Method of estimating channel bandwidth from a time domain reflectometer (tdr) measurement

Abstract

Bandwidth of a test channel is determined from a single port Time Domain Reflectometer (TDR) measurement with the channel terminated in a short or an open circuit. Bandwidth is estimated by: (1) making a TDR measurement of a channel terminated in a short or open circuit; (2) determining a maximum slope of the reflection from the TDR measurement; (2) calculating an interpolated rise or fall time, for example by taking 80% of the applied voltage between the 10% and 90% points, and then dividing the applied voltage by the maximum slope determined; (3) dividing the overall interpolated rise time by the square root of two to account for the TDR signal proceeding through the channel twice; (4) removing the contribution of rise time from measurement equipment; and (5) completing calculation of channel bandwidth using a formula to relate bandwidth to rise time, such as: bandwidth=0.35/rise time.

1 : A method to determine bandwidth of a test system channel containing a spring probe, the method comprising making a single port Time Domain Reflectometer (TDR) measurement of rise time of the channel and using the rise time to determine the bandwidth. 
   
   
       2 - 35 . (canceled)