Patent ID: 6831601
Filing Date: 2004-12-14
Classification: G01S,H01Q

Abstract:
An array antenna, with scannable beam sum and difference excitation, comprising:a circular array of radiating elements arranged to provide a beam pattern outward from the array circumference upon excitation of a sub array consisting of a fixed even number of contiguous radiating elements of said array; a first power divider having a first port and a number of divided power ports equal to one-half of said fixed even number; a second power divider having a first port and a number of divided power ports equal to one-half of said fixed even number; a circuit device, coupled to said first ports and arranged to provide at a sum port a signal representative of a sum of signals from said power dividers and at a difference port a signal representative of a difference between signals from said first power divider and signals from said second power divider; switching devices coupled between the radiating elements and said divided power ports of the first and second power dividers and arranged to provide said beam pattern by coupling the first and second power dividers to respective left and right subsets of a first said sub array of the radiating elements; and a control facility arranged to control said switching devices to scan said beam pattern by coupling said power dividers to a successive said sub array modified from said first sub array by initiating coupling to a radiating element contiguous in a forward beam scan direction and terminating coupling to the trailing radiating element of said first sub array, with the first and second power dividers coupled to respective left and right subsets of said successive sub array.