High frequency steerable beam antenna system

A high frequency antenna system whose characteristics are those desirable for long path ionospheric propagation in the high frequency range and whose beam is steerable in the azimuth plane is described. High gain at low angles of radiation with patterns containing a minimum of secondary lobes are features of this antenna. The steerable system discussed here is of the Wullenweber type, but of interest is the nature by which two separate and independent arrays are combined in one supporting structure. The lower frequency array is vertically polarized, while that of the higher frequency array is horizontal. On the basis of vswr remaining under 2:1, each array maintains a satisfactory input impedance over a bandwidth of 2:1.