Edgard Schweig - Academia.edu (original) (raw)

Papers by Edgard Schweig

STIN, Aug 1, 1982

Abstract : Dielectric properties have been measured at 94 GHz for thallium halide materials KRS-5... more Abstract : Dielectric properties have been measured at 94 GHz for thallium halide materials KRS-5 and KRS-6 using Fabry-Perot resonance transmission and short-waveguide reflection in dielectric-filled waveguide section. The dielectric constants are 31-32 for KRS-5 and 28-31 for KRS-6; the loss tangents are .02 for both. These values predict a waveguide loss of 8 dB/cm for a closely-confined HE sub 11 mode in KRS-5 at 94 GHz. Difficulties in coupling to such high dielectric constant fibers have so far prevented direct measurement, but scale model studies at 10 GHz yield a successful coupling technique to the HE sub 11 mode through an intermediate dielectric. Propagation in a 0.5 mm diameter KRS-5 fiber was observed with 0.2 dB/cm loss, much lower than that predicted for HE sub 11; the as-yet unidentified mode has a phase velocity about c, but small external fields and less than 1.5 dB loss from a 90 deg, 20 cm radius bend. Propagation constants for KRS-5 waveguides were calculated and losses estimated for various designs. A loosely coupled HE sub 11 KRS-5 fiber with foamed-teflon cladding could exhibit 3 dB/meter loss, with 3 dB/meter additional loss from 60 cm radius bends. A simple theory of relative guiding properties for multilayer cylindrical waveguides is given. (Author)

IEEE Transactions on Microwave Theory and Techniques, May 1, 1984

and, since 1976, on electncaf packaging analysis. He has "been awarded five US patents. Computer ... more and, since 1976, on electncaf packaging analysis. He has "been awarded five US patents. Computer Analysis of Dielectric Waveguides: A Finite-Difference M[ethod EDGARD SCHWEIG, hlH?f13ER,IEEE, AND WILLIAM B. BRIDGES, FELLOW, IEEE .&tract-A method for computing the modes of diel~tric guiding structures based on finite differences is described. The numerrcaf computation program is efficient and can be applied to a wide range of problems. We report here solutions for circular and rectangular dielectric waveguides and compare our solutions with those obtained by other methods. Limitations in the commonly used approximate formulas developed by Marcatili are discussed. I.

High dielectric constant rectangular dielectric waveguides are suitable transmission media for mi... more High dielectric constant rectangular dielectric waveguides are suitable transmission media for millimeter waves. We have made a finite-difference method study of the electromagnetic modes of such guides and determined the limitations of the commonly-used approximate formulas of Marcatili.

* We will often quote results from the excellent book by H.-G. Unger on "Planar Optical Waveguide... more * We will often quote results from the excellent book by H.-G. Unger on "Planar Optical Waveguides and Fibers" that presents a detailed and complete analysis of dielectric guides. * pipe mode, this particular solution to Eq. 17 has a zero cutoff and * This result can be obtained from the asymptotic behavior of Eq, 17 for small values of u and v, * By "air" we refer to a lossless medium of refractive index equal to unity, which is, in practice, a very good approximation to the dielectric parameters of air.

1981 International Conference on Submillimeter Waves and Their Applications, 1981

In this thesis, we analyze high-permittivity dielectric waveguides for use as guiding structures ... more In this thesis, we analyze high-permittivity dielectric waveguides for use as guiding structures of millimeter waves. Two basic geometries are considered: the circular and rectangular guides. In Part I, we describe the theory of round fibers surrounded by an infinite cladding. Millimeter wavelengths are comparable to the physical dimensions of the guide. Therefore, a large difference in permittivity between the core and the cladding is required in order to provide for a tight confinement of the fields. We present the results of computations of the propagation characteristics and losses of fibers of very high permittivity. We note that the distribution of the electromagnetic power between the core and the cladding can be deduced from the dispersion curves. Finally, we consider the feasibility of a dielectric fiber made of thallium bromide-iodide (KRS-5) for the long distance transmission of W-band signals (94 GHz). Using our measurements of the dielectric parameters of KRS-5, we find...

IEEE Transactions on Microwave Theory and Techniques, 1984

Applied Physics Letters, 1982

We investigate the room-temperature absorption saturation of p-Ge and p-Si for several samples ov... more We investigate the room-temperature absorption saturation of p-Ge and p-Si for several samples over a range of doping densities for light having wavelengths of 10.6 and 9.6 μm. The transmission data can be fairly well described using an intensity dependent absorption coefficient characteristic of an inhomogeneously broadened two-level system. Measurements of the saturation intensity of p-Ge show that Is increases monotonically with increasing hole concentration, and that the resonant transition is significantly easier to saturate in p-Ge than in p-Si for the samples we examined.

STIN, Aug 1, 1982

IEEE Transactions on Microwave Theory and Techniques, May 1, 1984

1981 International Conference on Submillimeter Waves and Their Applications, 1981

IEEE Transactions on Microwave Theory and Techniques, 1984

Applied Physics Letters, 1982