A power amplifier unit includes a power amplifier circuit that amplifies a radio-frequency input signal, a first impedance matching circuit that performs impedance matching for an output signal of the power amplifier circuit, a second-order harmonic termination circuit on an output side of the first impedance matching circuit and that reflects at least part of even-ordered and odd-ordered harmonics contained in a signal input from the first impedance matching circuit to output the at least part of the harmonics from an input terminal as a radio-frequency signal and outputs a radio-frequency signal containing a fundamental and the remainder of the harmonics from an output terminal, and a filter that is on a subsequent stage of the second-order harmonic termination circuit, that attenuates at least part of the even-ordered and odd-ordered harmonics, and that outputs a radio-frequency signal including the fundamental and the remainder of the even-ordered and odd-ordered harmonics.

An inductive heating device (1) for heating an aerosol-forming substrate (20) comprising a susceptor (21) comprises: a device housing (10) a DC power source (11) for providing a DC supply voltage (V.sub.DC) and a DC current (I.sub.DC) a power supply electronics (13) comprising a DC/AC converter (132), the DC/AC converter (132) comprising an LC load network (1323) comprising a series connection of a capacitor (C2) and an inductor (L2) having an ohmic resistance (R.sub.Coil), a cavity (14) in the device housing (10) for accommodating a portion of the aerosol-forming substrate (20) to inductively couple the inductor (L2) of the LC load network (1323) to the susceptor (21). The power supply electronics (13) further comprises a microcontroller (131) to determine from the DC supply voltage (V.sub.DC) and the DC current (I.sub.DC) an apparent ohmic resistance (R.sub.a), and from the apparent ohmic resistance (R.sub.a) the temperature (T) of the susceptor (21).

Apparatus, systems and methods for load-adaptive 3D wireless charging are disclosed. In a 3D charging system of an example embodiment, features comprise a 3D coil design that provides magnetic field distribution coverage for a 3D charging space, e.g.

hemi-spherical space/volume; a push-pull class EF2 PA with EMI filter and transmitter circuitry that provides constant current to the 3D coil, with current direction, phase and timing control capability to adapt to load conditions; reactance shift detection circuitry comprising a voltage sensor, current sensor and phase detector and hardware for fast, real-time, computation of reactance and comparison to upper and lower limits for load-adaptive reactance tuning and for auto-protection; and a switchable tuning capacitor network arrangement of shunt and series capacitors configured for auto-tuning of input impedance, e.g. in response to a X detection trigger signal, which enables both coarse-tuning and uniform fine-tuning steps over an extended reactance range.

A method for controlling a resonance type power converter including a first resonance circuit (L.sub.0, C.sub.0) and a shunt circuit (3), which converts and outputs the power of the DC power supply, shunting a current flowing into a first capacitor (C.sub.S) by controlling a second switching element (S.sub.2) during a predetermined period within turn-off period of a first switching element (S.sub.1), the first capacitor connected in parallel to the first switching element (S.sub.1), the second switching element (S.sub.2) included in the shunt circuit (3), and the first switching element (S.sub.1) operated in response to the resonance of the first resonance circuit (L.sub.0, C.sub.0).

In certain examples, methods and semiconductor structures are directed to circuit-based apparatus in which an amplifier includes stacked, first and second circuit amplification stages to operate out of phase from one another for providing a push-pull operation, with each of the first and second circuit stages including a switching circuit and an impedance path to drive the switching circuit. The apparatus further includes a waveform-shaping circuit to shape, in response to each of the first and second circuit stages, a voltage signal for presentation to the switching circuit. As may be implemented in various more-specific examples, the apparatus may generate a constant output voltage with high efficiency across a wide range of resistive loads.

A switching amplifier system includes an amplifier printed circuit board (PCB); a filter PCB coupled to the amplifier PCB and configured to receive an amplified signal from the amplifier PCB, and a resonant capacitor PCB coupled to the filter PCB and to one or more antennas The resonant capacitor PCB is physically separated from the amplifier PCB and the filter PCB by a distance of at least 10 mm. The filter PCB is physically separated from the amplifier PCB by a distance of at least 10 mm.

An adiabatic resonator, an adiabatic oscillator, and an adiabatic oscillator system are disclosed. An adiabatic system is one that ideally transfers no heat outside of the system, thereby reducing the required operating power. The adiabatic resonator, which includes a plurality of tank circuits, acts as an energy reservoir, the missing aspect of previously attempted adiabatic computational systems. By using the adiabatic resonator as a feedback element with an amplifier, an adiabatic oscillator is formed. An adiabatic oscillator system is formed with a primary adiabatic oscillator feeding a plurality of secondary adiabatic oscillators. In this manner, the adiabatic oscillator system may be used to generate the multiple clock signals required of adiabatic computational logic elements, such as Split-level Charge Recovery Logic and 2-Level Adiabatic Logic. The adiabatic oscillator system stores enough energy to drive many individual adiabatic computational logic elements, permitting implementation of complex logic circuits.

A scalable periphery tunable matching power amplifier is presented. Varying power levels can be accommodated by selectively activating or deactivating unit cells of which the scalable periphery tunable matching power amplifier is comprised. Tunable matching allows individual unit cells to see a constant output impedance, reducing need for transforming a low impedance up to a system impedance and attendant power loss. The scalable periphery tunable matching power amplifier can also be tuned for different operating conditions such as different frequencies of operation or different modes.

A bidirectional RF circuit, preferably including a plurality of terminals, a switch, a transistor, a coupler, and a feedback network. The circuit can optionally include a drain matching network, an input matching network, and/or one or more tuning inputs. In some variations, the circuit can optionally include one or more impedance networks, such as an impedance network used in place of the feedback network; in some such variations, the circuit may not include a coupler, switch, and/or input matching network. A method for circuit operation, preferably including operating in an amplifier mode, operating in a rectifier mode, and/or transitioning between operation modes.

An adiabatic resonator, an adiabatic oscillator, and an adiabatic oscillator system are disclosed. An adiabatic system is one that ideally transfers no heat outside of the system, thereby reducing the required operating power. The adiabatic resonator, which includes a plurality of tank circuits, acts as an energy reservoir, the missing aspect of previously attempted adiabatic computational systems. By using the adiabatic resonator as a feedback element with an amplifier, an adiabatic oscillator is formed. An adiabatic oscillator system is formed with a primary adiabatic oscillator feeding a plurality of secondary adiabatic oscillators. In this manner, the adiabatic oscillator system may be used to generate the multiple clock signals required of adiabatic computational logic elements, such as Split-level Charge Recovery Logic and 2-Level Adiabatic Logic. The adiabatic oscillator system stores enough energy to drive many individual adiabatic computational logic elements, permitting implementation of complex logic circuits.