Wide bandwidth attenuator input circuit for a measurement probe

摘要

A wide bandwidth attenuator input circuit for a measurement probe has a Z₀ attenuator circuit coupled in series with a compensated RC attenuator circuit. The series attenuator elements of the Z₀ and the compensated RC attenuator circuits are coupled via a controlled impedance transmission line to the shunt attenuator elements of the Z₀ and the compensated RC attenuator circuits. The shunt element of the Z₀ attenuator element terminates the transmission line in its characteristic impedance. The junction of the series and shunt attenuator elements are coupled to the input of a buffer amplifier. At low and intermediate frequencies, the compensated RC attenuator circuit attenuates an input signal while at high frequencies, the compensated RC attenuator circuit acts as a short and the Z₀ attenuator circuits attenuates the input signal.