Monolithic microwave integrated circuits are provided that include a substrate, a transmit/receive selection device that is formed on the substrate, a high power amplifier formed on the substrate and coupled to a first RF port of the transmit/receive selection device, a low noise amplifier formed on the substrate and coupled to a second RF port of the transmit/receive selection device and a protection circuit that is coupled to a first control port of the transmit/receive selection device.

Embodiments of RF amplifiers and packaged RF amplifier devices each include a transistor with a drain-source capacitance that is relatively low, an output impedance matching circuit, and a harmonic termination circuit. The impedance matching circuit includes a harmonic termination circuit, which includes a first inductance (a first plurality of bondwires) and a first capacitance coupled in series between the transistor output and a ground reference node. An equivalent capacitance from a combination of the first inductive element and the first capacitance in series effectively increases the drain-source capacitance by at least 10 percent. The impedance matching circuit also includes a second inductance (a second plurality of bondwires) and a second capacitance coupled in series between the transistor output and the ground reference node, where the second inductance and the second capacitance are directly connected. The first and second capacitances may be metal-insulator-metal capacitors in an integrated passive device.

Embodiments of RF amplifiers and packaged RF amplifier devices each include a transistor with a drain-source capacitance that is relatively low, an output impedance matching circuit, and a harmonic termination circuit. The impedance matching circuit includes a harmonic termination circuit, which includes a first inductance (a first plurality of bondwires) and a first capacitance coupled in series between the transistor output and a ground reference node. An equivalent capacitance from a combination of the first inductive element and the first capacitance in series effectively increases the drain-source capacitance by at least 10 percent. The impedance matching circuit also includes a second inductance (a second plurality of bondwires) and a second capacitance coupled in series between the transistor output and the ground reference node, where the second inductance and the second capacitance are directly connected. The first and second capacitances may be metal-insulator-metal capacitors in an integrated passive device.

A power amplifier circuit includes a first transistor that amplifies a first signal and outputs a second signal; a second transistor that amplifies the second signal and outputs a third signal; a bias circuit that supplies a bias current to a base of the second transistor; and a bias adjustment circuit that adjusts the bias current to be supplied by the bias circuit by subjecting the first signal to detection. The bias adjustment circuit controls the bias current to be supplied to the base of the second transistor by drawing, from the bias circuit, a current of a magnitude corresponding to a magnitude of the first signal. The current increases as the magnitude of the first signal increases.

Methods and circuital arrangements for turning OFF branches of a multi-branch cascode amplifier are presented. First and second switching arrangements coupled to a branch allow turning OFF the branch while protecting transistors of the branch from a supply voltage that may be greater than a tolerable voltage of the transistors. The first switching arrangement includes a transistor-based switch that is in series connection with the transistors of the branch. The first switching arrangement drops the supply voltage during the OFF state of the branch and provides a conduction path for a current through the branch during the ON state of the branch. A resistor and a shunting switch are coupled to a gate of the transistor-based switch to reduce parasitic coupling effects of the transistor-based switch upon an RF signal coupled to the branch during the ON state and OFF state of the branch.

Methods and circuital arrangements for turning OFF branches of a multi-branch cascode amplifier are presented. First and second switching arrangements coupled to a branch allow turning OFF the branch while protecting transistors of the branch from a supply voltage that may be greater than a tolerable voltage of the transistors. The first switching arrangement includes a transistor-based switch that is in series connection with the transistors of the branch. The first switching arrangement drops the supply voltage during the OFF state of the branch and provides a conduction path for a current through the branch during the ON state of the branch. A resistor and a shunting switch are coupled to a gate of the transistor-based switch to reduce parasitic coupling effects of the transistor-based switch upon an RF signal coupled to the branch during the ON state and OFF state of the branch.

Systems and methods for magnitude and phase trimming are provided. In one aspect, a radio frequency (RF) trimmer circuit includes an input terminal configured to receive an RF signal, an output terminal configured to output the RF signal, a control input configured to receive a control signal, at least one impedance element, and at least one transistor configured to selectively connect the impedance element onto a path between the input and output terminals. The selectively connecting the impedance element controls at least one of a magnitude trim and a phase trim of the RF signal.

Systems and methods for magnitude and phase trimming are provided. In one aspect, a radio frequency (RF) trimmer circuit includes an input terminal configured to receive an RF signal, an output terminal configured to output the RF signal, a control input configured to receive a control signal, at least one impedance element, and at least one transistor configured to selectively connect the impedance element onto a path between the input and output terminals. The selectively connecting the impedance element controls at least one of a magnitude trim and a phase trim of the RF signal.

A power amplifier can include a carrier amplifier having first and second differential amplification cells with outputs coupled by a primary loop of a carrier transformer, and a peaking amplifier having first and second differential amplification cells with outputs coupled by a primary loop of a peaking transformer. The power amplifier can further include a combiner having a quarter-wave circuit implemented between the secondary loop of the carrier transformer and a secondary loop of the peaking transformer. The quarter-wave circuit can be configured to provide a characteristic impedance, such that the carrier and peaking amplifiers are presented with an impedance that is approximately the same as the characteristic impedance when both of the carrier and peaking amplifiers are turned on, and the carrier amplifier is presented with an impedance that is approximately twice the characteristic impedance when the carrier amplifier is turned on and the peaking amplifier is turned off.

A power amplifier can include a carrier amplifier having first and second differential amplification cells with outputs coupled by a primary loop of a carrier transformer, and a peaking amplifier having first and second differential amplification cells with outputs coupled by a primary loop of a peaking transformer. The power amplifier can further include a combiner having a quarter-wave circuit implemented between the secondary loop of the carrier transformer and a secondary loop of the peaking transformer. The quarter-wave circuit can be configured to provide a characteristic impedance, such that the carrier and peaking amplifiers are presented with an impedance that is approximately the same as the characteristic impedance when both of the carrier and peaking amplifiers are turned on, and the carrier amplifier is presented with an impedance that is approximately twice the characteristic impedance when the carrier amplifier is turned on and the peaking amplifier is turned off.