DID YOU KNOW? DTIC has over 3.5 million final reports on DoD funded research, development, test, and evaluation activities available to our registered users. Click
HERE to register or log in.
Accession Number:
AD0255743
Title:
INVESTIGATIONS OF MAGNETICALLY TUNABLE NARROW BANDPASS NONRECIPROCAL FILTERS USING FERRIMAGNETIC RESONATORS
Corporate Author:
STANFORD UNIV CALIF STANFORD ELECTRONICS LABS
Report Date:
1961-04-24
Abstract:
The possibility of a narrow-bandwidth, smallinsertion-loss microwave filter with nonreciprocal characteristics is studied, and the findings are reported. The discussion is limited to single-resonance transmission-type filters. In order to obtain tunability over a wide band of frequencies, samples of ferrimagnetic materials such as crystals of yttrium iron garnet, are used as high-Q microwave resonators. An analysis is presented of an equivalent circuit for coupling between 2 microwave circuits using a YIG sphere as the coupling element when the RF magnetic fields due to the 2 circuits are circularly or, in general, elliptically polarized. The experimental device consisted of a cross guide coupler, like a Bethe hole coupler, with only one off-axis aperture which contained the YIG sphere. The experimental results on various filters with different off-axis locations of the aperture are reported. The filters are tunable over the entire X-band by changing the dc magnetic field. The experimental results obtained are in good agreement with those predicted from the theory. Author
Pages:
0001
File Size:
0.00MB