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.