Power transmission coefficients

MMW amplitude transmission coefficient MMW power transmission coefficient decay time of MMW signal in cavity... 

Inhomogeneous Media. The inhomogeneities considered here are on the macroscopic rather than microscopic scale. The first topic considered is layered media. To begin with, consider a flat boimdaiy between two media of different acoustic properties. When an acoustic wave traveling through one medium encounters at normal incidence the boimdaiy with another medium, some of the acoustic energy is reflected and some transmitted (12). The sound power transmission coefficient T is given by... 

For the finite values of A for light, the evanescent fields lose some of their power to the absorbing cladding. This loss in turn leads to a loss of power from the ray path. Ray power flows along narrow ray tubes, as discussed at the beginning of Chapter 4, from which loss can occur only at reflection or turning points, i.e. at positions where there is an abrupt discontinuity in the tube or its cross-sectional area is zero. At these points, we express the loss in terms of a power transmission coefficient T, also known as a loss coefficient, defined by the dimensionless ratio... 

Love, J. D. and Winkler, C. (1980) Generalized Fresnel power transmission coefficients for curved graded-index media. I.E.E.E. Trans. Microwave Theory Tech., 28, 689-94. 

The power transmission coefficient T will generally vary along a leaky-ray path. It is therefore convenient to introduce an average attenuation coefficient y, so that the power P(z) of the leaky ray will attenuate according to P(z) = P(0) exp (—yz).If Tf denotes the fraction of ray power lost at the ith reflection and z is the corresponding half-period, then y = z . Since T depends on the path parameters and on the fiber profile in the neighborhood of the caustic or interface, we employ the local transmission coefficients introduced in Section 7-14. 

To describe tunneling losses, we use the power transmission coefficient of Eq. (7-20) with = 0 andT =T, = cos 6. For refraction losses, we use the classical... 

The fraction of beam power transmitted across the interface depends on the product of E, and H and is given by the Fresnel power transmission coefficient T of Eq. (35-21) with and n replaced by Uj and n o, respectively. 

Consider two semi-infinite media of refractive indices and < n , separated by the planar interface x = 0 in Fig. 35-3(a). A ray, or plane wave, is incident on the interface from the denser medium at angle 6 to the z-direction. Plane wave reflection in this situation is well-known and the power transmission coefficient of Eq. (35-11) is identical to the classical Fresnel coefficient [2]. 

In this section we generalize the analysis of plane-wave incidence at a planar interface, and consider the incidence of local plane waves at a caustic in a slowly varying graded medium. Our goal is the derivation of the power transmission coefficient for tunneling rays. 

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