James D. Van de Ven Arthur G. Erdman University of Minnesota Mechanical Engineering Department 111 Church Street SE Minneapolis, Minnesota 55455 E-mail: [email protected] Abstract. Modeling laser transmission welding of thermoplastics requires knowledge of the optical properties of the two materials being joined. Previous work measuring optical properties for this purpose placed little import...

There has been considerable progress in the construction of fundamental bandwidth limits and near optimal design realisations for several classes of passive linear electromagnetic wave devices, most notably for radar absorbent materials, antennas and meta-materials. This article seeks to place balun design on a similar footing, for an important class of baluns; in particular those which are ‘pe...

This work presents a procedure to measure the effective dielectric permittivity in transmission lines. The procedure is based on an improved Frequency Domain Reflectometry (FDR) method. In this technique, the measured reflection coefficient as a function of the frequency is used to synthesize the response of a terminated transmission line to an ideal delta pulse in different finite bandwidths. ...

in this paper the reflection coefficient of electromagnetic wave incidence on the walls of the buildings and obstacles that occurs in mobile communication path was modified by solving the riccati nonlinear equations. for this purpose, the building walls are assumed inhomogeneous layers where their permittivity changes as function of the wall thickness. using this reflection coefficient, a new p...

Studies of thin films in the Extreme Ultraviolet (EUV) are difficult given that most materials readily absorb photons of these energies. By depositing a thin film of the material of interest on a silicon photodiode, transmission measurements can be made throughout the EUV. If the measurements are made in a range of low absorption, the extinction coefficient, k, can be found with relative ease. ...

A localized and strong RF magnetic field, created by a magnetic write head, is used to examine the linear electrodynamic properties of a Nb superconducting film. The complex reflection coefficient of the write head held in close proximity to the films is measured as a function of sample temperature. A model combining a magnetic circuit (magnetic write head inductively coupled to the sample) and...