Aspects of this disclosure relate to bandpass filters with enhanced out of band rejection. The bandpass filters include a stage that is modified using a network of three inductors two of which are mutually coupled inductors. Related methods, radio frequency systems, radio frequency modules, and wireless communication devices are also disclosed.

Aspects of this disclosure relate to bandpass filters with enhanced out of band rejection. The bandpass filters include a stage that is modified using a network of three inductors two of which are mutually coupled inductors. Related methods, radio frequency systems, radio frequency modules, and wireless communication devices are also disclosed.

A power supply circuit includes a switching element coupled in a current path between an input terminal and an output terminal and includes a smoothing capacitor coupled between the output terminal and a ground. A bypass capacitor is coupled between the input terminal and the ground. An antenna element shares the ground with the power supply circuit. A frequency filter having a stop band that is an operating frequency band of the antenna element is inserted in series in at least either a current path between the switching element and the smoothing capacitor or a current path between the bypass capacitor and the switching element. It is possible to suppress deterioration of wireless communication quality due to noise caused in a DC-DC converter.

A coiled electronic component includes: an electronic component body which includes a coil portion having a spiral structure and formed of an electrically conductive material, and electrically conductive connection portions arranged on both ends of the coil portion; and a pair of electrodes for respectively connecting the electrically conductive connection portions to assembly portions arranged on an assembly object. The electrode includes a pair of pinching pieces for pinching the electrically conductive connection portion, and the pair of pinching pieces is opened in a manner that the electrically conductive connection portion is received and fitted therebetween.

A coiled electronic component includes: an electronic component body which includes a coil portion having a spiral structure and formed of an electrically conductive material, and electrically conductive connection portions arranged on both ends of the coil portion; and a pair of electrodes for respectively connecting the electrically conductive connection portions to assembly portions arranged on an assembly object. The electrode includes a pair of pinching pieces for pinching the electrically conductive connection portion, and the pair of pinching pieces is opened in a manner that the electrically conductive connection portion is received and fitted therebetween.

A filter module includes a circuit board on or in which a ground electrode is provided, and a low pass filter on the circuit board. The low pass filter includes first and second inductors, and a capacitor. The first and second inductors are cumulatively connected to each other. Relationships of Lp+Lg−M≥0 and Lp−M<0 are satisfied, where Lp denotes an inductance of a path between a connection portion between the first and second inductors and a ground terminal, Lg denotes an inductance of a path between the ground terminal and the ground electrode, and M denotes a mutual inductance between the first and second inductors.

An electronic device includes an IC mounted on a substrate and a filter circuit connected to the IC. The filter circuit includes a coil component and a capacitor. The coil component includes a multilayer body, a first coil including a portion of multiple wiring patterns laminated in the multilayer body, a second coil provided on layers different from those of the first coil and including a portion of the multiple wiring patterns, and first, second and third electrodes provided on side surfaces. An opening of the first coil is at least partially overlapped with an opening of the second coil when viewed from a main surface direction. The third electrode is grounded via the capacitor. The first coil has an inductance lower than that of the second coil.

A semiconductor IC includes a first radio-frequency element (e.g., an inductor in a low-noise amplifier), a second radio-frequency element (e.g., an inductor in a low-noise amplifier), a first via conductor (e.g., a via conductor that is placed between the first radio-frequency element and the second radio-frequency element and that is connected to a ground potential.

A radio frequency filter includes communication bandpass filters disposed corresponding respectively to a plurality of communication bands, a switch, and a matching circuit. The switch includes a common terminal and a plurality of optionally selectable terminals, the plurality of optionally selectable terminals being individually connected to the plurality of bandpass filters in a one-to-one relation. The matching circuit is connected to the common terminal and is a common matching circuit to the plurality of communication bandpass filters. The plurality of communication bandpass filters are set such that filter characteristics of a serial circuit in combination of one of the plurality of communication bandpass filters, the one being selected by the switch, and the common matching circuit are improved in comparison with filter characteristics of the selected communication bandpass filter with respect to the communication band corresponding to the selected communication bandpass filter.

A signal transmission device includes a signal side electrode; a first signal line connected to one side of the signal side electrode; a second signal line connected to the other side of the signal side electrode; a power source side electrode that forms a pair with the signal side electrode and is connected to the signal side electrode via an electronic component including at least an inductor component; and a capacitive coupling part that capacitively couples the power source side electrode to a ground wiring or a power source wiring. The first signal line, the signal side electrode, and the second signal line form a transmission path for transmitting an electric signal. The first signal line and the second signal line transmit power via the signal side electrode, the electronic component, and the power source side electrode.