System and method for tuning transistor-based non-foster negative impedance circuits for low-frequency antennas

A method for tuning a transistor-based circuit, comprising the steps of:

• providing a negative impedance converter circuit having a capacitor, a first transistor, and a second transistor, and a third transistor in series with the capacitor;
• passing a current through capacitor;
• sampling, via the first transistor and the second transistor, a voltage at the capacitor;
• inverting, via the first transistor and the second transistor, the voltage at an input of the negative impedance converter circuit;
• and
• changing a base voltage of the third transistor, which changes the voltage sampled by the first transistor and the second transistor.

A system for tuning a transistor-based circuit for a low-frequency antenna, comprising:

• a resistively loaded dipole antenna having a negative impedance converter circuit with a capacitor, a first transistor, and a second transistor;
• a current traveling through the capacitor;
• wherein the first transistor and the second transistor each sample voltage at the capacitor and invert the voltage at an input of the negative impedance converter circuit;
• a third transistor in series with the capacitor, the third transistor having a base voltage;
• and
• wherein changing the base voltage of the third transistor changes the voltage sampled by the first transistor and the second transistor.