Hall-effect vector-product generators

Whereas conventional Hall multipliers make no use of the vectorial aspect of the Hall effect, the devices to be discussed here are genuine vector-product generators, able to accept vectorial input signals and to produce an output signal in the direction of, and proportional to, the vector product of the input vectors. In particular, devices will be considered which generate either an output vector of fixed direction from two rotating input vectors or a rotating vector from one rotating and one fixed-direction input vector (the rotations occurring at constant angular frequencies). In the first case an output signal containing either the sum or the difference of the input frequencies is obtained. In the second case separate vectorial output components rotating in the same plane but in different directions can be extracted. Possible applications of such devices to telecommunication problems will be indicated. The validity of the new principle was confirmed with a cube-shaped Hall-element (instead of a conventional thin plate), with low efficiency, and with a cruciform element, with improved efficiency (a thin-plate version, possessing the efficiency of conventional Hall multipliers will also be discussed). The choice of semiconductor material and the construction of the new devices will be treated in some detail.