Patent ID: 8471642
Filing Date: 2013-06-25
Classification: G06K,H03J

Abstract:
1. A controllable electric resonator comprising an inductor coupled to a first capacitor to form a resonant circuit, the resonator further comprising a controllable element and a second capacitor, said controllable element arranged to control a total effective capacitance of said first and second capacitors, said resonant circuit comprising said total effective capacitance, the resonator further comprising a control device to provide a voltage to control said controllable element, said voltage substantially constant over a cycle of oscillation of a signal on said resonator, wherein the controllable element comprises a transistor having a gate terminal configured to receive said voltage, a source terminal configured to receive a first resonance waveform of said resonant circuit and a drain terminal configured to receive a second resonance waveform of said resonant circuit, the transistor is configured to switch when a difference between said voltage and said received first resonance waveform on said source terminal reaches a threshold voltage of the transistor, the transistor thereby configured to turn on and off during said cycle of oscillation to vary said total effective capacitance of said first and second capacitors over said cycle of oscillation.