A receiver front end having low noise amplifiers (LNAs) is disclosed herein. A cascode having a “common source” configured input FET and a “common gate” configured output FET can be turned on or off using the gate of the output FET. A first switch is provided that allows a connection to be either established or broken between the source terminal of the input FET of each LNA. A drain switch is provided between the drain terminals of input FETs to place the input FETs in parallel. This increases the g.sub.m of the input stage of the amplifier, thus improving the noise figure of the amplifier.

A receiver front end having low noise amplifiers (LNAs) is disclosed herein. A cascode having a “common source” configured input FET and a “common gate” configured output FET can be turned on or off using the gate of the output FET. A first switch is provided that allows a connection to be either established or broken between the source terminal of the input FET of each LNA. A drain switch is provided between the drain terminals of input FETs to place the input FETs in parallel. This increases the g.sub.m of the input stage of the amplifier, thus improving the noise figure of the amplifier.

A temperature compensation circuit is configured to generate a first electrical signal corresponding to the current ambient temperature, use the first electrical signal to adjust a second electrical signal received by an electrical signal input end, and obtain a third electrical signal; and output the third electrical signal to a power control circuit. The power control circuit is configured to convert the third electrical signal into a fourth electrical signal and output the fourth electrical signal to a power amplifier. The fourth electrical signal is used for controlling the gain of the power amplifier to present a preset change rule following a temperature change. Thus, by adding the described temperature compensation circuit in a power amplification circuit, the stability of the gain and the stability of the output power of a power amplifier are ensured, and the performance of the power amplifier is not affected by a change in temperature.

A phase compensation circuit module includes at least a variable resistor, a detection component and a control component. The detection component has a detection end connected with a signal input end of a power amplifier, and is configured to detect an input signal of the signal input end. The control component is connected with the detection component, and is configured to output a control signal according to the input signal detected by the detection component. The variable resistor is connected with an output end of the control component, and is configured to change resistance linked to the power amplifier according to the control signal, the variable resistor constitutes a loop of the power amplifier and is configured to form on-resistance of a transistor of the power amplifier. The on-resistance of the transistor is configured to change as a phase of an output signal of the power amplifier changes.

The present disclosure generally relates to a high frequency amplifier, a system and a method for setting an operating state of a high frequency amplifier. The high frequency amplifier includes at least a first amplification circuit with a first frequency range, at least one second amplification circuit with a second frequency range, a hybrid coupler circuit with an isolated port, and a termination with at least one switch device. The hybrid coupler circuit is connected to output sides of the first amplification circuit and the second amplification circuit. The termination is connected with the isolated port. The high frequency amplifier has an operating range based on the first amplification circuit and the second amplification circuit. The high frequency amplifier has a load modulation in dependence of the first amplification circuit and the second amplification circuit. A first contact of the at least one switch device is directly coupled to ground.

The present disclosure generally relates to a high frequency amplifier, a system and a method for setting an operating state of a high frequency amplifier. The high frequency amplifier includes at least a first amplification circuit with a first frequency range, at least one second amplification circuit with a second frequency range, a hybrid coupler circuit with an isolated port, and a termination with at least one switch device. The hybrid coupler circuit is connected to output sides of the first amplification circuit and the second amplification circuit. The termination is connected with the isolated port. The high frequency amplifier has an operating range based on the first amplification circuit and the second amplification circuit. The high frequency amplifier has a load modulation in dependence of the first amplification circuit and the second amplification circuit. A first contact of the at least one switch device is directly coupled to ground.

Example embodiments relate to power amplifiers and Doherty amplifiers that include the same. One example embodiment includes a power amplifier. The power amplifier includes one or more radiofrequency (RF) output terminals. The power amplifier also includes a Gallium Nitride (GaN) semiconductor die on which a power field-effect transistor (FET) is integrated. The FET includes a plurality of FET cells that are adjacently arranged in a row. The FET cells are connected either directly or indirectly to the one or more RF output terminals via a respective first inductor. For FET cells arranged at opposing ends of the row of FET cells, a total FET cell gate width and an inductance of the first inductor is larger and smaller than the total FET cell gate width and inductance of the first inductor for one or more FET cells arranged in the middle of the row of FET cells, respectively.

Example embodiments relate to power amplifiers and Doherty amplifiers that include the same. One example embodiment includes a power amplifier. The power amplifier includes one or more radiofrequency (RF) output terminals. The power amplifier also includes a Gallium Nitride (GaN) semiconductor die on which a power field-effect transistor (FET) is integrated. The FET includes a plurality of FET cells that are adjacently arranged in a row. The FET cells are connected either directly or indirectly to the one or more RF output terminals via a respective first inductor. For FET cells arranged at opposing ends of the row of FET cells, a total FET cell gate width and an inductance of the first inductor is larger and smaller than the total FET cell gate width and inductance of the first inductor for one or more FET cells arranged in the middle of the row of FET cells, respectively.

A mixer with a filtering function and a method for linearization of the mixer are provided. The mixer includes at least one amplifier, a transconductance device and a feedback network. The at least one amplifier is configured to output a filtered voltage signal according to an input voltage signal. The transconductance device is coupled to the at least one amplifier, and is configured to generate a filtered current signal according to the filtered voltage signal. The feedback network is coupled between any output terminal among at least one output terminal of the transconductance device and an input terminal of the at least one amplifier. More particularly, the mixer is configured to output a modulated signal according to the filtered current signal.

A switch device includes a first node, a switch unit, an adjustment switch, an impedance element, a second node and a detection unit. A first terminal of the switch unit is coupled to the first node. A first terminal and a second terminal of the adjustment switch are respectively coupled to a second terminal of the switch unit and a reference voltage terminal. A first terminal and a second terminal of the impedance element are respectively coupled to the first terminal and the second terminal of the adjustment switch. The detection unit is coupled to the second node, and a control terminal of the switch unit and a control terminal of the adjustment switch. The detection unit detects a node signal at the second node to accordingly control the switch unit and the adjustment switch.