Apparatus and method for continuous variable reactive impedance control

A method of adjusting the reactive impedance of a circuit, the circuit having an oscillation frequency and including an oscillating circuit and a reactive component that is selectively coupled to the oscillating circuit, the method comprising the steps of:

• identifying the start and end of a half-cycle of the oscillation frequency;
• determining a duration, said duration being a portion of a quarter-cycle of the oscillation frequency;
• coupling the reactive component to the oscillating circuit for said duration beginning at the start of each half-cycle;
• decoupling the reactive component from the oscillating circuit after said duration;
• and
• re-coupling the reactive component to the oscillating circuit for said duration expiring at the end of each half-cycle.

A magnetic inductive transmitter having an oscillation frequency, comprising:

• an oscillating circuit, including an inductive antenna and a capacitive component;
• a secondary capacitor;
• a switch coupled to said secondary capacitor, said switch and said secondary capacitor being coupled to said capacitive component of said oscillating circuit;
• and
• a controller operatively coupled to said switch for controlling the opening and closing of said switch, said controller having a first component for determining a duration, said duration being a portion of a quarter cycle of the oscillation frequency, a second component for identifying the start and end of a half-cycle of the oscillation frequency, and a third component for closing said switch for said duration beginning at the start of each half-cycle and opening said switch after said duration.