A transformer that can increase a coupling coefficient of the transformer by suppressing a signal loss in the transformer. The transformer includes a balanced side coil, an unbalanced side coil, a wiring pattern portion, and a multilayer substrate. The balanced side coil has a first end, a second end, and an intermediate tap. The unbalanced side coil has a third end. The wiring pattern portion is electrically connected to the intermediate tap. The multilayer substrate has a plurality of dielectric layers, and the balanced side coil, the unbalanced side coil, and the wiring pattern portion are disposed on dielectric layers different from each other in the plurality of dielectric layers. The balanced side coil and the unbalanced side coil overlap each other in a plan view from a thickness direction of the multilayer substrate.

A radio frequency module includes: a first mounting board having a first principal surface and a second principal surface; a second mounting board having a third principal surface facing the second principal surface and a fourth principal surface; a transmission filter having a first mounting surface facing the second principal surface and a first top surface; and a reception filter having a second mounting surface facing the third principal surface and a second top surface; wherein the transmission and reception filters overlap at least partially in a plan view of the first and second mounting boards, an output terminal of the transmission filter is arranged on the first top surface, an input terminal of the reception filter is arranged on the second top surface, and the output and input terminals are connected by a conductive member not routed through the first mounting board or the second mounting board.

The wireless RF semiconductor system is described for use in wireless communication devices that operate in frequency range from 6 GHz to 100 GHz. The system comprises of at least one RF antenna and at least one active RF component fabricated (or built) on the same semiconductor substrate inside a one single packaged module. The wireless RF semiconductor system is described in a variety of different configurations with its functionality divided up over several single chip circuits. The system simplifies assembly, reduces size and cost, and allows for a quick time to market, while maximizing the RF performance demanded by fixed and mobile 4G, 5G and other wireless standards. The system uses a novel idea of design and packaging of active and passive RF components into a single package. This in turn allows RF designers to unlock the potential of very high frequencies operation that were previously thought too expensive and/or unattainable to average user. The wireless RF semiconductor system can be implemented in both mobile solutions (such as phones, tablets, and the like) and fixed applications (such as repeaters, base-stations, and distributed antenna system).

An amplifier with stacked transconducting cells in parallel and/or cascade current mode combining is disclosed herein. In one or more embodiments, a method for operation of a high-voltage signal amplifier comprises inputting, into each transconducting cell of a plurality of transconducting cells, a direct current (DC) supply current (Idc), an alternating current (AC) radio frequency (RF) input current (I.sub.RF_IN), and an RF input signal (RF.sub.IN). The method further comprises outputting, by each of the transconducting cells of the plurality of transconducting cells, the DC supply current (Idc) and an AC RF output current (I.sub.RF_OUT). In one or more embodiments, the transconducting cells are connected together in cascode for the DC supply current (Idc), are connected together in parallel (or in cascade) for the RF input signal (RF.sub.IN), and are connected together in parallel (or in cascade) for the AC RF output currents (I.sub.RF_OUT).

A power amplifier module can be formed that includes metamaterial matching circuits. This power amplifier module can be included as part of a front-end module of a wireless device. The front-end module can replace a passive duplexer with an active duplexer that uses the power amplifier module in combination with a low noise amplifier circuit that can include a metamaterial matching circuit. The combination of PA and LNA circuits that utilize metamaterials can provide the functionality of a duplexer without including a stand-alone or passive duplexer. Thus, in certain cases, the front-end module can provide duplexer functionality without including a separate duplexer. Advantageously, in certain cases, the size of the front-end module can be reduced by eliminating the passive duplexer. Further, the loss introduced into the signal path by the passive duplexer is eliminated improving the performance of the communication system that includes the active duplexer.

A power amplifier module includes a first amplifier that amplifies an input signal to generate a first amplified signal and outputs the first amplified signal, a second amplifier that amplifies the first amplified signal to generate a second amplified signal and outputs the second amplified signal, and a matching network disposed between an output terminal of the first amplifier and an input terminal of the second amplifier. The first amplifier is provided on a first chip, and the second amplifier is provided on a second chip. The matching network has an impedance transformation characteristic adjustable in accordance with a control signal.

A high frequency amplifier circuit includes a transistor including a drain, a gate, and a source, an inductance-capacitor (LC) tank connected to the drain, and a transformer connected to the gate and the source.

A power amplification module includes a first input terminal arranged to receive a first transmission signal in a first frequency band, a second input terminal arranged to receive a second transmission signal in a second frequency band higher than the first frequency band, a first amplification circuit that amplifies the first transmission signal, a second amplification circuit that amplifies the second transmission signal, a first filter circuit located between the first input terminal and the first amplification circuit, and a second filter circuit located between the second input terminal and the second amplification circuit. The first filter circuit is a low-pass filter that allows the first frequency band to pass therethrough and that attenuates a harmonic of the first transmission signal and the second transmission signal. The second filter circuit is a high-pass filter that allows the second frequency band to pass therethrough and that attenuates the first transmission signal.

A multiple-stage RF amplifier and a packaged amplifier device include driver and final-stage transistors, each having a control terminal, a first current-carrying terminal, and a second current-carrying terminal. The control terminal of the final-stage transistor is electrically coupled to the first current-carrying terminal of the driver transistor. The amplifier further includes an inter-stage circuit coupled between the first current carrying terminal of the driver transistor and a voltage reference node. The inter-stage circuit includes a first inductance, a first capacitor, and a second capacitor. The first inductance and the first capacitor are coupled in series between the first current carrying terminal and the voltage reference node, with an intermediate node between the first inductance and the first capacitor. The second capacitor has a first terminal electrically coupled to the intermediate node and a second terminal electrically coupled to the voltage reference node.

A power amplifier module includes a power amplifier circuit and a control IC. The power amplifier circuit includes a bipolar transistor that amplifies power of an RF signal and outputs an amplified signal. The control IC includes an FET, which serves as a bias circuit that supplies a bias signal to the bipolar transistor. The FET is operable at a threshold voltage lower than that of the bipolar transistor, thereby making it possible to decrease the operating voltage of the power amplifier module.