RADIATION CHARACTERISTICS OF AN ANTENNA. 235 



If now we recall that G = A -{- B, it will be seen that the equation 

 (104) is entirely in terms of A and B and /. 



For purpose of computation it is found advisable to expand all of 

 the trigonometrical expressions in power series and then perform 

 with them the indicated operations. This was done with considerable 

 labor and g•a^•e the following expression for mutual power: 



P = 



2/2 



A- ] .0166 B' - .00404 B^ + .000390 B^ - 



.0000144 5i«H i 



+ ^3 I .0083 B^ - .00480 B'' + .000729 B' - 



. 0000486 5^ + - • 

 + ^4 I - .00433 B* + .00104 B^ - .000102 B^ + 



.0000051 510 



+ ^» ■ - .00127 B' + .000741 B'' - .000106 B' + 



. 0000073 B^ ' 



+ A^ I .000404 B* - .000101 B^ + .0000101 B^ - 



+ 



.0000005 51" + 



(105) 



This equation gives the time average of the power radiated in the aerial 

 hemisphere by the mutual effect of the fields from both parts of the antenna 

 and is the correction to be added to the power radiated by the two parts, 

 estimated as independent of one another. The current I is in absolute 

 c.g.s. electrostatic units, and the power is in ergs per second. 



18. Summation of Flat-top Power and Mutual Power.— 



We have obtained in equation (81) the time aAerage of flat-top radi- 

 ated power, and in equation (105) the time average of mutual radiated 



