A power amplifier circuit includes a lower-stage transistor having a first power supply voltage supplied to a first terminal, a second terminal connected to ground, and a first signal supplied to a third terminal; an upper-stage transistor having a second power supply voltage supplied to a first terminal, a second signal obtained by amplifying the first signal being output from the first terminal, a second terminal connected to the first terminal of the lower-stage transistor via a first capacitor, and a third terminal connected to ground via a ground path; an inductor that connects the second terminal of the upper-stage transistor to ground; and an adjustment circuit that adjusts impedance seen from the third terminal of the upper-stage transistor. The adjustment circuit includes a second capacitor and at least one resistance element connected in series with the ground path between the third terminal of the upper-stage transistor and ground.

A first power amplifier amplifies first transmission signals in a first frequency band and outputs the resultant signals. A first matching circuit includes a plurality of first inductor portions and is connected to an output pad electrode of the first power amplifier. A second power amplifier amplifies second transmission signals in a second frequency band higher than the first frequency band and outputs the resultant signals. A second matching circuit includes at least one second inductor portion and is connected to an output side of the second power amplifier. A multilayer substrate has a first main surface and a second main surface located opposite to each other and is provided with the first and second power amplifiers and the first and second matching circuits. The first inductor portion closer than the other first inductor portions to the output pad electrode includes an inner-layer inductor portion located in the multilayer substrate.

A radio frequency amplifier circuit is provided. A matching circuit is configured on a radio frequency path of an input end or an output end of an amplifier. An inductance-capacitance resonance circuit and the matching circuit share an inductor included in the matching circuit to generate a corresponding resonance frequency. The matching circuit provides an input impedance or an output impedance matching two fundamental tones in a radio frequency signal at a first frequency and a second frequency. The inductance-capacitance resonance circuit provides a filtering path for filtering a signal component outside a frequency band formed by the first frequency and the second frequency in the radio frequency signal.

A power amplifier including a cascode output stage, a bias circuit, and a temperature compensation and bias boost circuit. The cascode output stage has an input and an output and includes first and second transistors connected in series. A base of the first transistor is coupled to the input, an emitter of the first transistor is coupled to a reference potential, a collector of the first transistor is coupled to an emitter of the second transistor, and a collector of the second transistor is coupled to a supply voltage and the output. The bias circuit is coupled to the base of the second transistor. The bias boost circuit is coupled to the base of the first transistor, compensates for changes in temperature of the cascode output stage, and increases a bias current provided to the first transistor responsive to an increase in the temperature of the cascode output stage.

An electromagnetic wave radiator may include: a first metal layer; a plurality of metal side walls vertically protruding along an edge of the first metal layer; and a second metal layer suspended over the first metal layer. The second metal layer includes a plurality of ports radially extending from edges of the second metal layer and a plurality of slots penetrating the second metal layer in a radial direction.

A dual-drive power amplifier (PA) where the PA core includes a differential pair of transistors M1 and M2 that are driven by a coupling network having two transmission-line couplers, where a first transmission line section of a coupler is configured to transmit an input signal Vin through to drive a gate of the opposite transistor, while the second transmission line section is grounded at one end and coupled with the first transmission line section such that a coupled portion aVin of the input signal Vin drives the source terminal of a corresponding transistor. The arrangement of the coupling network allows the source terminals to be driven below ground potential. Embodiments disclosed here further provide an input matching network, a driver, an inter-stage matching network, and an output network for practical implementation of the PA core.

A power amplifier circuit 10 includes amplifiers 102 and 103, bias circuits 1023 and 1033, and a control circuit 106 that controls the bias circuits 1023 and 1033. When the power amplifier circuit 10 operates in a low power mode, the control circuit 106 controls the bias circuit 1023 and the bias circuit 1033 such that a bias current or voltage is supplied to the amplifier 102 and a bias current or voltage is not supplied to the amplifier 103. When the power amplifier circuit 10 operates in a high power mode in which an output power is higher than an output power in the low power mode, the control circuit 106 controls the bias circuit 1023 and the bias circuit 1033 such that a bias current or voltage is supplied to the amplifier 102 and a bias current or voltage is supplied to the amplifier 103.

Methods and devices to implement efficiently an AUX terminal in RF front end receivers using LNAs are described. The described methods implement a smaller number of switches resulting in an overall performance improvement by reducing the noise figure at the input of the LNA. The presented devices can be used in low/high gain and bypass modes and can accommodate an arbitrary number of bands over a wide frequency range.

A switching circuit comprises a first transistor, a transformer including a first inductor and a second inductor that is co-centric with the first inductor, a first switch, a second switch, a second transistor, a first output, a second output, and coupling circuitry configured to couple the first inductor to the first transistor, a first end of the second inductor, the first switch, and the first output together at a first node, a second end of the second inductor, the second switch, and the second transistor together at a second node, and the second output to the second transistor.

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).