发明名称 |
Method and apparatus for low current RF signal detection |
摘要 |
A low signal detection circuit for use in an electronic tolling system which wakes up a receiver circuit associated with the tolling system based upon the type of signal received. An RF signal transmitted by the electronic tolling system is Manchester encoded and will therefore have a frequency within predetermined values. The system will detect the incoming RF signals or count the rising and falling edges of the baseband signal and apply the counts to a threshold circuit which will compare the number of counts to a predetermined value. If the number of counts falls within a predetermined range, then a signal indicating the presence of a valid RF signal will be output from the wake-up circuit. A power management circuit receives a clock signal from an oscillator circuit and provides a power signal which will wake up the detection circuitry for only a minimum predetermined period of time.
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申请公布号 |
US5533058(A) |
申请公布日期 |
1996.07.02 |
申请号 |
US19940208177 |
申请日期 |
1994.03.10 |
申请人 |
DELCO ELECTRONICS CORPORATION |
发明人 |
KADY, MARK A.;WENOS, VINCENT M. |
分类号 |
G06K19/07;G07B15/06;H04B1/16;(IPC1-7):H04L25/06 |
主分类号 |
G06K19/07 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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