eigenfrequency

Analysis of a distributed slot discontinuity in the ground plane of a microstrip line

This paper presentsa a method of analysis of distributed slot discontinuity in a microstrip line ground plane based on transverse resonance technique. The scattering characteristics of symmetrical and nonsymmetrical slot resonators of a complex shape have been calculated by Galerkin’s procedure and taking into account the harmonics of current density in the microstrip line and waveguide modes in the slot aperture.

Radio frequency resonances inside a human head

RF equipment compliance tests employ electromagnetic field calculation in a head phantom to derive Specific Absorption Rate values. We have hypo­thesized that a biological tissue in certain conditions could act like a dielectric resonator hence affecting the field estimation. To study the resonance effects in a human head, we have formulated an eigenfrequency problem for a structurally realistic 2D human head phantom and solved it by the finite element method. The results have revealed 124 underdamped eigen­frequencies within a 0,2–2 GHz frequency band.

Identifying the elastic moduli of composite plates by using high-order theories

The study aims to predict elastic and damping properties of composite laminated plates from the measured mechanical characteristics. The elastic constants and damping properties of a laminated element are determined by using experimental data and the results of a multi level theoretical approach. Solution examples for particular problems are given. On the basis of static three-point bending tests, measured eigenfrequencies, and refined calculation schemes, the elastic properties of layered composite beams were identified.