Apparatus and methods for true power detection are provided herein. In certain embodiments, a power amplifier system includes an antenna, a directional coupler, and a power amplifier electrically connected to the antenna by way of a through line of the directional coupler. The power amplifier system further includes a first switch, a second switch, and a combiner that combines a first coupled signal received from a first end of the directional coupler's coupled line through the first switch and a second coupled signal received from a second end of the directional coupler's coupled line through the second switch.

A LNA comprises an input, a transformer structure and a first transistor and a second transistor, each having gate, source, and drain terminals. The transformer structure has a first winding pair, a second winding pair and a third winding pair. Each winding of the first winding pair connects to the input node and one source terminals of the transistors. The second winding pair is proximate the first winding pair. The second winding pair connects to a ground node and the transistor source terminals. The third winding pair is proximate the first winding pair and it connects to a bias signal source and a gate terminal of the transistors. An output connects to the transistor drain terminals. The windings of the first and second winding pairs are offset and rotated 180 degrees with respect to the other winding in the pair. The third winding pair performs a Gm boost function.

A power amplifier arrangement (200) for amplifying an input signal to produce an output signal comprises a plurality N of amplifier sections (212, 213), a first input transmission line (221) comprising multiple segments and a first output transmission line (231) comprising multiple segments. Each amplifier section comprises one or more first transistors (T1) distributed along the first input transmission line (221) and the first output transmission line (231). Each amplifier section is configured to amplify a portion of the input signal to produce a portion of the output signal. A portion of the input signal is one of N portions of the input signal partitioned on any one or a combination of an amplitude basis and a time basis. The output signal is produced at an end of the first output transmission line (231) by building up N potions of the output signal from each amplifier section.

A transistor device includes a transistor cell comprising a channel region, a gate runner that is electrically connected to a gate electrode on the channel region and physically separated from the gate electrode, and a harmonic termination circuit electrically connected to the gate runner between the gate electrode and an input terminal of the transistor device, the harmonic termination circuit configured to terminate signals at a harmonic frequency of a fundamental operating frequency of the transistor device.

Methods and apparatus for implementing a power efficient amplifier device through the use of a main (primary) and auxiliary (secondary) power amplifier are described. The primary and secondary amplifiers operate as current sources providing current to the load. Capacitance coupling is used to couple the primary and secondary amplifier outputs. In some embodiments the combination of primary and secondary amplifiers achieve high average efficiency over the operating range of the device in which the primary and secondary amplifiers are used in combination as an amplifier device. The amplifier device is well suited for implementation using CMOS technology, e.g., N-MOSFETs, and can be implemented in an integrated circuit space efficient manner that is well suited for supporting RF transmissions in the GHz frequency range, e.g., 30 GHz frequency range. The primary amplifier in some embodiments is a CLASS-AB or B amplifier and the secondary amplifier is a CLASS-C amplifier.

Gallium nitride based RF transistor amplifiers include a semiconductor structure having a gallium nitride based channel layer and a gallium nitride based barrier layer thereon, and are configured to operate at a specific direct current drain-to-source bias voltage. These amplifiers are configured to have a normalized drain-to-gate capacitance at the direct current drain-to-source bias voltage, and to have a second normalized drain-to-gate capacitance at two-thirds the direct current drain-to-source bias voltage, where the second normalized drain-to-gate capacitance is less than twice the first normalized drain-to-gate capacitance.

Gallium nitride based RF transistor amplifiers include a semiconductor structure having a gallium nitride based channel layer and a gallium nitride based barrier layer thereon, and are configured to operate at a specific direct current drain-to-source bias voltage. These amplifiers are configured to have a normalized drain-to-gate capacitance at the direct current drain-to-source bias voltage, and to have a second normalized drain-to-gate capacitance at two-thirds the direct current drain-to-source bias voltage, where the second normalized drain-to-gate capacitance is less than twice the first normalized drain-to-gate capacitance.

A single servo control loop for amplifier gain control based on signal power change over time or system to system, having an amplifier configured to receive an input signal on an amplifier input and generate an amplified signal on an amplifier output. The differential signal generator processes the amplified signal to generate differential output signals. The single servo control loop processes the differential output signal to generates one or more gain control signals and one or more current sink control signals. A gain control system receives a gain control signal and, responsive thereto, controls a gain of one or more amplifiers. A current sink receives a current sink control signal and, responsive thereto, draws current away from the amplifier input. Changes in input power ranges generate changes in the integration level of the differential signal outputs which are detected by the control loop, and responsive thereto, the control loop dynamically adjusts the control signals.

A hybrid diode silicon on insulator front end module and related method are provided. The front end module includes a transmit branch that includes a transmit circuit and a receive branch that includes a receive circuit. The receive circuit includes a low noise amplifier, a pin diode including an anode and a cathode; and a switch. The anode of the pin diode is operatively connected to an antenna switch port and an input voltage source. The cathode of the pin diode is operatively connected to a cathode of the switch. Turning on the switch facilitates a drainage of residual electrical current at the pin diode.

A power amplifier circuit includes first and second bias circuits to each apply a bias to first and second amplifiers in first and second modes, respectively. The first bias circuit includes: a first transistor having a collector connected to a power supply electric potential, an emitter connected to the first amplifier, and a base connected to a current source; and a second transistor and a third transistor being diode-connected and connected between the base of the first transistor and a reference electric potential. The second bias circuit includes: a fourth transistor having a collector connected to a power supply electric potential, an emitter connected to the second amplifier, and a base connected to a current source; and a fifth transistor having a base connected to the emitter of the fourth transistor, a collector connected to the base of the fourth transistor, and an emitter connected to a reference electric potential.