S-4

Template:Plugin Sidebar 2 The Tektronix S-4 is a sampling head for 7000- and 3S-series samplers. It was designed by George Frye and introduced in 1968. It is the fastest of the S-series plug-in samplers. (An interesting comparison of different sampling heads is found in "AN-3042a, Revision 1, 2/89".)

The S-4 sampling gate is based upon a traveling wave trapped-charge transmission line in which the sampling window is set by the propagation time of a pulse edge through a thick-film transmission line. This technique requires only a sharp pulse edge rather than a precise pulse width, which is harder to generate. The sampling diodes are housed in a special coaxial connector that provides a high bandwidth signal path.

Key Specifications

Rise time	25 ps (observed with S-50 or S-52, 35 ps)
Bandwidth	14.5 GHz
Input impedance	50 Ω (terminated SMA port)
Input range	operating, 1 Vp-p; max. safe overload, ±5 V
Noise	< 5 mV
Features	trigger signal pick-off for internal triggering

Links

• S-4 page @ amplifier.cd

Pictures

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  Top view of the S4 plug-in

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  Left view

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  Right view

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  Schematic