Accession Number : ADD005502

Title :   Broadband Isotropic Antenna with Fiber-Optic Link to a Conventional Receiver.

Descriptive Note : Patent,


Personal Author(s) : Larsen,Ezra B ; Andrews,James R ; Baldwin,Eugene E

Report Date : 23 May 1978

Pagination or Media Count : 7

Abstract : Describes a broadband active isotropic receiving antenna for use with a conventional electromagnetic interference receiver to measure weak near-zone electric fields of unknown polarization. The antenna consists of three mutually orthogonal active dipoles, including RF amplifier circuitry and light emitting diode means, located therein coupled to fiber optic waveguide means. The frequency range of each of the three field components is amplified and used to modulate respective light emitting diodes whose modulated infrared or visible signals are guided through the fiber optic waveguide means to photo-detectors at the far end of the fiber optic guides. These photo-detectors recover the RF modulation from the IR carrier which is then time multiplexed for input to the electromagnetic interference receiver. The DC output from the receiver is processed to provide an output voltage proportional to the square root of the sum of the squares, i.e., the Hermitian magnitude of the three mutually orthogonal electric field components. (Author)

Descriptors :   *Patents, *Dipole antennas, *Broadband antennas, Radio receivers, Electromagnetic interference, Near field, Electric fields, Radiofrequency amplifiers, Light emitting diodes, Fiber optics, Infrared spectra, Photodetectors, Frequency modulation, Multiplexing, Intensity, Leakage(Electrical), Electromagnetic shielding

Subject Categories : Electrooptical and Optoelectronic Devices
      Radiofrequency Wave Propagation

Distribution Statement : APPROVED FOR PUBLIC RELEASE