Smart antenna systems for reception of digital television signals
A reconfigurable antenna is disclosed that includes a ground plane, an electrically-conductive microstrip patch element, and a plurality of switches. The patch element is spaced-apart from the ground plane with a dielectric medium between the patch element and the ground plane. The switches are coupled between the ground plane and the patch element. The switches are openable and closable, for example, in response to a control signal from an external television device to configure the state of the reconfigurable antenna. Additional reconfigurable antenna elements are disclosed. Antenna arrays including reconfigurable antenna elements, switchable fixed elements, or a combination thereof are also disclosed.
1. A reconfigurable antenna array for reception of digital television signals, the antenna array comprising:
a first ground plane;
a first electrically-conductive microstrip patch element spaced apart from the first ground plane with a first dielectric medium between the patch element and the first ground plane;
a first plurality of switches coupled between the first ground plane and the first patch element, the plurality of switches operable to open and close; and
a second ground plane;
a second electrically-conductive microstrip patch element spaced apart from the second ground plane with a second dielectric medium between the second patch element and the second ground plane;
a second plurality of switches coupled between the second ground plane and the second patch element, the second plurality of switches operable to open and close;
whereby the switches are openable and closable in response to a control signal from an external device to configure the state of the reconfigurable antenna; and
wherein the reconfigurable antenna array is configured to be in compliance with the CEA-909A single wire control interface standard and/or to fit in a form factor smaller than 20 inches×10 inches×12 inches (or equivalently 50.8 centimeters×25.4 centimeters×30.5 centimeters).
2. The reconfigurable antenna array of claim 1 further comprising a controller operable for opening and closing the plurality of switches in response to the control signal from the external device that is received by the controller.
3. The reconfigurable antenna array of claim 2 wherein:
the controller is operable to selectively change the resonant frequency and/or the polarization state in response to the control signal; and/or
the controller is operable for selectively coupling the first patch element and/or the second patch element to the external device in response to the control signal; and/or
the external device is one of a television, a receiver, and a converter.
4. The reconfigurable antenna array of claim 1 wherein:
the reconfigurable antenna is configured for receiving ultra high frequency (UHF) signals; and/or
at least one the first and second patch elements have a generally circular shape; and/or
at least one of the first and second dielectric mediums is air; and/or
at least one of the first and second patch elements is spaced-apart from the corresponding first and second ground planes a distance of about 25 millimeters.
5. The reconfigurable antenna array of claim 1 wherein the first and second patch elements comprise low-profile dual-polarized tunable microstrip disc elements.
6. The reconfigurable antenna array of claim 1 wherein the switches are each coupled to a corresponding point on the first or second patch element, for shorting the corresponding point to the first or second ground plane when said switch is closed.
7. The antenna array of claim 1 wherein the first and second patch elements are configured to radiate in different directions.
8. An antenna for receiving television signals, the antenna comprising:
a plurality of antenna elements, each having a primary radiation direction, the plurality of antenna elements oriented such that the primary radiation direction of at least a first antenna element of the plurality of antenna elements is a first direction and the primary radiation direction of at least a second antenna element of the plurality of antenna elements is a second direction; and
a controller operable for configuring a state of the antenna in response to a control signal from an external television device;
wherein at least one of the antenna elements comprises a cavity backed slot antenna element that comprises an electrically-conductive cavity having a bottom surface and an upper surface defining an opening, an antenna element spaced above the bottom surface of the cavity such that a slot is defined generally between the antenna element and the portion of the upper surface defining the opening, whereby the cavity backed slot antenna radiates primarily toward the opening of the electrically-conductive cavity and is reconfigurable by loading the slot and/or the electrically-conductive cavity.
9. The antenna of claim 8 wherein the state of the antenna includes an antenna radiation direction and the controller is configured to configure the antenna radiation direction by selectively coupling one of the first antenna element and the second antenna element to the external television device.
10. The antenna of claim 8 wherein the state of the antenna includes a desired radiation direction and the controller is configured to control the phase relationship between the plurality of antenna elements to achieve a higher gain in the desired radiation direction.
11. The antenna of claim 8 wherein each of the antenna elements comprises a dual-polarized tunable microstrip disc element spaced apart from a ground plane with a dielectric medium between and coupled to the ground plane by a plurality of openable/closable switches.
12. The antenna of claim 11 wherein:
the controller is operable to configure a state of any the dual-polarized tunable microstrip disc elements in response to the control signal; and/or
the controller is operable to selectively change the resonant frequency, polarization state, and/or radiation direction of any of the dual-polarized tunable microstrip disc elements in response to the control signal.
13. The antenna of claim 8 wherein:
the slot is generally circular; and/or
the cavity backed slot antenna element is fed by a T-bar feed; and/or
the cavity backed slot antenna element is configured for receiving ultra-high frequency (UHF) signals.
14. A reconfigurable cavity backed slot antenna suitable for receiving ultra-high frequency (UHF) signals, the antenna comprising:
an electrically-conductive cavity having a bottom surface and an upper surface defining an opening;
an antenna element spaced above the bottom surface of the cavity such that a generally circular slot is defined generally between the antenna element and the portion of the upper surface defining the opening;
whereby the cavity backed slot antenna radiates primarily toward the opening of the electrically-conductive cavity and is reconfigurable by loading the slot and/or the electrically-conductive cavity.
15. The antenna of claim 14 wherein the cavity backed slot antenna element is fed by a T-bar feed.