Device, method and system for estimating the termination to a wired transmission-line based on determination of characteristic impedance
First Claim
1. A method for matching a termination to a wired transmission-line using a closed-control loop, the transmission-line being connected to carry a signal and having a nominal characteristic impedance, the method comprising:
- connecting a termination having a controllable impedance value to the transmission-line;
measuring the power dissipated by the termination by conductive connection to the impedance to measure at least two of;
the voltage across the termination;
the current through the termination; and
the impedance of the termination; and
changing the termination impedance value to obtain a maximum power dissipation by the termination in response to the measurement of the power dissipated.
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Accused Products
Abstract
A system and method for measuring a characteristic impedance of a transmission-line comprises transmitting energy to the line, and shortly after measuring the voltage/current involved and thus measuring the equivalent impedance. The measured characteristic impedance may then be used in order to determine the termination value required to minimize reflections. In another embodiment, the proper termination is set or measured by adjusting the termination value to achieve maximum power dissipation in the terminating device. The equivalent characteristic impedance measurement may be used to count the number of metallic conductors connected to a single connection point. This abstract is not intended to limit or construe the scope of the claims.
48 Citations
22 Claims
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1. A method for matching a termination to a wired transmission-line using a closed-control loop, the transmission-line being connected to carry a signal and having a nominal characteristic impedance, the method comprising:
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connecting a termination having a controllable impedance value to the transmission-line; measuring the power dissipated by the termination by conductive connection to the impedance to measure at least two of;
the voltage across the termination;
the current through the termination; and
the impedance of the termination; andchanging the termination impedance value to obtain a maximum power dissipation by the termination in response to the measurement of the power dissipated. - View Dependent Claims (2, 3)
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4. A device for matching a termination to a wired transmission line using a closed-control loop, the transmission-line being connected to carry a signal and having a nominal characteristic impedance, said device comprising:
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a port for connecting to the wired transmission line, a termination having a variable impedance value coupled to said port and having a control port, means conductively connected to said termination for measuring the power dissipated by said termination by directly measuring at least two of;
the voltage across said termination;
the current through said termination; and
the impedance of said termination, andcontrol means coupled between said means for measuring and said control port for closed loop control operative for changing the impedance value of said termination to maximize power dissipated in said termination when power is supplied to the transmission line. - View Dependent Claims (5, 6)
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7. A method for estimating an optimum impedance value for a termination to a wired transmission line having a characteristic impedance Z0 comprising:
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connecting a characteristic impedance measuring device to the wired transmission line, instantaneously measuring the characteristic impedance Z0, and estimating an optimum termination value based on the measured value Z0. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A method for matching a termination to a wired transmission-line using a closed-control loop, the transmission-line being connected to carry a signal and having a nominal characteristic impedance, the method comprising:
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connecting a termination having a controllable impedance value to the transmission-line; measuring the power dissipated by the termination by non-conductive coupling to the termination; and changing the termination impedance value to obtain a maximum power dissipation by the termination in response to the measurement of power dissipated. - View Dependent Claims (18, 19)
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20. A device for matching a termination to a wired transmission line using a closed-control loop, the transmission-line being connected to carry a signal and having a nominal characteristic impedance, said device comprising:
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a port for connecting to the wired transmission line, a termination having a variable impedance value coupled to said port and having a control port, means non-conductively connected to the termination for measuring power dissipated by said termination, and control means coupled between said means for measuring and said control port for closed loop control and for changing the impedance value of said termination to maximize power dissipated in said termination when power is supplied to the transmission line. - View Dependent Claims (21, 22)
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Specification