arXiv subjects

Vojtech Neuman

Publications and source records attributed to Vojtech Neuman.

3 recordsLinked to original sources

arXiv2026

Multiport Antenna Q-factor

This article proposes an estimate of multiport antenna bandwidth based on a generalization of a single-port Q-factor. The explicit derivation is based on converting the stored energy matrix to its port equivalent and on the port parameters themselves. The work discusses the bandwidth dependencies on feeding and matching. Derived formulas are shown to utilize the total active reflection coefficient and allow for a single-frequency bandwidth evaluation. Examples comprising two different dipole arrays and electrically large patch antenna arrays validate the theory.

eess.SP↗

arXiv2025

Towards Manufacturing-Friendly Shapes in Discrete Topology Optimization

This paper deals with shape irregularity issues in discrete topology optimization algorithms whereby the design is created using the automated distribution of material in the design region. Graph theory is employed to derive appropriate regularity measures for any discrete optimization algorithm. Shape regularity is quantified by scalar figures ready to evaluate design choices in the form of Pareto-frontiers. Developed metrics deal with information concerning material usage, problematic distribution, and features that complicate manufacturing. The theory is verified by several examples demonstrating the treatment of isolated islands of materials, point connections between material segments, or homogeneity.

cs.IT↗

arXiv2023

Trade-off Between Optimal Efficiency and Envelope Correlation Coefficient for Antenna Clusters

This paper introduces a theory for assessing and optimizing the multiple-input-multiple-output performance of multi-port cluster antennas in terms of efficiency, channel correlation, and power distribution. A method based on a convex optimization of feeding coefficients is extended with additional constraints allowing the user to control a ratio between the power radiated by the clusters. The formulation of the problem makes it possible to simultaneously optimize total efficiency and channel correlation with a fixed ratio between power radiated by the clusters, thus examining a trade-off between these parameters. It is shown that channel correlation, total efficiency, and allocation of radiated power are mutually conflicting parameters. The trade-offs are shown and discussed. The theory is demonstrated on a four-element antenna array and on a mobile terminal antenna.

cs.IT↗