A power amplifier device includes a first amplifier, a second amplifier, a capacitor, a node, and an impedance matching circuit. The second amplifier amplifies a radio frequency signal transmitted from the first amplifier. The capacitor is coupled between an output terminal of the first amplifier and an input terminal of the second amplifier. The node is disposed between the input terminal of the second amplifier and the capacitor. The impedance matching circuit is coupled to the node and a common voltage terminal. The impedance matching circuit is substantially an open circuit at a center frequency of the radio frequency signal. The impedance matching circuit provides substantially a short-circuited path from the node to the common voltage terminal at a frequency twice the center frequency.

A CATV & MoCA splitter has an input and at least one output that is CATV & MoCA and at least one output that is MoCA only. The splitter functions as a building block to provide a customizable installation that supplies the needed number of CATV & MoCA outputs and the needed number of MoCA only outputs. The splitter includes a housing with first, second and third coaxial ports attached to the housing. In one embodiment, the second coaxial port is connected to the first coaxial port via a power divider so that all frequencies presented to the first coaxial port can pass to the second coaxial port, and vice versa. A high pass filter, which passes only MoCA signals, connects the power divider and third coaxial port.

The present disclosure relates to a radio frequency (RF) power transistor package. It further relates to a mobile telecommunications base station comprising such an RF power transistor package, and to an integrated passive die suitable for use in an RF power amplifier package. In example embodiments, an in-package impedance network is used that is connected to an output of the RF power transistor arranged inside the package. This network comprises a first inductive element having a first and second terminal, the first terminal being electrically connected to the output of the RF transistor, a resonance unit electrically connected to the second terminal of the first inductive element, and a second capacitive element electrically connected in between the resonance unit and ground, where the first capacitive element is arranged in series with the second capacitive element.

A variable-frequency LC filter that has sharp attenuation characteristics and that does not increase the size of a substrate and a high-frequency frontend module using such a variable-frequency LC filter are provided. A first variable capacitor and a second variable capacitor are disposed on a principal surface such that strength of magnetic field coupling caused between a first inductor and a third inductor is greater than strength of magnetic field coupling caused between a second inductor and the first inductor and than strength of magnetic field coupling caused between the second inductor and the third inductor.

An LC resonator includes a laminate body including dielectric layers that are laminated in a lamination direction. The LC resonator includes a first capacitor, a second capacitor, and an inductor connected between the first capacitor and the second capacitor. A first end of the inductor is isolated in a direct current from a ground node by the first capacitor. A second end of the inductor is isolated in a direct current from the ground node by the second capacitor.

A multilayer filter includes an element body formed by stacking a plurality of insulator layers, and an input terminal, a first output terminal, and a ground terminal arranged on outer surfaces of the element body, a first LC resonance circuit provided in a line connecting the input terminal to the first output terminal and including a first inductor and a first capacitor, and an open inductor having one end connected to the ground terminal and the other end open are provided in the element body, and the open inductor is arranged to face the first output terminal or the first inductor.

Radio frequency (RF) systems with tunable filters are provided herein. In certain embodiments, an RF system includes a first RF processing circuit configured to process a first frequency band of a first communication standard and a second frequency band of a second communication standard. The first frequency band and the second frequency band are close in frequency and/or partially overlapping in frequency. The first RF processing circuit includes a tunable filter for changing the bandwidth of the first RF processing circuit to enhance the robustness of the first RF processing circuit to blocker or jammer signals of a third frequency band.

The present disclosure relates to a radio frequency (RF) power transistor package. It further relates to a mobile telecommunications base station comprising such an RF power transistor package, and to an integrated passive die suitable for use in an RF power amplifier package. In example embodiments, an in-package impedance network is used that is connected to an output of the RF power transistor arranged inside the package. This network comprises a first inductive element having a first and second terminal, the first terminal being electrically connected to the output of the RF transistor, a resonance unit electrically connected to the second terminal of the first inductive element, and a second capacitive element electrically connected in between the resonance unit and ground, where the first capacitive element is arranged in series with the second capacitive element.

The present disclosure relates to a radio frequency (RF) power transistor package. It further relates to a mobile telecommunications base station comprising such an RF power transistor package, and to an integrated passive die suitable for use in an RF power amplifier package. In example embodiments, an in-package impedance network is used that is connected to an output of the RF power transistor arranged inside the package. This network comprises a first inductive element having a first and second terminal, the first terminal being electrically connected to the output of the RF transistor, a resonance unit electrically connected to the second terminal of the first inductive element, and a second capacitive element electrically connected in between the resonance unit and ground, where the first capacitive element is arranged in series with the second capacitive element.

Radio frequency (RF) systems with tunable filters are provided herein. In certain embodiments, an RF system includes a first RF processing circuit configured to process a first frequency band of a first communication standard and a second frequency band of a second communication standard. The first frequency band and the second frequency band are close in frequency and/or partially overlapping in frequency. The first RF processing circuit includes a tunable filter for changing the bandwidth of the first RF processing circuit to enhance the robustness of the first RF processing circuit to blocker or jammer signals of a third frequency band.