RADIATION CHARACTERISTICS OF AN ANTENNA, 237 



PART I\'. 



Computations of Radiation Resistance. • 



19. Equation for Radiation Resistance. — If 



a = length of vertical part in meters, 

 b = length of horizontal part in meters, 

 X(i = the natural wavelength of the antenna in meters, 

 X = the wa^•elength in meters of the antenna as loaded with inductance 

 at its base, 



. 27ra 



2x6 



"^' 



ttXo 



we may obtain the radiation resistance of the antenna by dividing the 

 power radiated by the mean square of the current at the base of the 

 antenna. This mean square current at the base of the antenna is by 



(5) 



j.,_ P sin^ (g/2) 

 2 



Performing this division as to the fiat-top power employing equation 

 (106) and adding the result to the radiation resistance for the vertical 

 portion as given in equation (44) we obtain for the total radiation 

 resistance of the antenna the equation 



^fi = sin2 (g/2) ] ^1 - -^2 cos q- Rz sin q + 



r2^2 _|_ rsA^ _ r^A^^ _ r,A^ _^ ^e^® + • • • [ • (107) 



