Claims:1. An antenna, comprising:
a substrate;
top and bottom grounded conductive layers formed on respective larger faces of the substrate;
at least one conductive wall formed to the top and bottom grounded conductive layers, and configured to form a short-circuit between the top and bottom grounded conductive layers,
wherein the substrate and the at least one conductive wall forms a plurality of antenna cavities configured to operate at specific, respective frequencies, and each of the plurality of antenna cavities comprises at least two edges not covered by a conductive layer; and
an antenna feed coupled to at least one of the top and bottom grounded conductive layers of each of the antenna cavities, and configured to feed radio signals to the respective antenna cavity.
, Description:TECHNICAL FIELD
The present disclosure generally relates to an antenna, and more specifically to an antenna having multiple cavities, an irregular contour and/or an irregular thickness.

BACKGROUND
A problem in antenna design for small-form factor devices, such as smartphones and smart-watches, is that significant antenna re-design effort is often required to deliver Stock Keeping Units (SKUs) to a world-wide market. Typically, this redesign is required to reduce the performance impact by objects that are in close proximity with the antenna. These objects include, for example, connectors, cables, display, speakers, microphones, battery, vibration motor, etc. In addition, antenna engineers need to ensure consistent antenna performance for various applications. If an industrial design with a metallic uni-body is preferred to improve look-and-feel and user experience, it becomes challenging to meet all of the antenna performance specifications, Federal Communications Commission (FCC) compliances, and industrial design preferences. Hence, a consequence is an increased per-unit antenna cost because of the higher material and manufacturing cost resulting from the lower volume of each SKU. Additionally, antenna re-design implies cost in terms of man-hours of specialized engineers, computing resources, and time to market.

BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1A illustrates a top view perspective diagram of a multi-cavity antenna in accordance with an aspect of the disclosure.
Figure 1B illustrates a bottom view perspective diagram of the multi-cavity antenna of Figure 1A.
Figure 2A illustrates a top view perspective diagram of a single-cavity antenna having an irregular contour and thickness in accordance with another aspect of the disclosure.
Figure 2B illustrates a bottom view perspective diagram of the single-cavity antenna of Figure 2A.
Figures 3A, 3B, and 3C illustrate top, bottom and side view perspective diagrams, respectively, of an antenna of any of Figures 1A, 1B, 2A, or 2B located underneath a display of a wireless device.
Figures 4A, 4B, and 4C illustrate top, bottom and side view perspective diagrams, respectively, of an antenna of any of Figures 1A, 1B, 2A, or 2B located underneath a back cover of a wireless device.
Figures 5A and 5B illustrate top and side view perspective diagrams, respectively, of an antenna of Figures 2A and 2B located underneath a display of a wireless device.
Figures 6A and 6B illustrate top and bottom view perspective diagrams, respectively, of an antenna of any of Figures 1A, 1B, 2A, or 2B located underneath as an integral portion of a back cover of a wireless device.
Figure 7A illustrates a top view perspective diagram of a wireless device having an antenna of any of Figures 1A, 1B, 2A, or 2B in an interchangeable card format.
Figure 7B illustrates a side view schematic diagram of a wireless device, antenna card, and antenna socket.
Figure 7C illustrates a side view schematic diagram of the antenna card of Figure 7B.
Figure 7D illustrates a side view schematic diagram of the antenna socket of Figure 7B.

DESCRIPTION OF THE ASPECTS
The present disclosure is directed to an antenna having multiple cavities, an irregular contour and/or an irregular thickness that results in multi-band operation, improved bandwidth, and enhanced efficiency.
Figure 1A illustrates a top view perspective diagram of a multi-cavity antenna 100A in accordance with an aspect of the disclosure. Figure 1B illustrates a bottom view perspective diagram of the multi-cavity antenna of Figure 1A.
The multi-cavity antenna 100A comprises a dielectric substrate 110, top and bottom grounded conductive layers 120T, 120B, conductive walls 130-1, 130-2, and antenna feeds 150-1, 150-2, 150-3.
The substrate 110 may be formed of any dielectric material, such as a low-loss dielectric, air, magnetic material, or any combination of these materials, which provides irregular permittivity. Air may be feasible if the conductive walls 130-1, 130-2 are thick enough to provide stability. Also, the substrate 110 may have an irregular permittivity and/or permeability.
The top and bottom grounded conductive layers 120T, 120B are formed on respective larger faces of the dielectric substrate 110. The top and bottom grounded conductive layers 120T, 120B may comprise copper or any other suitable conductive material. Because the top and bottom conductive layers 120T, 120B are grounded, other elements can be located very close thereto and have minimal effect on resonance.