Abstract: A sensor probe with reduced coupling between the various antenna elements and suppression of radio frequency interference. In one embodiment the sensor probe comprises a first antenna and a second antenna. A first and a second decoupling loop is electrically connected to one of the first and second antennas with current flow in opposite directions in the first and second decoupling loops. A third decoupling loop is electrically connected to another one of the first and second antennas and physically disposed between the first and second decoupling loops. Coupling between the first and second antennas is responsive to a location of the third decoupling loop relative to the first and second decoupling loops.

Abstract: A sensor probe with reduced coupling between the various antenna elements and suppression of radio frequency interference. In one embodiment the sensor probe comprises a first antenna and a second antenna. A first and a second decoupling loop is electrically connected to one of the first and second antennas with current flow in opposite directions in the first and second decoupling loops. A third decoupling loop is electrically connected to another one of the first and second antennas and physically disposed between the first and second decoupling loops. Coupling between the first and second antennas is responsive to a location of the third decoupling loop relative to the first and second decoupling loops.

Abstract: Antenna structures including two anti-symmetrically wound transformers to compensate for stray radiation. In one example an antenna structure includes a transformer assembly connected between an antenna and first and second balanced signal contacts, the transformer assembly including first and second transformer cores independently positionable in space relative to one another, a pair of primary windings connected to the antenna in parallel with one another, and a pair of balanced secondary windings connected in parallel with one another between the first and second balanced signal contacts.

Abstract: A system and method for detecting a nucleus of interest in a chemical using a nuclear quadrupole resonance transition. An excitation pulse is used to excite one or more nuclei of interest, if they present in a sample, to an excited state, the energy of which depends on the magnetic field in the sample. The magnetic field in the sample is modulated, after the end of the excitation pulse, while the nuclei of interest decay from the excited state, so that the radiation they emit is frequency modulated. The frequency modulation is detected in the emitted radiation. In some embodiments a DC magnetic field is applied to the sample, during the application of the excitation pulse, to tune the frequency of the transition being excited.

Abstract: Examples of passive diode-based transmitter detuning circuits and low-voltage active diode-based and receiver detuning circuits are provided.

Abstract: A system and method for detecting a nucleus of interest in a chemical using a nuclear quadrupole resonance transition. An excitation pulse is used to excite one or more nuclei of interest, if they present in a sample, to an excited state, the energy of which depends on the magnetic field in the sample. The magnetic field in the sample is modulated, after the end of the excitation pulse, while the nuclei of interest decay from the excited state, so that the radiation they emit is frequency modulated. The frequency modulation is detected in the emitted radiation. In some embodiments a DC magnetic field is applied to the sample, during the application of the excitation pulse, to tune the frequency of the transition being excited.

Abstract: Antenna structures including two anti-symmetrically wound transformers to compensate for stray radiation. In one example an antenna structure includes a transformer assembly connected between an antenna and first and second balanced signal contacts, the transformer assembly including first and second transformer cores independently positionable in space relative to one another, a pair of primary windings connected to the antenna in parallel with one another, and a pair of balanced secondary windings connected in parallel with one another between the first and second balanced signal contacts.

Abstract: Examples of passive diode-based transmitter detuning circuits and low-voltage active diode-based and receiver detuning circuits are provided.