To realize sampling (signal measurement) and analysis of a signal to be measured easily at low cost by capturing optical phase fluctuation even when low-speed sampling is carried out. This sampling method includes: a step for acquiring main sampling points at a repetition period equal to or less than a half of the band frequency of a signal to be measured; a step for acquiring sub-sampling points by executing sampling separately from that executed for the main sampling points; a step for acquiring an amplitude difference, a phase difference, and a frequency difference between the signal to be measured at each of the sub-sampling points and a reference signal; a step for acquiring a time difference, an amplitude difference (A), a phase difference (), and a frequency difference (f) between each of the main sampling points and each of the sub-sampling points; and a step for acquiring the amplitude fluctuation, the phase fluctuation, and the frequency fluctuation of the signal to be measured by using the time difference (t), the amplitude difference (A), the phase difference (), and the frequency difference (f) between each of the main sampling points and each of the sub-sampling points.

A continuous-time sampler has series-connected delay lines with intermediate output taps between the delay lines. Signal from an output tap can be buffered by an optional voltage buffer for performance. A corresponding controlled switch is provided with each output tap to connect the output tap to an output of the continuous-time sampler. The delay lines store a continuous-time input signal waveform within the propagation delays. Controlling the switches corresponding to the output taps with pulses that match the propagation delays can yield a same input signal value at the output. The continuous-time sampler effectively holds or provides the input signal value at the output for further processing without requiring switched-capacitor circuits that sample the input signal value onto some capacitor. In some cases, the continuous-time sampler can be a recursively-connected delay line. The continuous-time sampler can be used as the front end sampler in a variety of analog-to-digital converters.

A continuous-time sampler has series-connected delay lines with intermediate output taps between the delay lines. Signal from an output tap can be buffered by an optional voltage buffer for performance. A corresponding controlled switch is provided with each output tap to connect the output tap to an output of the continuous-time sampler. The delay lines store a continuous-time input signal waveform within the propagation delays. Controlling the switches corresponding to the output taps with pulses that match the propagation delays can yield a same input signal value at the output. The continuous-time sampler effectively holds or provides the input signal value at the output for further processing without requiring switched-capacitor circuits that sample the input signal value onto some capacitor. In some cases, the continuous-time sampler can be a recursively-connected delay line. The continuous-time sampler can be used as the front end sampler in a variety of analog-to-digital converters.

A method and apparatus for providing variable analog to digital converter (ADC) resolution is described.

The disclosure includes an electro-optical sensor. The electro-optical sensor includes a test signal input to receive a test signal from a device under test (DUT). A bias circuit is employed to generate a bias signal. The electro-optical sensor also includes a Mach-Zehnder Modulator (MZM) that employs an optical input, an optical output, and a bias input. The MZM is configured to receive an optical carrier signal via the optical input. The MZM also receives both the test signal and the bias signal on the bias input. The MZM modulates the test signal from the bias input onto the optical carrier to generate an optical signal while operating in a mode selected by the bias signal. The MZM also outputs the optical signal over the optical output.

A test and measurement instrument can include an input to receive an analog signal, a sampler to produce digital sample data corresponding to the analog signal, a buffer to store a portion of the sample data, a memory to store sample data from the buffer, a plurality of comparators to establish a vertical range, and a controller configured to configure the plurality of comparators to establish a first vertical range based on sample data in the buffer, and determine whether any of the sample data in the buffer transitions outside the first vertical range during a period of time.

A test and measurement instrument can include an input to receive an analog signal, a sampler to produce digital sample data corresponding to the analog signal, a buffer to store a portion of the sample data, a memory to store sample data from the buffer, a plurality of comparators to establish a vertical range, and a controller configured to configure the plurality of comparators to establish a first vertical range based on sample data in the buffer, and determine whether any of the sample data in the buffer transitions outside the first vertical range during a period of time.

A continuous-time sampler has series-connected delay lines with intermediate output taps between the delay lines. Signal from an output tap can be buffered by an optional voltage buffer for performance. A corresponding controlled switch is provided with each output tap to connect the output tap to an output of the continuous-time sampler. The delay lines store a continuous-time input signal waveform within the propagation delays. Controlling the switches corresponding to the output taps with pulses that match the propagation delays can yield a same input signal value at the output. The continuous-time sampler effectively holds or provides the input signal value at the output for further processing without requiring switched-capacitor circuits that sample the input signal value onto some capacitor. In some cases, the continuous-time sampler can be a recursively-connected delay line. The continuous-time sampler can be used as the front end sampler in a variety of analog-to-digital converters.

A continuous-time sampler has series-connected delay lines with intermediate output taps between the delay lines. Signal from an output tap can be buffered by an optional voltage buffer for performance. A corresponding controlled switch is provided with each output tap to connect the output tap to an output of the continuous-time sampler. The delay lines store a continuous-time input signal waveform within the propagation delays. Controlling the switches corresponding to the output taps with pulses that match the propagation delays can yield a same input signal value at the output. The continuous-time sampler effectively holds or provides the input signal value at the output for further processing without requiring switched-capacitor circuits that sample the input signal value onto some capacitor. In some cases, the continuous-time sampler can be a recursively-connected delay line. The continuous-time sampler can be used as the front end sampler in a variety of analog-to-digital converters.

A method and apparatus for providing variable analog to digital converter (ADC) resolution is described.