A filter circuit that secures the steepness from a pass range to an attenuation range while maintaining a wide-band transmission characteristic and a filter device including this filter circuit are formed. A filter circuit includes a first filter and a second filter. The first filter is a filter including an LC circuit in which a first frequency band is a pass band and a frequency band not higher than the first frequency band is an attenuation band. The second filter is a filter that attenuates a second frequency band within the first frequency band by using an attenuation pole produced by a resonance or an antiresonance of an acoustic wave resonator. Further, the first filter is placed closer to an antenna terminal than the second filter.

A multilayer electronic device may include a plurality of dielectric layers and a signal path having an input and an output. An inductor may include a conductive layer formed on one of the plurality of dielectric layers and may be electrically connected at a first location with the signal path and electrically connected at a second location with at least one of the signal path or a ground. The inductor may include an outer perimeter that includes a first straight edge facing outward in a first direction and a second straight edge parallel to the first straight edge and facing outward in the first direction. The second straight edge may be offset from the first straight edge by an offset distance that is less than about 500 microns and less than about 90% of a first width of the inductor in the first direction at the first straight edge.

Impedance matching circuit for radio-frequency amplifier. In some embodiments, an impedance matching circuit can include a primary metal trace having a first end configured to be capable of being coupled to a voltage source for the power amplifier, and a second end configured to be capable of being coupled to an output of the power amplifier. The impedance matching circuit can further include a secondary metal trace having first end coupled to the second end of the primary metal trace, and a second end configured to be capable of being coupled to an output node. The impedance matching circuit can further include a capacitance implemented between the first and second ends of the secondary metal trace, and be configured to trap a harmonic associated with an amplified signal at the output of the power amplifier.

Embodiments relate to circuitry to provide amplitude modulated waveforms in electrosurgical devices. The circuitry can be included in an electrosurgical generator device to provide the amplitude modulated waveforms to an electrosurgical probe coupled with the electrosurgical generator device.

A multilayer filter may include a signal path having an input, an output, and a conductive layer overlying at least one of a plurality of dielectric layers. The conductive layer may be elongated in the first direction and may have a first edge aligned with the first direction and a second edge parallel with the first edge. The conductive layer may include a protrusion extending in the second direction and having an end edge that is parallel with the first edge and offset from the first edge in the second direction by a protrusion length that is greater than about 50 microns. The multilayer filter may include an inductor that is electrically connected at a first location with the signal path and electrically connected at a second location with at least one of the signal path or a ground.

An integrated passive die includes a substrate, an input node, an output node, and RF filtering circuitry. The RF filtering circuitry includes a number of LC tank circuits coupled between the input node and the output node. Each one of the LC tank circuits include an inductor and a capacitor. The inductor is formed by a metal trace over the substrate. The capacitor is coupled in parallel with the inductor over the substrate. The inductor and the capacitor are provided such that a resonance frequency of the combination of the inductor and the capacitor is less than a self-resonance frequency of the inductor.

A frontend module includes a first filter having a passband of a first frequency band, a second filter having a passband of a second frequency band, the second frequency band being higher than the first frequency band, a third filter having a passband of a third frequency band, the third frequency band being higher than the second frequency band, and a sub-filter, connected to the second filter, configured to provide attenuation characteristics for the first frequency band, wherein the second filter comprises a plurality of parallel LC resonance circuits arranged between a ground and different nodes, from among a plurality of nodes between a first terminal and a second terminal, wherein an inductor is connected to a portion of the plurality of parallel LC resonance circuits.

According to various embodiments, an example wireless power transmitter may include a transistor configured to output an amplified signal based on an input signal and a driving voltage, a first capacitor coupled to the transistor in parallel, a first LC resonant circuit coupled to the transistor in parallel and including a first inductor and a second capacitor coupled to the first inductor in series, a third capacitor having a first end coupled to an output terminal of the transistor and the first LC resonant circuit, a feeding coil coupled to a second end of the third capacitor in series, and having at least a part configured to form a second LC resonant circuit with the third capacitor, and a transmission resonator including a transmission coil and a fourth capacitor coupled to the transmission coil in series. At least a part of the transmission coil may be magnetically coupled with the feeding coil, and at least a part of power received from the feeding coil may be output to an outside through the transmission resonator.

A wireless power transmitting device includes: a transistor configured to output a signal corresponding to a set operating frequency, based on an input signal and a driving voltage; a matching circuit connected with the transistor; a transmission coil connected with the matching circuit; an LC resonance circuit connected in parallel between the transistor and the matching circuit and configured to transfer a signal corresponding to at least one harmonic frequency of the operating frequency; and an impedance sensing circuit connected with the LC resonance circuit and configured to sense a load impedance of the wireless power transmitting device based on the signal corresponding to the at least one harmonic frequency transferred through the LC resonance circuit. The matching circuit is configured to provide impedance matching with the sensed load impedance by adjusting an impedance of the matching circuit or an impedance of the transmission coil.

A band antenna EMP filter apparatus having HEMP protection capability is disclosed. The apparatus includes a discharging part, a band pass filtering part, and a residual current eliminating part. The discharging part primarily discharges a transient voltage due to a high altitude electromagnetic pulse (HEMP) when the HEMP is inputted through an input part receiving a radio frequency (RF) signal of an antenna. The band pass filtering part secondarily blocks a residual current primarily discharged by the discharging part and passes only a signal of a preset frequency band to output it through an output part. The residual current eliminating part limits a transient voltage of the HEMP by eliminating a residual current passing through the band pass filtering part.