Phased array antennas using frequency multiplication for reduced numbers of phase shifters

摘要

The present invention relates to a phased array antenna system which, in the transmission mode, forms a directional planar wavefront (20) including a signal at a first frequency at a first array (18.sub.1 -18. sub.m) which is a sub-multiple of the frequency to be ultimately transmitted. By sending the wavefront through a lens or reflector, an image of the first array is formed on an image plane. A second array (26. sub.1 -26.sub.n) disposed at the image plane intercepts the wavefront and the received signal's frequency and phase is then harmonically multiplied by a predetermined number to permit reradiation of the resultant signal by a third array (32.sub.1 -32.sub.n) in the same direction as the original wavefront. The second and third arrays include corresponding elements and configurations with more elements than the first array. In the receive mode, the sequence is complementary to the transmit mode.