# US 9,435,893 B2 · Digital beam-forming apparatus and technique for a multi-beam global positioning system (GPS) receiver > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,435,893 B2 - Document ID: US9435893B2 - Status: Granted - Kind: B2 - Application number: 13/549,521 - Filed: 2012-07-16 - Published: 2012-12-27 - Granted: 2016-09-06 - Earliest claimed: 2007-05-21 - Assignees: Spatial Digital Systems, Inc. - Applicants: Donald C. D. Chang - Inventors: Donald C. D. Chang - Web page: https://patentgrep.com/patent/US9435893B2 ## CPC - G01S 19/21: Interference related issues {; Issues related to cross-correlation, spoofing or other methods of denial of service} - G01S 19/28: Satellite selection - G01S 19/35: Constructional details or hardware or software details of the signal processing chain - G01S 19/36: relating to the receiver frond end - H01Q 1/28: Adaptation for use in or on aircraft, missiles, satellites, or balloons - H01Q 3/2605: {Array of radiating elements provided with a feedback control over the element weights, e.g. adaptive arrays} - H01Q 3/267: {Phased-array testing or checking devices} - H01Q 3/2682: {Time delay steered arrays} - H01Q 25/00: Antennas or antenna systems providing at least two radiating patterns (arrangements for changing or varying the orientation or the shape of the directional pattern H01Q3/00) - 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 - H01Q: ANTENNAS, i.e. RADIO AERIALS (radiators or antennas for microwave heating H05B6/72) ## Abstract An advanced multiple-beam GPS receiving system is achieved that is capable of simultaneously tracking multiple GPS satellites independently, detecting multiple interference signals individually, and suppressing directional gain in the antenna pattern of each beam in the interference directions. The GPS receiving system can be used for both planar and non-planar receiving arrays, including arrays that are conformally applied to the surface of a platform such as an aircraft. The GPS receiver combines spatial filtering and acquisition code correlation for enhanced rejection of interfering sources. Enhanced gain in the direction of GPS satellites and the ability to shape the beam patterns to suppress gain in the direction of interfering sources make the GPS receiving system largely insensitive to interfering and jamming signals that plague conventional GPS receivers. ## Claims ### Claim 1 A method for calibrating multiple simultaneous beams, comprising: receiving a first signal from a first direction by multiple antenna elements arranged in a non-planar array; cross correlating said first signal received from one of said antenna elements with said first signal received from said antenna elements so as to calculate a first beam weighting vector of a first one of said simultaneous beams pointing at said first direction; receiving a second signal from a second direction by said antenna elements; and cross correlating said second signal received from one of said antenna elements with said second signal received from said antenna elements so as to calculate a second beam weighting vector of a second one of said simultaneous beams pointing at said second direction. ### Claim 2 (depends on 1) The method of claim 1, wherein said first beam weighting vector comprises a phase factor. ### Claim 3 (depends on 1) The method of claim 1, wherein said first beam weighting vector comprises an amplitude factor. ### Claim 4 (depends on 1) The method of claim 1, wherein said first beam weighting vector comprises a time-delay factor. ### Claim 5 (depends on 1) The method of claim 1 further comprising said cross correlating said first signal received from said one of said antenna elements with said first signal received from said one of said antenna elements so as to calculate said first beam weighting vector of said first one of said simultaneous beams pointing at said first direction. ### Claim 6 (depends on 1) The method of claim 1 further comprising said cross correlating said first signal received from said one of said antenna elements with said first signal received from another one of said antenna elements so as to calculate said first beam weighting vector of said first one of said simultaneous beams pointing at said first direction. ### Claim 7 A method of operation for a navigation receiver, comprising: identifying a first direction of an interfering source; performing a beam shaping process to form a first beam with a suppressed gain in said first direction of said interfering source within the field of view of an array of said navigation receiver; and correlating multiple navigation codes associated with said first beam so as to extract time and position data, wherein said identifying said first direction of said interfering source comprises creating a second beam tracking a first satellite and a third beam tracking a second satellite, turning on said second beam and off said third beam so as to obtain a first measurement from said first satellite, examining said first measurement for consistency, turning on said third beam and off said second beam so as to obtain a second measurement from said second satellite, and examining said second measurement for consistency. ### Claim 8 (depends on 7) The method of claim 7, wherein said first measurement from said first satellite comprises navigation information. ### Claim 9 (depends on 7) The method of claim 7 further comprising receiving a signal from a second direction by multiple antenna elements of said navigation receiver, and cross correlating said signal received from one of said antenna elements with said signal received from said antenna elements so as to calculate a beam weighting vector associated with said second direction. ### Claim 10 (depends on 9) The method of claim 9, wherein said beam weighting vector comprises a phase factor. ### Claim 11 (depends on 9) The method of claim 9, wherein said beam weighting vector comprises an amplitude factor. ### Claim 12 (depends on 9) The method of claim 9, wherein said beam weighting vector comprises a time-delay factor. ### Claim 13 A method of operation for a navigation receiver, comprising: creating a first beam with enhanced gain in a direction of a first source and suppressed gain in a direction of a second source; creating a second beam with enhanced gain in said direction of said second source and suppressed gain in said direction of said first source; and correlating multiple navigation codes associated with said first beam and said second beam so as to extract time and position data. ### Claim 14 (depends on 13) The method of claim 13, wherein said first source comprises a GPS satellite. ### Claim 15 (depends on 13) The method of claim 13, wherein said first source comprises a GPS satellite and said second source comprises another GPS satellite. ### Claim 16 (depends on 13) The method of claim 13, wherein said creating said first beam comprises multiplying multiple beam weighting factor by respective radiation patterns so as to form multiple weighted radiation patterns and summing said weighted radiation patterns. ### Claim 17 (depends on 13) The method of claim 13, wherein said creating said first beam comprises multiplying multiple beam weighting factor by respective array elements arranged in a non-planar array so as to form multiple weighted radiation patterns and summing said weighted radiation patterns. ### Claim 18 (depends on 13) The method of claim 13, wherein said creating said first beam comprises multiplying multiple beam weighting factor by respective array elements arranged in a non-contiguously distributed array so as to form multiple weighted radiation patterns and summing said weighted radiation patterns.