Multimode phased array element for wide scan angle impedance matching

A method of achieving a matched radiating element in both a phased linear array and a phased two-dimensional array over wide ranges of scan angle has been developed. This method uses two or more propagating modes in each array element such that the reflections of these modes from the array aperture produce a cancellation effect at the element driving terminal. An experimental 32-element linear array was constructed to verify this technique. The measured input VSWR for this experimental array was 1.17 or less over a scan range of ±54 degrees. This result agreed very well with the predicted value. The same method has been shown to be equally effective in achieving matched radiating elements for a two-dimensional array.