FREQUENCY SELECTIVE LIMITER USING NUCLEAR MAGNETIC RESONANCE

Abstract

The circuit and quantum mechanical theory of the device was extended and refined. The magnetic properties required to obtain frequency selective limiting over a band of frequencies were determined. Expressions for insertion loss and limiting threshold were derived. The amount of intermodulation and signal suppression was calculated as a function of the interference and signal power levels and the frequency separation between them. The effectiveness of the limiter in suppressing several types of interfering signals was analyzed and an experimental model of a frequency selective limiter operating at 30 mc/sec was designed, constructed and tested. The program confirmed that cw interference can be suppressed without significantly affecting a desired signal which is removed in frequency by only a few cycles per second. It was verified experimentally that the extreme case of limiting, in which an interfering signal was 30 db above a desired signal, required a frequency separation of no more than 64 cps between the two signals to assure negligible intermodulation and suppression of the desired signal.

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Document Details

Document Type
Technical Report
Publication Date
Apr 01, 1965
Accession Number
AD0615905

Entities

People

  • Darrell R. Jackson
  • Glenn B. Coughlan
  • Roger W. Orth

Organizations

  • Boeing

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Air Gaps
  • Convection
  • Diagrams
  • Distribution Functions
  • Equations
  • Equivalent Circuits
  • Frequency
  • Impedance
  • Magnetic Fields
  • Magnetic Properties
  • Magnetic Resonance
  • Nuclear Magnetic Resonance
  • Relaxation Time
  • Repetition Rate
  • Resonance
  • Resonant Circuits
  • Resonant Frequency

Fields of Study

  • Engineering

Readers

  • Materials Science and Engineering.
  • Phased Array Antenna Design.
  • Radar Systems Engineering.

Technology Areas

  • Quantum Computing