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 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: 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 device for generating a radio frequency electrical signals, delivering at least two separate signals having different frequencies, in the form of signals delivered by different primary sources and amplified with a predetermined gain. The device comprises a combining circuit (3), combining the signals delivered by the primary sources (2), a single channel power amplifier (4) and a multi-channel selection and routing unit (5) with a parallel structure. Each channel delivers at the output an amplified signal (S) at a frequency (F) characteristic of one of the primary sources (2) and comprises a filter circuit (6) adjusted to be passing for one of the different characteristic frequencies (F) of the different primary sources (2), an impedance adaptation circuit (7) and a rejection circuit (8) for frequencies other than the passing frequency of the filter circuit (6) of the channel in question.

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: A device for generating a radio frequency electrical signals, delivering at least two separate signals having different frequencies, in the form of signals delivered by different primary sources and amplified with a predetermined gain. The device comprises a combining circuit (3), combining the signals delivered by the primary sources (2), a single channel power amplifier (4) and a multi-channel selection and routing unit (5) with a parallel structure. Each channel delivers at the output an amplified signal (S) at a frequency (F) characteristic of one of the primary sources (2) and comprises a filter circuit (6) adjusted to be passing for one of the different characteristic frequencies (F) of the different primary sources (2), an impedance adaptation circuit (7) and a rejection circuit (8) for frequencies other than the passing frequency of the filter circuit (6) of the channel in question.

Abstract: A probe, particularly a urethral probe, for the heating of tissue by microwaves and for the measurement of temperature by radiometry. The probe comprises, on the one hand, at least one elongated antenna (1) formed by at least one conductive portion (2, 2') rolled up in a helicoidal manner on an elongated dielectric support (3) having a front end and a rear end, on the other hand, electrical connections (4) for the transfer of microwave signals toward and from the antenna, connected to a corresponding external generator and radiometer, and, finally, a catheter (5) covering the antenna (1) and, as the case may be, at least the portion of the electrical connections adjacent the antenna (1). The central dielectric support (3) has structure for circulation of thermostatic fluid of the antenna (1) at least present within the tubular channel delimited by the helicoidal conductor portion (2, 2'), this structure being connected to structure (6, 6', 6", 6'") for the supply and evacuation of the thermostatic fluid.

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').

Abstract: A synthesizer using the additive method of color synthesis and having a plurality of different color filters to provide corresponding primary color radiations which are combined to produce a tone having a specified color content. The filters are illuminated by either one or a plurality of gas discharge lamps equal in number to the number of color filters, the frequency and duration of the flashes from the lamp incident on each filter being determined by a control circuit to produce a predetermined luminous intensity for each primary color. The circuit may be programmed by specifying numerical values for the required luminous intensity of each primary color and the circuit adapted to control the frequency and duration of the flashes in accordance with the specified numerical values.