Imaging Reflector Arrangements to Form a Scanning Beam Using a Small Array

Use of a phased array in a satellite of large aperture diameter is proposed in Ref. 1 to form a narrow beam to communicate with ground stations in the United States. A large array in this case is not attractive, because of its weight and the loss and complexity of the long interconnections required by the large spacing between the array elements. Thus, we here propose the use of a small array combined with several reflectors as shown in Figs. 1 to 3. The reflectors are arranged so that a magnified image of the array So is formed over the aperture of the main reflector. The magnification M relating the diameters Do and D of the main reflector and the array, respectively, is chosen much greater than unity, i.e., M = (1)