Pattern control using a reactively loaded loop antenna

A method for obtaining continuous beam steering over ±30° from bore-sight by reactively loading a one-wavelength square wire loop antenna placed over a ground plane is presented. By introducing a small gap at the middle of one of the two non-radiating sides, the far-field radiation pattern of the antenna can be controlled in the plane perpendicular to the radiating sides by varying a single reactive load at the middle of the opposite non-radiating side. The input VSWR for the arrangement is shown to be relatively insensitive to the reactive component variation (from -∞ to +500 Ω). A numerical analysis with experimental verification is given