ABSTRACT
The analogy between light waves and hertzian waves can be demonstrated by using wavelengths between one centimetre and one decimetre. The receiving antenna is displaced on a circle of about 1 m radius, at the centre of which lies the emitting antenna. The two antennae are, to start with, normal to the plane of the circle, the indication of the receiver remains constant in all the positions. An antenna transmitter may supply power, with the help of flexible coaxial cables, to two identical and parallel antennae placed at a distance of the order of 4 to 5 wavelengths; the two antennae will be in phase. Plane monochromatic electromagnetic waves, reflected normally from a plain metallic mirror, interfere with the incident waves and give a system of stationary waves, which are formed of nodal planes parallel to the mirror and separated by anti-nodal planes alternating with the proceeding ones.
