Radiation characteristics of NRD leaky have antenna with tuning aperture

This paper presents a modified configuration of the NRD leaky wave antenna. A tunable aperture is introduced at the radiating open end. The taper in the antenna amplitude distribution is easily achieved by changing the height of the aperture instead of positioning the dielectric slab, which results in the easy design of such anantenna and the reduction of the requirement for the flexibility of the dielectric slab. The numerical results show that when the height of the aperture is appropriately chosen the phase constant is almost independent of the distance between the right-hand dielectric-to-air interface and the open end.