Examples disclosed herein relate to a dynamic supply modulation power amplifier architecture for millimeter wave applications. The architecture includes phase shifters coupled to a power input port, power amplifiers coupled to respective power output ports, variable gain amplifiers coupled to the phase shifters and to the power amplifiers and are configured to supply dynamically varying input power to the power amplifiers. The architecture includes a first look-up table coupled to the variable gain amplifiers to control the variable gain amplifiers. The architecture also includes a second look-up table coupled to the power amplifiers, where each of the power amplifiers is supply modulated by active drain voltage modulation controlled by the second look-up table and variable input power from the variable gain amplifiers. Other examples disclosed herein include a radar system for use in an autonomous driving vehicle and an analog beamforming antenna for millimeter wave applications.

Provided is a sound pickup loudspeaker apparatus which suppresses the influence of feedback produced when adding a speaker while also reducing a sense of unnaturalness in a sound image. The sound pickup loudspeaker apparatus collects a target sound emitted from a first seat in the vehicle, plays back the collected target sound to a listener seated in a second seat in the vehicle from a second sound amplifying device disposed in a direction different from the first seat from the perspective of the listener, and furthermore plays back the collected target sound to the listener from a first sound amplifying device disposed in the same direction as the first seat from the perspective of the listener. The apparatus multiplies the target sound by a first gain and outputs the target sound to the first sound amplifying device; delays the target sound by an amount of time obtained by adding a time for achieving a precedence effect to a delay time of the first sound amplifying device relative to the second sound amplifying device; and multiplies the delayed target sound by a second gain and outputs the target sound to the second sound amplifying device. A first gain adjustment unit adjusts the first gain to a low value and a second gain adjustment unit adjusts the second gain to a high value.

A leveling equalizer includes a graphic equalizer circuit, a first multiplication circuit, a second multiplication circuit, an addition circuit, and a gain control circuit. The graphic equalizer circuit processes a first input signal and output a first output signal and a second output signal. The first multiplication circuit multiplies the first output signal and one of an adjustable gain value and a fixed gain value to generate a first adjusted output signal. The second multiplication circuit multiplies the second output signal and another of the adjustable gain value and the fixed gain value to generate a second adjusted output signal. The addition circuit combines the first adjusted output signal and the second adjusted output signal to generate an equalizer output signal. The gain control circuit dynamically adjusts the adjustable gain value according to the equalizer output signal.

Improved dither detection, measurement, and voltage bias adjustments for an electro-optical modulator are described. The electro-optical modulator generally includes RF electrodes and phase heaters interfaced with semi-conductor waveguides on the arms of Mach-Zehnder interferometers, where a processor is connected to output a bias tuning voltage to the electro-optical modulator for controlling optical modulation. A variable gain amplifier (VGA) can be configured with AC coupling connected to receive a signal from a transimpediance amplifier (TIA) that is configured to amply a photodetector signal from an optical tap that is used to measure an optical signal with a dither signal. The analog to digital converter (ADC) can be connected to receive output from the VGA. The processor can be connected to receive the signal from the ADC and to output the bias tuning voltage based on evaluation of the signal from the tap.

A network element of a cable television network includes at least a first and a second upstream amplifier stage, a first attenuator and a first equalizer between the first and the second amplifier stage, and a second attenuator after the second upstream amplifier stage in upstream signal path direction. A target value is determined for total attenuation of the components of the amplifier. The total attenuation is a sum of attenuations of the first attenuator, the first equalizer, and the second attenuator. The attenuation of the first equalizer is preset. The attenuation of the first attenuator is set to a maximum value such the sum of the attenuations of the first attenuator and the first equalizer is below a first threshold value. The attenuation of the second attenuator is set such that the total attenuation reaches the target value.

A lookup table calibration apparatus and method are disclosed. The lookup table calibration apparatus includes a power amplifier circuit configured to amplify a radio frequency (RF) signal having time-variant power levels based on a modulated voltage. To ensure proper alignment between the modulated voltage and the time-variant power levels, the power amplifier circuit is further configured to phase-shift the RF signal based on a modulated phase correction voltage. Specifically, the modulated voltage is generated based on a modulated voltage lookup table and the modulated phase correction voltage is generated based on a phase correction voltage lookup table. Herein, the lookup table calibration apparatus can be configured to concurrently populate and/or calibrate the modulated voltage lookup table and the phase correction voltage lookup table based on a measured gain and a measured phase of the RF signal, respectively.

Radio frequency (RF) generators are disclosed. A RF generator may include an analog signal generator configured to generate a pulsed analog signal responsive to a digital pulsed waveform defined by one or more commands. The RF generator may also include a modulator configured to generate a pulsed radio frequency (RF) signal by modulating an RF carrier using the pulsed analog signal as a modulating signal. Further, the RF generator may include an amplification stage configured to amplify the pulsed RF signal output by the modulator. RF generation systems and methods of generating a pulsed RF signal also disclosed.

A radio frequency amplifying device according to an embodiment includes load impedance calculating circuitry and controlling circuitry. The load impedance calculating circuitry is configured to calculate a load impedance on the basis of information about a voltage standing wave rate and a phase on an output side of radio frequency amplifying circuitry. The controlling circuitry is configured to adjust a gain and a phase of a signal to be input to the radio frequency amplifying circuitry, in accordance with the load impedance calculated by the load impedance calculating circuitry.

An analog front-end circuit capable of dynamically adjusting gain includes a programmable gain amplifier (PGA) circuit, a sensor, a calculation circuit, a gain coarse control circuit and a gain fine control circuit. The PGA circuit includes an amplifier, a gain coarse adjustment circuit and a gain fine adjustment circuit. The gain coarse adjustment circuit is controlled by a coarse control signal, and a gain is adjusted in a coarse step according to an initial gain. The gain fine adjustment circuit is controlled by a fine control signal in a data mode, and the gain is adjusted in a fine step. The calculation circuit calculates a primary gain adjustment and a secondary gain adjustment. The gain coarse control circuit generates the coarse control signal according to the primary gain adjustment, and the gain fine control circuit generates the fine control signal according to the secondary gain adjustment.

A variable gain amplifier includes a first transistor group which is connected to an input terminal and an output terminal, and which amplifies a signal from the input terminal to output the amplified signal to the output terminal; a second transistor group connected to the input terminal; a third transistor group connected to the output terminal; and a controller configured to control the first transistor group, the second transistor group, and the third transistor group so that a total number of the number of transistors to be turned on in the first transistor group and the second transistor group is kept at a constant value, and total numbers of transistors to be turned on in the first transistor group and in the third transistor group are the same.