Patent attributes
A sparse phase-mode feed network for an antenna array is described. The waveguide assembly includes a plurality of radiating element probes for coupling to respective radiating elements of the antenna array, and a plurality of phase-mode feed probes. A variable phase shifter is positioned in the waveguide assembly in an annular region between the radiating element probes and the phase-mode feed probes to cause additional progressive electrical phase shifts of the radiating elements of the antenna array from 0 to 2πK radians, the phase shift progressing for one complete physical angular cycle in the plane of the waveguide assembly. A beam forming network couples the phase-mode feed probes to a plurality of phase-mode feed ports corresponding to respective consecutive-order phase modes of the antenna array. When coupled to the antenna array, respective orders of the phase modes provided at the phase-mode feed ports are selectable in accordance with K.
