Patent ID: 7256575

Claim:
A wide bandwidth differential input attenuation circuit for an active voltage measurement probe receiving an input signal from a device under test comprising: first and second compensated RC voltage divider networks having series resistive/capacitive elements coupled to shunt resistive/capacitive elements; first and second resistive Z 0 voltage divider networks with each resistive Z 0 voltage divider network having a series resistive element coupled to a shunt resistive element, the series resistive element of the first resistive Z 0 voltage divider network being coupled to the series resistive/capacitive elements of the first compensated RC voltage divider network and the shunt resistive element of the first resistive Z 0 voltage divider network being coupled to the shunt resistive/capacitive elements of the first compensated RC voltage divider network, and the series resistive element of the second resistive Z 0 voltage divider network being coupled to the series resistive/capacitive elements of the second compensated RC voltage divider network and the shunt resistive element of the second resistive Z 0 voltage divider network being coupled to the shunt resistive/capacitive elements of the second compensated RC voltage divider network; first and second transmission lines with the first transmission line coupling the series resistive/capacitive elements of the first compensated RC voltage divider network to the shunt resistive element of the first resistive Z 0 voltage divider network with the shunt resistive/capacitive elements of the first compensated RC voltage divider network coupled in series with the shunt resistive element of the first resistive Z 0 voltage divider network and the second transmission line coupling the series resistive/capacitive elements of the second compensated RC voltage divider network to the shunt resistive element of the second resistive Z 0 voltage divider network with the shunt resistive/capacitive elements of the second compensated RC voltage divider network coupled in series with the shunt resistive element of the second resistive Z 0 voltage divider network; a differential amplifier having first and second inputs with the first input of the differential amplifier coupled to the junction of the first transmission line with the shunt resistive element of the first resistive Z 0 voltage divider network and the second input of the differential amplifier coupled to the junction of the second transmission line with the shunt resistive element of the second resistive Z 0 voltage divider network.