A dual mode notch filter for use in a multi-band millimeter wave (mmW) transmitter includes a transmit filter circuit disposed between two amplifiers in a mmW transmit signal path, the transmit filter circuit formed by at least one switch, at least one capacitor, and a double-tuned transformer, the transmit filter circuit having at least two modes configured to selectively filter a spurious signal in at least a first communication band.

An autotuning controller is provided for improving power efficiency and linearity of digital power amplifiers (DPAs). The controller includes an interface including input and output terminals connected to the DPAs, the interface being configured to acquire input signals and output signals, a digital pre-distortion (DPD)-DPA adaptive controller including a processor and a memory running and storing a DPD algorithm, an efficiency enhancement method and a learning cost function. The DPD adaptive controller is configured to perform steps of computing DPD coefficients to define a learning cost function based on a DPD model by use of a data-driven optimization method, wherein the leaning cost function includes both variables of a DDA performance and a DPD performance, updating the learning cost function based on the DPD performance, optimizing the updated learning cost function by solving the updated learning cost function with respect to the variables of the DDA performance, and providing optimal parameters for DPA and DPD via the interface.

A power amplifier circuit amplifies a radio-frequency signal in a transmit frequency band. The power amplifier circuit includes an amplifier, a bias circuit, and an impedance circuit. The amplifier amplifies power of a radio-frequency signal and outputs an amplified signal. The impedance circuit is connected between a signal input terminal of the amplifier and a bias-current output terminal of the bias circuit and has frequency characteristics in which attenuation is obtained in the transmit frequency band. The impedance circuit includes first and second impedance circuits. The first impedance circuit is connected to the signal input terminal. The second impedance circuit is connected between the first impedance circuit and the bias-current output terminal.

Disclosed in the present invention are a balanced radio frequency power amplifier, a chip and a communication terminal. The radio frequency power amplifier divides, by means of a 90-degree power splitter unit, a radio frequency input signal into two equal-amplitude signals having a phase difference of 90 degrees, the two radio frequency input signals are amplified and then inputted into an adjustable 90-degree power combiner, and the values of a adjustable capacitor and an adjustable resistor in the adjustable 90-degree power combiner are controlled by means of a control unit, so as to synthesize the two radio frequency input signals into one radio frequency input signal when the phase difference and amplitude difference of the two signals at different frequencies are the smallest, and to input the radio frequency input signal into a circuit of the next stage by means of a specific radio frequency transmission path.

An amplifier circuit comprises a first gain circuit path configured to provide a first signal gain to an input signal, a second gain circuit path configured to provide a second signal gain to an input signal, an auxiliary gain circuit path configured to provide an auxiliary signal gain to an auxiliary input signal, wherein the auxiliary signal gain is equal to the first signal gain minus the second signal gain, a summing circuit configured to sum the second gain signal path and the auxiliary signal path, and logic circuitry configured to change an output of the circuit between the first gain circuit path and the sum of the second gain signal path and the auxiliary signal path, and set the auxiliary input signal equal to the input signal before the changing.

An electronic switch for switching between signal outputs comprises a 6-way symmetric hybrid ring combiner. Each port within the 6-way symmetric hybrid ring combiner is positioned at λ/4 wavelength increments around a circumference of the 6-way symmetric hybrid ring combiner.

A balanced-to-Doherty (B2D) mode-reconfigurable power amplifier (PA) has the capability of maintaining high linearity and high efficiency against load mismatch. The reconfigurable PA includes a switch to alternatively connect to a pre-determined resistive load or a pre-determined pure reactive load (jX), i.e., short, open, or finite reactance between an output quadrature coupler and ground. The biasing of Doherty mode is adaptive dependent on the value of reactive loading (jX). The Doherty operation of this PA is based on an architecture configured from a balanced amplifier, e.g., a quasi-balanced amplifier.

Systems and devices are provided for tracking pullup current generated by power amplifiers regardless of variations in PVT conditions. An apparatus may include one or more power amplifiers that powers components of the apparatus, a tracking circuit, and a pulse generation circuit. The tracking circuit may include an amplifier. Further, the tracking circuit may include pullup current tracking circuitry that is coupled to the amplifier and generates a first current that tracks pullup current generated by the one or more power amplifiers. Furthermore, the pulse generation circuit may include pullup current generator circuitry that generates a second current that mirrors the first current. In addition, the pulse generation circuit may also include pulse generator circuitry that is coupled to the pullup current generator circuitry and that generates a pulse to control operation of the one or more power amplifiers based at least in part on the second current.

An amplifier includes a semiconductor die and a substrate that is distinct from the semiconductor die. The semiconductor die includes a III-V semiconductor substrate, a first RF signal input terminal, a first RF signal output terminal, and a transistor (e.g., a GaN FET). The transistor has a control terminal electrically coupled to the first RF signal input terminal, and a current-carrying terminal electrically coupled to the first RF signal output terminal. The substrate includes a second RF signal input terminal, a second RF signal output terminal, circuitry coupled between the second RF signal input terminal and the second RF signal output terminal, and an electrostatic discharge (ESD) protection circuit. The amplifier also includes a connection electrically coupled between the ESD protection circuit and the control terminal of the transistor. The substrate may be another semiconductor die (e.g., with a driver transistor and/or impedance matching circuitry) or an integrated passive device.

A radio-frequency module includes a module substrate and a power amplification circuit that includes first to fourth amplification elements, a transformer including primary and secondary coils, an output terminal to which the secondary coil is connected, and a circuit component disposed on the module substrate. Output terminals of the first and third amplification elements and output terminals of the second and fourth amplification elements are respectively connected to a first terminal and a second terminal of the primary coil. A capacitor is connected to a wiring line path connected between the output terminal of the first amplification element and the first terminal of the primary coil and to a wiring line path connected between the output terminal of the second amplification element and the second terminal of the primary coil. The primary or secondary coil includes a conductive layer surrounding at least part of the circuit component.