Advanced physics

Consider four short dipoles of length L, carrying triangular currents I=a_zI with a maximum amplitude of I_o. The dipoles are positioned along the z-direction as shown in the figure and with a radiation pattern of F()=sin . If phase shift and spacing between adjacent elements are, respectively =0 and (1) d= /2 and (2) d= 3 /4, in the x-z plane

a. calculates the main beam directions.

b. calculates the null directions.

Z 3B/2 B/2 d X B/2 -3 8/2