Tektronix, Inc.

Textronix, Inc.

Yi He

Marcus K DaSilva

Marcus Kieling Da Silva

Kathryn A Engholm

Alfred K Hillman, Jr

Thomas C Hill

Edward C Gee

Thomas C Iii Hill

A method and apparatus for improved video bandwidth resolution in DFT-based spectrum analysis is disclosed. A first embodiment comprises an emulation of a continuous range of video bandwidths in DFT-based spectrum analysis using overlapping resolution bandwidth frames. A second embodiment utilizes frame weighting to reduce the standard deviation in the spectrum of noise signal to emulate a corresponding standard deviation of a specified video bandwidth.

Video bandwidth resolution in DFT-based spectrum analysis

A method of correcting the frequency response of an RF receiver having a frequency translation device and a fixed IF frequency section uses calibration data representing frequency responses over a wide frequency range for multiple center frequencies. The calibration data are based upon a multi-dimensional model for the frequency translation device that includes at least center frequency and offset frequency. The calibration data are stored in the RF receiver during factory calibration. A run-time normalization of the RF receiver produces a normalization frequency response at a reference frequency, and a relative frequency response at a desired center frequency is derived from the calibration data. The normalized and relative frequency responses are combined to produce an overall frequency response that is used by the RF receiver to configure an inverse filter to correct channel linear distortion produced by the frequency response of the frequency translation device at the desired center frequency.

Frequency response correction for a receiver having a frequency translation device

A modulation domain trigger generator demodulates a modulated input signal to extract information content, and a trigger is generated from the extracted information content in response to specified trigger criteria. The modulation domain trigger generator may be combined with a plurality of different types of trigger generators, including frequency domain and time domain trigger generators, to process the input signal in response to different trigger criteria to produce more than one trigger. The different trigger outputs may be combined to produce an acquisition trigger to acquire data surrounding an anomalous or identifiable event within the input signal.

Modulation domain trigger

A method of characterizing the frequency response of a frequency translation device over a wide IF bandwidth is based on a two-dimensional model to generate calibration data for a device at run-time. The model is a function of a center frequency and frequency offset for a plurality of center frequencies over a wide system bandwidth to produce a frequency response at each center frequency. The frequency responses at each center frequency are scaled and normalized relative to a reference frequency and stored.

Characterization of a frequency response for a frequency translation device

A filter equalization technique for an analog signal path, such as in an instrument that simultaneously measures a signal over a band of frequencies, uses magnitude measurement data for high frequency bands for which phase-calibrated sources are not readily available. A sinusoidal signal source together with an accurate power meter is used to provide a stepped frequency input over a desired frequency band to the analog signal path with an accurate measured magnitude. The output of the analog signal path is digitized and the resulting frequency magnitudes are computed. Then the resulting power meter results are deducted from the frequency magnitudes measured each time by the instrument to determine the magnitude response of the analog signal path. Using a Hilbert transform the corresponding phase response is determined based on a minimum phase assumption over the desired frequency band. From the magnitude and phase responses an inverse or digital equalization filter may be designed for the analog signal path.

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Portland, OR, United States of America

Yi He