Broadband Reflectometry: Theoretical Background - Broadband Reflectometry for Enhanced Diagnostics and Monitoring Applications - page 45

Fig. 3.17 Sequence of the gating operation. a frequency response of a cable. b time domain
response. c gating applied to remove the first discontinuity. d frequency response with gating
on and off [5]

at a specific section is to be
seen as the resultant of infinite contributions, that can be mathematically repre-
sented through the multiple reflection theory [20]. The measurement cell can be
considered as a multi-section transmission line, and M is the number of sections
where impedance changes occur. Let k

This approach is based on the fact that the S 11 ( f )

= 0 , ..., M be the number of sections starting

from the end of the probe ( k M ). For the sake of

example, Fig. 3.18 shows the 'main' sections of a three rod probe.

= 0) up to the TDR output ( k =

Fig. 3.18 Schematization of the 'main' sections of a typical three-rod probe