Preselector filter with tunable narrowband excision
AssigneeThe United States of America as represented by the Secretary of the Army
InventorElio A. Mariani
Life of this patent
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Abstract
A planar preselector filter with tunable narrowband excision composed of a errite substrate having a microstrip line with a fixed-tuned bandpass filter on one surface and a plurality of slotline resonators etched in a ground plane on an opposing surface. The fixed tuned bandpass filter is composed of short resonant elements of microstrip, having a length that is one-half the guide wavelength at the center frequency of its passband. The slotline resonators are positioned on the opposing surface of the substrate such that it suppresses or excises a predetermined narrowband of frequencies within the passband of the fixed-tuned bandpass filter. Moreover, the center frequency of the narrowband excision is varied by applying a tunable magnetic bias field of a predetermined strength across the ferrite substrate.
Claims4
A planar microwave/millimeter-wave preselector with tunable narrowband excision, comprising:
- a ferrite substrate having a first and a second opposing surface, and a first and a second end;
- a microstrip line traversing the length of said first surface of said substrate from said first end to said second end, said microstrip having a fixed-tuned bandpass filter located substantially toward said first end of said substrate, said bandpass filter fixed-tuned to a predetermined passband;
- a ground plane substantially covering said second surface of said substrate;
- and
- a plurality of tunable slot-line resonators etched in said ground plane substantially toward said second end of said substrate, said plurality of slot-line resonators comprising a tunable band-rejection slot-line filter for excising a predetermined narrowband of frequencies within said predetermined passband, said slotline resonators tunable by the application of a tunable magnetic field bias, having a predetermined strength and direction, transversely across said ferrite substrate.
Dependencies are inferred from the claim text.