- -20 



-40 



-60 



-80 



-100 



-120 



Cose 3-0 

 for z/d=O.I 



J I 



tt/4 ir/2 3T7-/4 t/T 5tt/4 3*r/2 7ir/4 2tr 



Figure 6. Case 3-D, f n and f. versus phase angle. 



