hampered by deployment errors, a prominent form of error that has significant implications on radiation performance, and surface errors. Traditional calculation methods often overlook the relationship between errors on individual petals, thus leading to an overestimation of the interval calculation. This study presents a novel interval analysis method based on an ad hoc auxiliary formulation to effectively manage the influence of deployment angle error. The proposed methodology addresses the overestimation issue inherent in the interval estimation, offers a more straightforward computation process, and presents potential synergy with antenna shaping techniques to enhance antenna design. The validity and efficiency of this method are corroborated through several representative numerical examples.

This work presents an interval analysis (IA) based method for the tolerance analysis and robust design of shaped reflector antennas generating contour beams. First, the expression of the power pattern of the contour beam is properly defined in terms of the azimuth and elevation angles and the Cartesian IA (CIA) is then used to derive the lower and upper bounds of the corresponding interval function. The reliability of the proposed CIA tolerance method is analyzed through a set of representative numerical examples including random surface deformations of the reflector surface. Finally, the Particle Swarm Optimizer (PSO) is integrated with the CIA-based interval analysis method for the robust design of shaped reflector antennas. The robustness of the obtained solutions is validated against the results from analytic Monte Carlo simulations and the commercial solver GRASP.

A transmission-band-switchable absorptive/ transmissive frequency selective surface (ATFSS) based on liquid metal is proposed herein. The ATFSS realizes C-band absorption, and the transmissive Ku band can be turned on or off using loaded or unloaded liquid metal and by changing the spacing between the lossy layer and the transmission layer. The simulation shows that the ATFSS maintains an absorption rate of >80% at 3.1–8.9 GHz; when the transmission band is opened, the |S ₂₁ | < 3 dB band is 10.7–17.22 GHz. When the transmission band is closed, all the electromagnetic waves at the Ku band are reflected. An ATFSS prototype was fabricated, and the measurement results effectively validated the above design. Moreover, the ATFSS could be used in high-temperature environments owing to the good thermal conductivity of liquid metal.

This article presents a heuristic best-fitting-paraboloid (BFPH) method, tailored for reflector antennas subject to gravitational distortion. First, the best fitting problem is formulated a nonlinear least-squares problem (NLSP) for the distorted reflector, wherein three heuristic rules (DRs), crucial for the problem at hand, are derived based on two typical distortion modes observed in antennas. Then, a suitable optimization algorithm is employed to solve the NLSP, in which a customized strategy is developed for the definition of the initial value in order to guarantee effective and reliable final solutions. A set of numerical results are reported and discussed to demonstrate the superior performance of the BFPH method in comparison to existing state-of-the-art methods. More specifically, it supplies higher antenna gain, reduced pointing error, enhanced robustness, and better symmetry in the far-field pattern.

In this study, a dual-band dual-beam shared-aperture reflector antenna based on a Cassegrain configuration is designed using a frequency-selective surface (FSS) subreflector. The antenna generates two shaped beams that operate at different frequencies and can spatially overlap. One beam contour can be independently optimized by properly designing the shape of the main reflector. The contour of the second beam is defined by optimizing the unit cell and geometry of the FSS-based subreflector once the shape of the main reflector is set. The reflector antenna design is cast as the optimization of a suitably defined cost function aimed at yielding the desired directivity performance in the regions of coverage. In order to validate the proposed solution, a set of numerical experiments was conducted using most of China and Shaanxi province as benchmark examples.