The invention relates to a circuit (100) able to achieve simultaneous impedance matching between a generator (G) and a load (CH) for a power supply signal comprising at least two distinct frequencies.

An integrated isolator circuit for isolating receiver and transmitter in a Time-Division Duplex transceiver is disclosed. The integrated isolator circuit comprises a first node, a second node and a third node. The integrated isolator circuit further comprises a fist capacitor connected in series with a first switch and connected between the first and second nodes. The integrated isolator circuit further comprises a first inductor connected between the first and second nodes and a second capacitor connected between the second node and the third node. The first switch has an on state and an off state, and the integrated isolator circuit is configured to have a different impedance at a certain operating frequency by controlling the state of the first switch.

An apparatus includes an RF apparatus, and a wideband multi-band matching balun. The wideband multi-band matching balun includes a multi-band balun, which includes at least one three-element frequency-dependent resonator (TEFDR). The wideband multi-band matching balun further includes a differential-to-differential matching circuit coupled to the RF apparatus. The differential-to-differential matching circuit includes at least one TEFDR.

An apparatus includes a radio-frequency (RF) apparatus, and a multi-band matching balun coupled to the RF apparatus. The multi-band matching balun including a plurality of capacitors and a plurality of inductors. None of the plurality of capacitors and none of the plurality of inductors is variable or tunable.

An apparatus includes an RF apparatus, and a multi-band matching balun coupled to the RF apparatus. The multi-band matching balun includes at least one three-element frequency-dependent resonator (TEFDR) and at most three reactive elements.

An antenna includes a metal tube, a coaxial cable disposed along a central axis of the metal tube, and a variable-impedance transmission wire structure. A dielectric body and a metal part are arranged along an axial direction of the cable. The antenna makes the resulting structure stable and reliable, achieves miniaturization of a multi-band antenna and provides a sufficiently wide bandwidth for each frequency band. The antenna also realizes easy control of the radiation pattern and is convenient for practical applications.

A self-tuning impedance-matching microelectromechanical (MEMS) circuit, methods for making and using the same, and circuits including the same are disclosed. The MEMS circuit includes a tunable reactance element connected to a first mechanical spring, a separate tunable or fixed reactance element, and an AC signal source configured to provide an AC signal to the tunable reactance element(s). The reactance elements comprise a capacitor and an inductor. The AC signal source creates an electromagnetically energy favorable state for the tunable reactance element(s) at resonance with the AC signal. The method of making generally includes forming a first MEMS structure and a second mechanical or MEMS structure in/on a mechanical layer above an insulating substrate, and coating the first and second structures with a conductor to form a first tunable reactance element and a second tunable or fixed reactance element, as in the MEMS circuit.

A high-frequency module (20) includes a reception-side filter (21) that uses a first frequency band as a pass band and a second frequency band as an attenuation band, an LNA (23), and a matching circuit (22) disposed between the reception-side filter (21) and the LNA (23). In a Smith chart, the matching circuit (22) makes an interval between impedance in the second frequency band of the reception-side filter (21) and a second gain circle center point indicating impedance at which gain in the second frequency band of the LNA (23) is maximized greater than an interval between impedance in the first frequency band of the reception-side filter (21) and a first gain circle center point indicating impedance at which gain in the first frequency band of the LNA (23) is maximized.

The present disclosure includes a first circuit that is connected between a power feed port and an antenna port, and a second circuit that is connected between the power feed port and the ground or between the antenna port and the ground. The first circuit is a circuit in which for example a first variable capacitance element is connected in series with a first inductor, and the second circuit is a circuit in which for example a second variable capacitance element is connected in parallel with a second inductor. A switch performs switching at least between a first state in which a second end of the second circuit is connected to a first end of the first circuit and a second state in which the second end of the second circuit is connected to a second end of the first circuit.

An electronic device may include processing circuitry having a first impedance coupled to a first circuit board, where the electronic device uses the processing circuity to generate one or more radio frequency signals. The electronic device may also include power circuitry to amplify the one or more radio frequency signals, where the power circuitry is coupled to a second circuit board. An interposer may be disposed between the first circuit board and the second circuit board. The interposer may include a via structure having a characteristic impedance to match the first impedance and the second impedance, where the via structure may transmit the one or more radio frequency signals through the interposer between the processing circuitry and the power circuitry.