Abstract: A microwave integrated circuit having planar and mesa components and microstrip lines and method of making the same is disclosed. To preserve a constant impedance for the microstrip lines, the mesa component is buried in a recess, which is then filled with a dielectric having substantially the same thermal expansion coefficient and the same dielectric constant as the insulating substrate. The surface of the mesa component and of the dielectric is in the plane of the planar part of the integrated circuit. Between the interconnecting microstrip lines on the planar face and the ground plane on the face of the substrate, the thickness and the dielectric constant of the material is constant.

Abstract: A circuit for measuring the dynamic characteristics of encapsulating packages for high-speed integrated circuits includes at least two amplifiers integrated on a semiconductor substrate. These amplifiers have the same input and output impedances as those of the high-speed circuit to be encapsulated within the package. The amplifiers are located in widely spaced relation in order to ensure that there is no internal coupling. Depending on the measurements to be performed, the two amplifiers are mounted in parallel or in antiparallel relation. In order to measure the dynamic characteristics of a package, a measuring circuit is mounted within a package and a signal (V.sub.e) is addressed to an input connection of the package. The transmission and coupling coefficients are deduced from measurement of the signal (V.sub.S) collected on an output connection.

Abstract: In order to interconnect an unprotected bare chip of MMIC (microwave monolithic integrated circuit), a ceramic substrate carries a double-face circuit. A network of microstrip lines which radiate from the center to the periphery is disposed on the first face of said double-face circuit. The bare MMIC chip and its microwave environment is fixed on the second face which is metallized as a ground plane. The microwave circuit is interconnected with the network of microstrips by means of plugged metallized holes. A sole-piece provided with a housing for the MMIC is fixed on the ground plane. The first face can carry self-protected components.

Abstract: A microwave integrated circuit having planar and mesa components and microstrip lines. To preserve a constant impedance for the microstrip lines, the mesa component is buried in a recess, which is then filled with a dielectric having substantially the same thermal expansion coefficient and the same dielectric constant as the insulating substrate. The surface of the mesa component and of the dielectric is in the plane of the planar part of the integrated circuit. Between the interconnecting microstrip lines on the planar face and the ground plane on the face of the substrate, the thickness and the dielectric constant of the material is constant.

Abstract: A field-effect transistor comprises an ancillary electrode in addition to the source, gate and drain electrodes. In this device, a semiconducting body bears source, gate and drain metallizations which define a main transistor. The metallization of the drain is separated into two parts which are separated by a channel on which is placed a second gate metallization defining a secondary transistor. The two parts of the drain are coupled by this secondary transistor, the channel of which is separated from the main channel. The secondary transistor can be used to control the gain of the main transistor or to modulate its amplitude signal or to mix two frequencies addressed on the two gates.

Abstract: A differential comparator, working with microwaves and using only one clock, is disclosed. This comparator has a differential amplifier and a divergence circuit in which are included two voltage level translators. The coupling between the amplifier and the divergence circuit is made at the gates of the load transistors of the divergence circuit. Two insulation transistors, working in either saturated mode or resistive mode, are used to provide the amplifier with an automatic control loop which stabilizes all the rest voltages. The clock signal, applied to two transistors which short circuit the two feedback transistors of the divergence circuit, controls the passage from the measuring phase to the divergence phase.

Abstract: A microwave transistor made with group III-V materials, such as GaAs and AlGaAs, is disclosed. This transistor essentially comprises a double heterojunction formed by a first layer of material with a big forbidden gap, n doped for example, a second non-doped layer with a narrow forbidden gap and a third p doped layer with a wide forbidden gap. Under the effect of the electrical field, there may be formed, simultaneously or not simultaneously, in the second layer, a two-dimensional electron gas at the interface with the first layer and a two-dimensional hole gas at the interface with the third layer. By bringing the thickness of the layers into play, the characteristics of the n and p channels can be made symmetrical.

Abstract: A digital/analog converter designed for very high frequencies is described. It has a first stage, which is a standard stage, in which several parallel-mounted controllable loads deliver currents in geometrical progression in a current/voltage converting transistor. Each controllable load has an input transistor, to the gate of which a bit is addressed as well as a diode and a saturable resistor. The second stage is a shifter formed by a transistor mounted as a follower source, in series with at least one diode and one pull-back transistor, the source of which is at a negative potential. The voltage at the drain of the converting transistor is applied to the gate of the shifter transistor, and the output voltage at the drain of the pull-back transistor is looped to the gate of the converting transistor.

Abstract: In an analog-digital converter working at microwave frequencies, the input signal is addressed in parallel to bit levels which are in cascade with one another. Each bit level has a transducer which converts the voltage into a current, and compares this current with a calibrated source. The resultant current is addressed to a logic circuit, the output of which delivers a bit. An intermediate output of the logic circuit constitutes a control signal which regulates the currents of the analog comparators of the less significant bit levels. The calibrated currents are in geometrical progression.

Abstract: Disclosed is a hyperfrequency device which includes a triple plate line in which at least two diodes exert their action at the same point on the suspended line. Instead of connecting the two diodes on both sides of the suspended line, they are mounted on the same side, this is possible by providing two subsidiary line sections orthogonal to the main line and in the same hyperfrequency plane. A diode is connected to the end of each subsidiary line at a point distant by .lambda.g/2 from the central point of the main line. The action of the two diodes is thus brought back to this point.

Abstract: A circuit for measuring the dynamic characteristics of encapsulating packages for high-speed integrated circuits includes at least two amplifiers integrated on a semiconductor substrate. These amplifiers have the same input and output impedances as those of the high-speed circuit to be encapsulated within the package. The amplifiers are located in widely spaced relation in order to ensure that there is no internal coupling. Depending on the measurements to be performed, the two amplifiers are mounted in parallel or in antiparallel relation. In order to measure the dynamic characteristics of a package, a measuring circuit is mounted within a package and a signal (V.sub.e) is addressed to an input connection of the package. The transmission and coupling coefficients are deduced from measurement of the signal (V.sub.S) collected on an output connection.

Abstract: An ultra-high frequency transistor is mounted in a hermetically sealed package in order to be made usable and in order to improve its performance characteristics to the optimum level. To diminish the noise factor of an ultra-high frequency transistor, the geometrical dimensions of the gate must be reduced. But the transistor changes its impedance and maximum frequency and can no longer be used in a package or at the external impedance of the circuit. It has to be pre-matched by having a choke mounted between its gate, its drain and the corresponding external connections. Each choke consists of a long metallic wire, forming a hairpin, soldered inside the package between the gate metallization and the internal end of its external connection or between the drain metallization and the internal end of its external connection. The invention can be applied to low-noise ultra-high frequency amplifiers.

Abstract: An ultrahigh-frequency oscillator. To double the frequency of an oscillator having a single field-effect transistor (10), whose fundamental frequency is adjusted by an impedance of gate (13) and an impedance of source (15), a filter (16+17) is mounted between the drain of transistor (10) and the ground. This filter, formed by a self-induction coil (16) in series with a varactor (17) is adjusted to the fundamental frequency: it assures the rejection, and favors the generation of the second harmonic, at double frequency. Application to ultrahigh-frequency sources.

Abstract: An microwave device of the diode-operated amplitude modulator or switch type is disclosed. The ring is formed by a source of symmetrical currents which powers the diodes connected to a load. When the diodes are off, they show a capacitance which gives a reactive current. To improve isolation or attenuation, the current in the load must be zero. This is obtained by mounting, on diagonals of the ring, two capacitors which give two currents that are equal and opposite to the two reactive currents.

Abstract: A negative-resistance diode oscillator tuned by a varactor as applicable to frequency-modulated transmitters or to receiver oscillators operating within the 56-100 GHz frequency band is integrated in a waveguide. The diode is encapsulated in a capped package and mounted on a ground-connected base. A coupling capacitor is fixed on the metallic cap of the package. A varactor having beam-lead connections is mounted as a bridge between the capacitor and a ground-connected metallic stud. The bias voltages are brought in the plane of the waveguide by means of two wires and two capacitors housed within orifices formed through the waveguide walls.

Abstract: A device is used to handle small-sized semiconductor chips, such as ultra-high frequency chips delivered loose. In order to lift up these chips one by one at a precise point by means of a pipette, the device uses the charges of static electricity which make the chips adhere to an endless tape made of plastic. In a first, vertical part, the tape is loaded with chips in passing through a feeder bin. A stop retains all the chips on one side of the tape, and another stop lets through only those chips that are flat on the other side of the tape. In a second, horizontal part the tape passes through a tunnel in which the chips are oriented and then stored and taken up by a suction pipette. The invention can be applied to the assembly of semi-conductor chips in packages or on substrates.

Abstract: The invention provides a method for cutting out very small sized semiconductor devices, mounted on a gold base, including the formation of depth indicators etched through the active layer, on a manufacturing wafer, and penetrating into the substrate, said indicators being metallized then, after masking, the gold bases are deposited. A mechanical metal support makes it possible to thin down the substrate and to etch the mesa diodes on their gold bases, the metal of the mechanical support then being etched by an acid solution which cuts out the diodes.

Abstract: A device fixed on a measuring instrument provides access to the terminals of a microwave component in order to measure scattering, noise or output power parameters. In order to minimize the length of connections between the access lines of the device and the input and output terminals of the component to be measured, two access blocks which carry the access lines are positionally adjustable with respect to the component to be measured in such a manner as to permit two degrees of freedom in relative-spacing displacement and in lateral translational displacement. Irrespective of the type of component to be measured (chip, package, or hybrid circuit), the component is carried by an insert block placed between the two access blocks and having dimensions equal to those of the component.

Abstract: A hyperfrequency circulator is provided in which the gyrator is integrated in the wave-guide, comprising a wave-guide whose two main faces are pierced with two holes, aligned with the center of symmetry of the junction. Through these holes a one-piece gyrator passes formed by at least one magnet, a pole piece, a solid dielectric resonator and a second pole piece. The gyrator is cylindrical in shape, and the pole pieces each have a flange of the same diameter as the holes in the wave-guide, the cooling plates immobilizing the one piece gyrator in the wave-guide.

Abstract: In an opto-electronic head, an optic fiber is coupled with a laser or a light-emitting diode. According to the invention, a plane ceramic substrate acts as a reference plane for the alignment. It is separated into two zones: one zone dedicated to the semi-conductor device and one zone dedicated to the fiber. The second zone supports a heating resistor placed between two insulating layers. A heat barrier, consisting of a slit in the substrate, reduces heat transfers towards the layer to the minimum. To align the two components, a solder preform or polymer preform is put on the resistor. When the preform melts, it forms a drop in which the fiber 4 can be moved in three directions. The invention can be applied to opto-electronic systems.