RF transistor amplifiers are provided that include a submount and an RF transistor amplifier die that is mounted on top of the submount. A multi-layer encapsulation is formed that at least partially covers the RF transistor amplifier die. The multi-layer encapsulation includes a first dielectric layer and a first conductive layer, where the first dielectric layer is between a top surface of the RF transistor amplifier die and the first conductive layer.

Bias circuits and methods for silicon-based amplifier architectures that are tolerant of supply and bias voltage variations, bias current variations, and transistor stack height, and compensate for poor output resistance characteristics. Embodiments include power amplifiers and low-noise amplifiers that utilize a cascode reference circuit to bias the final stages of a cascode amplifier under the control of a closed loop bias control circuit. The closed loop bias control circuit ensures that the current in the cascode reference circuit is approximately equal to a selected multiple of a known current value by adjusting the gate bias voltage to the final stage of the cascode amplifier. The final current through the cascode amplifier is a multiple of the current in the cascode reference circuit, based on a device scaling factor representing the relative sizes of the transistor devices in the cascode amplifier and in the cascode reference circuit.

A broadband power amplifier device includes an input matching network including first, second and third inductors, a driver amplifier, and first, second and third frequency modulators. First inductor has one end connected to output of a mixer and the other end connected to one end of the first frequency modulator, with the other end of the first frequency modulator being grounded. The second inductor has one end connected to one end of first inductor and the other end connected to input of driver amplifier, with second frequency modulator being connected across second inductor. Third inductor has one end connected to output of driver amplifier and the other end connected to input of power amplifier, with third frequency modulator being connected across third inductor. Bandwidth of power amplifier device can be extended and area and current consumption thereof can be reduced, while power can be improved without large LO driver.

Disclosed herein are power amplification systems that are dynamically biased based on a signal indicative of an envelope of the signal being amplified. The power amplification systems include a power amplifier configured to amplify an input radio-frequency (RF) signal to generate an output RF signal when biased by a biasing signal. The power amplification systems also include a bias component configured to generate the biasing signal based on an envelope signal indicative of an envelope of the input RF signal. The biasing signal can improve or enhance the linearity of the power amplification systems.

A power amplifier module includes an amplifier that amplifies an input signal and outputs an amplified signal, a matching circuit disposed between an output terminal of the amplifier and a subsequent circuit, a choke inductor having a first end to which a power supply voltage is applied and a second end from which power supply is provided to the amplifier through the output terminal of the amplifier, and a first attenuation circuit disposed between the output terminal of the amplifier and the second end of the choke inductor and configured to attenuate a harmonic component of the amplified signal.

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.

The present disclosure discloses a Doherty power amplifier, including at least one carrier power amplifier and at least one peak power amplifier connected in parallel, each carrier power amplifier includes at least one carrier power amplifier unit connected in parallel for power combination, and each peak power amplifier includes at least one peak power amplifier unit connected in parallel for power combination, each of the carrier power amplifier unit and the peak power amplifier unit includes two power amplifier circuits connected in parallel for power combination, and each of the two power amplifier circuits includes a medium-low power amplifier transistor having saturation power less than or equal to a preset threshold. The present disclosure further discloses a power amplification method.

Improvement in heat dissipation capability is intended. A radio-frequency module includes a mounting substrate, a plurality of transmission filters, a resin layer, and a shield layer. The mounting substrate has a first major surface and a second major surface opposite to each other. The plurality of transmission filters is mounted on the first major surface of the mounting substrate. The resin layer is disposed on the first major surface of the mounting substrate and covers at least part of an outer peripheral surface of each of the plurality of transmission filters. The shield layer covers the resin layer and at least part of each of the plurality of transmission filters. At least part of a major surface of each of the plurality of transmission filters on an opposite side to the mounting substrate side is in contact with the shield layer.

Provided is a power amplification circuit that includes: an amplifier that amplifies an input signal and outputs an amplified signal; a first bias circuit that supplies a first bias current or voltage to the amplifier; a second bias circuit that supplies a second bias current or voltage to the amplifier; a first control circuit that controls the first bias current or voltage; and a second control circuit that controls the second bias current or voltage. The current supplying capacity of the first bias circuit is different from the current supplying capacity of the second bias circuit.

A multi-bit digital signal that is generated by modulating a baseband signal by a modulation circuit and includes components in a radio frequency band is amplified by switch-mode amplifiers (100-1, 100-2) on a bit-by-bit basis, amplified signals are band-limited by frequency-variable variable band limiting units (201-1, 201-2) and thereafter subjected to voltage-to-current conversion by voltage/current source conversion units (202-1, 202-2) provided with variable capacitances, the signals converted to current are synthesized at a synthesis point X, and a resultant signal is impedance-corrected by an impedance correction unit (203) and output as a transmission signal to an antenna of a load (300). Consequently, the present invention provides a transmitter capable of synthesizing output signals from a plurality of switch-mode amplifiers and transmitting a resultant signal while maintaining an impedance characteristic with respect to a plurality of transmit frequencies without increasing a circuit size.