Phased array antenna with coarse/fine electronic scanning for ultra-low beam granularity

Abstract From the Canadian patent

An antenna and scanning means therefor particularly useful in an aircraft landing system operating in the microwave frequency range. The antenna is of the line phased array type which includes digitally controlled phase shifters for each of the radiating elements of the array. The beam formed by the antenna is steered by incrementing the phase shift applied at each of the array radiating elements by an amount of phase which is dependent in part upon the position of the radiating element in the array. Phase increments sufficient to shift the beam position by one coarse step (0.01°) are supplied to symmetrically located radiating element pairs, pair by pair until all, elements have been …