An amplification circuit includes an input terminal for receiving a radio frequency input signal, an output terminal for outputting an amplified radio frequency signal, a bias circuit for providing a bias voltage, an impedance circuit, a transistor, and a filter circuit. The impedance circuit is coupled to the bias circuit and the input terminal, and provides a voltage drop between the first terminal and the second terminal of the impedance circuit. The first transistor has a first terminal coupled to the output terminal, a second terminal coupled to a first reference voltage terminal, and a control terminal coupled to the impedance circuit and for receiving the radio frequency input signal. The filter circuit is coupled to the first transistor and the impedance circuit, filters out a harmonic signal, and provides a feedback signal including a primary frequency signal of the amplified radio frequency signal to the impedance circuit.

A bias circuit generates a bias current to an RF power amplifier used for transmitting RF signals, and the amount of the bias current supplied to the RF power amplifier can be configured in multiple modes through transistor switches that are controlled by mode control signals, so that the bias current supplied to the RF power amplifier can be adjusted according to the required power level of the transmitting RF signals. In addition, the bias current can be turned off by another transistor switch that is controlled by a power control signal for saving power while the RF power amplifier is not transmitting RF signals.

A millimeter wave power amplifier device has multiple millimeter wave power amplifier circuits. Each millimeter wave power amplifier circuit includes a transistor, a first serial connection resonation unit, a second serial connection resonation unit, multiple first frequency band adjustment units and multiple second frequency band adjustment units. The transistor has a first end connected with an input end, a second end connected with a grounding end and a third end connected with an output end. Each of the first and second frequency band adjustment units has a switch member and two storage members. The switch member and the storage members of the first and second frequency band adjustment units are serially connected. The millimeter wave power amplifier device can achieve multi-frequency band adjustable effect to lower the cost.

A power amplifier module includes an output-stage amplifier, a driver-stage amplifier, an input switch, an output switch, an input matching circuit, an inter-stage matching circuit, an output matching circuit, and a control circuit. The input switch selectively connects one of a plurality of input signal paths to an input terminal of the driver-stage amplifier. The output switch selectively connects one of a plurality of output signal paths to an output terminal of the output-stage amplifier. The control circuit controls operations of the driver-stage amplifier and the output-stage amplifier. The input switch, the output switch, and the control circuit are integrated into an IC chip. The control circuit is disposed between the input switch and the output switch.

A power amplifier module includes first and second amplifiers, a first bias circuit, and an adjusting circuit. The first amplifier amplifies a first signal. The second amplifier amplifies a second signal based on an output signal from the first amplifier. The first bias circuit supplies a bias current to the first amplifier via a current path on the basis of a bias drive signal. The adjusting circuit includes an adjusting transistor having first, second, and third terminals. A first voltage based on a power supply voltage is supplied to the first terminal. A second voltage based on the bias drive signal is supplied to the second terminal. The third terminal is connected to the current path. The adjusting circuit adjusts the bias current on the basis of the power supply voltage supplied to the first amplifier.

A transistor amplifier includes at least one differential pair of transistors and a plurality of transformers having a primary winding and a tapped secondary winding. The secondary winding is connected across emitters or sources of each transistor pair. The tap of each secondary has a current source. The primary windings of the plurality of transformers are connected in series. The transistor bases or gates are alternating current (AC) grounded. The collector or drain terminal pairs are connected in parallel. The transistor amplifier exhibits improved input impedance and improved linearity.

In one embodiment, an impedance matching network includes a variable reactance circuit providing a variable capacitance or inductance. The variable reactance circuit includes reactance components and corresponding switching circuits. Each of the switching circuits includes a diode and a driver circuit to switch the diode. The driver circuit includes first and second switches coupled in series. A first driver is coupled to the first switch, a second driver is coupled to the second switch, and a third driver is coupled to the first and second drivers. The third driver provides a first signal to the first driver, and a second signal to the second driver. In providing the signals, the third driver increases and decreases a duration of a dead time between (a) driving the first driver on and the second driver off, or (b) driving the second driver on and the first driver off.

Provided is a power amplification module that includes: a first transistor, a first signal being inputted to a base thereof; a second transistor, the first signal being inputted to a base thereof and a collector thereof being connected to a collector of the first transistor; a first resistor, a first bias current being supplied to one end thereof and another end thereof being connected to the base of the first transistor; a second resistor, one end thereof being connected to the one end of the first resistor and another end thereof being connected to the base of the second transistor; and a third resistor, a second bias current being supplied to one end thereof and another end thereof being connected to the base of the second transistor.

The present disclosure relates to devices and methods for detecting and preventing occurrence of a saturation state in a power amplifier. A power amplifier module can include a power amplifier including a cascode transistor pair. The cascode transistor pair can include a first transistor and a second transistor. The power amplifier module can include a current comparator configured to compare a first base current of the first transistor and a second base current of the second transistor to obtain a comparison value. The power amplifier module can include a saturation controller configured to supply a reference signal to an impedance matching network based on the comparison value. The impedance matching network can be configured to modify a load impedance of a load line in electrical communication with the power amplifier based at least in part on the reference signal.

The present disclosure relates to devices and methods for detecting and preventing occurrence of a saturation state in a power amplifier. A power amplifier module can include a power amplifier including a cascode transistor pair. The cascode transistor pair can include a first transistor and a second transistor. The power amplifier module can include a current comparator configured to compare a first base current of the first transistor and a second base current of the second transistor to obtain a comparison value. The power amplifier module can include a saturation controller configured to supply a reference signal to an impedance matching network based on the comparison value. The impedance matching network can be configured to modify a load impedance of a load line in electrical communication with the power amplifier based at least in part on the reference signal.