A signal transmitter circuit includes an output driver circuit configured to transmit a signal using a multi-level pulse amplitude modulation (PAM) scheme comprising a plurality of discreet signal levels. During operation, the output driver initiates a first transition of the signal to a first level of the multi-level PAM scheme from a second level of the multi-level PAM scheme, and initiates a second transition of the signal to the first level from a third level of the multi-level PAM scheme. The signal transmitter further includes a control circuit configured to control a slew rate of the signal transmitter circuit to cause the signal to reach a threshold voltage level at a first time, the first time occurring a first duration of time after the first transition is initiated, and to cause the signal to reach the threshold voltage level at a second time, the second time occurring the first duration of time after the second transition is initiated.

Apparatuses, systems, and methods for high-pass filtering pre-emphasis circuits. A device may use a pre-emphasis driver to provide a multi-level signal based on multiple binary signals. The pre-emphasis driver includes a primary driver coupled in parallel with at least one equalizer path, each of which includes an equalizer driver and a filtering element. The filtering element may be an AC filtering element, such as a capacitor. The equalizer paths may contribute equalized signal(s) which have a high-pass filtering behavior. The pre-emphasis circuit may combine the primary signal from the primary driver and the equalized signals to generate an overall output multi-level signal. In some embodiments, the pre-emphasis driver may be a pulse amplitude modulated (PAM) driver, such as a PAM4 driver with four levels of the multi-level driver.

Apparatuses, systems, and methods for high-pass filtering pre-emphasis circuits. A device may use a pre-emphasis driver to provide a multi-level signal based on multiple binary signals. The pre-emphasis driver includes a primary driver coupled in parallel with at least one equalizer path, each of which includes an equalizer driver and a filtering element. The filtering element may be an AC filtering element, such as a capacitor. The equalizer paths may contribute equalized signal(s) which have a high-pass filtering behavior. The pre-emphasis circuit may combine the primary signal from the primary driver and the equalized signals to generate an overall output multi-level signal. In some embodiments, the pre-emphasis driver may be a pulse amplitude modulated (PAM) driver, such as a PAM4 driver with four levels of the multi-level driver.

Aspects described herein relate to configuring devices for performing full duplex communications, which may include inband full duplex communications for a given device or concurrent uplink and downlink communications for pairs or groups of devices.

The present invention is to generate a spatially phase modulated electron wave. A laser radiating apparatus, a spatial light phase modulator, and a photocathode are provided. The photocathode has a semiconductor film having an NEA film formed on a surface thereof, and a thickness of the semiconductor film is smaller than a value obtained by multiplying a coherent relaxation time of electrons in the semiconductor film by a moving speed of the electrons in the semiconductor film. According to the configuration, a spatial distribution of phase and a spatial distribution of intensity of spatial phase modulated light are transferred to an electron wave, and the electron wave emitted from an NEA film is modulated into the spatial distribution of phase and the spatial distribution of intensity of the light. Since the spatial distribution of phase of the light can be modulated as intended by a spatial phase modulation technique for light, it is possible to generate an electron wave having a spatial distribution of phase modulated as intended.

The present invention is to generate a spatially phase modulated electron wave. A laser radiating apparatus, a spatial light phase modulator, and a photocathode are provided. The photocathode has a semiconductor film having an NEA film formed on a surface thereof, and a thickness of the semiconductor film is smaller than a value obtained by multiplying a coherent relaxation time of electrons in the semiconductor film by a moving speed of the electrons in the semiconductor film. According to the configuration, a spatial distribution of phase and a spatial distribution of intensity of spatial phase modulated light are transferred to an electron wave, and the electron wave emitted from an NEA film is modulated into the spatial distribution of phase and the spatial distribution of intensity of the light. Since the spatial distribution of phase of the light can be modulated as intended by a spatial phase modulation technique for light, it is possible to generate an electron wave having a spatial distribution of phase modulated as intended.

Various embodiments relate to an amplitude shift keying (ASK) demodulator for demodulating an input signal, including: a frequency filter configured to receive the input signal, wherein the frequency filter includes adjustable components configured to adjust the frequency response of the frequency filter; a rectifier configured to rectify an output of the frequency filter, wherein the rectifier includes an adjustable current source configured to adjust the current consumption of the rectifier; a reference signal generator configured to produce a reference signal; a current to voltage converter configured to convert the current of the rectified signal to a rectified voltage and to convert the current of the reference signal to a reference voltage; and a comparator configured to compare the rectified voltage to the reference voltage and to produce a demodulated output signal.

An isolated gate driver includes a first input terminal to receive gate information and one or more input terminals to receive configuration information. A modulation circuit generates a modulated signal having four possible states, each of the four possible states corresponding to a different unique pair of values of the gate information and the configuration information. The modulation circuit represents two of the states using on-off keying (OOK) while the configuration information is at a first value and represents two of the states as a modification to the OOK modulation based on the configuration information being at a second value. The modulated signal is sent over an isolation communication channel coupling a transmitter and receiver of the isolated gate driver.

An isolated gate driver includes a first input terminal to receive gate information and one or more input terminals to receive configuration information. A modulation circuit generates a modulated signal having four possible states, each of the four possible states corresponding to a different unique pair of values of the gate information and the configuration information. The modulation circuit represents two of the states using on-off keying (OOK) while the configuration information is at a first value and represents two of the states as a modification to the OOK modulation based on the configuration information being at a second value. The modulated signal is sent over an isolation communication channel coupling a transmitter and receiver of the isolated gate driver.

Bias arrangements for amplifiers are disclosed. An example arrangement includes a bias circuit, configured to produce a bias signal for the amplifier, and a linearization circuit, configured to improve linearity of the amplifier by modifying the bias signal based on an RF signal indicative of an RF input signal to be amplified by the amplifier. The linearization circuit includes a bias signal input for receiving the bias signal, an RF signal input for receiving the RF signal, and an output for providing a modified bias signal. The linearization circuit further includes at least a first linearization transistor, having a first terminal, a second terminal, and a third terminal, where each of the bias signal input and the RF signal input of the linearization circuit is coupled to the first terminal of the first linearization transistor, and the output of the linearization circuit is coupled to the third terminal of the first linearization transistor.