What You Can Do With MICROWAVES

THERE is no point in making whether or not the radio amateur will work in the new part of the spectrum where wave-lengths are only a few centimeters long, and which has become generally known asthe microwave band. He requires only two things to try only almost anything pertaining to radio, the availability of a few parts and a vista of interesting possibilties. He will surely get the parts once the demands of the armed forces really drop off because the whole electronic industry has expanded to the point to which it can and will supply even rather complicated items at a reasonable cost. The interest is also surely there because of the many things that are possible with these miniaturewaves. The amateur will, for example, find that at microwave frequencies he can have Q’s of 10,000 or more instead of 10 or a 100, and that he can really know where his radiated energy is going instead of just sending it up to the antenna and then wondering.

This matter of control over radiant energy is really the heart of the whole microwave business. Radio waves of any kind are definitely a three-dimensional proposition. At broadcast frequencies a vertical half-wave antenna is a directional device of sort inasmuch as it transmits most of the energy out horizontally, but it does not do a very thorough job and, as everyone knows, the coverage of a given station is affected by all sorts of meteorological conditions, all the way from the night-and-day effect to the conditions of the soil near the transmitting antenna. If the ground is wet or covered with snow the energy striking it is reflected quite differently and the over-all pattern of the transmitting antenna is radically changed. A single conductor a half wavelength long, or even a combination of such