Abstract: Cascode amplifier having feedback circuits. In some embodiments, an amplifier can include a first transistor and a second transistor arranged in a cascode configuration, with each transistor having a gate. The amplifier can further include a first feedback circuit implemented between an output of the second transistor and the gate of the second transistor. The amplifier can further include a second feedback circuit implemented between the output of the second transistor and the gate of the first transistor.

Abstract: Apparatus and methods for low noise amplifiers (LNAs) are provided herein. In certain configurations, an LNA includes a gain stage and a bypass stage electrically connected in parallel with one another between an input and an output. The bypass stage and the gain stage are selectively activated based on a mode of the LNA. For example, the gain stage provides inverting amplification to an input signal received at the input in a gain mode. Additionally, the bypass stage provides a low gain path from the input to the output in a bypass mode. Additionally, the bypass stage includes a balun that provides inversion to the bypass stage such that a phase delay through the bypass stage is similar to a phase delay of the gain stage.

Abstract: Cascode amplifier having feedback circuits. In some embodiments, an amplifier can include a first transistor and a second transistor arranged in a cascode configuration, with each transistor having a gate. The amplifier can further include a first feedback circuit implemented between an output of the second transistor and the gate of the second transistor. The amplifier can further include a second feedback circuit implemented between the output of the second transistor and the gate of the first transistor.

Abstract: Feedback and impedance circuits, devices and methods for broadband radio-frequency (RF) amplifiers. An RF amplifier architecture can include an amplifier having a first field-effect transistor (FET) and a second FET arranged in a cascode configuration. The gate of the first FET can be configured to receive an RF signal, the drain of the first FET can be coupled to the source of the second FET, and the drain of the second FET can be configured to output an amplified RF signal. The RF amplifier architecture can further include a first feedback circuit implemented between the drain of the second FET and the gate of the second FET to provide gain control, and a second feedback circuit implemented between the drain of the second FET and the gate of the first FET to provide an increase in a frequency range having a desirable range of gain.

Abstract: Disclosed are circuits, devices, systems and methods related to an enable circuit for a radio-frequency (RF) amplifier. In some embodiments, the enable circuit can be configured to control a low-noise amplifier (LNA). The enable circuit includes a plurality of input ports, with each input ports being configured to receive a control signal. The enable circuit further includes a logical section connected to the input ports and configured to be capable of generating a plurality of output signals based on different combinations of the plurality of control signals. The output signals include either or both of enable and power shut-off signals for the LNA.

Abstract: Feedback and impedance circuits, devices and methods for broadband radio-frequency (RF) amplifiers. An RF amplifier architecture can include an amplifier having a first field-effect transistor (FET) and a second FET arranged in a cascode configuration. The gate of the first FET can be configured to receive an RF signal, the drain of the first FET can be coupled to the source of the second FET, and the drain of the second FET can be configured to output an amplified RF signal. The RF amplifier architecture can further include a first feedback circuit implemented between the drain of the second FET and the gate of the second FET to provide gain control, and a second feedback circuit implemented between the drain of the second FET and the gate of the first FET to provide an increase in a frequency range having a desirable range of gain.

Abstract: Disclosed are circuits, devices, systems and methods related to an enable circuit for a radio-frequency (RF) amplifier. In some embodiments, the enable circuit can be configured to control a low-noise amplifier (LNA). The enable circuit includes a plurality of input ports, with each input ports being configured to receive a control signal. The enable circuit further includes a logical section connected to the input ports and configured to be capable of generating a plurality of output signals based on different combinations of the plurality of control signals. The output signals include either or both of enable and power shut-off signals for the LNA.