Question

8.2-4 Usually, the interelement spacing of an array is about one-half wavelength. Spacings much greater than this produce major lobes in undesired directions. To illustrate this point, use the techniques of Fig. 8-6 to sketch the array factor for a two-element array with equal amplitude, in-phase elements in polar form for the following spacings: (a) d31/4 and (b) d- 22. Examples 3-2 and 8-1 and this problem show the effects of spacing on an array of fixed excitation. 2π -Visible region βά d cose Figure 8-6 Construction technique for finding the array factor as a function of polar angle θ.

Answer 1

3147 24 120 60 150 30 20 180 210 330 300 240 270

Thus, it can be clearly seen that increasing the distance increases the side lobes. Another figure (same figure in x-y plane) is provided below:

3/4А. 24 10 20 30 40 50 -60 -70 -80 020406080100 120 140 160 180