Tektronix, Inc.

Leroy J Willmann

Linley F Gumm

Kyle L Bernard

Xiaofen Chen

Thomas C Hill

Soraya J Matos

An improved calibration method for a vector network analyzer stores sparse calibration data, interpolates system error data from the sparse calibration data for each measurement by the vector network analyzer, and creates calibrated measurement data from the system error data and uncorrected measurement data at each measurement frequency. The sparse calibration data may be generated by measuring every Nth frequency step over a calibration frequency range greater than a specified measurement frequency range, or by measuring every frequency step over the calibration frequency range and compressing the resulting measurement data. The interpolation may be achieved by using a curve-fit algorithm, such as a parametric polynomial curve fitting algorithm.

Calibration for vector network analyzer

A method of determining distance to fault of a transient event in a transmission system uses per frequency triggered I and Q data representing voltage and phase of a return signal in the frequency domain. Initially a result set of data entries, one for each discrete frequency in a specified frequency range, is filled with zeros and an initial acquisition set of per frequency I and Q data from the transmission system is used to fill a reference set of data entries. Subsequent acquisitions of per frequency data sets are used to fill a current set of data entries. Between each acquisition of data sets for the current set a comparison is made, entry by entry, between the current set and the reference set, and the data from the current set is used to update the corresponding entry in the result set when the difference exceeds a specified tolerance. When all of the entries of the current set have been compared, the result set is displayed by performing an inverse Fourier transform on the result set to provide a distance to fault display in the time domain. The data acquisitions occur while the transmission cable is being perturbed to stimulate the transient event.

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Portland, OR, United States of America

Leroy J Willmann