Application: Simple dipole antenna. Suppose you need a good antenna in a hurry for a CB (citizen's band) transmitter at 27 MHz. A friend suggests the following: Take a two wire cable, with impedance of 72 Ω. Split the cable for a length of 2.77 m. Bend the two wires so that they are perpendicular to the cable and on a line as shown in Figure 18.43. To support it, the friend suggests tacking it onto a non-conducting wall.
(a) What kind of antenna is this antenna?
(b) If the conductor is 1-mm thick and made of copper (σ = 5.7 x 107 S/m), what is the efficiency of the antenna?
