Radiolocation system for determining the direction of incident electromagnetic waves

Claim 1

In a radiolocation system, in combination: an antenna array adapted to intercept incident electromagnetic waves, said array comprising three loop antennas in mutually orthogonal planes and three dipole antennas extending along the intersections of said planes; a first set of output terminals each connected to an individual dipole antenna of said array; a second set of output terminals each connected to an individual loop antenna of said array; a first and a second receiving channel; first and second switch means for respectively connecting individual outputs of said first set to said first receiving channel and individual outputs of said second set to said second receiving channel; scanning means for jointly operating said first and second switch means to connect said receiving channels to a multiplicity of different combinations of a loop antenna with a dipole antenna during successive phases of a recurrent cycle, thereby feeding a pair of analog output voltages from selected antennas to said channels in each of said phases; multiplication means connected to said receiving channels for forming the product of said pair of output voltages in each phase, said multiplication means comprising a multiplier, a low-pass filter and an integrator in cascade; a memory with a multiplicity of stages respectively assigned to said different combinations; third switch means controlled by said scanning means for sequentially connecting said multiplication means to said stages, thereby loading same with the voltage products obtained in respective phases; and arithmetic means connected to said memory for algebraically combining the voltage products loaded into said stages in each cycle to derive directional data therefrom.