# US 12,216,151 B2 · Measurement instrument, measurement system, and testing method of testing a device under test > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,216,151 B2 - Document ID: US12216151B2 - Status: Granted - Kind: B2 - Application number: 18/306,829 - Filed: 2023-04-25 - Published: 2024-10-31 - Granted: 2025-02-04 - Earliest claimed: 2023-04-25 - Assignees: Rohde & Schwarz GmbH & Co. KG - Applicants: Rohde & Schwarz GmbH & Co. KG - Inventors: Paul Gareth Lloyd; Markus Loerner - Web page: https://patentgrep.com/patent/US12216151B2 ## CPC - G01R 31/2841: {Signal generators} - G01R 31/2837: {Characterising or performance testing, e.g. of frequency response (transient response G01R27/28)} - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) ## Abstract A measurement instrument for testing a DUT comprises a common port configured to be connectable to a signal output of the DUT for receiving a forward-travelling signal from the DUT. The measurement instrument further comprises a signal line connected to the common port, a signal analysis circuit and a signal generator circuit. The signal analysis circuit receives the forward-travelling signal from the common port. The signal analysis circuit is configured to analyze the forward-travelling signal in order to assess a performance of the DUT. The signal generator circuit is connected to the signal line and is configured to generate a backward-travelling signal that is forwarded to the common port. The signal generator circuit comprises a reference signal input configured to receive a reference signal from a reference signal generator. The signal generator circuit is configured to generate the backward-travelling signal based on the reference signal. ## Claims ### Claim 1 A measurement instrument for testing a device under test, the measurement instrument comprising: a common port configured to be connectable to a signal output of the device under test, wherein the common port is configured to receive a forward-travelling signal from the device under test; a signal line connected to the common port; and a signal processing circuit, wherein the signal processing circuit comprises a signal analysis circuit and a signal generator circuit, wherein the signal analysis circuit is connected with the common port so as to receive the forward-travelling signal from the common port, wherein the signal analysis circuit is configured to analyze the forward-travelling signal in order to assess a performance of the device under test, wherein the signal generator circuit is connected to the signal line, wherein the signal generator circuit is configured to generate a backward-travelling signal that is forwarded to the common port, wherein the signal generator circuit comprises a reference signal input, the reference signal input being configured to receive a reference signal from a reference signal generator, and wherein the signal generator circuit is configured to generate the backward-travelling signal based on the reference signal. ### Claim 2 (depends on 1) The measurement instrument of claim 1, wherein the signal generator circuit is configured to generate the backward-travelling signal based on the reference signal such that the backward-travelling signal is forwarded to the common port in time with receiving an output signal of the device under test via the common port. ### Claim 3 (depends on 1) The measurement instrument of claim 1, wherein the signal line comprises a first directional coupler portion, wherein the signal analysis circuit is connected with the common port via the first directional coupler portion. ### Claim 4 (depends on 1) The measurement instrument of claim 1, further comprising a signal shaping circuit, wherein the signal shaping circuit is interconnected between the signal generator circuit and the common port. ### Claim 5 (depends on 4) The measurement instrument of claim 4, wherein the signal shaping circuit comprises at least one of an amplifier circuit, an attenuator circuit, or a filter circuit. ### Claim 6 (depends on 1) The measurement instrument of claim 1, wherein the signal generator circuit is configured to generate the backward-travelling signal such that the forward-travelling signal and the backward-travelling signal have a predefined amplitude relation and/or a predefined phase relation. ### Claim 7 (depends on 1) The measurement instrument of claim 1, wherein the signal generator circuit is configured to generate the backward-travelling signal such that the forward-travelling signal and the backward-travelling signal have the same modulation type. ### Claim 8 (depends on 1) The measurement instrument of claim 1, wherein the reference signal corresponds to an input signal of the device under test or to a signal generated by the device under test. ### Claim 9 (depends on 1) The measurement instrument of claim 1, wherein the signal line comprises a second directional coupler portion, wherein the signal analysis circuit is connected with the signal generator circuit via the second directional coupler portion so as to receive the backward-travelling signal. ### Claim 10 (depends on 9) The measurement instrument of claim 9, wherein the signal analysis circuit is configured to determine an impedance presented to the device under test based on the forward-travelling signal and based on the backward-travelling signal. ### Claim 11 (depends on 9) The measurement instrument of claim 9, wherein the signal analysis circuit is configured to assess the performance of the device under test based on the forward-travelling signal and based on the backward-travelling signal. ### Claim 12 (depends on 1) The measurement instrument of claim 1, wherein the measurement instrument is configured to operate the signal generator circuit independent of the signal analysis circuit. ### Claim 13 (depends on 1) The measurement instrument of claim 1, wherein the backward-travelling signal corresponds to at least one of a desired load impedance, a DUT distortion, a DUT modulation, a DUT input power, or a DUT output power. ### Claim 14 (depends on 1) The measurement instrument of claim 1, wherein the backward-travelling signal is generated based on pre-recorded measurement results obtained with a known-good device under test. ### Claim 15 (depends on 1) The measurement instrument of claim 1, wherein the backward-travelling signal is generated based on a mathematical model of the device under test. ### Claim 16 (depends on 1) The measurement instrument of claim 1, wherein the measurement instrument is established as a signal analyzer, a vector signal analyzer, an oscilloscope, a digital oscilloscope, or a vector network analyzer. ### Claim 17 (depends on 1) The measurement instrument of claim 1, wherein the signal analysis circuit is configured to determine at least one of a error vector magnitude (EVM) or an adjacent channel leakage ratio (ACLR) based on the forward-travelling signal. ### Claim 18 (depends on 1) A measurement system, the measurement system comprising a measurement instrument according to claim 1 and a device under test. ### Claim 19 (depends on 18) The measurement system of claim 18, wherein the reference signal generator is established separately from the device under test and from the measurement instrument. ### Claim 20 (depends on 18) The measurement system of claim 18, wherein the reference signal generator is integrated into the device under test. ### Claim 21 A testing method of testing a device under test by a measurement instrument, the measurement instrument comprising a common port and a signal processing circuit, wherein the common port is connectable to a signal output of the device under test, wherein the signal processing circuit comprises a signal analysis circuit and a signal generator circuit, and wherein the signal generator circuit comprises a reference signal input, the testing method comprising the steps of: receiving, by the common port, a forward-travelling signal from the device under test; receiving, by the reference signal input, a reference signal from a reference signal generator; generating, by the signal generator circuit, a backward-travelling signal based on the reference signal; forwarding the backward-travelling signal to the common port; and analyzing, by the signal analysis circuit, the forward-travelling signal in order to assess a performance of the device under test.