DEVICE, METHOD AND SYSTEM FOR ESTIMATING THE TERMINATION TO A WIRED TRANSMISSION-LINE BASED ON DETERMINATION OF CHARACTERISTIC IMPEDANCE

• US 20080144546A1
• Filed: 02/15/2008
• Published: 06/19/2008
• Est. Priority Date: 01/23/2005
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: SercoNet Limited (Yehuda Binder, MBA)
• Inventors: Hazani, Ami, Binder, Yehuda
• Granted Patent: US 7,919,970 B2
• Time in Patent Office: Days
• US Class Current: 370/295
• CPC Class Codes: G01R 27/02 Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant by measuring phase angle only G01R25/00
• CPC Class Codes: G01R 27/04 in circuits having distributed constants , e.g. having very long conductors or involving high frequencies

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.

Claims

1. A device for estimating the termination to a wired transmission-line, the device comprising:

a port for connecting to the wired transmission-line,

impedance measuring unit coupled to said port for instantaneously measuring the lumped impedance Z of the transmission-line, and

means coupled to said impedance measuring unit for estimating the optimal termination value of the transmission-line based on the measured value Z.

2. The device according to claim 1, further comprising a memory coupled for storing the measured lumped impedance value.

3. The device according to claim 1, wherein the estimated value is equal to the measured value Z.

4. The device according to claim 1 further comprising means for connecting a termination having the estimated value to the wired transmission-line.

5. The device according to claim 1, wherein the wired transmission-line comprises a wire pair at least partially hidden in the wall of a building and connected to an outlet having a front faceplate, and said port comprises a connector for connecting to a further connector on the front faceplate of the outlet.

6. The device according to claim 5, wherein the wire pair is part of a telephone, AC power, or CATV wiring infrastructure, and the outlet is a telephone, AC power, or CATV outlet, respectively.

7. The device according to claim 6, wherein the infrastructure carries a signal in a first frequency band, and said impedance measuring unit comprises:

an energy transmitter coupled to said connector for transmitting energy to the wired transmission-line;

the energy being carried in a second frequency band distinct from the first frequency band.

8. The device according to claim 1, being integrated into an outlet.

9. The device according to claim 1, for use with a modem for communication over the wired transmission-line, wherein said device further comprises a switch for disconnecting the modem from the wired transmission-line, and for re-connecting the modem to the transmission-line.

10. The device according to claim 1, further comprising a selector for operating said device either periodically, or upon application of an external signal, or upon a manual action, or upon powering up of the device.