Cree Gmbh

Cree Microwave, Inc.

Raymond Sydney Pengelly

Simon Maurice Wood

Christopher Harris

James Milligan

William Pribble

John Phillip Quinn

E James Crescenzi

Tom Stewart Dekker

The disclosure relates to an enhanced Doherty amplifier that provides significant performance improvements over conventional Doherty amplifiers. The enhanced Doherty amplifier includes a power splitter, combining node, a carrier path, and a peaking path. The power splitter is configured to receive an input signal and split the input signal into a carrier signal provided at a carrier splitter output and a peaking signal provided at a peaking splitter output. The carrier path includes carrier power amplifier circuitry, a carrier input network coupled between the carrier splitter output and the carrier power amplifier circuitry, and a carrier output network coupled between the carrier power amplifier circuitry and the Doherty combining node. The peaking path includes peaking power amplifier circuitry, a peaking input network coupled between the peaking splitter output and the peaking power amplifier circuitry, and a carrier output network coupled between the power amplifier circuitry and the Doherty combining node.

Enhanced doherty amplifier

The present disclosure relates to transmission circuitry of a wireless communication device. The transmission circuitry includes power amplifier circuitry, an output matching network, and impedance control circuitry. The power amplifier circuitry amplifies a radio frequency (RF) input signal to provide an amplified RF output signal, which is passed through the output matching network and transmitted via one or more antennas. As the center frequency of the RF input signal and conditions of operating parameters change, the impedance control circuitry adjusts the values of one or more variable impedance elements of the output matching network in a desired fashion. The values of the variable impedance elements are adjusted such that the output matching network concurrently and dynamically presents the desired load impedances at the center frequency and at one or more harmonics of the RF input signal to achieve a given performance specification.

Matching network for transmission circuitry

Enhanced Doherty amplifier

A power amplifier circuit includes an unequal power splitter that splits an input signal using an unequal power split and provides a first power level signal and a second power level signal. A first amplifier path includes a first transistor amplifier that amplifies the first power level signal, and a second amplifier path includes a second transistor amplifier that amplifies the second power level signal. The second transistor amplifier is configured to turn on at a different power level of the input signal than the first transistor amplifier. An unequal combiner combines the amplified first power level signal and the amplified second power level signal.

Progressive power generating amplifiers

A power amplifier circuit includes a power splitter that splits an input signal into a plurality of component input signals. At least two sets of transistor amplifiers are each coupled in parallel to the power splitter to receive and amplify different ones of the component input signals to generate amplified component output signals. The two transistor amplifiers of each set of transistor amplifiers are configured to turn on at different power levels of the input signal relative to each other. A combiner is configured to receive and combine the amplified component output signals from the at least two sets of transistor amplifiers into an output signal. An integrated circuit package encloses the power splitter, the at least two sets of transistor amplifiers, and the combiner.

Integrated circuit with parallel sets of transistor amplifiers having different turn on power levels

A switch mode power amplifier includes a transistor responsive to input signals above 1.0 GHz and which includes one terminal coupled to ground and another terminal conductively coupled to a power source. A resonant circuit coupled the second terminal to an output with a resistive load coupled across the output and ground. When the transistor is turned on the second terminal is coupled to ground and when the transistor is turned off, current from the power supply to the second terminal is steered into internal capacitance of the transistor and causes voltage on the second terminal to rise to a maximum value and then decrease, the voltage at the second terminal being coupled to the output terminal through the resonant circuit. In preferred embodiments, the transistor comprises a compound semiconductor field effect transistor with the first terminal being a source terminal and the second terminal being a drain terminal. The field effect transistor is preferably a compound high electron mobility transistor (HEMT) or compound MESFET, but in other embodiments the transistor can be the compound LDMOS, compound bipolar transistor, or compound MOSFET.

High efficiency switch-mode power amplifier

High power, high frequency switches include a transmission line having at least three portions that are serially coupled between an input port and an output port to define at least two nodes and to carry a high power, high frequency signal between the input port and the output port. First and second power transistors are provided. At least a third power transistor also is provided. The controlling electrode(s) (gate) of the first, second and/or third power transistor(s) are responsive to a switch control input. The controlled electrodes (source/drain) of a respective one of the first and second power transistors, and of a respective one of the third power transistor(s) are serially coupled between a respective one of the at least two nodes and a reference voltage. The power transistors may be silicon carbide MESFETs.

High power, high frequency switch circuits using strings of power transistors

A high power Doherty RF amplifier utilizes multi-stage amplifier modules for both the main amplifier and the peak amplifiers. In one embodiment of a two way two stage amplifier, the first stage of each amplifier module can include signal pre-distortion whereby the first stage compensates for distortion in both the first and second stages. The design is simple and results in a high efficiency amplifier with high gain. In one embodiment, a commercially available CREE PFM19030SM power module is used in both the main amplifier and the peak amplifier.

High power Doherty amplifier using multi-stage modules

The linearity of a transistor amplifier comprising a plurality of transistors operating parallel is improved by reducing the odd order transconductance derivatives of signals generated by the transistors. The transistors can be provided in groups with each group having a different bias voltage applied thereto or each group of transistors can have a different input signal applied thereto. The groups of transistors can have different physical parameters such as the width to length ratio of gates in field effect transistors and threshold voltages for the transistors.

RF transistor amplifier linearity using suppressed third order transconductance

Disclosed are a multi-chip power amplifier comprising a plurality chips with each chip being a transistor amplifier, and a housing in which all of the semiconductor chips are mounted. A plurality of input leads extend into the housing and a plurality of output leads extend from the housing. A plurality of first matching networks couple a semiconductor chip to an input lead and a plurality of second matching networks couple each semiconductor chip to an output lead whereby each chip has its own input lead and output lead. By providing all amplifier chips within a single housing with matching networks within the housing coupling the chips to the input and output leads, manufacturing cost is reduced and the overall package footprint on a mounting substrate is reduced. Further, the close proximity of the chips within the housing reduces phase differences among signals in the semiconductor chips.

Single package multi-chip RF power amplifier

An RF power amplifier circuit for amplifying an RF signal over a broad range of power with improved efficiency includes a carrier amplifier for amplifying an RF signal over a first range of power and with a power saturation level below the maximum of the broad range of power is disclosed. A plurality of peak amplifiers are connected in parallel with the carrier amplifier with each of the peak amplifiers being biased to sequentially provide an amplified output signal after the carrier amplifier approaches saturation. The input signal is applied through a signal splitter to the carrier amplifier and the plurality of peak amplifiers, and an output for receiving amplified output signals from the carrier amplifier and the plurality of peak amplifiers includes a resistive load R/2. The split input signal is applied through a 90&deg; transformer to the carrier amplifier, and the outputs of the peak amplifiers are applied through 90&deg; transformers to a output load. When operating below saturation, the carrier amplifier delivers power to a load of 2R and the carrier amplifier delivers current to the load, which is one-half the current at maximum power when the amplifier is saturated. In one embodiment with the output having an impedance, Z, the carrier amplifier and each peak amplifier is connected to the output through an output-matching network presenting an output impedance of less than Z to each amplifier and with each output-matching network having selected phase length to reduce reactance of the output impedance.

N-way RF power amplifier circuit with increased back-off capability and power added efficiency using selected phase lengths and output impedances

An RF power amplifier circuit for amplifying an RF signal over a broad range of power with improved efficiency includes a carrier amplifier for amplifying an RF signal over a first range of power and with a power saturation level below the maximum of the broad range of power is disclosed. One or more peak amplifiers are connected in parallel with the carrier amplifier with each of the peak amplifiers being biased to sequentially provide an amplified output signal after the carrier amplifier approaches saturation. The input signal is applied through a signal splitter to the carrier amplifier and the plurality of peak amplifiers, and an output for receiving amplified output signals from the carrier amplifier and the plurality of peak amplifiers includes a resistive load R/2. The split input signal is applied through a 90&deg; transformer to the carrier amplifier, and the outputs of the peak amplifiers are applied through 90&deg; transformers to a output load. When operating below saturation, the carrier amplifier delivers power to a load of 2R when the carrier amplifier delivers current to the load, which is one-half the current at maximum power and the amplifier is saturated. The signal splitter can split the input signal power equally among the carrier and one or more peak amplifiers, or the input signal can be split unequally with the carrier amplifier receiving less input power than each of the peak amplifiers and vice versa.

N-way RF power amplifier circuit with increased back-off capability and power added efficiency using unequal input power division

An RF power amplifier for amplifying an RF signal over a broad range of power with improved efficiency includes a main amplifier for amplifying an RF signal over a first range of power and with a power saturation level below the maximum of the broad range of power. A plurality of auxiliary amplifiers are connected in parallel with the main amplifier with each of the auxiliary amplifiers being biased to sequentially provide an amplified output signal after the main amplifier approaches saturation. The input signal is applied through a signal splitter to the main amplifier and the plurality of auxiliary amplifiers, and an output for receiving amplified output signals from the main amplifier and the plurality of auxiliary amplifiers includes a resistive load R/2. The split input signal is applied through a 90&deg; transformer to the main amplifier, and the outputs of the auxiliary amplifiers are applied through 90&deg; transformers to a output load. When operating below saturation, the main amplifier delivers power to a load of 2R and the main amplifier delivers current to the load which is one-half the current at maximum power and the amplifier is saturated.

Growing community of inventors

Hillsborough, NC, United States of America

Raymond Sydney Pengelly