Abstract: This invention relates to a method for improving the performance of a nuclear quadrupole resonance detection system by reducing the coupling between one or more excitation coils that provide a radio frequency magnetic field that excites quadrupole nuclei, and one or more high temperature superconductor receive coils that detect the resulting nuclear quadrupole resonance signal.

Abstract: This invention provides a laser trimming method for tuning the frequency of a spiral resonator, and for improving the characteristics of a high temperature superconductor filter comprised of high temperature superconductor spiral resonators, by tuning the individual high temperature superconductor spiral resonators. This invention also provides a method for tuning the resonance frequency of a high temperature superconductor planar coil. This invention also provides a laser ablation process for creating high temperature superconductor circuit elements.

Abstract: The use of a bias controlled diode in the Q-damping circuit of a high temperature superconductor transmit, receive, or transmit and receive self-resonant coil in a nuclear quadrupole resonance detection system results in improved performance. The diode is operated with a forward bias such that the diode is resistive with a resistance of about 10 to about 1000 ohms.

Abstract: The methods of the invention for scanning a band of frequencies using a nuclear quadrupole resonance detection system with an array of high temperature superconductor sensors to detect nuclear quadrupole resonance signals improve the nuclear quadrupole resonance detection system performance.

Abstract: The methods of the invention for scanning a band of frequencies using a nuclear quadrupole resonance detection system with an array of high temperature superconductor sensors to detect nuclear quadrupole resonance signals improve the nuclear quadrupole resonance detection system performance.

Abstract: The methods of the invention for scanning a band of frequencies using a nuclear quadrupole resonance detection system with an array of high temperature superconductor sensors to detect nuclear quadrupole resonance signals improve the nuclear quadrupole resonance detection system performance.

Abstract: The decoupling of an array of two or more closely spaced high temperature superconductor sensors can be accomplished by introducing a capacitive decoupling circuit.

Abstract: High temperature superconductor mini-filters and mini-multiplexers are comprised of improved self-resonant spiral resonators and have very small size, very low cross-talk between adjacent channels and low sensitivity to variations in substrate thickness and resonator patterning.