Controlling the beam scanning limits of a microstrip leaky-wave antenna

An electronically controlled half-width microstrip leaky-wave antenna (HW-MLWA) that can scan the main beam at a fixed frequency is presented. A technique is described to change the upper and lower limits of the beam direction without changing the scanning range itself. By varying the reactance profile at the free edge, the main beam of the proposed antenna can scan a range of 23° in discrete steps. There are 30 stubs positioned at the free edge of the antenna that gives the freedom to the designer to change the upper and lower scanning limits of the antenna without changing the scanning range itself.