The example embodiments are directed to a push-pull amplifier embedded with cross-coupled transistor feedback cancellation. In one example, the amplifier may include a first load, a second load, a circuit comprising first and second field effect transistors (FETs) that are electrically coupled to each other and that are electrically coupled to the first load and the second load, and a feedback cancellation circuit that interconnects the first and second FETs and comprises coupling capacitors configured to increase gain, circuit stability, and Power Added Efficiency (PAE) from the first and second FETs.

An amplifier device is presented that may include an integrated passive device (IPD). The IPD includes a substrate and a power splitter on the substrate. The power splitter includes a power splitter input terminal, a first power splitter output terminal having a first output impedance, and a second power splitter output terminal having a second output impedance that is different from the first output impedance. The power splitter is an asymmetric Wilkinson power splitter configured to receive a first signal at the power splitter input terminal, divide the first signal into a first output signal and a second output signal, output the first output signal at the first power splitter output terminal, and output the second output signal at the second power splitter output terminal.

A wideband amplifier includes an input matching network for matching a transconductor stage to an input impedance and includes an output matching network for matching the transconductor stage to an output impedance. Both the input and output matching networks each includes a parallel LC tank circuit arranged in parallel with a series LC tank circuit. The tank circuit arrangements configure the input and output matching networks to be resonant at a first frequency, a midrange frequency that is greater than the first frequency, and a second frequency that is greater than the midrange frequency to provide wideband matching.

According to one aspect, an integrated circuit having a radio frequency amplifier includes at least two amplifier stages and an impedance matching device between two amplifier stages of the radio frequency amplifier. The matching device includes two lines which are coupled by electromagnetic induction. The first line is connected to an output of the first amplifier stage and the second line is connected to an input of the second amplifier stage.

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.

This disclosure relates to bipolar transistors, such as heterojunction bipolar transistors, having retrograde doping concentration in the collector. One aspect of this disclosure is a bipolar transistor that includes a collector having a retrograde doping profile in which a doping concentration is highest at a junction of the base and the collector and decreases through a portion of the collector to about 95% less to about 99.5% less. Such bipolar transistors can be implemented, for example, in power amplifiers.

Apparatus and methods for biasing power amplifiers are provided herein. In certain embodiments, a power amplifier includes a bipolar transistor having a base biased by a bias network having a reactance that controls an impedance at the transistor base to achieve substantially flat phase response over large dynamic power levels. For example, the bias network can have a frequency response, such as a high-pass or band-pass response, that reduces the impact of power level on phase distortion (AM/PM).

A matching circuit includes: a first wire having one end connected to a first terminal and another end; a second wire having one end connected to the other end of the first wire and another end connected to a first reference potential and electromagnetically coupled to the first wire; and a third wire having one end connected to the one end of the second wire and another end connected to a second terminal and electromagnetically coupled to at least one of the first wire and the second wire.

The present disclosure provides methods for manufacturing Doherty power amplifiers. The methods include: providing at least one main amplifier operated at a fundamental frequency; providing at least one peaking amplifier connected to the main amplifier in parallel and sharing a common load or a load; and connecting a first hybrid integrated matching circuit between output terminals of the at least one main amplifier and the at least one peaking amplifier. Connecting the first hybrid integrated matching circuit includes connecting a first circuit between the output terminals of the at least one main amplifier and the at least one peaking amplifier. The first circuit contributes as a part of an impedance inverting network of the first hybrid integrated matching circuit of the Doherty power amplifier.

Provided are an interstage matching circuit and a push-pull power amplifier circuit. The push-pull power amplifier circuit comprises a pre-stage push-pull amplifier circuit and a post-stage push-pull amplifier circuit. The interstage matching circuit comprises a first matching capacitor connected in series between the pre-stage push-pull amplifier circuit and the post-stage push-pull amplifier circuit; and a second matching capacitor connected in series between the pre-stage push-pull amplifier circuit and the post-stage push-pull amplifier circuit; a first matching inductor is connected with a connection node between the pre-stage push-pull amplifier circuit and the first matching capacitor, the first matching inductor is connected with a second matching inductor, the second matching inductor is connected with a connection node between the pre-stage push-pull amplifier circuit and the second matching capacitor, and a connection node between the first matching inductor and the second matching inductor is used for connecting with a feed power supply.