Polarization Dependent Electromagnetic Bandgap Antenna And Related Methods
AssigneeRaytheon Company
InventorsJackson Ng, Charles G. Gilbert
Life of this patent
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Abstract
A rotationally polarized antenna includes a radiating element that is held in a skewed orientation with respect to an underlying polarization-dependent electromagnetic band gap (PDEBG) structure. The radiating element and the PDEBG structure are both housed within a conductive cavity. The radiating element, the PDEBG structure, and the cavity are designed together to achieve an antenna having improved operational characteristics (e.g., an enhanced circular polarization bandwidth, etc.). In some embodiments, the antenna may be implemented as a flush mounted or conformal antenna on an outer surface of a supporting platform.
Claims32
A rotationally polarized antenna comprising:
- a ground plane;
- a polarization dependent electromagnetic hand gap (PDEBG) structure disposed above the ground plane, the PDEBG structure having a number of unit cells arranged in rows and columns;
- a radiating element disposed above the PDEBG structure, the radiating element having a long dimension and a short dimension;
- and
- a conductive cavity encompassing the PDEBG structure and the radiating element, the conductive cavity being open on a radiating side of the antenna;
- wherein the radiating element is oriented at a non-zero angle with respect to the rows and columns of the PDEBG structure.
An antenna assembly for use in forming a rotationally polarized antenna, comprising:
- a polarization dependent electromagnetic band gap (PDEBG) structure having a plurality of unit cells arranged in rows and columns;
- and
- a radiating element disposed above the PDEBG structure, the radiating element having a long dimension and a short dimension, the radiating element being held in a fixed position with respect to the PDEBG structure so that the long dimension of the radiating element forms a non-zero angle with both the rows and columns of the PDEBG structure;
- wherein the antenna assembly is configured for insertion into a conductive cavity having dimensions that are selected to form an antenna having radiation performance that is characteristic of a larger antenna.
A method for designing a rotationally polarized antenna having at least one radiating element disposed above a polarization-dependent electromagnetic band gap (PDEBG) structure within a conductive cavity, the at least one radiating element being oriented at a non-zero angle with respect to the PDEBG structure, the method comprising:
- determining an approximate size of the conductive cavity;
- selecting a dielectric material and a number and arrangement of unit cells to use in the PDEBG structure that will fit within the approximate size of the conductive cavity;
- selecting a radiating element;
- designing a unit cell of the PDEBG structure that will result in a 90 degree phase shift between total horizontal and vertical electric field components of the antenna, wherein designing a unit cell takes into consideration performance effects of the conductive cavity on the operation of the PDEBG structure;
- and
- adjusting a size of at least the conductive cavity to achieve an enhanced bandwidth for the rotationally polarized antenna.
Dependencies are inferred from the claim text.