Radio Wave Properties: Electric and Magnetic Dipole Antennae

An HP model 3200B VHF Oscillator and ENI model 5100-L NMR RF Broadband Power Amplifier provide a 300 MHz signal to a half-wave dipole antenna. The voltage variation along the length of the dipole transmitting antenna is made evident by touching one end of a 8-Watt fluorescent lamp. A copper rod of the same length as the transmitting antenna is used to show a similar standing wave in voltage along it. A second receiver antenna with an incandescent bulb wired in the middle shows the polarization and shape of the radiation pattern emitted by the transmitter. Finally, a loop antenna is used to show the polarization of the magnetic component of the electromagnetic wave.

For lots more details on our setup, see https://sciencedemonstrations.fas.harvard.edu/presentations/radio-wave-properties