# US 11,309,636 B2 · Antenna structure for reducing beam squint and sidelobes > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,309,636 B2 - Document ID: US11309636B2 - Status: Granted - Kind: B2 - Application number: 16/718,689 - Filed: 2019-12-18 - Published: 2021-06-24 - Granted: 2022-04-19 - Earliest claimed: 2019-12-18 - Assignees: Waymo LLC - Applicants: Waymo LLC - Inventors: Edwin Lim; Matt Markel - Web page: https://patentgrep.com/patent/US11309636B2 ## CPC - H01Q 21/0037: {linear waveguide fed arrays} - H01Q 21/064: {using horn or slot aerials (slotted waveguides arrays H01Q21/005)} - G01S 7/03: Details of HF subsystems specially adapted therefor, e.g. common to transmitter and receiver - G01S 7/2813: {Means providing a modification of the radiation pattern for cancelling noise, clutter or interfering signals, e.g. side lobe suppression, side lobe blanking, null-steering arrays (specially adapted to secondary radar systems G01S13/762; aerials or aerials systems H01Q21/29, H01Q25/00)} - G01S 13/282: {using a frequency modulated carrier wave (G01S13/286 takes precedence)} - G01S 13/428: {within the pulse scanning systems} - G01S 13/931: of land vehicles - H01Q 1/3233: {particular used as part of a sensor or in a security system, e.g. for automotive radar, navigation systems} - H01Q 3/22: varying the orientation in accordance with variation of frequency of radiated wave - H01Q 3/2611: {Means for null steering; Adaptive interference nulling} - G01S 13/90: using synthetic aperture techniques {, e.g. synthetic aperture radar [SAR] techniques} - H01Q: ANTENNAS, i.e. RADIO AERIALS (radiators or antennas for microwave heating H05B6/72) - 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 An example radar system includes a transmission array and a reception array, each aligned as a linear array. The radar system also includes a transmitter configured to cause transmission of radar signals having a center frequency by the transmission array. The radar system also includes a receiver configured to receive radar signals having the center frequency that are received by the reception array. The radar system also includes a processor configured to process received radar signals from the receiver, and adjust the center frequency from a first center frequency to a second center frequency. The adjusting of the center frequency from the first center frequency to the second center frequency causes the frequency-dependent transmission radiation pattern of the transmission array to tilt in a first direction and the frequency-dependent reception radiation pattern of the reception array to tilt in an opposite direction from the first direction. ## Claims ### Claim 1 A radar system comprising: a transmission array aligned as a linear array, wherein the transmission array is configured having a frequency-dependent transmission radiation pattern; a reception array aligned as a linear array, wherein the reception array is configured having a frequency-dependent reception radiation pattern; a transmitter configured to cause transmission of radar signals having a center frequency by the transmission array; a receiver configured to receive radar signals having the center frequency that are received by the reception array; a processor configured to: process received radar signals from the receiver, and adjust the center frequency from a first center frequency to a second center frequency; and wherein an adjusting of the center frequency from the first center frequency to the second center frequency causes: the frequency-dependent transmission radiation pattern to tilt in a first direction, and the frequency-dependent reception radiation pattern to tilt in an opposite direction from the first direction. ### Claim 2 (depends on 1) The radar system of claim 1, wherein the tilt in the first direction has approximately equal magnitude to the tilt in the opposite direction from the first direction. ### Claim 3 (depends on 1) The radar system of claim 1, wherein the transmission array is coupled to a transmission feed waveguide and wherein the reception array is coupled to a reception feed waveguide. ### Claim 4 (depends on 3) The radar system of claim 3, wherein a direction of propagation of energy from the transmission feed waveguide into the transmission array is the same direction as a direction of propagation of energy from the reception array into the reception feed waveguide. ### Claim 5 (depends on 3) The radar system of claim 3, wherein the transmission feed waveguide is coupled to a bottom end of the transmission array and the reception feed waveguide is coupled to a top end of the reception waveguide. ### Claim 6 (depends on 1) The radar system of claim 1, further comprising a plurality of transmission arrays. ### Claim 7 (depends on 1) The radar system of claim 1, further comprising a plurality of reception arrays. ### Claim 8 (depends on 1) The radar system of claim 1, wherein the frequency-dependent transmission radiation pattern has a transmission sidelobe and the frequency-dependent reception radiation pattern has a reception sidelobe, and wherein a direction of the transmission sidelobe and a direction of the reception sidelobe minimize sidelobe levels in a combination of the transmission sidelobe and the reception sidelobe. ### Claim 9 (depends on 1) The radar system of claim 1, wherein the first center frequency and the second center frequency fall within a bandwidth of operation for the radar system and the bandwidth is greater than 2 Gigahertz. ### Claim 10 A method comprising: feeding a transmission array with a radar signal having a center frequency, wherein the transmission array transmits the radar signal based on a frequency-dependent transmission radiation pattern; receiving radar reflection signals by a reception array, wherein the reception array receives the reflection signals based on a frequency-dependent reception radiation pattern; and adjusting the center frequency from a first center frequency to a second center frequency, wherein an adjusting of the center frequency from the first center frequency to the second center frequency causes: the frequency-dependent transmission radiation pattern to tilt in a first direction, and the frequency-dependent reception radiation pattern to tilt in an opposite direction from the first direction. ### Claim 11 (depends on 10) The method of claim 10, further comprising: repeating the feeding and receiving for a center frequency different from the first center frequency. ### Claim 12 (depends on 10) The method of claim 10, wherein the tilt in the first direction has approximately equal magnitude to the tilt in the opposite direction from the first direction. ### Claim 13 (depends on 10) The method of claim 10, wherein feeding the transmission array comprises feeding the transmission array by a transmission feed waveguide and wherein radar reflection signals received by the reception array are coupled to a reception feed waveguide. ### Claim 14 (depends on 13) The method of claim 13, wherein a direction of propagation of energy from the transmission feed waveguide into the transmission array is the same direction as a direction of propagation of energy from the reception array into the reception feed waveguide. ### Claim 15 (depends on 13) The method of claim 13, further comprising feeding energy from the transmission feed waveguide into a bottom end of the transmission array and receiving energy into the reception feed waveguide from a top end of the reception array. ### Claim 16 (depends on 10) The method of claim 10, further comprising: feeding a plurality of transmission arrays; and receiving radar reflection signals by a plurality of reception arrays. ### Claim 17 (depends on 10) The method of claim 10, wherein the frequency-dependent transmission radiation pattern has a transmission sidelobe and the frequency-dependent reception radiation pattern has a reception sidelobe, and wherein a direction of the transmission sidelobe and a direction of the reception sidelobe minimize sidelobe levels in a combination of the transmission sidelobe and the reception sidelobe. ### Claim 18 (depends on 10) The method of claim 10, wherein the first center frequency and the second center frequency fall within a bandwidth of operation and the bandwidth is greater than 2 Gigahertz. ### Claim 19 A vehicle-mounted radar system comprising: a radar unit comprising: a plurality of transmission arrays each aligned as a vertically-oriented linear array, wherein each transmission array is configured having a frequency-dependent transmission radiation pattern, wherein each transmission array comprises a respective transmission feed waveguide connected to a bottom end of the transmission array; a plurality of reception arrays each aligned as a vertically-oriented linear array, wherein each reception array is configured having a frequency-dependent reception radiation pattern, wherein each reception array comprises a respective reception feed waveguide connected to a top end of the reception array; at least one transmitter configured to cause transmission of radar signals having a center frequency by the plurality of transmission arrays; at least one receiver configured to receive radar signals having the center frequency that are received by the plurality of reception arrays; and a processor configured to: process received radar signals from the at least one receiver, and adjust the center frequency from a first center frequency to a second center frequency; and wherein an adjusting of the center frequency from the first center frequency to the second center frequency causes: the frequency-dependent transmission radiation pattern of each transmission array to tilt in a first direction in an elevation plane, and the frequency-dependent reception radiation pattern of each reception array to tilt in an opposite direction from the first direction in the elevation plane, wherein the tilt in the first direction has approximately equal magnitude to the tilt in the opposite direction from the first direction. ### Claim 20 (depends on 19) The vehicle-mounted radar system of claim 19, wherein: the frequency-dependent transmission radiation pattern has a transmission sidelobe and the frequency-dependent reception radiation pattern has a reception sidelobe, and wherein a direction of the transmission sidelobe and a direction of the reception sidelobe minimize sidelobe levels in a combination of the transmission sidelobe and the reception sidelobe; and the first center frequency and the second center frequency fall within a bandwidth of operation and the bandwidth is greater than 2 Gigahertz.