A 10 cm long 10 mm diameter copper wire is used as a Hertzia

A 1.0 cm long, 1.0 mm diameter copper wire is used as a Hertzian dipole radiator at 1.0 GHz. (a) Find R_rad.

Solution

Given data

Length is 1.0 cm= 0.01m

diameter 1mm= 0.001m

Given frequency is 1.0GHz

(Wave length) = c/f where c is light velocity

= 3x10⁸/1x10⁹=0.3 m

Radiation resistance R_rad=80² (d l / )²

= 80² (0.001x0.01/0.3)²

^{= 8.77 (Micro ohms)}