Methods for slot antenna design for wearable electronic devices and conductive housings

Patent metadata

Field	Value
Publication number	US-10637129-B2
Application number	US-201916254395-A
Country	US
Kind code	B2
Filing date	Jan 22, 2019
Priority date	Dec 14, 2016
Publication date	Apr 28, 2020
Grant date	Apr 28, 2020

Abstract

A wearable computing device can include a monopole-excited slot antenna formed by a gap between a housing (such as a highly conductive housing) and a bracket (such as a highly conductive bracket) within the highly conductive housing and by a back cavity between the highly conductive bracket and the PCB. The antenna configuration can include a monopole antenna electrically coupled to a printed circuit board and a slot antenna that is excited through coupled electromagnetic fields. The highly conductive bracket is positioned near a display window of the device, mostly below and partially enclosing a battery. The highly conductive bracket is positioned above the printed circuit board. This configuration allows for a relatively small dead band in the display window, a larger battery, compact and mechanically simple configuration, and superior water resistance.

First claim

What is claimed is:

1. A computing device, comprising:
a conductive housing having one or more interior surfaces, the device further comprising, within the conductive housing, internal components, the internal components including:
a power source;
a conductive bracket having one or more edges or surfaces,
the one or more edges or surfaces of the conductive bracket and the one or more interior surfaces of the conductive housing forming a gap there between; at least one of: a monopole antenna an antenna matching circuit, a display, a display module, a touch module, or a printed circuit board (PCB) having one or more edges wherein the one or more interior surfaces of the conductive housing forming a and an edge of at least one of the internal components form a first gap therebetween, at least a portion of the gap forming a slot antenna, the PCB coupled to the monopole antenna through the antenna matching circuit and configured to drive a monopole radiator, of the monopole antenna; and
a first arrangement configured to induce the slot antenna to transmit or receive radio frequency signals, further wherein the PCB and the conductive bracket form a back cavity therein, the back cavity comprising a dielectric gap and facilitating resonance of the slot antenna; and a display within the conductive housing, wherein a dead band of the display overlaps with a dead band of the monopole antenna; wherein the power source, the conductive bracket, the monopole antenna, the antenna matching circuit, and the PCB are within the conductive housing.

2. The device of claim 1 , wherein:
the first arrangement includes the monopole antenna, the PCB and the antenna matching circuit;
the PCB is coupled to the monopole antenna through the antenna matching circuit and is configured to drive a monopole radiator of the monopole antenna; and
the monopole radiator is configured to generate electromagnetic fields that induce the slot antenna to transmit or receive the radio frequency signals.

3. The device of claim 2 , wherein the internal components include the display and the monopole antenna is disposed proximate to a dead band of the display.

4. The device of claim 3 , wherein the dead band of the display is a non-active area of a window of the display or a portion of the display that does not display information.

5. The device of claim 4 , wherein the monopole antenna includes a monopole radiator on a plastic carrier proximate to the dead band of the display area.

6. The device of claim 5 , wherein the monopole antenna is configured as a flex film antenna radiator assembled on the plastic carrier.

7. The device of claim 3 , wherein the slot antenna is located below the display and radiates through the display.

8. The device of claim 2 , wherein the monopole radiator is connected through an antenna clip on a printed circuit board (PCB) to a radio frequency (RF) engine.

9. The device of claim 2 , wherein the one or more edges or surfaces of the conductive bracket and the one or more interior surfaces of the conductive housing form the first gap.

10. The device of claim 2 , wherein the PCB and the conductive bracket form a back cavity therebetween, the back cavity comprising a dielectric gap and being configured to facilitate resonance of the slot antenna.

11. The device of claim 2 , wherein the slot antenna is not directly excited by an antenna feed physically coupled to the PCB.

12. The device of claim 2 , wherein the monopole radiator and slot antenna are capacitively coupled such that the monopole radiator generates a varying electric field that induces varying electric fields at the slot antenna.

13. The device of claim 2 , wherein the monopole radiator is positioned proximate to the first gap and is configured to excite the slot antenna through electromagnetic field coupling.

14. The device of claim 2 , wherein the slot antenna is configured to provide one or both of BLUETOOTH™ functionality and BLUETOOTH Low Energy™ functionality.

15. The device of claim 2 , wherein one or both of the monopole antenna and the slot antenna are configured to be compatible with two or more wireless networks and radio technologies, selected from: wireless wide area network (WWAN), wireless local area network (WLAN), Long Term Evolution (LTE) frequency bands, GPS (Global Positioning System) or GNSS (Global Navigation Satellite System) frequency bands, an 802.11 wireless standard, and ZigBee™.

16. The device of claim 2 , wherein the slot antenna is configures as a half-wavelength antenna.

17. The device of claim 2 , wherein the PCB includes a ground plane area that forms a ground plane for the monopole antenna.

18. The device of claim 1 , wherein:
the first arrangement includes the PCB including the antenna matching circuit, and a direct feed configured to couple the matching circuit to one or both of the conductive bracket and the conductive housing; and
the direct feed is configured to induce the slot antenna to transmit or receive radio frequency signals.

19. The device of claim 18 , further comprising a power source, wherein a top surface of the power source is adjacent to a bottom surface of the conductive bracket.

20. The device of claim 18 , wherein the PCB and the conductive bracket form a back cavity therebetween, the back cavity comprising a dielectric gap configured to facilitate resonance of the slot antenna.

21. A device, comprising:
a conductive housing having one or more interior surfaces, the device further comprising, within the conductive housing, internal components, the internal components including:
a conductive bracket having one or more edges or surfaces, the one or more edges or surfaces of the conductive bracket and the one or more interior surfaces of the conductive housing forming a first gap therebetween, at least a portion of the first gap forming a slot antenna;
a monopole antenna; an antenna matching circuit;
a display within the conductive housing; and
a printed circuit board (PCB), the PCB coupled to the monopole antenna through the antenna matching circuit and configured to drive a monopole radiator of the monopole antenna, wherein:
the monopole radiator is configured to generate electromagnetic fields that induce the slot antenna to transmit or receive radio frequency signals.

22. The device of claim 21 , wherein the internal components include the display and the monopole antenna is disposed proximate to a dead band of the display.

23. The device of claim 21 , wherein:
the PCB and the conductive bracket form a back cavity therebetween, the back cavity comprising a dielectric gap and being configured to facilitate resonance of the slot antenna.

24. The device of claim 21 , wherein the slot antenna is not directly excited by an antenna feed physically coupled to the PCB.

25. The device of claim 21 , wherein the PCB includes a ground plane area that forms a ground plane for the monopole antenna.

26. A device, comprising:
a conductive housing having one or more interior surfaces; the device further comprising, within the conductive housing, internal components, the internal components including:
at least one of: a display module, a touch module, or a printed circuit board (PCB), wherein the one or more interior surfaces of the conductive housing and an edge of at least one of the internal components form a first gap therebetween, at least a portion of the first gap forming a slot antenna; and
a

Assignees

• Fitbit Inc

Inventors

• Wei Yonghua
• Li Kevin
• Markan Patrick James
• Wang Allen Yu-Li
• Kaiponen Teemu Taneli Raafael
• Ioannou Christos Kinezos

Classifications

• H01Q1/38

  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 title

• H01Q1/273 Primary

  Adaptation for carrying or wearing by persons or animals · CPC title

• H01Q1/48

  Earthing means; Earth screens; Counterpoises · CPC title

• H01Q1/243

  with built-in antennas · CPC title

• H01Q1/27

  Adaptation for use in or on movable bodies (H01Q1/08, H01Q1/12, H01Q1/18 take precedence) · CPC title