24 
Then the directivity function becomes 
_sin( 1 cose’ ') sin(W.722(cosy’ - 1)) 
Tae TOD e ere —..0000 O——— 
A MN, warn cos8’ ) Nz sin(722(cosy’-1)) 
a Ts cosa eae) 
R 
W381 
: ok 
or rearranging, 
2. Continuous Distribution of Elements 
(a) Line Array 
From the general directivity function for a continuous 
distribution of elements, the directivity function for a 
line array (fig. 7) (see Part I, section 2(c)) becomes: 
LjP 
R= ; rca exp ji[ x2(cosa- cosa +p (x) (cosy (x)- 1) ] 
x=-L/2 
When this integral is evaluated, the answer does not 
appear ina closed form. However, if D-~, the integral 
> 
“Reference 6, page 15 
(11) 
