System and method for automatic tuning of a magnetic field generator
US7515012B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 22, 2006 |
| Grant date | Apr 7, 2009 |
| Priority date | — |
| Expiry date | Nov 25, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03J2200/10
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
An automatic tuning system for a magnetic field generating tuned circuit includes a processor configured to maintain the resonant frequency of a tuned circuit equal to a reference frequency. The tuned circuit is driven by a power amplifier whose output provides an amplified signal at the reference frequency. The tuned circuit includes a magnetic field generating inductor and a bank of individually switchable capacitors controlled by the processor capable of adding and removing the respective capacitances to and from the tuned circuit. The inductor includes a Faraday shield to shield the tuned circuit from the influence of electric fields. In an embodiment of the invention, the variable capacitor is in the form of a diode variable capacitor (varicap) in parallel circuit relationship with the tuned circuit capacitor and the inductor. In an alternate embodiment the inductor and a fixed capacitor are in series circuit relationship with the varicap in parallel circuit relationship with the fixed capacitor and the tuning sequence relies on a phase locked loop using the phase of a reference frequency signal and the phase of the inductor voltage as control parameters.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.