Boundary conditions	Feb. 28, 2007

+ Fields change across interfaces of different media?
Source free boundary conditions (Sect 6.3.2):
[equation] ; [equation] . [equation] ; [equation]
t -- tangent to boundary; n -- normal to boundary
note: [equation] is normal to the interface and points from medium 2 to medium 1
Example 2.9: Magnetic field boundary conditions
Example 2.10: Electric field boundary conditions

+ Interface between two lossless media: Tangential components of [equation] and [equation] are equal at a boundary.

+ Review TEM wave: [equation] & [equation] [equation] [equation] and [equation] , e.g. [equation] (pp. 281-282).
Insulator [equation] and conductor [equation] .
Recall [equation] where [equation] accounts for conductor and dielectric losses.
Loss tangent [equation] .
[equation] (Sect. 7.5.1)
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HW #11	Due 3/8/07

1. The amplitude of [equation] just inside (i.e. at z=0) a liquid is 10V/m and the liquid's constants are [equation] , [equation] and [equation] . Determine the amplitude of E at distance of 10cm inside the medium for frequencies of a) 5MHz and b) 500Mhz. (notice check if the liquid behaves like conductor before applying formula.)
2. Problem 7.5 (a), (b) and (d) only (assuming [equation] ).
3. Given [equation] C/[equation] in the region z<0, where [equation] , a) find [equation] at the boundary on the z>0 side, for which [equation] . b) Also find the angle between the normal and [equation] on the z>0 side.
Extra-credit
A plane wave with a frequency of [equation] Hz traveling in the +x direction in a lossy medium ([equation] , [equation] , [equation] ) has amplitude of 50 V/m at x=0. Find a) the attenuation coefficient, b) an expression for [equation] that applies for all x with polarization direction of y, c) the wave impedance and d) the [equation] .

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Last Modified: February 25, 2007
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