Computer Studies 



Some important factors in the development of scanning antenna systems are 

 the inherent limitations on desired performance imposed by the geometry of the 

 configuration, and the ability to implement the amplitude and phase distributions 

 required to give the radiation pattern. Computer methods can be used to determine 

 relatively smooth distributions that can be practically implemented, and although 

 they may be somewhat idealized, they are useful in the design of the power- 

 dividing and phasing networks. 7 



The radiation pattern of the cylindrical array can be written 



^' = 2,2'' 



,G(q> -a n ,6) exp(jqu) (1) 



where l pq is the excitation of the p th element in the q th ring, G(<p - a p ,9) is the 



element pattern with the phase referred to the center of the ring, u = — dsinO, 



A 



d is the spacing between the rings and oc is the angular location of the p ele- 

 ment of any ring. In the present analysis we will consider only current distribu- 

 tions of the form 



Then (1) can be written 

 where 



and 



I pg = / c <a p )/ e <Z,) (2) 



E(<p,e)= E c (q>,e)E e (9) 



E e (q>,6>= V 7(a p )G(<p-a p ,9) 



E c (9) = ^J(Z g )exp(j<?u) 



Q 



E c (<p,6) is just the ring-array pattern due to a current distribution / c (oc p ) and 

 element pattern G(q> - a ,6). E e (9) is the space factor of a linear array with 



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