Abstract: A system including a first station (1) known as a beacon and at least one second station (2) known as a badge, each station having a transmission channel with an antenna and a reception channel with an antenna.To allow multiplex exchanges, using simultaneous transmission and reception, the two antennas (6, 11) (13, 15) in any given station are decoupled by cross-polarization but antennas which communicate with each other (6, 13) (11, 15) have compatible polarization.Applications to identification systems using microwave transmission.

Abstract: A self-encapsulated power conductor component with improved heat transfer has a chip bearing at least one power transistor having at least one interdigitated electrode, provided with an air bridge, and a sink provided with at least one metal islet in relief. The air bridge is reinforced and the chip is brazed in reverse to the islet of the sink by its air bridge. Other islets brazed to the metallizations on the rim of the chip reinforce the mechanical fixing. The access to the electrodes is obtained by via holes and the second face of the substrate may receive non-integrable components. The device can be applied to power transistors and integrated circuits, notably on GaAs.

Abstract: In order to increase the sensitivity and range of a system for the exchange of data by microwaves between a fixed station, or reader, and a mobile station, or badge, the modem of the badge includes an oscillator. A single transistor works, under a first bias, as a detector of the wave transmitted by the reader and demodulates this wave, and then, under a second bias, it works as an oscillator and modulates the response transmitted by the badge. Applications to the exchange of data at a distance.

Abstract: A method of phase-shifting an electrical signal (E) of given amplitude and phase angle. The basic function in the method comprises vectorial adding (.SIGMA.) of the two input signals (E1, E2) of the same amplitude but with different phase angles, an operator to correct the amplitude of the vectorial sum (.SIGMA.1), and an operator (C) to select one of the three signals (E1, E2, .SIGMA.1), which have different phase angles. The phase-shifter operates iteratively until the required phase-shift is obtained. All applications, mainly in the microwave range, to radars, telecommunications, etc.

Abstract: This active antenna is incorporated in the terminal station of a system for data exchange with a central station, by the modulation of a microwave carrier. The terminal station is of the chip card type. The modem of the active antenna is constituted by a transistor, the bias current of which is switched over from a low value at demodulation to a high value at modulation. The switch-over is obtained by a circuit with three resistors (R.sub.d, R.sub.gd, R.sub.g), which themselves have their values switched over by two transistors parallel connected with the resistors, these transistors being controlled by two signals emitted by the control circuit of the terminal station. The active antenna can be applied to long-distance data exchange, for example in the remote management of toll-charge systems, remote cash dispensing, localization of moving bodies etc.

Abstract: A system intended for the simultaneous reception of several TV channels retransmitted by satellites. This system comprises a multi-frequency microwave frequency head, installed in an external unit, whose inputs are connected to the satellite antennas. Wide band demodulation is made possible by a microwave frequency source controlled by a synthesizer. Digital signals transmitted by a link cable ensure programming of the synthesizer and therefore of the selected TV channels. A remodulation in amplitude modulation is performed for supplying signals in the 40-860 MHz band, carried by an existing link cable for terrestrial antennas. The system finds particular application to the simultaneous reception of several TV channels.

Abstract: In a system for the exchange of data by microwaves between a fixed station and a mobile station or portable badge, the information bit rate is limited, in the standby state, by the low power consumption of the badge and the high output impedance of the modem. To increase the information bit rate of the modem of a badge, the information processing circuit associated with the modem sends the modem an activation signal to reduce its output impedance. The means implemented are transistors that switch over the load of the detector transistor or of the amplifier transistor.

Abstract: Disclosed is a method for making a mushroom gate for a microwave transistor. Three masking layers are deposited on the semiconductor body of a transistor. At least two of these masking layers are different and have selective solvents. After the opening of the external layer, the intermediate layer is dissolved with sub-etching with respect to the external layer, then the base of the gate is etched in the internal layer. The edges of the sub-etching prevent the metal deposited on the mask from adhering to the gate, thus facilitating the lift-off of the mask. Application to microwave transistors with symmetrical or disymmetrical mushroom gate.

Abstract: The disclosure relates to the field of data exchange by microwaves between a fixed station, or reader, and a mobile station, or badge. To achieve economy in the energy consumption of the badge, which has a "chip card" format, its input circuit or modem connected to the antenna does not transmit the modulated signal towards the reader. It reflects, in varying degrees, the carrier transmitted by the reader. The modulation of the reflection coefficient of the antenna is obtained by variation of the gate-source junction capacitance, which it itself related to the variation of the gate-source bias voltage of the input transistor of the modem. Application to remote-control toll-gates, remote money transactions and security checks.

Abstract: Disclosed is a method for the interconnection of an integrated circuit to a support, replacing the connection wires. An integrated circuit chip is fixed to a support by the brazing of the ground plane metallizations. However, the input/output pads of the integrated circuit are connected to the metallized tracks of the support by means of metallized holes. The method can be applied to microwave circuits. FIG. 3.

Abstract: Disclosed is a pre-diffused logic integrated circuit, a part of which is converted into an analog circuit. A pre-diffused logic circuit includes a plurality of logic circuits, each formed by non-wired signal transistors. If the fan-out of a logic operator has to be increased, the transistors of a neighboring logic cell are parallel mounted so that at least two signal transistors are parallel mounted to make an amplifier transistor therefrom and at least two transistors are connected to make a current source therefrom for this amplifier. This conversion is done during the final metallizations for customizing the pre-diffused circuit.The present invention finds particular application in fast logic circuits.

Abstract: A microwave circuit intended for either direct modulation or direct demodulation of a microwave link communications signal is characterized in that a local oscillator (8) is incorporated in the circuit. The local oscillator supplies two signals that are in phase opposition at 180 degrees. Each signal is sent to a phase shifter. The first phase shifter (9) supplies two signals that are in quadrature, at 0 and 90 degrees. The second phase shifter supplies two signals in quadrature at 180 and 270 degrees. The 0 and 180 degree signals are sent to a first mixer (2), while the 90 and 270 degree signals are sent to a second mixer (3). In the case of a modulator, the first and second mixers receive, respectively, in-phase and quadrature signals, and the outputs of the mixers are combined to form a modulated signal. In the case of a demodulator, a modulated signal is applied through a .div.2 divider to inputs of the two mixers, and in-phase and quadrature signals are obtained at respective mixer outputs.

Abstract: Disclosed is a logic integrated circuit for which the time of switching over between two logic states, 0 and 1, is adjustable. In a logic operator such as an inverter, the switch-over time, at the output, is a function of the current put through by the load transistor or by the signal transistor. This time is adjustable, either as rising time or as fall time, by the replacement of at least one single-drain transistor by a multiple-drain transistor, the throughput rate of which is fixed by the number of connected drains. The disclosed device can be applied to pre-diffused (Si) circuits or pre-implanted (GaAs) circuits.

Abstract: The disclosure concerns a microwave amplifier. To improve the efficiency of an amplifier having a field-effect transistor, an input quadripole and an output quadripole, the voltage applied to the gate is limited to a deviation between the pinch-off voltage V.sub.P and the positive maximum gate voltage V.sub.GS, using a diode of a second order harmonic reverse feedback circuit. Application to microwave circuits.

Abstract: This interface constitutes an adaptation of the output signals of a first circuit, made of silicon for example, to the limit values of the input signals in a second digital circuit, made of GaAs for example. It includes a first stage (A) consisting of two parallel-mounted shifters, in which the input signal (E) and a reference (Ref) are shifted. A second stage (B), of the BFL type, compares these two values and a third stage (C) regenerates and amplifies the signals. A fourth stage (D) may give a complementary value. This interface is integrated into the chip of the second digital circuit which is made of GaAs.

Abstract: In a cascaded analog-digital converter, a first ADC determines the most significant bits. To determine the least significant bits, in a second ADC, it is necessary to assess the difference between the input analog signal V.sub.E and its already digitized part, reconverted into analog form. The subtractor/amplifier receives, firstly, the input signal V.sub.E which is converted into a current i.sub.E and, secondly, the most significant bits on a digital-analog converter. This constitutes a source, capable of being modulated, which gives a current i.sub.c. Two parallel-mounted transistors differentiate between the current i.sub.c of the source capable of being modulated and the current i.sub.E corresponding to the input signal V.sub.E, and amplify it. The disclosure is applicable to cascaded ADCs.

Abstract: This interface constitutes a matching of the output signals of a first circuit, made of GaAs for example, with the limit values of the input signals of a second digital circuit, made of silicon for example. It has a current amplifier which receives the output signal of the GaAs circuit. The voltages at the high level are controlled by a diode in series with a transistor which is then on. At the low level, the transistor is off, and it is two diodes, in parallel with the transistor, that control the output voltage. This interface is integrated into the chip of the digital circuit, made of GaAs. Single figure.

Abstract: Disclosed is a device enabling a transistor of submicronic gate length to be constructed using optical means of masking. The process includes a stage during which a resin, deposited on a wafer of semiconducting materials, is etched in order to isolate a pattern as a future gate mask. The mask is eroded, and a layer of silica deposited. Because of the erosion, the sides of the pattern and of the mask are inclined. After etching of the layer of silica and the masking resin, there remain therefore two silica masks whose sloping sides leave a submicronic aperture, through which the gate is deposited.

Abstract: Disclosed is an automatic control circuit for a device comprising at least one transistor mounted as a current source. To achieve the automatic control of its mean off-load voltage at a given level, this circuit includes an automatic control of the voltage Vgs of said transistor by a follower-shifter circuit; wherein the control of the shift voltage of the follower circuit is accomplished by the charge from a capacitor, wherein the capacitor is charged, in a calibrating step, by shifter circuit looped to the capacitor, through a switch control by a clock.

Abstract: Disclosed is a sample-and-hold unit more especially designed to work at microwave frequencies (>1 GHz). In order to increase the sampling frequency, the disclosed circuit has at least two identical parallel channels. Each channel has a first follower switch (9) a capacitor (11) and a second holding switch (15). The channels are controlled by a single clock, the complementary or phase-shifted signals (H, H) of which address the samples sequentially towards the output (8). The disclosed device can be applied to the processing of analog signals.