A transmitter apparatus that performs beamforming with phase correction uses power detectors present between power amplifiers (PAs) and antennas are used to measure power amplitudes on at least two transmission paths. The sum and difference of these amplitudes are then evaluated to determine a phase difference therebetween. A phase of one signal contributing to the sum and difference may be modified until the sum and difference are the same. Based on an amount of phase modification, a correction signal may be sent to a beamforming circuit to provide phase correction during beamforming.

An encoding and decoding method for an optical isolation amplifier including an encoder, an optical driver, a light source, an optical detector, and a decoder, and employing sigma-delta modulation technology is provided. The method includes: generating a plurality of first pulses, each having a predetermined pulse width, through the encoder when an input digital signal experiences an input pulse rising or falling edge; outputting an encoded signal having the plurality of first pulses to the optical driver; driving the light source through the optical driver, according to the plurality of first pulses, so as to output an encoded optical signal; generating a detected signal through the optical detector detecting the encoded optical signal, and the detected signal has a plurality of second pulses; and duplicating the input digital signal of the encoder through the decoder, according to the detected signal having the plurality of second pulses.

A delta-sigma modulator includes a first integrator and a comparator. The comparator's positive input couples to the first integrator's positive output, and the comparator's negative input couples to the first integrator's negative output. A first current DAC comprises a current source device, and first and second transistors. The first transistor hays a first transistor control input and first and second current terminals. The first current terminal couples to the current source device, and the second current terminal couples to the first integrator positive output. The second transistor has a second transistor control input and third and fourth current terminals. The third current terminal couples to the current source device, and the fourth current terminal couples to the first integrator negative output. A first capacitive device couples to the second transistor control input and to both the second current terminal and the first integrator positive output.

The invention provides a signal processing system, for transferring analog signals from a probe to a remote processing unit. The system comprises a first ASIC at a probe, which is adapted to receive an analog probe signal. The first ASIC comprises an asynchronous sigma-delta modulator, wherein the asynchronous sigma-delta modulator is adapted to: receive the analog probe signal; and output a binary bit-stream. The system further comprises a second ASIC at the remote processing unit, adapted to receive the binary bit-stream. The asynchronous may further include a time gain function circuit, the first ASIC may further comprise a multiplexer, the second ASIC may further comprise a time-to-digital converter. The time to digital converter may be a pipelined time-to-digital converter.

The present invention provides an ADC for receiving at least an input signal to generate a digital output signal, wherein the ADC includes an input terminal and a plurality of output terminals, the input terminal is arranged to receive the input signal, and each of the output terminals is configured to output one bit of the digital output signal. The ADC is controlled to operate in a normal mode or a low power mode, and when the ADC operates in the normal mode, all of the output terminals are enabled to output the bits to form the digital output signal; and when the ADC operates in the low power mode, only a portion of the output terminals are enabled to output the bits to form the digital output signal.

A sigma-delta analog-to-digital converter (ADC) is disclosed. The sigma delta ADC has an analog input and a digital output. A sigma-delta modulator input is coupled to the analog input and a sigma-delta modulator output. A first filter having a first filter input is coupled to the sigma-delta modulator output and a first filter output. A second filter having a second filter input is coupled to the sigma-delta modulator output and a second filter output. The sigma-delta ADC operates in a first and second mode. In a first mode, the first filter output is coupled to the digital output. In a second mode, the second filter output is coupled to the digital output.

The present technology relates to a signal processing apparatus, a signal processing method, and a program that allow an improvement in the rate of modulation of PWM signals. Pulse width modulation (PWM) is performed to convert one of a 0 or 1 represented by a bit of a pulse density modulation (PDM) signal into which an audio signal has been PDM-modulated, into a maximum-length pulse of a maximum pulse width of a PWM signal having a period equal to the period of the PDM signal, and convert the other of the 0 or 1 of the PDM signal into a minimum-length pulse of a minimum pulse width of the PWM signal at a position adjacent to the center of the period of the PWM signal. The present technology is applicable, for example, to audio reproduction systems that reproduce audio signals.

Described herein is an improved apparatus for increasing the performance of a modulator, which may function as an ADC. In one embodiment, the modulator comprises a voltage to current converter, a capacitor connected between two outputs of the voltage to current converter to receive a differential input current, and a switch that can switch between connecting each output of the voltage to current converter to ground while disconnecting the other output of the voltage to current converter. In this embodiment, the modulator has no common mode control loop, and no reference current. This results in decreased complexity, i.e., fewer components, as well as reduced noise.

A digital filter and a method for filtering a pulse density modulation (PDM) signal are presented. The digital filter has a first filter circuit to receive an input signal with input values at successive time steps to provide a filtered input signal with filtered values at successive time steps. The digital filter does not require sample-rate or data format conversions. Also, the digital filter is area and power efficient when implemented in hardware. Optionally, the digital filter has a sigma-delta modulator including the quantiser, the sigma-delta modulator being used to receive the filtered input signal and to process the filtered input signal before and/or after being quantised by the quantiser. This digital filter does not require sample-rate or data format conversions. This digital filter is area and power efficient when implemented in hardware.

Described herein are apparatus and methods for low speed characterization of a high-speed signal. A circuit includes a sub-sampling circuit configured to sub-sample a high-speed signal received from a device, a reconstruction loop circuit configured to reconstruct a low-speed signal from the sub-sampled high-speed signal, a low pass filter configured to filter the reconstructed low-speed signal, a discrete time low pass filter configured to mitigate skew rate requirements of the filtered low-speed signal for a digitization circuit, a continuous time low pass filter configured to smooth the skew rate mitigated low-speed signal and the digitization circuit is configured to generate a digital representation of the smoothed low-speed signal for characterization by a characterization device, and shape a noise associated with the smoothed low-speed signal outside a frequency range of interest of the smoothed low-speed signal.