{"schema_version":"1.0","canonical_url":"https://patentable.app/patents/US-9817121","patent":{"patent_number":"US-9817121","title":"Radar apparatus and method of determining sign of velocity","assignee":null,"inventors":[],"filing_date":"2014-12-23T00:00:00.000Z","publication_date":"2017-11-14T00:00:00.000Z","cpc_codes":["G01S","G01S","G01S","G01S"],"num_claims":1,"abstract":"A radar apparatus which can simply determine the sign of velocity of an object is provided. Laser light reflected by the object undergoes quadrature optical heterodyne detection performed by mixers, optical detectors, and a π/2 phase shifter, whereby I and Q component signals are output. A frequency analyzer performs FFT on a complex signal composed of the I component signal (real part) and the Q component signal (imaginary part) to thereby obtain its frequency spectrum. Since the frequency spectrum is calculated without being folded back even in a region where the frequency is negative, the sign of the Doppler frequency fd can be determined. When the Doppler frequency fd is positive, the sign of the velocity of the object is a direction toward the radar apparatus. When the Doppler frequency fd is negative, the sign of the velocity of the object is a direction away from the radar apparatus."},"analysis":{"summary":null,"layman_explanation":null,"technical_analysis":null,"business_analysis":null,"faqs":null,"topics":[],"tech_cluster":null},"seo":{"title":"Radar apparatus and method of determining sign of velocity","description":"A radar apparatus which can simply determine the sign of velocity of an object is provided. Laser light reflected by the object undergoes quadrature optical heterodyne detection performed by mixers, o","keywords":[]},"attribution":{"source":"Patentable","source_url":"https://patentable.app","canonical_url":"https://patentable.app/patents/US-9817121","license":"CC-BY-4.0-like","license_terms":"AI-generated analysis on this page (summary, layman_explanation, technical_analysis, business_analysis, faqs) may be reused with attribution and a visible link back to the canonical URL above. Patent abstracts, claims, and bibliographic data are USPTO public domain.","required_link":"https://patentable.app/patents/US-9817121","citation_suggestion":"Patentable. \"Radar apparatus and method of determining sign of velocity\" (US-9817121). https://patentable.app/patents/US-9817121","copyright_holder":"Nomic Interactive Technology LLC"},"links":{"html":"https://patentable.app/patents/US-9817121","json":"https://patentable.app/api/llm-context/US-9817121","site":"https://patentable.app","llms_txt":"https://patentable.app/llms.txt"},"generated_at":"2026-06-06T16:30:07.602Z"}