A Radio Frequency (RF) circuit including a receive path, a transmit path, a switching circuit, and an output configured to receive RF signals from an antenna in a receive mode of operation, and to provide RF signals to the antenna in a transmit mode of operation. The receive path is configured to be coupled between a low-noise amplifier and the output. The switching circuit is located in the receive path and is configured, in the receive mode, to selectively couple the low-noise amplifier to the output and to pass the received RF signals from the output to the low-noise amplifier. The transmit path is configured to be coupled between a power amplifier and the output, to provide, in the transmit mode, signals from the power amplifier to the output, bypassing the switching circuit, and to have, in receive mode of operation, an off-state impedance of at least 200+j*13 Ohm.

A directional coupler includes a main line through which a first signal in a first frequency band and a second signal in a second frequency band pass from a first port to a second port, a sub-line electromagnetically coupled to the main line and having a third port and a fourth port, the third port outputting a first coupled signal corresponding to the first signal and a second coupled signal corresponding to the second signal, a first termination circuit connected to the fourth port and used in outputting the first coupled signal, a second termination circuit connected to the fourth port and used in outputting the second coupled signal, and a first filter circuit disposed between the fourth port and the first termination circuit, wherein the first filter circuit has frequency characteristics allowing the first coupled signal to pass therethrough and attenuating the second coupled signal.

A sequenced transmit muting wideband power amplifier is provided that includes at least one pre-driver stage having at least a first pre-driver and a second pre-driver. A mute switch selectively establishes a communication path between the first and second pre-drivers or couples the second pre-driver to a termination resistor. A pre-driver switch selectively activates/deactivates the first and second pre-drivers. A driver stage is in communication with the pre-driver stage and includes a first driver. A final amplifier stage is in communication with the driver stage and includes at least one second driver. At least one S-NBS switch is configured to selectively activate/deactivate the first driver and second driver. A controller is configured to activate the at least one pre-driver switch, the mute switch, the at least one S-NBS switch to selectively place the amplifier in one of a transmit mode and a mute mode.

An amplification device includes a plurality of amplifiers arranged in parallel, a plurality of directional couplers coupled to the plurality of amplifiers, respectively, and configured to receive output signals of the plurality of amplifiers, respectively, a phase shifter coupled to a first directional coupler of the plurality of directional couplers, and configured to generate a first signal to which a phase of an output signal of the first directional coupler is inverted, a combining circuit coupled to the phase shifter and a second directional coupler of the plurality of directional couplers, and configured to combine an output signal of the phase shifter and an output signal of the second directional coupler, and a processor configured to control at least one of the plurality of amplifiers so that a level of an output signal of the combining circuit is minimized.

An amplification device includes a plurality of amplifiers arranged in parallel, a plurality of directional couplers coupled to the plurality of amplifiers, respectively, and configured to receive output signals of the plurality of amplifiers, respectively, a phase shifter coupled to a first directional coupler of the plurality of directional couplers, and configured to generate a first signal to which a phase of an output signal of the first directional coupler is inverted, a combining circuit coupled to the phase shifter and a second directional coupler of the plurality of directional couplers, and configured to combine an output signal of the phase shifter and an output signal of the second directional coupler, and a processor configured to control at least one of the plurality of amplifiers so that a level of an output signal of the combining circuit is minimized.

Examples disclosed herein relate to a vector modulator architecture, having an input splitter network configured to receive a radio frequency (RF) input signal and generate a plurality of quadrature signals at different phases, a variable gain amplifier (VGA) stage coupled to the input splitter network and configured to apply a first gain to one or more of the plurality of quadrature signals, a power combiner coupled to the VGA stage and configured to combine the plurality of quadrature signals into a combined RF signal, and a power amplifier (PA) stage coupled to the power combiner and configured to apply a second gain to the combined RF signal and generate an output RF signal. Other examples disclosed herein relate to an antenna system for autonomous vehicles and a radar system for use in an autonomous driving vehicle.

A gallium nitride (GaN) power amplifier having a plurality of amplifier stages integrated into a monolithic integrated circuit is disclosed. The plurality of amplifier stages is coupled together between a radio frequency signal input and a radio frequency signal output, wherein at least one of the plurality of amplifier stages includes a first GaN transistor that is configured to have a first breakdown voltage that is no more than 75% of a second breakdown voltage of a second GaN transistor included in a different one of the plurality of amplifier stages.

A power amplifier apparatus supporting reverse intermodulation product (rIMD) cancellation is provided. The power amplifier apparatus includes an amplifier circuit configured to amplify and output a radio frequency (RF) signal for transmission via an antenna port. The antenna port may receive a reverse interference signal, which may interfere with the RF signal to create a rIMD(s) that can fall within an RF receive band(s). A reverse coupling circuit is provided in the power amplifier apparatus to generate an interference cancellation signal based on the reverse interference signal. The amplifier circuit is configured to amplify the interference cancellation signal and the RF signal to create an intermodulation product(s) to suppress the rIMD(s) to a determined threshold. By suppressing the rIMD(s) in the power amplifier apparatus, it is possible to support concurrent transmissions and receptions in a number of RF spectrums while in compliance with stringent regulatory spurious emissions (SEM) requirements.

A directional coupler includes a main line through which a first signal in a first frequency band and a second signal in a second frequency band pass from a first port to a second port, a sub-line electromagnetically coupled to the main line and having a third port and a fourth port, the third port outputting a first coupled signal corresponding to the first signal and a second coupled signal corresponding to the second signal, a first termination circuit connected to the fourth port and used in outputting the first coupled signal, a second termination circuit connected to the fourth port and used in outputting the second coupled signal, and a first filter circuit disposed between the fourth port and the first termination circuit, wherein the first filter circuit has frequency characteristics allowing the first coupled signal to pass therethrough and attenuating the second coupled signal.

Methods and apparatuses for facilitating wide bandwidth power amplification with high efficiency for analog RF signals. A passive load modulated balanced amplifier (LMBA) device comprises a balanced power amplifier (BPA) and a directional coupler. The BPA comprises a first power amplifier (PA) configured to amplify a first portion of an input power, a second PA configured to amplify a second portion of the input power, an isolation port, and an output port that outputs the amplified first and second portions of the input power as an output power. The directional coupler is configured to provide a portion of the output power from the output port to the isolation port to modulate a load impedance of the first and second PAs.