Method and system for power line impedance detection and automatic impedance matching

• US 6,515,485 B1
• Filed: 04/19/2000
• Issued: 02/04/2003
• Est. Priority Date: 04/19/2000
• Status: Expired due to Fees

• Current Assignee: Low Environ AG LLC (Intellectual Ventures LLC)
• Original Assignee: Phonex Broadband
• Inventors: Bullock, Scott R., Hoobler, Ryan
• Primary Examiner(s): Oda, Christine
• Assistant Examiner(s): KERVEROS, DEMETRIOS C
• Application Number:
  US09/552,513
• Time in Patent Office: 1,021 Days
• Field of Search: 324/601, 324/607, 324/616, 324/627, 324/628, 324/663, 340/310.05, 379/394, 379/397, 379/398
• US Class Current: 324/601
• CPC Class Codes: H04B 2203/5425 improving S/N by matching impedance, noise reduction, gain control
• CPC Class Codes: H04B 2203/5445 Local network
• CPC Class Codes: H04B 2203/5495 having measurements and testing channel
• CPC Class Codes: H04B 3/54 Systems for transmission via power distribution lines

Abstract

A system and method for the automatic detection and matching of power line impedance which makes use of level detection and source impedance circuits in electronic communication with the existing circuitry of a power line communication devices are disclosed. This invention uses modified power line communication device circuitry to sense the impedance of the power line and to correct its impedance to match the impedance of the power line. By automatically sensing and adjusting the source impedance of the power line jack this invention maximizes power transfer to and from the power line, reduces radiated power as well as the power line reflection coefficient.

Claims

1. A system for detecting and matching power line impedance, comprising:

(A) an AC power line communication device having an existing AC power line connection circuitry;

(B) a source impedance circuit, connected to said existing AC power line connection circuitry of said communication device;

(C) a level detection circuit electrically connected to said source impedance circuit; and

(D) an AC power line connected to said source impedance circuit and said level detection circuit, said AC power line providing a power line communication channel.

2. A method for detecting and matching power line impedance, comprising:

(A) outputting a tone;

(B) measuring a voltage level at the output of a source impedance connected to an AC power line; and

(C) adjusting the output impedance to match an AC power line communication channel impedance.

3. A method for detecting and matching power line impedance, comprising:

(A) sensing the impedance of an AC power line communication channel; and

(B) adjusting a variable resistance to reduce the signal level at a source resistor to ½

its previous level.