Novel structures and methods for forming useful high temperature superconducting
devices, most particularly resonators, are provided. Structures resulting in reduced
peak current densities relative to known structures achieve numerous desirable
benefits, especially including the reduced intermodulation effects of earlier resonators.
In one aspect of this invention, a spiral in, spiral out resonator is provided,
characterized in that it has an odd number of long runs, at least equal to five
long runs, where the long runs are connected by turns, and wherein there are at
least two sequential turns of the same handedness, followed by at least two turns
of the opposite handedness. In yet another aspect of this invention, it has been
discovered that reducing the size of the input and output pads of HTS resonators
increases the relative inductance compared to the capacitance. Yet another resonator
structure is a spiral snake resonator having a terminal end disposed within the
resonator. A wide in the middle structure and wide at peak current density resonator
structures utilize enlarged width portions of the resonator in those areas where
current density is largest. In yet another aspect of this invention, operation
of resonators in high modes, above the fundamental mode, reduce peak current densities.
Resonators operated in modes in which current in adjacent long runs are in the
same direction further serve to reduce current densities, and intermodulation effects.
Symmetric current structures and modes of operation are particularly advantageous
where far field effects are compensated for.
