Time Domain Reflectometry Step to S-Parameter Conversion

Abstract

A method and apparatus are provided for calculating s-parameters of a device under test from step waveforms acquired by a time domain network analyzer.

What is claimed is: 
     
         1 - 19 . (canceled) 
     
     
         20 . A method for measuring s-parameters of a device under test, comprising the steps of:
 defining a first subset of a plurality of samplers employed in a network analyzer;   acquiring a first one or more step-like waveforms by a network analyzer employing only one pulser providing an incident step-like waveform and the first subset of the plurality of samplers;   calculating a first set of s-parameters of the device under test in accordance with the acquired first one or more step-like waveforms;   defining a second subset of the plurality of samplers employed in the network analyzer;   acquiring a second one or more step-like waveforms by a network analyzer employing only one pulser providing an incident step-like waveform and the second subset of the plurality of samplers; and   calculating a second set of s-parameters of the device under test in accordance with the acquired second one or more step-like waveforms.   
     
     
         21 . The method of  claim 20 , wherein the calculated first and second sets of s-parameters are causal s-parameters of the device under test by the network analyzer. 
     
     
         22 . The method of  claim 20 , wherein the calculated first and second sets of s-parameters are reciprocal s-parameters of the device under test by the network analyzer. 
     
     
         23 . The method of  claim 20 , wherein the calculated first and second sets of s-parameters are passive s-parameters of the device under test by the network analyzer. 
     
     
         24 . A non-transitory computer readable storage medium having a computer program stored thereto, the computer program causing a computer processor to perform steps comprising a method for measuring s-parameters of a device under test, comprising the steps of:
 creating one or more symbolic sub-circuits, each sub-circuit being based at least in part upon a number of pulsers and samplers in a network analyzer, a number of ports in the device under test, and an interrelationship therebetween; and   employing at least in part one of the one or more symbolic sub-circuits to calculate the s-parameters of the device under test.   
     
     
         25 . The storage medium of  claim 24 , wherein a number of samplers is less than a number of ports in the device under test. 
     
     
         26 . The storage medium of  claim 24 , wherein the calculation of the s-parameters employs a non-linear algorithm. 
     
     
         27 . The storage medium of  claim 26 , wherein the calculation of the s-parameters comprises the steps of: calculating an approximate solution employing a linear algorithm; and applying the solution to the linear algorithm as a guess in accordance with the non-linear algorithm. 
     
     
         28 . The storage medium of  claim 24 , wherein the calculation of the s-parameters comprises calculating an approximate solution employing a linear algorithm. 
     
     
         29 . The storage medium of  claim 28 , wherein the approximate solution is based upon an assumption of ideal termination. 
     
     
         30 . A method for calculating s-parameters in a device under test, comprising the steps of:
 acquiring one or more measurements by a network analyzer for measuring the s-parameters of the device under test; and   calculating the s-parameters of the device under test by the network analyzer while enforcing reciprocity on a result thereof such that the result is an optimum reciprocal solution in a least squares sense involving all of the calculated s-parameters of the device.   
     
     
         31 . A method for calculating s-parameters in a device under test, comprising the steps of:
 acquiring one or more measurements by a network analyzer for measuring the s-parameters of the device under test; and   calculating the s-parameters of the device under test by the network analyzer while enforcing passivity on a result thereof such that the result is an optimum solution in a least squares sense.   
     
     
         32 . (canceled)