# US 12,222,436 B2 · Radar method and radar system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,222,436 B2 - Document ID: US12222436B2 - Status: Granted - Kind: B2 - Application number: 17/641,729 - Filed: 2020-08-11 - Published: 2022-10-20 - Granted: 2025-02-11 - Earliest claimed: 2019-09-09 - Assignees: Symeo GmbH - Applicants: Symeo GmbH - Inventors: Peter Gulden; Martin Vossiek; Michael Gottinger - Web page: https://patentgrep.com/patent/US12222436B2 ## CPC - G01S 7/023: {Interference mitigation, e.g. reducing or avoiding non-intentional interference with other HF-transmitters, base station transmitters for mobile communication or other radar systems, e.g. using electro-magnetic interference [EMI] reduction techniques (auxiliary means for detecting or identifying radar signals or the like G01S7/021; means for anti-jamming G01S7/36)} - G01S 7/03: Details of HF subsystems specially adapted therefor, e.g. common to transmitter and receiver - G01S 7/35: Details of non-pulse systems - G01S 7/352: {Receivers} - G01S 7/4017: {of HF systems} - G01S 7/4021: {of receivers} - G01S 13/003: {Bistatic radar systems; Multistatic radar systems} - G01S 13/34: using transmission of continuous, frequency-modulated waves while heterodyning the received signal, or a signal derived therefrom, with a locally-generated signal related to the contemporaneously transmitted signal - G01S 13/42: Simultaneous measurement of distance and other co-ordinates (indirect measurement G01S13/46) - G01S 13/87: Combinations of radar systems, e.g. primary radar and secondary radar - G01S 13/931: of land vehicles - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES ## Abstract A radar method comprising transmitting and receiving signals simultaneously or overlapping in time by spatially separated transceiver units. Comparison signals are formed from transmitted and received signals by respective transceiver units. A phase correction is formed for each of a plurality of sample values, to generate a measure of phase difference per sample value between the comparison signals. A measure of phase difference is used to improve accuracy of distance or velocity measurements between the transceiver units. A radar system includes transceiver units and an evaluation unit configured to perform the method. ## Claims ### Claim 1 A radar method, comprising: transmitting and receiving signals, simultaneously or overlapping in time, by at least two transceiver units that spatially separated from one another; forming respective comparison signals comprising mixed signals, the mixed signals respectively formed from a signal transmitted and received by a respective transceiver unit amongst the at least two transceiver units; forming a phase correction for each of a plurality of time sample values, comprising a phase correction value for each of a plurality of time sample values from the mixed signals, to generate a measure of a phase difference per time sample value between the mixed signals; and using the phase correction to improve accuracy of at least one of a distance measurement or a velocity measurement between the at least two transceiver units. ### Claim 2 (depends on 1) The method of claim 1, wherein forming the phase correction comprises multiplying one mixed signal with a complex-valued conjugate of another mixed signal. ### Claim 3 (depends on 1) The method of claim 1, wherein forming the phase correction comprises representing the mixed signals according to absolute value and phase and determining a difference in phase between a second mixed signal and a first mixed signal for each sample. ### Claim 4 (depends on 3) The method of claim 3, wherein differences in phase for each sample form a phase correction function; and wherein phase correction function is applied to a sampled time signal to correct the sampled time signal. ### Claim 5 (depends on 1) The method of claim 1, wherein the signals are linear frequency-modulated signals. ### Claim 6 (depends on 1) The method of claim 1, wherein the at least two transceiver units are in line-of-sight with one another. ### Claim 7 (depends on 1) The method of claim 1, wherein the at least two transceiver units are configured for earth remote sensing. ### Claim 8 (depends on 1) The method of claim 1, wherein the at least two transceiver units are attached to separate flying objects. ### Claim 9 (depends on 1) The method of claim 1, further comprising estimating a phase error using baseband signals of at least one receiving channel and compensating for the phase error in at least one further receiving channel. ### Claim 10 (depends on 1) The method of claim 1, wherein at least one transceiver unit amongst that at least two transceiver units uses an antenna element for both transmitting and receiving. ### Claim 11 A radar system comprising: at least two transceiver units that are spatially separated and configured to transmit and receive signals simultaneously or overlapping in time; and at least one evaluation unit configured to: form respective comparison signals comprising mixed signals respectively formed from a signal transmitted and received by a respective transceiver unit amongst the at least two transceiver units; form a phase correction for each of a plurality of time sample values from the mixed signals to generate a measure of a phase difference per time sample value between the mixed signals from the at least two transceiver units; and use the phase correction to improve accuracy of at least one of a distance measurement or a velocity measurement between the at least two transceiver units. ### Claim 12 (depends on 11) The radar system of claim 11, wherein the at least one evaluation unit is configured to form the phase correction by multiplying one mixed signal with a complex-valued conjugate of another mixed signal. ### Claim 13 (depends on 11) The radar system of claim 11, wherein the at least one evaluation unit is configured to form the phase correction by representing the mixed signals according to absolute value and phase and determining a difference in phase between a second mixed signal and a first mixed signal for each sample. ### Claim 14 (depends on 11) The radar system of claim 11, wherein differences in phase for each sample form a phase correction function; and wherein the at least one evaluation unit is configured to apply the phase correction function to a sampled time signal to correct the sampled time signal. ### Claim 15 (depends on 11) The radar system of claim 11, wherein the signals are linear frequency-modulated signals. ### Claim 16 (depends on 11) The radar system of claim 11, wherein the at least two transceiver units are in line-of-sight with one another. ### Claim 17 (depends on 11) The radar system of claim 11, wherein the at least two transceiver units are configured for earth remote sensing. ### Claim 18 (depends on 11) The radar system of claim 11, wherein the at least two transceiver units are attached to separate flying objects. ### Claim 19 (depends on 11) The radar system of claim 11, wherein the at least one evaluation unit is configured to estimate a phase error using baseband signals of at least one receiving channel and compensate for the phase error in at least one further receiving channel. ### Claim 20 (depends on 11) The radar system of claim 11, wherein at least one transceiver unit amongst that at least two transceiver units uses an antenna element for both transmitting and receiving.