Wire Antennas

Abstract

As was briefly mentioned in section 1.7, ‘wire’ antennas are analysed through the radiating properties of r.f. currents on wires. The simplest wire antenna is the dipole, shown in figure 2.1(a). It is usually easier to derive the radiating properties of antennas when transmitting, and then to invoke the reciprocity theorem for receive. For the dipole of figure 2.1, an r.f. voltage is applied to the terminals, and r.f. currents are set up in the dipole arms. These currents radiate into free space, with a characteristic radiation pattern, gain and polarisaion.