Tektronix, Inc.

Shigetsune Torin

Thomas C Hill

Kathryn A Engholm

Thomas L Kuntz

Soraya J Matos

Thomas Hill

Thomas C Iii Hill

Embodiments of the invention include a test and measurement instrument including a test signal input and a sampler coupled to the test signal input to generate a sampled test signal. The instrument also includes a noise reduction system that includes an additional oscillator coupled to the sampler and structured to generate a sampled oscillating signal, as well as a phase detector coupled to the sampled oscillating signal for measuring noise introduced by the sampler. The noise reduction system further includes a phase corrector coupled to the phase detector for removing the measured amount of noise from the sampled test signal. Methods of noise detection are also described.

Phase noise correction system for discrete time signal processing

A two stage adaptive filter for use in a batch receiver includes an equalizer filter having as inputs an acquired signal representing a batch of data points and an equalizer filter value. The filtered signal is batch processed to produce reference and data symbols, which symbols are input to a residual filter to generate iteratively over the batch an error value. The error value is convolved with the equalizer filter value to produce a new equalizer filter value for use by the equalizer filter when a next batch of data points is processed.

Two stage adaptive equalizer for a batch receiver

A method of measuring the phase transient response of a device under test automatically provides a flattened phase transient response without any user intervention. The method comprises the steps of calculating an instantaneous phase waveform based on an instantaneous voltage waveform that represents an output signal of the device under test as it steps from a first frequency to a second frequency, calculating an instantaneous frequency waveform based on the instantaneous phase waveform, automatically estimating the second frequency based on the instantaneous frequency waveform without any user intervention, and flattening the instantaneous phase waveform based on the estimate of the second frequency.

Phase transient response measurements using automatic frequency estimation

An enhanced impulse response measurement for a pulsed frequency modulation (FM) radar signal provides a more accurate measurement of the amplitude of a secondary response relative to the amplitude of a main response. The pulsed FM radar signal is sampled to produce a time-domain sample record. The sample record is windowed to produce a windowed sample record. The windowed sample record is transformed into a frequency-domain spectrum. The spectrum is multiplied with the complex conjugate of a frequency-domain estimate of a transmitted pulsed FM radar signal to produce a de-spreaded pulse. The de-spreaded pulse is transformed into the time domain to produce a measurement of the impulse response having a main response and a secondary response. The amplitude of the secondary response is corrected to eliminate errors caused by the windowing.

Enhanced impulse response measurement of an FM radar transmitter pulse

A trigger generator and trigger method are provided for determining whether or not a signal under test matches a modulation signature. The modulation signature may be provided as a magnitude signature, a phase signature or both. When the magnitude values, phase values, or both of a signal under test are the same as their respective modulation signature, an error computation will be close to zero. If this value is within a threshold value, a trigger signal or other indication of a match is produced.

Modulation signature trigger

An improved interpolation technique for reconstructing a complex signal from sampled data estimates a carrier phase for each sampled data time. The carrier phase is then used to compensate for frequency variation in the complex signal. The complex components of the sampled data are then interpolated separately with the interpolated results being used to produce an interpolated magnitude that is the reconstructed complex signal.

Growing community of inventors

Beaverton, OR, United States of America

Shigetsune Torin