Capacitively coupled compound loop antenna

• US 9,431,708 B2
• Filed: 11/05/2012
• Issued: 08/30/2016
• Est. Priority Date: 11/04/2011
• Status: Active Grant

• Current Assignee: DockOn AG
• Original Assignee: DockOn AG
• Inventors: Orsi, Ryan James, Foster, Matthew Robert, Poilasne, Gregory
• Primary Examiner(s): Purvis, Sue A
• Assistant Examiner(s): Munoz, Daniel J
• Application Number:
  US13/669,389
• Publication Number:
  US 20130113666A1
• Time in Patent Office: 1,394 Days
• Field of Search: 343/700.MS, 343/726, 343/745, 343/866, 343/788
• US Class Current: 1/1
• CPC Class Codes: H01Q 21/29 Combinations of different interacting antenna units for giving a desired directional characteristic H01Q25/00 takes precedence
• CPC Class Codes: H01Q 5/35 using two or more simultaneously fed points
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
• CPC Class Codes: H01Q 9/30 with feed to end of elongated active element, e.g. unipole H01Q9/44 takes precedence

Abstract

A compound loop antenna (CPL) is described that includes a capacitively fed magnetic loop and/or a capacitively fed electric field radiator. Embodiments include single-band CPL antennas and multi-band CPL antennas. The CPL antennas have been reduced in physical size by capacitively feeding the loop and/or radiator. The embodiments include at least one e-field radiation element that is capacitively coupled or not capacitively coupled, at least one magnetic loop element that is capacitively coupled. A continuation of the magnetic loop may be continued with either a wire or a connection to a second layer.

Claims

1. A compound loop antenna, comprising:

a magnetic loop located on a first plane and generating a magnetic field, the magnetic loop including a downstream portion and an upstream portion, the upstream portion connected to a feed, the downstream portion separated from the upstream portion by a capacitive gap that capacitively feeds the downstream portion of the magnetic loop and causes at least in part a first electric field orthogonal to the magnetic field to be emitted from the upstream portion;

an electric field radiator located on the first plane, the electric field radiator coupled to the downstream portion of the magnetic loop at approximately a 90 electrical degrees location relative to the feed, a 270 electrical degrees location relative to the feed, or a reflective minimum point where a current flowing through the magnetic loop is at a reflective minimum and configured to emit a second electric field orthogonal to the magnetic field;

a radiator feed coupled to the magnetic loop, wherein at least a first portion of the electric field radiator is separated from the radiator feed by a second capacitive gap that capacitively feeds at least the first portion of the electric field radiator; and

an electrical return trace coupling the electric field radiator to the magnetic loop, wherein the electrical return trace is positioned on a second plane below the first plane.

2. The antenna as recited in claim 1, further comprising an electrical trace coupling at least a second portion of the radiator feed to the magnetic loop, wherein the second capacitive gap is between the first portion of the electric field radiator and the second portion of the electric field radiator.

3. The antenna as recited in claim 1, wherein a first width of a first portion of the magnetic loop is greater than or less than a second width of a second portion of the magnetic loop.

4. The antenna as recited in claim 1, wherein adjusting a position of the capacitive gap along the magnetic loop tunes an impedance of the antenna.

5. The antenna as recited in claim 1, wherein the first electric field and the second electric field are at a same frequency and radiate in phase at the same frequency.

6. The antenna as recited in claim 1, wherein the first electric field and the second electric field are at different frequencies.

7. A multi-band compound loop antenna, comprising:

a magnetic loop located on a first plane and generating a magnetic field, wherein a first portion of the magnetic loop is configured to emit a first electric field orthogonal to the magnetic field at a first frequency band;

a radiator feed located on the first plane and coupled to the magnetic loop, wherein the radiator feed is configured to resonate in phase with the first portion of the magnetic loop at the first frequency band; and

an electric field radiator located on the first plane, the electric field radiator coupled to the magnetic loop via an electrical return trace positioned on a second plane below the first plane, the electric field radiator positioned adjacent to the radiator feed and separated from the radiator feed by a capacitive gap, wherein the electric field radiator is configured to emit a second electric field at a second frequency band and orthogonal to the magnetic field.

8. The antenna as recited in claim 7, wherein the electric field radiator and the radiator feed are positioned inside of the magnetic loop.

9. The antenna as recited in claim 7, wherein the electric field radiator and the radiator feed are positioned outside of the magnetic loop.

10. The antenna as recited in claim 7, wherein the radiator feed couples to the magnetic loop at a connection point, the connection point including an electrical degree location approximately 90 degrees or approximately 270 degrees from a drive point of the magnetic loop, or a reflective minimum point where a current flowing through the magnetic loop is at a reflective minimum.

11. The antenna as recited in claim 7, wherein the electrical return trace couples to the magnetic loop at a connection point, the connection point including an electrical degree location approximately 90 degrees or approximately 270 degrees from a drive point of the magnetic loop, or a reflective minimum point where a current flowing through the magnetic loop is at a reflective minimum.

12. The antenna as recited in claim 7, wherein a first width of the first portion of the magnetic loop is greater than or less than a second width of a second portion of the magnetic loop.

13. The antenna as recited in claim 7, wherein adjusting a position of the capacitive gap tunes an impedance of the antenna.

14. A multi-band antenna, comprising:

a magnetic loop at least partially located on a first plane and generating a magnetic field, the magnetic loop including a downstream portion and an upstream portion, the upstream portion connected to a feed, the downstream portion separated from the upstream portion by a capacitive gap that capacitively feeds the downstream portion of the magnetic loop, the upstream portion configured to emit a first electric field at a first frequency band, wherein the downstream portion is separated into a first part on the first plane and a second part on the first plane and includes a three dimensional wire extending away from the first plane that couples the first part to the second part; and

an electric field radiator located on the first plane, the electric field radiator coupled to the downstream portion of the magnetic loop at approximately a 90 electrical degrees location relative to the feed, a 270 electrical degrees location relative to the feed, or a reflective minimum point where a current flowing through the magnetic loop is at a reflective minimum, wherein the electric field radiator couples with the upstream portion and the downstream portion of the magnetic loop to emit a second electric field orthogonal to the magnetic field at a second frequency band, wherein the electric field radiator is configured to resonate in phase with the upstream portion and the downstream portion of the magnetic loop at the second frequency band.

15. The antenna as recited in claim 14, wherein the electric field radiator is positioned inside of the magnetic loop.

16. The antenna as recited in claim 14, wherein the electric field radiator is coupled to the magnetic loop via an electrical trace at a connection point, the connection point including an electrical degree location approximately 90 degrees or approximately 270 degrees from a drive point of the magnetic loop, or a reflective minimum point where a current flowing through the magnetic loop is at a reflective minimum.

17. The antenna as recited in claim 14, wherein a first width of a first portion the downstream portion of the magnetic loop is greater than or less than a second width of a second portion of the downstream portion of the magnetic loop.

18. The antenna as recited in claim 14, wherein adjusting a position of the capacitive gap tunes an impedance of the antenna.

19. The antenna as recited in claim 14, wherein the first electric field and the second electric field are at a same frequency and radiate in phase at the same frequency.

20. The antenna as recited in claim 14, wherein the first electric field and the second electric field are at different frequencies.

21. A multi-band antenna, comprising a magnetic loop at least partially located on a first plane and generating a magnetic field, the magnetic loop including a downstream portion and an upstream portion, the upstream portion connected to a feed, the downstream portion separated from the upstream portion by a capacitive gap that capacitively feeds the downstream portion of the magnetic loop, the upstream portion configured to emit a first electric field at a first frequency band, wherein the downstream portion is separated into a first part on the first plane, a second part on the first plane and a third part on a second plane that couples the first part to the second part;

and

an electric field radiator located on the first plane, the electric field radiator coupled to the downstream portion of the magnetic loop at approximately a 90 electrical degrees location relative to the feed, a 270 electrical degrees location relative to the feed, or a reflective minimum point where a current flowing through the magnetic loop is at a reflective minimum, wherein the electric field radiator couples with the upstream portion and the downstream portion of the magnetic loop to emit a second electric field orthogonal to the magnetic field at a second frequency band, wherein the electric field radiator is configured to resonate in phase with the upstream portion and the downstream portion of the magnetic loop at the second frequency band.

22. The antenna as recited in claim 21, wherein a width and a length of the third part is used to tune the antenna.

23. The antenna as recited in claim 21, wherein a physical shape of the third part is used to add inductance to a total inductive reactance of the antenna.