Accession Number : AD0659454

Title :   HIGH POWER MICROWAVE FERRITES AND DEVICES.

Descriptive Note : Quarterly progress rept. no. 1, 1 Jul-30 Sep 60,

Corporate Author : RAYTHEON CO WALTHAM MASS RESEARCH DIV

Personal Author(s) : Schlomann,E. ; Green,J. J. ; Saunders,J. H. ; Owen,J. Q. ; Booth,A.

Report Date : 30 SEP 1960

Pagination or Media Count : 140

Abstract : Three-magnon processes appear to play an important role in the relaxation of YIG at low microwave frequencies provided no rare earth impurities are present. It appears very unlikely that the instability threshold of a mode pair with frequencies different from half the pump frequency can even be lower than the instability threshold of mode pairs at half the pump frequency. The frequency dependence of the relaxation rates observed by means of the parallel pumping technique indicate that three-magnon processes play an important role in the relaxation process. The effectiveness of holmium substitution in enhancing the power handling capability of garnets has been confirmed. Such substitutions are particularly effective at high microwave frequencies (X-band and above), and considerably less effective at lower frequencies (L-band). A circulator capable of handling 20 kw/CW over the specified frequency range can be developed with the materials presently available (R-151). The development of a circulator capable of handling 15 kw/CW and 1.5 Mw/peak, however, requires considerable improvements in the power handling capability of the presently available microwave ferrites. (Author)

Descriptors :   (*FERRITES, MICROWAVE EQUIPMENT), (*WAVEGUIDE CIRCULATORS, MICROWAVE EQUIPMENT), FERROMAGNETIC MATERIALS, RADIOFREQUENCY POWER, RELAXATION TIME, EXCITONS, MAGNETIC PROPERTIES, MICROWAVE FREQUENCY, YTTRIUM COMPOUNDS, IRON COMPOUNDS, GARNET, ALUMINUM COMPOUNDS, HOLMIUM, PHASE SHIFT CIRCUITS, MAGNETIC FIELDS, PUMPING(ELECTRONICS)

Subject Categories : Electrical and Electronic Equipment
      Electricity and Magnetism

Distribution Statement : APPROVED FOR PUBLIC RELEASE