Accession Number : AD0641994

Title :   INVESTIGATIONS OF BROADBAND FERROMAGNETIC POWER LIMITERS AND EXPANDERS AS DUPLEXING ELEMENTS FOR MICROWAVE SYSTEMS.

Descriptive Note : Final rept., 1 Jun 65-31 May 66,

Corporate Author : MICROWAVE ELECTRONICS PALO ALTO CALIF

Personal Author(s) : Mehta,K. ; Olson,F. A.

Report Date : OCT 1966

Pagination or Media Count : 40

Abstract : Coincidence limiting has been observed over a continuous passband from 2.2 to 3.9 GHz with a traveling-wave limiter employing magnetostatic modes in single-crystal YIG. Insertion loss was between 7 and 11 db with a 20-db dynamic limiting range. Insertion loss as low as 5 db has been observed at slightly reduced bandwidths. A theory for magnetostatic waves in axially and transversely magnetized ferrimagnetic rods has been formulated to aid in identification of specific magnetostatic modes. Progress has been made in devising new methods to reduce the insertion loss of the traveling-wave limiter. The utilization of ferrimagnetic materials to achieve broadband expanding (inverse of limiting) has been demonstrated. The expander operates at coincidence utilizing a single-crystal ferrimagnetic material in an absorption coupling configuration. Stripline and helical structures have been developed for expander operation, with the helical structure preferred because of the tight RF coupling that can be obtained between the structure and the ferrimagnetic resonators. A single YIG sphere in a helix structure yielded greater than 10-db expansion over a 400-MHz band centered at 3 GHz. (Author)

Descriptors :   (*LIMITERS, FERROMAGNETIC MATERIALS), (*FERROMAGNETIC MATERIALS, MICROWAVE EQUIPMENT), (*DUPLEXERS, FERROMAGNETIC MATERIALS), HELIXES, BROADBAND, YTTRIUM COMPOUNDS, IRON COMPOUNDS, GARNET

Subject Categories : Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE