Benchmark problem definition and cross-validation for characteristic mode solvers

In October 2016, the Special Interest Group on Theory of Characteristic Modes (TCM) initiated a coordinated effort to perform benchmarking work for characteristic mode (CM) analysis. The primary purpose is to help improve the reliability and capability of existing CM solvers and to provide the means for validating future tools. Significant progress has already been made in this joint activity. In particular, this paper describes several benchmark problems that were defined and analyzes some results from the cross-validations of different CM solvers using these problems. The results show that despite differences in the implementation details, good agreement is observed in the calculated eigenvalues and eigencurrents across the solvers. Finally, it is concluded that future work should focus on understanding the impact of common parameters and output settings to further reduce variability in the results

A Novel Singularity-Free Analysis of Coaxial-Fed Thick Monopole Antennas

An accurate and novel analysis of coaxial-fed thick tubular monopole antenna is presented. Pocklington's integrodifferential equation is solved with method of moments (MoM) for the z-directed surface current density. By using segmentation along the perimeter, we have taken circumferential variation of the current density into account. Exact kernel formulation is used in MoM where a novel representation of the kernel free of singularities is introduced. Same representation is used for modeling the source as magnetic frill current in order to handle existing singularities. Favorable comparison of the input impedance and admittance between computed and published measured and computed data is demonstrated. Circumferential change of the surface current density is displayed for the case of a plane wave incidence on a thick wire

Compact and Directional Printed Dipole Antenna Pair Conformed on a Conical Surface

© 2021 URSI.In this paper, a small sized transmitting and receiving conformal antenna pair is proposed on a conical surface for C-band radar applications. The antenna pair consists of printed dipole elements and a truncated reflector plane, printed on a flexible and multilayer circuit board. As the antenna pair is wrapped around a conical surface, it can fit in a very small volume, and yet sufficiently low mutual coupling between antennas can be achieved. The antenna also yields wideband characteristics with a directional radiation towards the tip of the cone. As a compact and flexible antenna, it can be well utilized in radar applications such as radio altimeters and proximity sensors

Design and Implementation of Transmitting and Receiving Antenna Pair on Flat Ring Surface

In this work, design and implementation of broadside altimeter antenna on circular ring surface are performed. Utilizing array factor formulation, possible locations for circular array elements are chosen. Slitted microstrip patch antennas are used for an efficient design. Satisfactory results are obtained for an altimeter antenna that can be utilized in missile, aircraft or spacecraft applications

A Low-Profile DielectricWaveguide Altimeter Antenna

© 2020 URSI.In this paper, design and implementation of a compact, low-profile and low-cost altimeter antenna is presented. A top-open dielectric waveguide is utilized to obtain a radiation pattern that illuminates from 20 to 70 degrees on the elevation plane. The proposed antenna pair can be used efficiently as a radar altimeter antenna in the course of landing. The antenna can cope with high skin temperatures, especially in supersonic flights because a high-temperature resistant dielectric material is used. Satisfactory results are obtained from EM simulations and antenna measurements