Invention Grant
- Patent Title: Detection apparatus and method for near field communication devices
- Patent Title (中): 近场通信设备检测装置及方法
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Application No.: US11926734Application Date: 2007-10-29
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Publication No.: US07652578B2Publication Date: 2010-01-26
- Inventor: Mark Braun , Louis Vannatta
- Applicant: Mark Braun , Louis Vannatta
- Applicant Address: US IL Schaumburg
- Assignee: Motorola, Inc.
- Current Assignee: Motorola, Inc.
- Current Assignee Address: US IL Schaumburg
- Agent Gary J. Cunningham; Phillip H. Burrus, IV
- Main IPC: G08B13/14
- IPC: G08B13/14

Abstract:
A near-field communication circuit (100), such as a radio frequency identification circuit, includes a communication coil (104) and a communication circuit (108) configured to transmit data (109) through the communication coil (104). When the communication circuit (108) is in an idle mode, probing circuitry (124) is configured to detect the presence of a magnetically conductive object within close proximity of a communication coil (104). In one embodiment, a control circuit (110) selectively couples a capacitance (125) in parallel with the communication coil (104). The control circuit (110) then applies a probing signal (116) to the communication coil (104). A comparator (118) monitors a secondary parameter of the communication coil (104), such as inductance or impedance. When a magnetically conductive object is detected, the communication circuit (108) transitions to a communication state and attempts to communicate with the object.
Public/Granted literature
- US20090109032A1 Detection Apparatus and Method for Near Field Communication Devices Public/Granted day:2009-04-30
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