Abstract: A power circuit of a coil, includes two power or transmission line segments that are each connected to one of two ends of this coil, the line segments forming with the coil an oscillating circuit exhibiting a determined resonance frequency. The circuit has two line segments each including at least two conductors, of which one is connected to coil, and between them exhibit identical structures and identical lengths of connected conductors, whereby this common length is essentially a multiple of half of the resonance wavelength of the oscillating circuit. The conductors which are connected to coil at one of their ends are connected to one another at their other end by an adjustable symmetrical tuning component that completes this oscillating circuit, which with symmetrical structure is powered by a primary power circuit.

Abstract: A multifrequency power circuit of an NMR coil, includes two power or transmission line segments called principal line segments, each including a segment of a conductor that is attached to the coil, which attached segments together with the coil constitute a first oscillating circuit that exhibits a determined resonance frequency. The principal line segments consist of controlled-impedance multiconductor line segments, each including at least one other conductor segment that is not attached to coil and that extends into the principal line segment beside corresponding respectively attached conductor segment and that exhibits with the latter a capacitive coupling that is distributed along segments located beside or opposite the conductors.

Abstract: A power circuit of a coil, includes two power or transmission line segments that are each connected to one of two ends of this coil, the line segments forming with the coil an oscillating circuit exhibiting a determined resonance frequency. The circuit has two line segments each including at least two conductors, of which one is connected to coil, and between them exhibit identical structures and identical lengths of connected conductors, whereby this common length is essentially a multiple of half of the resonance wavelength of the oscillating circuit. The conductors which are connected to coil at one of their ends are connected to one another at their other end by an adjustable symmetrical tuning component that completes this oscillating circuit, which with symmetrical structure is powered by a primary power circuit.

Abstract: A multifrequency power circuit of an NMR coil, includes two power or transmission line segments called principal line segments, each including a segment of a conductor that is attached to the coil, which attached segments together with the coil constitute a first oscillating circuit that exhibits a determined resonance frequency. The principal line segments consist of controlled-impedance multiconductor line segments, each including at least one other conductor segment that is not attached to coil and that extends into the principal line segment beside corresponding respectively attached conductor segment and that exhibits with the latter a capacitive coupling that is distributed along segments located beside or opposite the conductors.

Abstract: An L-C type filter module comprising at least two capacitors and at least one inductor. Each of the capacitors consists of a first elongated element made of conductive material partially fitted in a hole made in a second element made of conductive material, connected electrically to the second elements of the other capacitor(s) or possibly common to the various capacitors, at least the internal lateral surfaces defining the holes being covered with dielectric material, as are the edges of the openings of the holes or perforations and at least parts, or preferably all, of the external surfaces of the second element(s) adjoining the edges, and the coil of each inductor is carried by a support body made of dielectric material, possibly contiguous with the second element(s) or the dielectric coating at least partially covering the external face of each second element.

Abstract: A variable capacitor includes a first component made of conductive material in the form of an at least partially hollow rod, comprising a hole or perforation extending axially into the body of the first component to form a tube portion, and a second component also made of conductive material in the form of a rod able to be fitted to a variable depth into the axial hole, the engagement depth of the second component in the first component determining the degree of capacitive coupling between them and therefore the value of the resulting capacitor. The capacitor tube portion is provided on its internal face, preferably substantially over the whole depth of the axial hole, with a layer of dielectric material, the latter extending in a continuous manner over the edge defining the access aperture of the hole and onto an adjacent part of the external face of the tube portion.

Abstract: The present invention relates to an L-C type filter module comprising at least two capacitors and at least one inductor, characterised in that each of the capacitors (2, 2′) consists of a first elongated element (4, 4′) made of conductive material partially fitted in a hole (5) made in a second element (6) made of conductive material, connected electrically to the second elements of the other capacitor(s) or possibly common to the various capacitors (2, 2′), at least the internal lateral surfaces defining said holes (5) being covered with dielectric material (7), as are the edges (5′) of the openings of the holes or perforations (5) and at least parts, or preferably all, of the external surfaces of the second element(s) (6) adjoining said edges (5′), and in that the coil (3′) of each inductor (3) is carried by a support body (8) made of dielectric material, possibly contiguous with the second element(s) (6) or the dielectric coating (7) at least partially covering the exter

Abstract: The object of the present invention is a variable capacitor comprising on the one hand a first component made of conductive material in the form of an at least partially hollow rod, comprising a hole or perforation extending axially into the body of said first component to form a tube portion and, on the other hand, a second component also made of conductive material in the form of a rod able to be fitted to a variable depth into said axial hole, the engagement depth of the second component in the first component determining the degree of capacitive coupling between them and therefore the value of the resulting capacitor.

Abstract: An excitation circuit of a probe for measuring and recovering the signal emitted in return by this latter in an NMR spectrometric apparatus, connecting the probe under conditions defined by switching elements forming a portion of the circuit, to a high frequency excitation signal generator by a portion of the line or emission line, and by a portion of the line or reception line, to a receiver for acquiring and using signals emitted by the probe as a function of the specimen to be analyzed which it contains, a device being provided to carry out or verify the tuning of the measuring probe with the excitation signal generator, associated with the circuit. The device includes a directive coupler, mounted to the portion of the emission line.

Abstract: An excitation circuit of a probe for measuring and recovering the signal emitted in return by this latter in an NMR spectrometric apparatus, connecting the probe under conditions defined by switching elements forming a portion of the circuit, to a high frequency excitation signal generator by a portion of the line or emission line, and by a portion of the line or reception line, to a receiver for acquiring and using signals emitted by the probe as a function of the specimen to be analyzed which it contains, a device being provided to carry out or verify the tuning of the measuring probe with the excitation signal generator, associated with the circuit. The device includes a directive coupler, mounted to the portion of the emission line.

Abstract: A method for determining a temperature of a body by measuring emitted thermal noise includes measurement of thermal noise with a double radiofrequency signal amplification chain, one of whose branches continuously measures a thermal noise signal generated by a predetermined reference source. The heterodyne frequency transposition of the radiofrequency signal frequencies of the thermal noise processed in the two branches is changed with two converter circuits whose continuous signals are transmitted to a unit for control, processing and evaluation to determine in real time a temperature of a body.

Abstract: Radiometer for the determination of a temperature of a body by measuring emitted thermal noise and measurement process using this radiometer. The radiometer includes a double radiofrequency signal amplification chain (1) for thermal noises, one of whose branches (2') continuously measures a thermal noise signal generated by a predetermined reference source (3), two converter circuits (5, 5', 6, 6') whose continuous signals are transmitted to a unit (8) for control, processing and evaluation, and means (9, 10, 11) for changing the heterodyne frequency transposition of the radiofrequency signal frequencies of the thermal noise processed in the two branches (2 and 2').