US 11,852,658 B2
Measurement input circuit and measurement device
Martin Peschke, Munich (DE)
Assigned to Rohde & Schwarz GmbH & Co. KG, Munich (DE)
Filed by Rohde & Schwarz GmbH & Co. KG, Munich (DE)
Filed on Jan. 4, 2022, as Appl. No. 17/568,070.
Application 17/568,070 is a division of application No. 15/632,458, filed on Jun. 26, 2017, granted, now 11,287,447.
Prior Publication US 2022/0120786 A1, Apr. 21, 2022
Int. Cl. G01R 1/30 (2006.01); G01R 13/22 (2006.01); G01R 1/067 (2006.01)
CPC G01R 1/30 (2013.01) [G01R 1/06766 (2013.01); G01R 13/22 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A measurement input circuit for a measurement device for measuring an electric signal in a device under test, the measurement input circuit comprising:
a signal input that receives the electronic signal from the device under test and provides the received electronic signal at a signal node,
a direct signal coupling path that is coupled between the signal node and an electrical ground and comprises a first impedance value,
wherein the direct signal coupling path comprises an offset circuit with an offset source and a summing or differentiating circuit,
wherein the offset source is coupled between the electrical ground and a first resistor,
wherein an input of the summing or differentiating circuit is coupled between the offset source and the first resistor,
wherein the summing or differentiating circuit is configured such to form the sum or difference, respectively, of the electric signal and an output signal of the offset source,
an alternating signal coupling path that is coupled between the signal node and the electrical ground, and comprises a second impedance value that is lower than the first impedance value,
a signal output that is coupled to the signal node and outputs the received electronic signal, and
a measurement amplifier, wherein a first input port of the measurement amplifier is connected to the signal node and a second input of the measurement amplifier is coupled to an output of the summing or differentiating circuit, and wherein the signal output is connected to an output of the measurement amplifier.