The Bistatic Scattered Field from a Finite Array

8 THE BISTATIC SCATTERED FIELD FROM A FINITE ARRAY 

In the previous section we gave a physical explanation of how various current components on finite arrays came about. Furthermore, we used the SPLAT program in conjunction with a Fourier analysis to determine the actual element currents on a finite array. We decomposed these according to their phase velocities and found one strong component at Tcx = = 0.707 for 45° angle of 

Furthermore, it is often convenient to introduce the concept of residual currents, defined as the difference between the actual currents on the finite array and the Floquet currents. In other words, the residual currents are simply here defined as the sum of the two surface waves and the end currents. 

These current components will radiate. Their radiation patterns are obtained simply by considering the entire periodic structure as an antenna (the notion that surface waves do not radiate is true only if they are associated with an infinite structure. This is usually the case as presented in most textbooks). 

based on the current components obtained rigorously in the previous section, we shall nextpresent the radiation pattern associated with these components. 

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