A Doherty amplifier module includes a substrate, an RF signal splitter, a carrier amplifier die, and first and second peaking amplifier dies. The RF signal splitter divides an input RF signal into first, second, and third input RF signals, and conveys the input RF signals to splitter output terminals. The carrier amplifier die includes one or more first power transistors configured to amplify, along a carrier signal path, the first input RF signal to produce an amplified first RF signal. The peaking amplifier dies each include one or more additional power transistors configured to amplify, along first and second peaking signal paths, the second and third input RF signals to produce amplified second and third RF signals. The dies are coupled to the substrate so that the RF signal paths through the carrier and one or more of the peaking amplifier dies extend in substantially different (e.g., orthogonal) directions.

An amplifier includes amplification stages connected in parallel between an input point and an output point and a feedback circuit, wherein the amplification stages each include a transistor configured to amplify a signal supplied from the input point, a harmonic processing unit configured to process harmonics present in an amplified signal output from an output node of the transistor, a connection point between the output node and the harmonic processing unit, and a transmission line connecting the connection point and the output point, wherein the feedback circuit feeds back a signal at the output point or a midway point of the transmission line of a given one of the amplification stages to a first end of a resistor connected to the connection point of the given one of the amplification stages, a second end of the resistor being connected to the connection point of another one of the amplification stages.

In a case where the power of a signal to be amplified is greater than or equal to a threshold value, a signal distributor (2) outputs one of signals to a carrier amplifier (6), outputs another signal, a phase of which is 90 degrees behind that of the one of the signals, to a peak amplifier (8), and adjusts a phase shift amount of a signal shifted by a phase shifter (7) depending on the frequency of the signal to be amplified. In a case where the power of the signal to be amplified is less than the threshold value, the signal distributor (2) outputs the one of the signals to the carrier amplifier (6) without outputting the other signal to the peak amplifier (8).

A power amplifier (PA) system is provided for multi-mode multi-band operations. The PA system includes one or more amplifying modules, each amplifying module including one or more banks, each bank comprising one or more transistors; and a plurality of matching modules, each matching module being configured to be adjusted to provide impedances corresponding to frequency bands and conditions. A controller dynamically controls an input terminal of each bank and adjusts the matching modules to provide a signal path to meet specifications on properties associated with signals during each time interval.

An embodiment of an amplifier includes a first amplifier with a first output terminal, a second amplifier with a second output terminal, and a plurality of microstrip transmission lines electrically connected to the amplifiers. The transmission lines include an impedance inverter line electrically connected between the first and second output terminals, and an output line electrically connected between the second output terminal and an output of the amplifier, where the output line forms a portion of an output impedance transformer. The amplifier also includes a directional coupler formed from a main line and a coupled line positioned in proximity to the main line, where the main line is formed from a portion of one of the transmission lines. The amplifier may also include a module substrate with a plurality of metal layers, where the main line and the coupled line are formed from different portions of the metal layers.

An embodiment of an amplifier includes a first amplifier with a first output terminal, a second amplifier with a second output terminal, and a plurality of microstrip transmission lines electrically connected to the amplifiers. The transmission lines include an impedance inverter line electrically connected between the first and second output terminals, and an output line electrically connected between the second output terminal and an output of the amplifier, where the output line forms a portion of an output impedance transformer. The amplifier also includes a directional coupler formed from a main line and a coupled line positioned in proximity to the main line, where the main line is formed from a portion of one of the transmission lines. The amplifier may also include a module substrate with a plurality of metal layers, where the main line and the coupled line are formed from different portions of the metal layers.

An embodiment of a Doherty amplifier module includes a substrate, an RF signal splitter, a carrier amplifier die, and a peaking amplifier die. The RF signal splitter divides an input RF signal into first and second input RF signals, and conveys the first and second input RF signals to first and second splitter output terminals. The carrier amplifier die includes one or more first power transistors configured to amplify, along a carrier signal path, the first input RF signal to produce an amplified first RF signal. The peaking amplifier die includes one or more second power transistors configured to amplify, along a peaking signal path, the second input RF signal to produce an amplified second RF signal. The carrier and peaking amplifier die are coupled to the substrate so that the RF signal paths through the carrier and peaking amplifier die extend in substantially different (e.g., orthogonal) directions.

An electronic device may include wireless circuitry having one or more radio-frequency amplifiers coupled to differential coupled lines. The differential coupled lines may provide routing and impedance matching for the radio-frequency amplifiers with minimal power loss. The differential coupled lines may include a first pair of coupled lines and a second pair of coupled lines. The first pair of coupled lines may include a first conductive routing path coupled to a first voltage line and a second conductive routing path routed along the first conductive routing path and coupled to a second voltage line. The second pair of coupled lines may include a third conductive routing path coupled to the first voltage line and a fourth conductive routing path routed along the third conductive routing path and coupled to the second voltage line.

A distributed circuit includes: a first transmission line that has an input end to which an input signal is input; a second transmission line that has an output end from which an output signal is output; a plurality of unit cells that are disposed along the first and second transmission lines, the input terminals of the unit cells being connected to the first transmission line, the output terminals of the unit cells being connected to the second transmission line; two input termination resistors connected in parallel to an end of the first transmission line; and two output termination resistors connected in parallel to an end of the second transmission line. In the distributed circuit, at least one input termination resistor is a temperature-gradient resistor, and voltages at the two input termination resistors are changed symmetrically.

A power amplifier (PA) system is provided for multi-mode multi-band operations. The PA system includes one or more amplifying modules, each amplifying module including one or more banks, each bank comprising one or more transistors; and a plurality of matching modules, each matching module being configured to be adjusted to provide impedances corresponding to frequency bands and conditions. A controller dynamically controls an input terminal of each bank and adjusts the matching modules to provide a signal path to meet specifications on properties associated with signals during each time interval.