hochfrequenzdaempfungsglied with high eingangsimpedanz and multiple eichmassverfahren, application thereof in an active probe and an oscilloscope.

摘要

Attenuator having a high input impedance and several switching levels for high frequencies and oscilloscope and active probe comprising such an attenuator. A high frequency attenuator (15) having a high input impedance and several switching stages intended to attenuate a high-frequency electric signal introduced at an input terminal (10) of the attenuator. The attenuator supplies at a low-impedance output terminal (11) an output signal corresponding to the attenuated input signal. The attenuator comprises k broadband amplifiers An (1/=n/=k) having a very small input capacitance, capacitances Dn arranged between each input and each output of each amplifier, and capacitances Cn arranged between each input of each amplifier and the input terminal of the attenuator. The accurate attenuation switching levels are obtained by using different ratios Cn/Dn to produce approximated switching levels which can be transformed to accurate switching levels by a low-impedance amplifier having a variable amplification. This attenuator may be used in oscilloscopes.