Abstract: A magnetically-tunable ferrimagnetic radio frequency (RF) circuit sub-assembly can include a resonant cavity comprising a first magnetically conductive member spaced apart from a second magnetically conductive member, and a side wall. The sub-assembly can include first and second ferrimagnetic elements arranged in spaced apart relation within the resonant cavity. The sub-assembly can include a transmission line comprising a first portion located for RF coupling to the first ferrimagnetic element and a second portion located for RF coupling to the second ferrimagnetic element.

Abstract: A magnetically tunable ferrimagnetic filter, including a top casing, a top magnetic conductor, a bottom magnetic conductor, coils, a balance coil, ferrimagnetic-based filters, and a bottom casing. The ferrimagnetic-based filters utilize ferrimagnetic resonator elements, such as yttrium-iron-garnet (YIG), configured to reduce a magnetic gap of the YIG filter and thereby to improve performance.

Abstract: A low loss unidirectional conductive sheet using magnetic field biasing and electron spin precession for coupling RF power to ferrite resonators, comprising the step of placing a plurality of ferrite resonators in a bias magnetic field to excite the electron spins of the materials of said ferrite resonators into precession.

Abstract: A low loss unidirectional conductive sheet using magnetic field biasing and electron spin precession for coupling RF power to ferrite resonators, comprising the step of placing a plurality of ferrite resonators in a bias magnetic field to excite the electron spins of the materials of said ferrite resonators into precession.

Abstract: A differential resonant ring oscillator (“DRRO*) circuit using a ring oscillator topology to electronically tune the oscillator over multi-octave bandwidths. The oscillator tuning is substantially linear, because the oscillator frequency is related to the magnetic tuning of a YIG sphere, which has a resonant frequency equal to a fundamental constant multiplied by the DC magnetic field. The simple circuit topology uses half turn or multiple half turn loops magnetic coupling methods connecting a differential pair of amplifiers into a feedback loop configuration having a four port YIG tuned filter, thus creating a closed loop ring oscillator. The oscillator may use SiGe bipolar junction transistor technology and amplifiers employing heterojunction bipolar transistor technology SiGe is the preferred transitor material as it keeps the transistor's 1/f noise to an absolute minimum in order to achieve minimum RF phase noise.

Abstract: A differential resonant ring oscillator (“DRRO*) circuit using a ring oscillator topology to electronically tune the oscillator over multi-octave bandwidths. The oscillator tuning is substantially linear, because the oscillator frequency is related to the magnetic tuning of a YIG sphere, which has a resonant frequency equal to a fundamental constant multiplied by the DC magnetic field. The simple circuit topology uses half turn or multiple half turn loops magnetic coupling methods connecting a differential pair of amplifiers into a feedback loop configuration having a four port YIG tuned filter, thus creating a closed loop ring oscillator. The oscillator may use SiGe bipolar junction transistor technology and amplifiers employing heterojunction bipolar transistor technology SiGe is the preferred transitor material as it keeps the transistor's 1/f noise to an absolute minimum in order to achieve minimum RF phase noise.

Abstract: A coupling structure for a ferrite-based resonator comprises a short, stiff mounting rod and ferrite sphere are mechanically coupled to a substrate that provides support for a stiff coupling loop. The structure reduces differential movement between the sphere and the coupling loop, thereby reducing vibration-induced degradation of resonator performance. This resonator structure may be used in tunable, wideband oscillator, filter, or amplifier circuits, for example. In one embodiment, the mounting rod is a poor thermal conductor, thereby thermally isolating the sphere, which becomes nearly isothermal.

Abstract: A coupling structure for a ferrite-based resonator comprises a short, stiff mounting rod and ferrite sphere are mechanically coupled to a substrate that provides support for a stiff coupling loop. The structure reduces differential movement between the sphere and the coupling loop, thereby reducing vibration-induced degradation of resonator performance. This resonator structure may be used in tunable, wideband oscillator, filter, or amplifier circuits, for example. In one embodiment, the mounting rod is a poor thermal conductor, thereby thermally isolating the sphere, which becomes nearly isothermal.

Abstract: A multi-octave ferrite oscillator topology that utilizes transformer coupling to provide the proper phase shift in the feedback loop. In a specific embodiment, a 10 mil YIG sphere is loosely coupled to 20 mil input and output loops, both of which are connected to a GaAs integrated circuit that includes a Darlington pair of bipolar transistors. The Darlington pair provides high gain, high output power, and low parasitic reactance up to about 10 GHz. A resistor bridge across the base of the input transistor of the Darlington pair insures a substantially real input impedance over a wide bandwidth.

Abstract: A magnetic structure for a ferrite-based electromagnetic resonator comprises a toroidal permanent magnet which surrounds high permeability material forming a gap in which there is for example a YIG sphere which is tunably resonant in a magnetic field. The high permeability material also forms part of a magnetic circuit. A main electromagnetic coil, preferably a solenoid, surrounds the permanent magnetic structure and the high permeability material, and a modulation coil, also preferably in the form of a toroid, also surrounds the gap in the magnetic circuit.

Abstract: Ferromagnetic resonant devices include special coupling loops formed of multi-conductor transmission lines to increase the RF electromagnetic coupling to the ferromagnetic resonators, while decreasing coupling to spurious resonant modes.