Phased array antenna system with two dimensional scanning

A phased array antenna system with two dimensional scanning includes a two dimensional array A of antenna elements A1,1 to A12,12 arranged in lines; each line is associated with a respective first rank corporate feed network 161 to 1612 having outputs 171,1 to 1712,12 connected to respective antenna elements A1,1 to A12,12 and inputs for variable relative phase input signals. These corporate feed networks each have first and second inputs A1/B1 to A12/B12 connected respectively to outputs 171 CD/1712CD to 171EF/1712EF of different second rank corporate feed networks 16CD and 16EF. The corporate feed networks 161 to 16EF convert input signals of variable relative phase into relatively greater numbers of output signals for a phased array. The system (30) includes a phase varying circuit 40 for varying phase differences between input signals to each second rank corporate feed network 16CD or 16EF and between input signals to different second rank corporate feed networks 16CD and 16EF to provide control of antenna beam direction in two dimensions.