A MINIATURE AUTOMATIC DIRECTION FINDER
HARRY DIAMOND LABS ADELPHI MD
Pagination or Media Count:
A miniaturized unambiguous direction finder with no moving parts is described. At a frequency of 1000 mc, a complete system, consisting of a two- wire spiral antenna, with cavity backing, operating in the first two radiation modes can be built into a cylinder 10 in. in diameter and 3 in. deep. Direct scaling laws apply, so that at 2000 mc, for example, the cylinder would be 5 in. in diameter and 1 12 in. deep. Since there are no moving parts, and printed- circuit techniques can be used, the total weight excluding power supply and readout or display will be less than 12 lb. The pattern of this antenna array gives hemispheric coverage. The output, fed into an analog device, gives a determination of the elevation and azimuth of a received signal, with no ambiguities, in the hemisphere bounded by the plane of the spiral. The processing network consists of two 3-way power dividers and a pair of hybrids, which can be mounted on the back of the cavity by using strip-line techniques. An experimental version of the system has been built and preliminary data are presented.
- Direction Finding