HYBRID RADIO FREQUENCY / INDUCTIVE LOOP CHARGER

• US 20160036118A1
• Filed: 10/12/2015
• Published: 02/04/2016
• Est. Priority Date: 01/15/2013
• Status: Active Grant

• Current Assignee: Fitbit, Inc. (Alphabet Inc.)
• Original Assignee: Fitbit, Inc. (Alphabet Inc.)
• Inventors: Baringer, William B., Martinez, Mark Manuel
• Granted Patent: US 9,543,636 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61B 5/0002 Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network A61B5/07 takes precedence; transmission systems for measured values G08C; transmission H04B; transmission of digital information H04L; wireless communication networks H04W
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/02427 Details of sensor
• CPC Class Codes: A61B 5/02433 for infrared radiation
• CPC Class Codes: A61B 5/02438 with portable devices, e.g. worn by the patient
• CPC Class Codes: A61B 5/1123 Discriminating type of movement, e.g. walking or running A61B5/1116, A61B5/112 take precedence
• CPC Class Codes: A61B 5/4812 Detecting sleep stages or cycles
• CPC Class Codes: H01Q 1/22 by structural association with other equipment or articles
• CPC Class Codes: H01Q 1/2291 used in bluetooth or WI-FI devices of Wireless Local Area Networks [WLAN] H01Q1/241 takes precedence; WLAN in general H04W
• CPC Class Codes: H01Q 1/273 Adaptation for carrying or wearing by persons or animals
• CPC Class Codes: H01Q 1/38 formed by a conductive layer on an insulating support patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142
• CPC Class Codes: H01Q 1/48 Earthing means; Earth screens; Counterpoises
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• 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 9/0421 with a shorting wall or a shorting pin at one end of the element H01Q9/0414 takes precedence
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 7/345 using capacitors as storage or buffering devices
• CPC Class Codes: H04B 5/26 using coils
• CPC Class Codes: H04L 67/12 specially adapted for proprietary or special-purpose networking environments, e.g. medical networks, sensor networks, networks in vehicles or remote metering networks
• CPC Class Codes: H04W 4/027 using movement velocity, acceleration information
• CPC Class Codes: H04W 4/80 : Services using short range communication, e.g. near-field communication [NFC], radio-frequency identification [RFID] or low energy communication
• CPC Class Codes: Y10T 29/49016 : Antenna or wave energy "plumbing" making

Abstract

Biometric monitoring devices, including various technologies that may be implemented in such devices, are discussed herein. Additionally, techniques, systems, and apparatuses are discussed herein for providing a hybrid antenna including an RF radiator and an electrically coupled inductive loop. The hybrid antenna is capable of providing both RF and induction functionality, e.g., radio frequency transmission/reception capabilities for Bluetooth as well as near-field-communications (NFC) functionality via the inductive loop. The inductive loop may be in conductive contact with the RF radiator or may be inductively coupled with the RF radiator and not in conductive contact with the RF radiator. The inductive loop may act as a planar element of a planar inverted-F antenna (PIFA).

Claims

1. An apparatus comprising:

a ground plane;

a radio-frequency radiator;

a feed post conductively connected to the radio-frequency radiator; and

an inductive charging system including a multi-turn inductive charging loop configured to couple electrically with the radio-frequency radiator, the multi-turn inductive charging loop either in conductive contact with the radio-frequency radiator or not in conductive contact with the radio-frequency radiator, wherein the multi-turn inductive charging loop is configured to inductively couple with an electromagnetic field to provide power to the inductive charging system, and wherein the multi-turn inductive charging loop, the radio-frequency radiator, the ground plane, and the feed post together form an antenna configured to produce and receive electromagnetic radio-frequency signals.

2. The apparatus of claim 1, wherein the radio-frequency radiator is offset from the ground plane by at least a first distance.

3. The apparatus of claim 1, wherein the multi-turn inductive charging loop is offset from the ground plane in a direction normal to the ground plane.

4. The apparatus of claim 1, wherein the multi-turn inductive charging loop, the radio-frequency radiator, the ground plane, and the feed post together form a planar inverted-F antenna (PIFA).

5. The apparatus of claim 1, wherein the radio-frequency radiator at least partially overlaps the turns in the multi-turn inductive charging loop.

6. The apparatus of claim 5, wherein the turns in the multi-turn inductive charging loop that the radio-frequency radiator at least partially overlaps are the outermost turns of the multi-turn inductive charging loop.

7. The apparatus of claim 5, wherein the radio-frequency radiator follows a path that is substantially aligned with paths followed by the turns of the multi-turn inductive charging loop with which the radio-frequency radiator at least partially overlaps.

8. The apparatus of claim 1, wherein the turns in the multi-turn inductive charging loop follow a path that defines a major surface that faces towards the radio-frequency radiator.

9. The apparatus of claim 1, wherein the turns of the multi-turn inductive charging loop at least partially overlaps the ground plane.

10. The apparatus of claim 1, wherein the radio-frequency radiator at least partially overlaps between about 1% and about 20% of the turns in the multi-turn inductive charging loop.

11. The apparatus of claim 1, wherein the multi-turn inductive charging loop is separated from the radio-frequency radiator by a first gap and the multi-turn inductive charging loop is electrically coupled with the radio-frequency radiator and not in conductive contact with the radio-frequency radiator.

12. The apparatus of claim 11, further comprising:

a first housing portion of a wearable device; and

a second housing portion of the wearable device and mated to the first housing portion, wherein the radio-frequency radiator is supported in a recess between the first housing portion and the second housing portion.

13. The apparatus of claim 12, wherein the first housing portion and the second housing portion are mated such that the inductive charging system and the radio-frequency radiator are separated by the first gap.

14. The apparatus of claim 11, further comprising:

a housing having a first surface and a second surface, wherein the first surface and the second surface are nominally on opposing sides of a portion of the housing and define the first gap, the radio-frequency radiator is formed by a metallization layer deposited on the first surface, the inductive charging system is located on or adjacent to the second surface such that the second surface is interposed between the first surface and the inductive charging system.

15. The apparatus of claim 11, wherein the ground plane is provided by a structure located on an opposite side of the first housing portion from the radio-frequency radiator, wherein the structure is selected from the group consisting of:

a printed circuit board, a flexible circuit board, a metal plate contained within the apparatus, and a metal plate at least partially providing an exterior surface of the apparatus.

16. The apparatus of claim 11, wherein the radio-frequency radiator has a nominal width of between about 0.5 mm and 1.5 mm and an average length of between about 10 mm and 25 mm, and the multi-turn inductive charging loop has an average path length of about 500 mm to 600 mm.

17. The apparatus of claim 11, wherein the radio-frequency radiator is substantially the shape of a rectangle having a length-to-width aspect ratio of at least 10:

1.

18. The apparatus of claim 11, wherein the radio-frequency radiator is L-shaped, U-shaped, or C-shaped.

19. The apparatus of claim 1, wherein the inductive charging system includes a rechargeable battery, a capacitor, or a capattery.

20. The apparatus of claim 1, wherein the first distance is between about 0.5 mm and 10 mm.

21. The apparatus of claim 1, wherein the ground plane is a non-planar surface.

22. The apparatus of claim 1, wherein the radio-frequency radiator and the multi-turn inductive charging loop are in electrically conductive contact with one another.

23. The apparatus of claim 1, wherein the radio-frequency radiator and the multi-turn inductive charging loop are formed from the same electrically conductive trace.

24. The apparatus of claim 1, further comprising:

a shorting post conductively connecting the radio-frequency radiator to the ground plane, wherein the multi-turn inductive charging loop, the radio-frequency radiator, the ground plane, the shorting post, and the feed post together form a planar inverted-F antenna (PIFA) configured to produce and receive electromagnetic radio-frequency signals in a Bluetooth-compatible frequency band, wherein the multi-turn inductive charging loop serves as a radiator extension to the radio-frequency radiator when producing and receiving electromagnetic radio-frequency signals in the Bluetooth-compatible frequency band.

25. The apparatus of claim 1, further comprising:

a shorting post conductively connecting the radio-frequency radiator to the ground plane, wherein the multi-turn inductive charging loop, the radio-frequency radiator, the ground plane, the shorting post, and the feed post together form a planar inverted-F antenna (PIFA) configured to produce and receive electromagnetic radio-frequency signals in a GPS-compatible frequency band, wherein the multi-turn inductive charging loop serves as a radiator extension to the radio-frequency radiator when producing and receiving the electromagnetic radio-frequency signals in the GPS-compatible frequency band.

26. The apparatus of claim 1, wherein the radio-frequency radiator, the ground plane, and the multi-turn inductive charging loop are located on a common, non-recurvate reference surface.

27. The apparatus of claim 26, wherein the radio-frequency radiator, the ground plane, and the multi-turn inductive charging loop are formed from a common conductive trace.

28. A method comprising:

a) providing a radio-frequency radiator;

b) mounting the radio-frequency radiator to a first surface of a first housing component;

c) providing an inductive charging system, wherein the inductive charging system includes a multi-turn inductive charging loop; and

d) placing the multi-turn inductive charging loop such that the multi-turn inductive charging loop is configured to couple electrically with the radio-frequency radiator, the radio-frequency radiator at least partially overlapping the turns in the multi-turn inductive charging loop, the multi-turn inductive charging loop configured to inductively couple with an electromagnetic field to provide power to the inductive charging system.

29. The method of claim 28, wherein the turns in the multi-turn inductive charging loop follows a path that defines a major surface that faces towards the radio-frequency radiator.

30. The method of claim 28, wherein the inductive charging system includes a rechargeable battery, a capacitor, or a capattery.