# US 12,000,921 B2 · Radar apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,000,921 B2 - Document ID: US12000921B2 - Status: Granted - Kind: B2 - Application number: 17/204,274 - Filed: 2021-03-17 - Published: 2021-09-30 - Granted: 2024-06-04 - Earliest claimed: 2020-03-18 - Assignees: Panasonic Automotive Systems Co., Ltd. - Applicants: Panasonic Intellectual Property Management Co., Ltd. - Inventors: Takaaki Kishigami - Web page: https://patentgrep.com/patent/US12000921B2 ## CPC - G01S 13/343: {using sawtooth modulation} - G01S 13/347: {using more than one modulation frequency} - G01S 7/352: {Receivers} - G01S 13/003: {Bistatic radar systems; Multistatic radar systems} - G01S 13/325: {using transmission of coded signals, e.g. P.S.K. signals} - G01S 13/42: Simultaneous measurement of distance and other co-ordinates (indirect measurement G01S13/46) - G01S 13/5246: {post processors for coherent MTI discriminators, e.g. residue cancellers, CFAR after Doppler filters} - G01S 7/356: {involving particularities of FFT processing} - G01S 2013/0254: {Active array antenna} - 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 The target detection accuracy of a radar apparatus is improved. The radar apparatus includes signal generation circuitry, which, in operation, generates a first transmission signal and a second transmission signal, and transmission circuitry, which, in operation, transmits a multiplexed signal resulting from code-multiplexing the first transmission signal and the second transmission signal, wherein a modulation frequency of the first transmission signal at a first timing is identical to a modulation frequency of the second transmission signal at a second timing that is later than the first timing. ## Claims ### Claim 1 A radar apparatus, comprising: signal generation circuitry, which, in operation, generates a first transmission signal and a second transmission signal per a transmission period; and transmission circuitry, which, in operation, transmits a multiplexed signal resulting from code-multiplexing the first transmission signal and the second transmission signal, wherein, per the transmission period, a modulation frequency of the first transmission signal at a first timing is identical to a modulation frequency of the second transmission signal at a second timing that is later than the first timing. ### Claim 2 (depends on 1) The radar apparatus according to claim 1, further comprising reception circuitry, which, in operation, down-mixes a reflected wave signal being the multiplexed signal reflected by an object, with reference to the second transmission signal. ### Claim 3 (depends on 2) The radar apparatus according to claim 2, wherein a sampling rate in AD conversion for the reflected wave signal periodically varies. ### Claim 4 (depends on 1) The radar apparatus according to claim 1, wherein the first transmission signal and the second transmission signal are chirp signals. ### Claim 5 (depends on 4) The radar apparatus according to claim 4, wherein a frequency sweep width of at least one of the chirp signals periodically varies. ### Claim 6 (depends on 1) The radar apparatus according to claim 1, wherein, per the transmission period, a transmission start timing of the first transmission signal is earlier than a transmission start timing of the second transmission signal. ### Claim 7 (depends on 1) The radar apparatus according to claim 1, wherein the modulation frequency of the first transmission signal is higher than the modulation frequency of the second transmission signal at the first timing and a third timing that is different from the first timing. ### Claim 8 (depends on 7) The radar apparatus according to claim 7, wherein a difference between the modulation frequency of the first transmission signal and the modulation frequency of the second transmission signal at the third timing is set based on a distance range where detection is performed using the first transmission signal. ### Claim 9 (depends on 1) The radar apparatus according to claim 1, wherein a difference between the first timing and the second timing is set based on a distance range where detection is performed using the first transmission signal. ### Claim 10 (depends on 1) The radar apparatus according to claim 1, wherein a difference between the first timing and the second timing periodically varies. ### Claim 11 (depends on 1) The radar apparatus according to claim 1, wherein the multiplexed signal is code-multiplexed by using a part of a plurality of code sequences with a code length greater than a number of code multiplexing for the multiplexed signal. ### Claim 12 (depends on 11) The radar apparatus according to claim 11, wherein, a first code sequence and a second code sequence included in the plurality of code sequences include code elements so that, between the first code sequence and the second code sequence, either odd-numbered code elements are the same and even-numbered code elements have signs inverted, or even-numbered code elements are the same and odd-numbered code elements have signs inverted, and either one of the first code sequence and the second code sequence is used for code multiplexing of the first transmission signal, and the other one of the first code sequence and the second code sequence is used for code multiplexing of the second transmission signal. ### Claim 13 (depends on 1) The radar apparatus according to claim 1, wherein different transmission delays are cyclically set for the first transmission signal and the second transmission signal for each transmission period corresponding to a code length of a code sequence used for code multiplexing for the multiplexed signal. ### Claim 14 (depends on 13) The radar apparatus according to claim 13, further comprising reception circuitry, which, in operation, determines aliasing, in Doppler frequency domain, of a reflected wave signal being the multiplexed signal reflected by an object, in a range (the code length x 2) times as large as a Doppler analysis range for the reflected wave signal. ### Claim 15 A radar apparatus, comprising: signal generation circuitry, which, in operation, generates a first transmission signal and a second transmission signal; and transmission circuitry, which, in operation, transmits a multiplexed signal resulting from code-multiplexing the first transmission signal and the second transmission signal, wherein different transmission delays are cyclically set for the first transmission signal and the second transmission signal for each transmission period corresponding to a code length of a code sequence used for code multiplexing for the multiplexed signal.