HP 8753E Scale Reference Menu, Electrical Delay, Or ~~~~~~~~~~, Assuming a relative permeability

Scale Reference Menu

The @GiZGTj key provides access to the scale reference menu. Softkeys within this menu can be used to define the scale in which measured data is to be displayed, as well as simulate phase offset and electrical delay. The following softkeys are located within the scale reference menu.

Electrical Delay

The ~T~~~~~~~ softkey adjusts the electrical delay to balance the phase of the test
_ _ _ _	/.A . . . . ......\....i...........; ...........;..;......;.. ....;a;.....v. . . I. I. ../
device. l’l-& softkey mu& be used h conjjun&ion with ~~~~~~.~~~~~	or ~~~~~~~~~~

(with cut-off frequency) in order to identify which type of transmission line the delay is being added to.

Electrical delay simulates a variable length lossless transmission line, which can be added to or removed from a receiver input to compensate for interconnecting cables, etc. This function is similar to the mechanical or analog “line stretchers” of other network analyzers. Delay is

annotated in units of time with secondary labeling in distance for the current velocity factor.
	_ .,. .,.,.,.,.,.,.,.,.,.,.	_ _ _
Witi this featwe, and dti ~~~~~~~ (see “UsingMarkers”), a equivalent length of
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air-filled, lossless transmission line is added or subtracted according to the following formula:

Length (meters) = (Freq (MHf) x 1.20083)

Once the linear portion of the test device’s phase has been removed, the equivalent length of the lossless, transmission line can be read out in the active marker area. If the average relative permittivity (e,) of the test device is known over the frequency span, the length calculation can be adjusted to indicate the actual length of the test device more closely. This can be done by entering the relative velocity factor for the test device using the calibrate more menu. The relative velocity factor for a given dielectric can be calculated by:

Velocity Factor = 1

A

assuming a relative permeability of 1.

Appliwtion and Operation Concepts 641