{
  "patent_number": "US 2292387",
  "country": "US",
  "title": "Hedy Lamarr and George Antheil's Frequency Hopping Secret Communication System",
  "original_title": "Secret communication system",
  "summary": "A 1942 patent for a radio-controlled torpedo guidance system that used synchronized player piano rolls to hop between frequencies, preventing enemies from jamming the signal.",
  "what_it_does": "The system uses two synchronized mechanisms, similar to those found in player pianos, to change the carrier frequency of a radio transmitter and receiver simultaneously. By rapidly switching frequencies in a predetermined sequence, the signal becomes extremely difficult for an adversary to detect or jam. The patent describes using perforated paper rolls to control the timing of these frequency shifts, ensuring both the sender and receiver stay perfectly aligned.",
  "what_it_does_not_cover": [
    "Does not cover digital frequency hopping methods using modern microprocessors.",
    "Does not cover encryption or scrambling of the actual message content.",
    "Does not cover non-mechanical methods of frequency synchronization.",
    "Does not cover the use of radio waves for anything other than remote control of a torpedo."
  ],
  "filed": "1941-06-10",
  "granted": "1942-08-11",
  "expires": "1961-06-10",
  "status": "expired",
  "holder": "Individual",
  "holder_url": "https://patentbrief.org/company/individual",
  "inventors": [
    {
      "name": "Antheil George",
      "url": "https://patentbrief.org/inventor/antheil-george"
    },
    {
      "name": "Markey Hedy Kiesler",
      "url": "https://patentbrief.org/inventor/markey-hedy-kiesler"
    }
  ],
  "times_cited": 82,
  "tags": [
    "telecommunications",
    "mechanical",
    "aerospace"
  ],
  "abstract": null,
  "url": "https://patentbrief.org/patent/us/2292387/hedy-lamarr-frequency-hopping",
  "markdown_url": "https://patentbrief.org/patent/us/2292387/hedy-lamarr-frequency-hopping/md",
  "google_patents_url": "https://patents.google.com/patent/US2292387",
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}