NOVEL MICROWAVE FILTER DESIGN TECHNIQUES.
Quarterly progress rept. no. 4, 1 Oct-31 Dec 63,
STANFORD RESEARCH INST MENLO PARK CA
Pagination or Media Count:
A magnetically tunable directional filter was designed and constructed, and its performance was evaluated against theory. The filter used two YIG resonators mounted in a rectangular waveguide structure, which was designed to operate over the 8.0 to 11.5-Gc tuning range. The 3-db bandwidth of the band-pass response of the device was approximately 17 Mc, and the minimum loss in the pass band ranged from 1.2 to 1.65 db. The offresonance isolation of the band-pass response was in excess of 50 db. The band-pass response of the filter showed very little evidence of any spurious responses due to magnetostatic modes, although the transmission through the ports that gave a band-stop-type of response showed a number of prominent spurious responses. This filter has properties similar to those of a conventional cavity-type directional filter, but also some additional properties which are due to the non-reciprocal nature of the YIG ferrimagnetic resonators. The measured performance of the device was in satisfactory agreement with the theory. Author