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Cataloged from PDF version of article. We report free space transmission and the first reflection measurements of a composite double negative (DNG) metamaterial, also known as a left-handed material (LHM). The metamaterial composes of the split-ring-resonators and discontinuous thin wires. Very high transmission values of the metamaterial are observed within a frequency range for which both effective permeability and permittivity are expected to be negative.

It is demonstrated that in the near field of suitably designed applicators, the penetration depth of the electromagnetic wave can greatly exceed the usual skin depth. The application of this principle in therapy is suggested.

The trans-horizon signal is assumed to be adequately described by a simple Waterman scatter model and to be ascribable to a partial reflection from a "rippled atmospheric layer." Here it is assumed that the boundary of this layer is space sinusoidal in a plane normal to the line determined by the transmitter and receiver points. The thickness of the layer is approximately uniform and the permittivity is assumed to vary in a Gaussian manner. Theoretical and experimental descriptions of the vertical-transverse permittivity spectrum are obtained and compared. A corresponding comparison is made between the theoretical and Waterman experimental received power vs azimuth angle patterns. In both cases, there is qualitative agreement provided the ratio of ripple amplitude to ripple wavelength is large. In addition, an estimate of the trans-horizon signal power spectrum is compared with experimental observations. Experimentally, the power spectrum is found to broaden with increasing scattering angle and beamwidth, while the present scatter model yields a power spectrum whose width is an inverse function of scattering angle and beamwidth.

Expressions are obtained for the electromagnetic fields transmitted into the time-varying medium when a plane wave is incident upon either a dielectric or dispersive half-space. Solutions are obtained for the case when the medium is changed in a stepwise fashion, and also for the case when the medium varies slowly and continuously.

The generalized ray optics formulas in lossy media are derived, and the role of absorption in the scattering of a transverse electromagnetic wave by random density fluctuations is studied by the use of the Born approximation in a medium with complex permittivity for the case in which the scale of turbulence is large compared to the wavelength. Formulas for the autocorrelation of phase and amplitude are obtained.

Analytical expressions obtained from electromagnetic field theory are used to plot propagated ray paths as functions of frequency and launch angle. From these plots the dispersive effects are predicted for signals transmitted between any two selected points.

This communication refers the reader to a report where we have studied the effect of atmospheric winds on the frequency spectrum of an electromagnetic wave.