Horizontal multiple-input multiple-output wireless antennas
High gain, multi-pattern multiple-input multiple-output (MIMO) antenna systems are disclosed. These systems provide for multiple-polarization and omnidirectional coverage using multiple radios, which may be tuned to the same frequency. The MIMO antenna systems may include multiple high-gain beams arranged (or capable of being arranged) to provide for omnidirectional coverage. These systems provide for increased data throughput and reduced interference without sacrificing the benefits related to size and manageability of an associated access point.
1. A multiple-input multiple-output (MIMO) antenna system, comprising:
a data encoder configured to encode data into a format appropriate for transmission by a radio;
a plurality of parallel radios coupled to the data encoder, the plurality of parallel radios configured to up-convert the data from the encoders into RF signals; and
a MIMO antenna apparatus coupled to the plurality of parallel radios, the MIMO antenna apparatus forming directional radiation patterns for transmission of the RF signals to a remote receiving node, the MIMO antenna apparatus occupying a horizontal space.
2. The MIMO antenna system of claim 1 , further comprising a series of parasitic elements.
3. The MIMO antenna system of claim 2 , wherein the series of parasitic elements are positioned around the MIMO antenna apparatus.
4. The MIMO antenna system of claim 3 , wherein the MIMO antenna apparatus is positioned centrally on a printed circuit board (PCB).
5. The MIMO antenna system of claim 4 , wherein the PCB is circular.
6. The MIMO antenna system of claim 4 , where in the parasitic elements and MIMO antenna apparatus are each etched on the same PCB.
7. The MIMO antenna system of claim 3 , wherein one or more of the series of parasitic elements are coupled to a switching element, the switching element changing the length of the one or more of the series of parasitic elements thereby making the one or more of the series of parasitic elements transparent to radiation.
8. The MIMO antenna system of claim 3 , wherein one or more of the series of parasitic elements are coupled to a switching element, the switching element changing the length of the one or more of the series of parasitic elements thereby making the one or more of the series of parasitic elements reflective to radiation.
9. The MIMO antenna system of claim 8 , wherein the reflection of radiation by the one or more of the series of parasitic elements increases the gain of directional radiation pattern generated by the MIMO antenna apparatus.
10. A multiple-input multiple-output (MIMO) antenna apparatus, comprising:
a substrate defining a horizontal space within a housing;
a first plurality of antenna elements configured for selective coupling to a first radio and generating a first directional radiation pattern via a radio frequency feed port, the first plurality of antenna elements located on the substrate;
a second plurality of antenna elements configured for selective coupling to a second radio and generating a second directional radiation pattern via the radio frequency feed port, the second plurality of antenna elements located on the substrate;
one or more parasitic antenna elements located on the substrate; and
a coupling network, the coupling network including a control bus configured to receive a control signal for biasing one or more antenna selector elements, the antenna selector elements selectively coupling the first and second plurality of antenna elements to the radio frequency feed port.
11. The MIMO antenna apparatus of claim 10 , wherein the coupling network includes a series of p-type, intrinsic, n-type (PIN) diodes for selectively coupling antenna elements to the radio frequency feed port.
12. The MIMO antenna apparatus of claim 10 , wherein the coupling network includes a series of gallium arsenide field-effect transistors (GaAs FETs) for selectively coupling the antenna elements to the radio frequency feed port.
13. The MIMO antenna apparatus of claim 10 , wherein the coupling network further includes one or more light emitting diodes (LEDs) placed in circuit with an antenna element such that the selection of an associated antenna element illuminates the LED thereby providing a visual indication of antenna element selection.
14. The MIMO antenna apparatus of claim 10 , wherein the directional radiation pattern of the first radio and the directional radiation pattern of the second radio are in different polarizations.
15. The MIMO antenna apparatus of claim 10 , wherein the directional radiation pattern of the first radio and the directional radiation pattern of the second radio are opposite one another.
16. The MIMO antenna apparatus of claim 10 , wherein the directional radiation pattern of the first radio and the directional radiation pattern of the second radio partially overlap one another.
17. The MIMO antenna apparatus of claim 10 , wherein the directional radiation pattern of the first radio and the directional radiation pattern of the second radio form a substantially omnidirectional radiation pattern.
18. The MIMO antenna apparatus of claim 10 , wherein the one or more parasitic antenna elements operate as a reflector.
19. The MIMO antenna apparatus of claim 10 , wherein the one or more parasitic antenna elements operate as a director.
20. The MIMO antenna apparatus of claim 10 , wherein the one or more parasitic elements are selectively coupled to one another via a switching network, the switching network configured to receive a control signal for coupling one or more of the parasitic elements to one another thereby changing the length of the one or more parasitic elements and influencing the directional radiation pattern emitted by the first radio or the second radio.