Embodiments of the present disclosure provide a circuit structure including: a switching transistor including a gate terminal, a back-gate terminal, a source terminal, and a drain terminal; a biasing node coupled to the back-gate terminal of the switching transistor, the biasing node being alternately selectable between an on state and an off state; a first capacitor source-coupled to the switching transistor; a second capacitor drain-coupled to the switching capacitor; and a first enabling node source-coupled to the switching transistor, the first enabling node being alternately selectable between an on state and an off state.

An electronic device may be provided with wireless circuitry and control circuitry. The wireless circuitry may include an antenna with an inverted-F antenna resonating element formed from portions of a peripheral conductive electronic device housing structure and may have an antenna ground that is separated from the antenna resonating element by a gap. The antenna may include a first adjustable component coupled between the antenna resonating element arm and the antenna ground on a first side of the antenna feed and a second adjustable component coupled between the antenna resonating element arm and the antenna ground on a second side of the antenna feed. Control circuitry in the electronic device may adjust the first and second adjustable components between a first tuning mode, a second tuning mode, and a third tuning mode.

An electronic device may be provided with wireless circuitry and control circuitry. The wireless circuitry may include an antenna with an inverted-F antenna resonating element formed from portions of a peripheral conductive electronic device housing structure and may have an antenna ground that is separated from the antenna resonating element by a gap. The antenna may include a first adjustable component coupled between the antenna resonating element arm and the antenna ground on a first side of the antenna feed and a second adjustable component coupled between the antenna resonating element arm and the antenna ground on a second side of the antenna feed. Control circuitry in the electronic device may adjust the first and second adjustable components between a first tuning mode, a second tuning mode, and a third tuning mode.

An electronic power converter is configured to receive power from a power source. The power operates at a switching frequency. The electronic power converter includes a resonant tank circuit operatively connected to the power converter. The resonant tank circuit operates at a tank resonant frequency. The electronic power converter includes a controller operatively connected to the resonant tank circuit. The electronic power converter further includes a variable inductor operatively connected to the resonant tank circuit. The variable inductor is configured to modify the tank resonant frequency to match the switching frequency within a predetermined margin.

A method for controlling a semiconductor circuit, including forming an inductor and a capacitor on a substrate, which are inductively coupled to one another. The inductor has an inductance value while the capacitor has a capacitance value. The inductor and capacitor make up an oscillator circuit with two terminals. Eddy currents are generated through the capacitor when an operating current flows along the inductor. These eddy currents influence, by inductive coupling, the inductance value and performance of the oscillator circuit, thus simultaneously tuning the inductance and capacitance of the oscillator circuit.

A method for controlling a semiconductor circuit, including forming an inductor and a capacitor on a substrate, which are inductively coupled to one another. The inductor has an inductance value while the capacitor has a capacitance value. The inductor and capacitor make up an oscillator circuit with two terminals. Eddy currents are generated through the capacitor when an operating current flows along the inductor. These eddy currents influence, by inductive coupling, the inductance value and performance of the oscillator circuit, thus simultaneously tuning the inductance and capacitance of the oscillator circuit.

Embodiments of the present disclosure provide a circuit structure including: a switching transistor including a gate terminal, a back-gate terminal, a source terminal, and a drain terminal; a biasing node coupled to the back-gate terminal of the switching transistor, the biasing node being alternately selectable between an on state and an off state; a first capacitor source-coupled to the switching transistor; a second capacitor drain-coupled to the switching capacitor; and a first enabling node source-coupled to the switching transistor, the first enabling node being alternately selectable between an on state and an off state.