Agilent Technologies, Inc.

Hewlett-packard Company

Keysight Technologies, Inc.

David V Blackham

Kenneth H Wong

Joel P Dunsmore

Keith Frederick Anderson

Loren C Betts

James C Liu

Hassan Tanbakuchi

Robert E Shoulders

Dara Sariaslani

Erwin Frederick Siegel

Shigetsune Torin

Jason A Chodora

Douglas K Rytting

Lisa Shenton

Xiaolong Li

Bernadette Smith

Matt Todhunter

Nicholas C Leindecker

Doug Bender

Michael C Dobbert

Brad R Hokkanen

A method determines operating characteristics of a signal generator. The method includes performing a first set of measurements of an output signal generated by the signal generator and corresponding reflected signal, where the first set of measurements is performed over multiple frequencies and amplitudes of the output signal; applying an external signal to the output port of the signal generator; performing a second set of measurements of the output signal and corresponding reflected signal while the external signal is being applied to the output port, where the second set of measurements is performed over frequencies and amplitudes of the output signal, the external signal having the same frequency as the output signal for each measurement of the second set of measurements. A set of coefficients describing the operating characteristics of the signal generator is determined by processing results of the first and second sets of measurements through a non-linear model.

Determining operating characteristics of signal generator using measuring device

A measurement and correction method provides for a complete full correction of a true-mode system using only the single ended error matrix developed for 4 port correction of single ended measurements. The degree of misalignment of the balanced sources may be determined from these measurements.

Differential vector network analyzer

An impedance analyzer includes a reference signal, a first converter a first coupler, a second converter, a second coupler, a modification circuit, a reference signal detector, and a reflected signal detector. The first coupler couples the reference signal to the first converter. The first converter produces a reference intermediate frequency signal. The second coupler couples a reflected signal to the second converter. The second converter produces a reflected intermediate frequency signal. A reflection coefficient for a device under test is determined by using a reflected value detected by the reflected signal detector and a reference value detected by the reference signal detector. In a first operating mode of the impedance analyzer, the reflected intermediate frequency signal is forwarded directly to the reflected signal detector. In a second operating mode of the impedance analyzer, the modification circuit operates on the reference intermediate frequency signal to produce an adjustment signal that is combined with the reflected intermediate frequency signal before a resulting signal is forwarded to the reflected signal detector.

Impedance analyzer

In one embodiment, a vector network analyzer (VNA) comprises a plurality of ports for coupling to a device under test (DUT), at least one reference receiver for measuring signals associated with the DUT, and logic for processing measurement data from the at least one reference receiver to compensate for transmission line effects, wherein the logic for processing evaluates a function, of several controllable variables, that is a sum of multiple transmission line models, wherein each of the controllable variables is related to a respective transmission line length associated with a corresponding transmission line model.

VNA and method for addressing transmission line effects in VNA measurement data

In one embodiment, a method comprises storing parameters that are related to switch error correction terms of a vector network analyzer (VNA), and applying a calibration process of a TRL group of calibration processes to the VNA to generate calibration measurements, wherein the calibration process generates calibration measurements, calculates a switch error correction matrix using the stored parameters and a subset of the calibration measurements, and applies the switch error correction matrix to calibration measurements before solving for eight-systematic error terms associated with the calibration process.

Method for implementing TRL calibration in VNA

A power calibration method for a multi-port vector network analyzer (VNA) performs a two-port S-parameter calibration between a pair of ports of the multi-port VNA, and performs a power calibration of one of the ports in the pair of ports. From the two-port S-parameter calibration and the power calibration at the one port, power can be determined at one or more ports of a device under test (DUT) coupled to the ports of the multi-port VNA.

Power calibration for multi-port vector network analyzer (VNA)

In one embodiment, a method of operating a network analyzer, comprises applying a stimulus signal on at least one port of the network analyzer for provision to a device under test (DUT) within a test fixture coupled to the network analyzer; generating measurement data from the DUT in response to the stimulus signal on at least one port of the network analyzer; and generating an amplitude response of the DUT across a frequency range, wherein a port extension module of the network analyzer automatically applies loss compensation to the amplitude response in a manner that is non-linearly related to frequency according to at least one controllable parameter.

Network analyzer applying loss compensation using port extensions and method of operation

In one embodiment, a method of calibrating a multi-port vector network analyzer (VNA) includes (i) performing two-port calibrations on pairs of ports to determine forward and reverse systematic error terms associated with each pair of ports, wherein the pairs of ports are selected such that each port's systematic error terms (directivity, source match, reflection tracking, and load match) are determined, (ii) generating a switch error correction matrix using data from the two-port calibrations, and (iii) performing unknown thru calibration for at least one pair of ports that was not utilized in step (i), wherein the unknown thru calibration comprises applying the switch error correction matrix to measurement data and determining transmission tracking error terms using the corrected measurement data.

Multiport calibration simplification using the 'unknown thru' method

Noise power is measured within one or more designated frequency bands of an applied signal. The measurement includes frequency translating the applied signal by a set of equally spaced frequencies to form a corresponding set of intermediate frequency signals, measuring the noise in at least two measurement bands of each of the intermediate frequency signals that are separated by the frequency spacing of the equally spaced frequencies, and determining the noise power in the designated frequency band of the applied signal based on the noise measurements.

Noise measurement system and method

In one embodiment, a method comprises applying a stimulus signal to a reference frequency translation device (FTD) by a vector network analyzer during a calibration mode, wherein the reference FTD possesses equal conversion efficiency in forward and reverse directions and the reference FTD possesses unknown input and output reflection characteristics; measuring a response of the reference FTD; and determining forward and reverse transmission tracking error terms using data from the measured response and single-port error calibration terms.

Vector network analyzer mixer calibration using the unknown thru calibration

A method and a vector network analyzer compensate for unequal source match and load match of a test port of the vector network analyzer. The method characterizes the source match and the load match, computes a delta-match factor from the characterized source match and load match, and uses the delta-match factor to compensate for the difference. The method compensates S-parameter data for a device under test measured by the vector network analyzer. The vector network analyzer comprises a computer program that, when executed by a controller, implements a calibration compensation.

Compensating for unequal load and source match in vector network analyzer calibration

A system and method are disclosed which provide for flexible and accurate test apparatus error value calculation. Error value calculation of a testing apparatus requires at least one unique measurement for each unknown error value using the equation that relates the measured response, the predicted response and the error value. When more equations than unknowns can be acquired, the system of equations is over-determined and an improvement of accuracy is possible, but accuracy may be lost when the predicted responses are not trusted to the same degree. The disclosed system and method provide the increased accuracy of an over-determined system, while accounting for predicted responses of varying degrees of trust.

System and method for determining measurement errors of a testing device

Method and apparatus to determine scattering coefficients for a device under test (DUT) using a vector network analyzer (VNA) is disclosed. Traditionally, for a DUT having P ports, all combinations of reflective and transmission coefficients are measured and calculated. This is true even for reciprocal devices where S &equals;S because, during the measurement, the source and load matches vary. However, the present invention teaches that, for reciprocal devices, only one of the two transmission coefficients between a first port and a second port need be measured. Under the inventive technique, error terms are removed from the measured scattering coefficients. Then, the source and the load matches may be normalized to a normalization match value. The normalization process removes the differences of the source and the load matches. Accordingly, for reciprocal devices, only one of two reciprocal transmission coefficients need be measured to determine the transmission coefficients for both directions between the first and the second port. The reduction of the measurement requirement reduces the amount of hardware required for a VNA, time required to characterize a DUT, or both.

Method and apparatus for efficient measurement of reciprocal multiport devices in vector network analysis

Effects of adapters present only during calibration of a network analyzer are removed. Scattering parameters are obtained for the adapters. For example, the scattering parameters for the adapters are obtained by characterizing the adapters. Systematic error terms for the calibration which remove adapters effects are generated using the scattering parameters for the adapters. In one embodiment, the scattering parameters for the adapters are used to pre-load adapter error terms into the network analyzer before the calibration. The calibration is then performed with the adapter error terms pre-loaded to generate systematic error terms for the calibration. In an alternative embodiment, the calibration is performed (without pre-loading error terms) in order to generate preliminary systematic error terms for the calibration. The preliminary systematic error terms and the scattering parameters for the adapter are used to generate the systematic error terms which do not include effects of the adapters.

Removing effects of adapters present during vector network analyzer calibration

An error correction method improves measurement accuracy of a vector network analyzer by reducing reflection measurement errors for a broad class of devices, such as filters, switches, cables, couplers, attenuators, and other passive devices tested by vector network analyzers (VNAs) that are reciprocal, having a forward transmission coefficient S.sub.21 and a reverse transmission coefficient S.sub.12 that are equal. Errors due to impedance mismatches at the load port of a transmission/reflection (T/R) test set are corrected without impacting the measurement speed of the VNA. The source port of the T/R test set is calibrated and a reflection measurement is performed while an impedance matched thruline standard of known electrical length is coupled between the source port and load port of the T/R test set. The reflection measurement is corrected for the electrical length of the thruline standard to obtain a reflection measurement of the load port of the T/R test set. Then, the transmission and reflection characteristics of the DUT are measured. The reciprocity of the DUT and the reflection measurement of the load port are used to extract the actual input reflection coefficient of the DUT.

Growing community of inventors

Santa Rosa, CA, United States of America

David V Blackham