Apparatus and methods for envelope tracking systems with automatic mode selection are provided herein. In certain configurations, a power amplifier system includes a power amplifier that amplifies a radio frequency signal and that receives power from a power amplifier supply voltage. The power amplifier system further includes an envelope tracker that generates the power amplifier supply voltage based on an envelope signal corresponding to an envelope of the radio frequency signal. The envelope tracker includes a signal bandwidth detection circuit that processes the envelope signal to generate a detected bandwidth signal, and a mode control circuit that controls a mode of the error amplifier based on the detected signal bandwidth.

Apparatus and methods for envelope tracking systems are provided. In certain configurations, an envelope tracking system includes a digital filter that generates a filtered envelope signal based on a digital envelope signal representing an envelope of a radio frequency signal, a buck converter controllable by the filtered envelope signal and including an output electrically connected to a power amplifier supply voltage, a digital-to-analog converter module including an output electrically connected to the output of the buck converter and that provides an output current, and a digital shaping and delay circuit configured to generate a shaped envelope signal based on shaping the filtered envelope signal. The shaped envelope signal controls a magnitude of the output current, and the digital shaping and delay circuit controls a delay of the shaped envelope signal to align the output of the digital-to-analog converter module and the output of the buck converter.

A multi-band RF power amplifier circuit fabricated using GaN technology includes a RF power amplifier coupled to a multi-band RF switch without an intervening impedance matching network between the RF power amplifier and the multi-band RF switch. The multi-band RF switch includes a plurality of Unit HEMT cells. In one IC package, the RF power amplifier, the multi-band RF switch, a controller for controlling the switch and all connection therebetween are totally contained within the IC package. In another IC package, the RF power amplifier and the multi-band RF switch are disposed on a single substrate.

A multi-band RF power amplifier circuit fabricated using GaN technology includes a RF power amplifier coupled to a multi-band RF switch without an intervening impedance matching network between the RF power amplifier and the multi-band RF switch. The multi-band RF switch includes a plurality of Unit HEMT cells. In one IC package, the RF power amplifier, the multi-band RF switch, a controller for controlling the switch and all connection therebetween are totally contained within the IC package. In another IC package, the RF power amplifier and the multi-band RF switch are disposed on a single substrate.

A distributed amplification device with p inputs, p outputs, p amplification paths comprises a redundant reservoir of n amplifiers including n-p back-up amplifiers, an input redundancy ring and an output redundancy ring formed by rotary switches, the input and output redundancy rings sharing the same technology. The internal amplification pathways associated with the n-p back-up amplifiers frame in an interlaced manner the internal amplification pathways associated with the p nominal amplifiers and the amplification paths of the routing configurations each pass through at least five rotary switches. The input and output redundancy rings are topologically and geometrically configured and the family of the routing configurations is chosen such that the electrical lengths of all the paths of one and the same routing configuration of the family are equal.

In a sensor reader, an IC chip has a function for amplifying and outputting a sensor signal from each sensor element included in a sensor array, and includes a plurality of channel amplifiers connected each of the sensor elements. When an output switch is closed and the IC chip is in the outputting state, channel switches operate sequentially, and sensor amplification signals are output sequentially from the channel amplifiers. When the output switch is open and the IC chip is in the non-outputting state, a bias current of an operational amplifier of the channel amplifier is decreased, the IC chip is set to a low power consumption state, and gain of the operational amplifier is decreased.

A communication device including a signal generator configured to generate a transmitting signal that uses a plurality of frequency bands, an amplifier configured to amplify and output the transmitting signal, a plurality of duplexers configured to separate and output a receiving signal and the transmitting signal, and a controller. The controller is configured to control power amplification of the transmitting signal by the amplifier based on the transmitting signal output from the duplexer, and control power amplification of the transmitting signal by the amplifier based on the transmitting signal input to the duplexer from the amplifier when a temperature is a predetermined value or more or the frequency of the transmitting signal is a predetermined value or more.

A wireless communication device includes an amplifier block amplifying a radio frequency (RF) input signal. The amplifier block includes: a first amplification unit and a second amplification unit. The first amplification unit amplifies the RF input signal to generate a first RF amplified signal including a first non-linearity factor and a second RF amplified signal including a second non-linearity factor, and combines the first and second RF signals to generate a third RF amplified signal. The second amplification unit receives and amplifies the third RF amplified signal to output an RF output signal corresponding to the at least one carrier.

Disclosed are systems, devices, and methodologies to reduce harmonics in a radio frequency output signal. A power amplifier system comprises a power amplifier and a tunable output matching network electrically connected between the output of the power amplifier and an output of the tunable output matching network. The tunable output matching network reduces second-order harmonics in an amplified radio frequency signal when the power amplifier operates in a low frequency mode. The tunable output matching network includes traps such as a series inductor and a first capacitor in series with a first switch, a second capacitor in series with a second switch, and a third capacitor in series with a third switch, where the traps are tuned to selected harmonic frequencies when the power amplifier operates in the low frequency band of the operating band of frequencies.

Integrated filter and electromagnetic coupler assemblies. In certain examples, an integrated filter and electromagnetic coupler assembly includes a filter having a capacitance and a series inductance, the series inductance being connected between an input port and an output port of the integrated filter and electromagnetic coupler assembly, and combination of the capacitance and the series inductance being selected to provide the filter with a passband and a stopband. The integrated filter and electromagnetic coupler assembly further includes a coupling element positioned physically proximate the series inductance and extending between a coupled port and an isolation port of the integrated filter and electromagnetic coupler assembly, the integrated filter and electromagnetic coupler assembly being configured to provide at the coupled port a coupled signal via inductive coupling between the series inductance and the coupling element responsive to receiving an input signal at the input port.