Fundamental Frequency of Oscillation in LSA Circuits.

Abstract

The report traces out the development of the low frequency equivalent circuit of the diode-on-a-post type waveguide LSA oscillator and shows that circuit conditions exist for the low frequency oscillations. The input impedance presented to a diode mounted in a rigid waveguide combined with a three-quarter wavelength choke is analyzed in some detail and it is shown that this structure also can support a low frequency oscillation. Experiments in a coaxial cavity have shown the existence of two modes of oscillation. In the higher frequency mode, thought to be LSA, the effective diode capacitance was 1.6 times the cold capacitance, and N/f for the fundamental frequency of oscillation was less than 200,000 sec/cc. A description is given of a resonant waveguide iris structure combined with a ridge waveguide which produces X band output as only the second harmonic frequency. Preliminary experiments have given 13 watts at 4% efficiency at X band and over 50 watts at 10% at the fundamental frequency. (Author)

Document Details

Document Type
Technical Report
Publication Date
Feb 01, 1970
Accession Number
AD0865744

Entities

People

  • Kenneth W. H. Foulds

Organizations

  • Cornell University College of Engineering

Tags

DTIC Thesaurus Topics

  • Capacitance
  • Circuits
  • Efficiency
  • Equivalent Circuits
  • Frequency
  • Impedance
  • Oscillation
  • Oscillators
  • Waveguide Irises
  • Waveguides
  • X Band

Fields of Study

  • Physics

Readers

  • Electronics Engineering
  • Microwave Engineering.