Abstract: A fluid sensor and method for determining at least one parameter of a fluid of a wellbore is provided. The fluid sensor has a base positionable on a downhole tool and a pair of electrodes. The base is provided with insulation. The pair of electrodes is operatively positioned in the insulation. The pair of electrodes has a space therebetween for passage of the wellbore fluid therethrough. A first of the pair of electrodes is interlaced with a second of the pair of electrodes such that at least a portion of the second of the pair of electrodes is surrounded by the first of the pair of electrodes. A voltage applied across the pair of electrodes generates a current therebetween whereby at least one parameter of the wellbore fluid may be determined. The fluid sensor is deployable into the wellbore via the downhole tool.

Abstract: A fluid sensor and method for determining at least one parameter of a fluid of a wellbore is provided. The fluid sensor has a base positionable on a downhole tool and a pair of electrodes. The base is provided with insulation. The pair of electrodes is operatively positioned in the insulation. The pair of electrodes has a space therebetween for passage of the wellbore fluid therethrough. A first of the pair of electrodes is interlaced with a second of the pair of electrodes such that at least a portion of the second of the pair of electrodes is surrounded by the first of the pair of electrodes. A voltage applied across the pair of electrodes generates a current therebetween whereby at least one parameter of the wellbore fluid may be determined. The fluid sensor is deployable into the wellbore via the downhole tool.

Abstract: The invention relates to a semiconductor device including an amplifier, and a mobile telecommunication terminal comprising this semiconductor device. The amplifier has a very high frequency a.c. signal and comprises a last stage but one of depletion-layer MESFET transistors (T3) and a last transistor stage (T4) of the same type, coupled by a d.c. isolation capacitor (C4). This capacitor (C4) forms with the intrinsic diode (.increment.4) of the transistor (T4) of the last stage a series-arranged rectifier circuit. The latter imposes a shift of the mean level of the a.c. signal on the terminals of said isolation capacitor once the amplitude of the positive part of this a.c. signal has exceeded the conduction threshold of the intrinsic diode (.increment.4). This shift of the mean level (-1.5 volts) is used as a negative voltage (-VG) for biasing the coupled gates of all the stages of the amplifier circuit.

Abstract: A mobile terminal device for telecommunications includes a switch circuit which comprises two field effect transistors connected in series to an input terminal, an output terminal and a common input/output terminal respectively, for AC signals. The switch circuit includes control devices which are cyclically shifted for the two transistors. The control devices are formed by pulsed multiplexed bias voltages of amplifiers which produce and receive the AC signals, and by a logic OR-circuit of diodes and resistor. The voltages on the terminals of the diodes are connected between the gate and source of the transistors for their cyclically time-shifted control.

Abstract: The invention relates to a method of manufacturing field-effect transistors having a self-aligned grid in the submicron range without using a mask of submicron size. The invention is remarkable in that it consists of undercutting the drain electrode at an edge covered with a lacquer over a distance typically smaller than one micron, depositing the source electrode, etching the semiconductor material between the drain electrode and source electrode at the undercut area, and depositing the grid electrode in the cavity thus formed. The invention also relates to field-effect transistors thus obtained.

Abstract: A thermo-ionic diode with a very noise figure, using a special semiconductor structure, is provided. The structure comprises, upon a P.sup.+ doped silicon substrate, a succession of N-doped layers whose thicknesses and impurity ratios are designed to optimize the noise figure, a final P.sup.+ type layer covering the structure. The injecting junction of the diode is located at the transition between the said P.sup.+ layer and the nearest N type layer having a weak doping.