The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 16, 2013
Filed:
Mar. 31, 2008
Joel Ironstone, Toronto, CA;
David Wang, Toronto, CA;
Frank Zhang, Scarborough, CA;
Chung Shing Fan, Toronto, CA;
Morrie Altmejd, Toronto, CA;
Kenneth Carless Smith, Toronto, CA;
Joel Ironstone, Toronto, CA;
David Wang, Toronto, CA;
Frank Zhang, Scarborough, CA;
Chung Shing Fan, Toronto, CA;
Morrie Altmejd, Toronto, CA;
Kenneth Carless Smith, Toronto, CA;
Impedimed Limited, Pinkenba, Queensland, AU;
Abstract
In various embodiments, applicants' teachings are related to an active guarding circuit and method for reducing parasitic impedance signal loading on a signal-transmission channel that is shunted by a parasitic impedance. The presence of an electrical signal on the signal-transmission channel causes a leakage current to flow through the parasitic impedance. In various embodiments, the circuit comprises an amplifier and an impedance, one terminal of the impedance is coupled to the signal-transmission channel. The input of the amplifier is coupled to the signal-transmission channel and the output is coupled to the other terminal of the impedance so as to cause a compensation current to flow through the impedance. The gain of the amplifier and the value of the impedance are selected so that the compensation current has a magnitude substantially equal to the leakage current magnitude.