The Mutual Impedance Z Between a Column Array q and an External Element

3 The Mutual Impedance Z Between a Column Array q and an External Element q  

As indicated above, the mutual impedance between a column array q and a single external element (namely the reference element of another array q ) is simply defined as 

Let us finally consider the more general case where the reference points of the column arrays are given by and (p respectively, as shown 

If we limit ourselves to scan the yz plane, the orthogonal terms x P are either zero or cancel when k varies. We then note that (3.27) and (3.28) are similar as far as variation in the z direction is concerned, which should not surprise us since Floquet s theorem is valid for both cases in this direction. However, their behavior in the xy plane clearly indicates a planar wave in the double infinite case and a cylindrical wave in the collinear case. 

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