Wireless charger having E-field shield

Patent metadata

Field	Value
Publication number	US-9520740-B2
Application number	US-201514845254-A
Country	US
Kind code	B2
Filing date	Sep 3, 2015
Priority date	Sep 13, 2012
Publication date	Dec 13, 2016
Grant date	Dec 13, 2016

Abstract

A shielding arrangement for preventing AM radio interference when a wireless charger is used in a vehicle has a plurality of parallel conductors arranged at a distance from one another responsive to a frequency desired to be attenuated. An interconnection arrangement includes a solid conductive junction and connects the conductors to one another without forming loops, and to ground. The conductors are traces disposed on a PCB. Additional parallel conducts are disposed on the other side of the PCB at an orthogonal orientation with respect to the first conductors. The spacing between the conductors is determined in response to the frequency desired to be attenuated, as well as frequencies thereabove that are desired to be propagated therethrough, such as mobile telephone signals. The solid conductive junction that is disposed on the printed circuit board is electrically and thermally conductive, such as copper.

First claim

The invention claimed is:

1. A wireless charging arrangement for charging a handheld device, the wireless charging arrangement comprising:
a primary charging coil having an electrical input for receiving input electrical pulses, the input electrical pulses causing the primary charging coil to radiate a time-varying magnetic field and a time-varying electric field, responsive to the input electrical pulses; and
an E-field shield that attenuates the time-varying electric field, the E-field shield interposed between the primary charging coil and the handheld device, and including:
a first plurality of substantially parallel conductors disposed on a first side of a printed circuit board;
a second plurality of substantially parallel conductors disposed on a second side of the printed circuit board in a substantially orthogonal angular orientation relative to the first parallel conductors, the second side of the printed circuit board being coplanar with and opposite the first side of the printed circuit board.

2. The wireless charging arrangement of claim 1 , wherein the time-varying electric field contains frequency components in the AM radio transmission band, and said E-field shield is configured to attenuate a component of the time-varying electric field that would create interference with electromagnetic signals in the AM radio transmission band.

3. The wireless charging arrangement of claim 2 , wherein said E-field shield is configured to prevent the creation of eddy currents in the time-varying magnetic field.

4. The wireless charging arrangement of claim 2 , wherein said E-field shield is configured to permit propagation therethrough of electromagnetic signals having frequencies above those of the AM radio transmission band.

5. The wireless charging arrangement of claim 4 , wherein said E-field shield is arranged to surround around the wireless charging arrangement.

6. The wireless charging arrangement of claim 3 , wherein said E-field shield is interposed between said primary charging coil and the handheld device.

Assignees

• Visteon Global Tech Inc
• Powermat Tech Ltd

Inventors

• Chiles Karen Lee
• Balint Iii John Robert
• Grady Kevin
• Greenwald Oola
• O'Brien Gary

Classifications

• H01F38/14

  Inductive couplings {(for wireless supply or distribution of electric power using inductive coupling H02J50/10)} · CPC title

• H02J50/10

  using inductive coupling · CPC title

• H02J7/04

  Regulation of charging current or voltage · CPC title

• H02J7/65

  against overtemperature · CPC title

• H05K9/00

  Screening of apparatus or components against electric or magnetic fields (devices for absorbing radiation from an antenna H01Q17/00) · CPC title