Abstract: A Yttrium Iron Garnet (YIG) tuned band reject filter using one or more Shunt YIG resonators provides for much wider minimum rejection bandwidths without increasing maximum 3 db bandwidths or spurious response. Various configurations of a tunable shunt YIG tuned band reject filter achieves a wide rejection bandwidth at the low end of the tuning range while keeping the maximum 3 db bandwidth, normally occurring at the high end of the tuning range, to a minimum.

Abstract: A Yttrium Iron Garnet (YIG) tuned band reject filter using one or more Shunt YIG resonators provides for much wider minimum rejection bandwidths without increasing maximum 3 db bandwidths or spurious response. Various configurations of a tunable shunt YIG tuned band reject filter achieves a wide rejection bandwidth at the low end of the tuning range while keeping the maximum 3 db bandwidth, normally occurring at the high end of the tuning range, to a minimum.

Abstract: A Yttrium Iron Garnet (YIG) tuned band reject filter using one or more Shunt YIG resonators provides for much wider minimum rejection bandwidths without increasing maximum 3 db bandwidths or spurious response. Various configurations of a tunable shunt YIG tuned band reject filter achieves a wide rejection bandwidth at the low end of the tuning range while keeping the maximum 3 db bandwidth, normally occurring at the high end of the tuning range, to a minimum.

Abstract: A YIG oscillator is provided having a YIG enclosure with a top housing and a bottom housing, and a YIG sphere magnetically tuned by a permanent magnet. The YIG sphere has a zero temperature compensation (ZTC) axis and is attached to an end portion of a sphere holder. The sphere holder has a mounting surface which is configured to attach the sphere holder directly to the bottom housing of the YIG enclosure. The YIG sphere is aligned with the sphere holder such that the ZTC axis is at a predetermined angle to the mounting surface. A coupling loop is configured to transceive resonance signals to and from the YIG sphere. In one embodiment, the mounting surface is substantially planar and the predetermined angle is zero.

Abstract: A YIG oscillator is provided having a YIG sphere magnetically coupled to a permanent magnet, a field straightener, and a ferromagnetic ring. The field straightener is attached to the permanent magnet and has a predetermined circumference. The ferromagnetic ring is configured to fit around the predetermined circumference of the field straightener. The ferromagnetic ring fine-tunes the magnetic field combination of the permanent magnetic and the field straightener. A coupling loop is configured to transceive resonance signals to and from the YIG sphere.

Abstract: Disclosed is a microwave notch filter which includes a plurality of serially connected YIG tuned resonators, each YIG resonator including a coupling wire and a PIN diode connected in parallel with the coupling wire. A first interconnect interconnects one end of the plurality of serially connected YIG resonators to an RF signal source, and a second inter-connect interconnects another end of the plurality of serially connected YIG band reject filters to a load. An inductor connects one of the interconnects to a circuit ground potential, and an inductor means connects the other interconnect to a DC voltage source, whereby the PIN diodes in the YIG resonators can be forward-biased or reverse-biased by an applied DC voltage. The DC voltage source selectively provides a positive DC voltage and a negative DC voltage which effectively controls the functioning of said YIG band reject filters.