Steerable leaky wave antenna capable of both forward and backward radiation
AssigneeHRL Laboratories, LLC
InventorDaniel F. Sievenpiper
Life of this patent
Estimating the term…
Abstract
Leaky wave antenna beam steering that is capable of steering in a backward direction, as well as further down toward the horizon in the forward direction than was previously possible, and also directly toward zenith. The disclosed antenna and method involve applying a non-uniform impedance function across a tunable impedance surface in order to obtain such leaky wave beam steering.
Claims16
A method for leaky wave beam steering of an antenna in a backward direction relative to a conventional forward direction of propagation of the antenna, the method comprising:
- (a) disposing the antenna on a tunable impedance surface;
- (b) applying a non-uniform impedance function across the tunable impedance surface, which impedance function is periodic or nearly periodic, thereby folding a surface wave band structure in upon itself and creating a band having group velocity and phase velocity in opposite directions in said tunable surface.
An antenna comprising:
- (a) a tunable impedance surface:
- (b) an antenna disposed on said tunable impedance surface, said antenna having a conventional forward direction of propagation when disposed on said tunable impedance surface while said surface has an uniform impedance pattern;
- (c) means for adjusting the impedance of pattern of the tunable impedance surface along the normal direction for propagation so that the impedance pattern assumes a cyclical pattern along the normal pattern of propagation.
A method for beam steering an antenna in a desired radiation angle, the method comprising:
- (a) disposing the antenna on a tunable impedance surface;
- (b) launching a wave across the tunable impedance surface in response energizing the antenna;
- and
- (c) applying a cyclic impedance function across the tunable impedance surface whereby the wave which is launched across the surface in response to energizing the antenna is scattered by said impedance function to said desired radiation angle.
Dependencies are inferred from the claim text.