Microstrip phase scan antenna array

A microstrip phase scan antenna array for planar radar scanning with a substantially pencil-shaped beam comprising

• a microstrip transmission line dielectric substrate having top and bottom surfaces;
• an electrically conductive ground plane mounted on the bottom surface of said substrate;
• a plurality of microstrip antenna radiating elements mounted on the top surface of said substrate in a columnar array of columns and rows of said elements for radiating a substantially pencil-shaped beam in a first plane which is perpendicular to said columns of elements and in a second plane which is perpendicular to said first plane when the elements in each of said columns are serially interconnected and all of said columns are coupled to a source of millimeter wave energy, the sequence of the elements in each of said rows of elements defining the sequence of said columns in said array;
• a plurality of rectangular ferrite rods mounted on the top surface of said substrate, the number of said rods being equal to the number of said columns in said array, each of said rods having
• a first rod side thereof mounted on the top surface of said substrate,
• a dielectric constant which is greater than the dielectric constant of said substrate,
• a dielectric plate mounted thereon having top and bottom surfaces and a dielectric constant which is substantially the same as the dielectric constant of said substrate, said plate extending the length of the rod and having the bottom surface thereof mounted on another side of the rod which is parallel to said first rod side,
• a pair of ramp-shaped dielectric waveguide members mounted on the top surface of said substrate at opposite ends of the rod, each of said ramp-shaped members having a dielectric constant which is substantially the same as the dielectric constant of the rod, a bottom surface abutting the top surface of said substrates and a downwardly-sloping top surface extending between the end of said plate and the top surface of said substrate, and
• a length of electrically conductive microstrip conductor mounted on the top surfaces of said ramp-shaped members and the top surface of said plate and having an input end and an output end;
• means mounted on said substrate for serially interconnecting the elements in each of said columns of elements;
• means mounted on said substrate for supplying the input ends of the microstrip conductor lengths associated with said plurality of rods with millimeter wave energy of equal amplitude and phase and for coupling the output end of each of said conductor lengths to a different one of said columns of elements so that the sequence of columns in said array is coupled to a sequence of said rods;
• and
• means for simultaneously magnetically biasing all of said rods along the longitudinal axes thereof to create magnetic biasing fields in the rods having simultaneous magnitudes which progressively increase from rod to rod in accordance with the sequential position of the rod in said sequence of rods.