Patent · US Expired

Radio direction finding system

US4551727A · kind A · utility

12Cited by
4References
15Claims
0Family size

Inventor

Key dates

Filing dateDec 23, 1982
Grant dateNov 5, 1985
Priority date
Expiry dateDec 23, 2002

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01S3/046
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A radio direction finding system based on the doppler frequency shift principle is disclosed which utilizes a polygonal shaped antenna array and a conventional FM receiver. Voltages from each antenna are combined in an rf summing circuit which may be located remotely from the antenna. Audio output from the FM receiver is processed to measure the phase angle of the commutation frequency phase modulation imparted to the rf receiver input signal by gain variations within the rf summer circuit. Bearing angle proportional to the measured phase angle is displayed in a circular array of light emitting diodes and a three digit decimal display and is provided for recording or remote display through a serial interface.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.