Full and partial crosswalls between unit cells of endfire slotline arrays

Endfire slotline antenna arrays, also known as Vivaldi notch arrays, may be used to build broad-band phased arrays with wide scanning capabilities. However, scan blindnesses may render the phased array unusable over portions of its intended operating frequency range and scan volume. One such scan blindness occurs in the E-plane of single polarized arrays and can be predicted by a simple formula. By inserting full and partial crosswalls between unit cells of the array, this blindness can be moved to higher frequencies, moved toward endfire, or totally eliminated. Arrays with upper crosswalls exhibit another type of scan blindness. This scan blindness can he utilized to reduce far-out sidelobes of a limited-scan array.