Variable capacitor with linear impedance and high voltage breakdown

A method of adjusting capacitance of a variable capacitor, comprising:

• providing an enclosure having an interior;
• providing a movable capacitor plate assembly disposed in the interior of the enclosure, the movable capacitor plate assembly including a first capacitor plate, a first electrode, and a first mounting plate;
• providing a flexible structure having a first end sealed around an opening into the interior of the enclosure and a second end sealed to a rear side of the first mounting plate;
• providing a fixed capacitor plate assembly disposed proximal to the first capacitor plate assembly, the fixed capacitor plate assembly including a second capacitor plate, a second electrode, and a second mounting plate;
• providing an actuator coupling assembly coupled to the rear side of the first mounting plate;
• providing an actuator having a longitudinal axis, extending into the opening and through the first flexible structure, a distal end of the actuator engaging with the actuator coupling assembly;
• and
• advancing and retracting the movable capacitor plate assembly with respect to the fixed capacitor plate assembly;
• wherein the first and second capacitor plates comprise respective interdigitated concentric cylindrical coils, the coil of the second capacitor plate having a greater height at a center portion and a lower height at an outer portion.

A variable capacitor, comprising:

• an enclosure having an interior;
• a movable capacitor plate assembly disposed in the interior of the enclosure, the movable capacitor plate assembly including a first capacitor plate, a first electrode, and a first mounting plate;
• a flexible structure having a first end sealed around an opening into the interior of the enclosure and a second end sealed to a rear side of the first mounting plate;
• a fixed capacitor plate assembly disposed proximal to the first capacitor plate assembly, the fixed capacitor plate assembly including a second capacitor plate, a second electrode, and a second mounting plate;
• an actuator coupling assembly coupled to the rear side of the first mounting plate;
• an actuator having a longitudinal axis, extending into the opening and through the first flexible structure, a distal end of the actuator engaging with the actuator coupling assembly, the actuator for advancing and retracting the movable capacitor plate assembly with respect to the fixed capacitor plate assembly;
• wherein the first and second capacitor plates comprise a first and second coil respectively having a conical shape where the height of the first and second coils from a base is varied along its radius, the peaks of which being interdigitated to varying extents depending upon the advancement and retraction of the movable capacitor plate assembly.