Abstract: The field of the invention is that of devices for detecting objects concealed on human subjects. These devices are more particularly dedicated to the surveillance and protection of airport areas and transport airplanes. Currently, the devices rely either on X-ray detection or on microwave imaging. In the former case, the system can prove hazardous to human beings, and in the other case, the device raises ethical problems. The invention proposes a device whose operation relies on the reflective properties of the microwave signals polarized by the suspect objects that we are seeking to detect. This device can be portable or installed on security gates. This technique is simple to design, inexpensive, does not require any great computing power and is very well suited to the objects to be detected. The complete measurement is extremely quick and requires no sophisticated measuring instrument.

Abstract: The surface mounting of a backset microwave package on a printed circuit. After the package has been accurately positioned against the printed circuit the connections are produced by soldering the conducting elements in direct contact. A chip is enclosed in a sort of cage constituting a screen which replaces a conventional cover, the cage is formed by layouts borne respectively by the package and the printed circuit and is linked together by metal links. The surface mounting is particularly applicable to packages operating in millimetric microwaves.

Abstract: A device, and a method for making the same, for bonding two millimeter elements, which include a substrate having an upper face and a lower face, a conducting line on the upper face and oriented substantially perpendicular to an edge of the substrate, and two continuous bounding zones on the upper face and along the edge of the substrate, each continuous bounding zone being electrically grounded, and having a length along said edge between about two and about five times the width of the conducting lines.

Abstract: A mechanical protection of a chip by an encapsulation product poured onto the chip and then cured. The problem is one of depositing only a small thickness of encapsulation product above the chip and above its wire bonds so as not to disturb the operation of the chip. In order to control this thickness, the chip is mounted on a tab, the height of which is chosen so that the difference in height between the top of the chip and the top of the surrounding printed circuits is equal to the desired thickness of the encapsulation. The encapsulation product is then poured onto the chip until it reaches the upper level of the printed circuits, without exceeding it. Such a mechanical protection may find particular application to electronic chips operating at microwave frequencies.

Abstract: A process and a device for bonding two millimeter elements. The process makes, at determined locations of each of the two millimeter elements, bonding zones set to the potential of a second plane. Then, the process makes the bond by determined connections between the bonding zones and between conducting lines of the two millimeter elements. The device includes a coplanar line. Such a process and device may find particular application to millimeter circuits implementing conducting lines of the microstrip type.

Abstract: Disclosed are electronic elements with variable electrical characteristics, each element including at least one microcavity in which there shifts, with a limited clearance or range of play, at least one moving element made of an insulator material that is at least partially covered with electrically conductive material, and that works together with at least one microwave circuit of the substrate, and means creating an electrical field to shift the moving element.

Abstract: The integrated circuit chips (5) are mounted on a ferrite support (20). The ferrite support is metallized uniformly (26) on its lower face and bears metallization zones (21, 24) on its other face. To certain of these zones (24) serving as a ground plane, there are attached the integrated circuit chips (5). The other zones (21) act as relays to connect the supply voltages that are applied by means of a linking wire (7') and a thin film decoupling capacitor (10, 11, 12) borne by the chip. The ground zones (24) are connected to the general ground plane (26) by metallized holes (25). The linking wire (7') is positioned so as to face a bared part of the ferrite to prevent any parasitic resonance.

Abstract: The antenna is provided with an array of optically controlled elementary reflectors with phase-shifters. The array of elementary reflectors comprises a substrate made of a dielectrical material with low microwave losses, transparent to light, the substrate being coated, on the side exposed to the microwaves, with a layer of photoconductive elements distributed in an array and, on the opposite side, with a conductive electrode transparent to light. An optical system for the selective illumination of the photoconductive elements are used to make these elements go from an electrically insulating state to a conductive state and vice versa to modify the path of the microwave within the reflectors and enable the formation of the beam. The array of photoconductive elements forms a lattice of smaller meshes sub-dividing the lattice of the array of elementary reflectors.

Abstract: A semiconducting component with a Schottky junction with stacked electrodes has a lower electrode forming an emitter or source, a central electrode forming a base or grid and an upper electrode forming either a collector or a drain. Semiconductor material is between the upper electrode and the lower electrode. The central control electrode is in the form of several adjacent conducting fingers. An insulating material is in the region directly below the fingers between the control electrode and the lower electrode, thereby reducing parasitic capacitance between the control electrode and the lower electrode.

Abstract: A microwave switch comprises a transmission line section which separates into two arms, at least one of which can go from a normal state to a superconductive state at a critical temperature, a junction rejoining the two arms in a second microwave transmission line section, and means to control the normal or superconductive state of one arm or of the two arms. The difference in length between the two arms is chosen to be substantially equal to an odd of half wavelengths of operation of the switch in such a way that the switch is off or on when the two arms are respectively in the same state, namely normal or superconductive, or in a different state. The state of the arms can be controlled by a magnetic field which causes the critical temperature to vary.

Abstract: A millimeter wave transmitting and receiving head having an excellent technical quality, which is inexpensive to produce and has minimum overall dimensions. The head has for example a guide with a square cross-section connected by a duplexer provided with fins to two guides having rectangular cross-sections and with crossed polarizations. One of the rectangular guides is semicircular so that it can receive through an opening an orifice of the other rectangular guide. A symmetrical mixer having two diodes receives the signal from the two guides and has two outputs. A Gunn diode-type or avalanche-type oscillator serves as the transmitter and the local signal generator. The head is completed by a receiving amplifier and an antenna for constituting a transmitter-receiver. A radar can be obtained by addition of a quarter-wave plate level with antenna.

Abstract: The invention aims at obtaining an intermediate beat frequency from two millimeter wave frequencies by attenuating as much as possible the amplitude variations of the frequency coming from the local oscillator.The mixer of the invention comprises two modules each containing a diode, one electrode of which is grounded to a conducting support. The modules are face to face. The diodes detect the electric field of the wave of the signal to be processed reigning in a cavity, and through conducting strips serving as outputs for the mixer and extending into a cavity where the electric field radiated by the local oscillator reigns, each module also detects a part of this electric field. The output terminals of the intermediate frequency are connected to an operational amplifier.

Abstract: A millimeter wave source, wherein an active diode, for example an avalanche diode, forming the emitter of the source is arranged opposite to a variable capacity diode, so as to have the source frequency-modulated by varying the biassing voltage of the variable capacity diode. In this source, each diode is mounted in a "module" comprising a thermally and electrically conductive support onto which a diode is in contact by one of its electrodes, the other electrode being in contact with a metallization deposited on a thick layer of dielectric material surrounding the diode. Owing to the capacitive coupling between the metallizations of both modules, the source can be frequency-modulated with a high efficiency.

Abstract: A source of millimeter waves adjustable in power and frequency and embodied as a cylindrical waveguide one end of which is provided with a movable piston and the other end with a directive antenna generally a radiating horn. Between the ends is tapped a cylindrical waveguide branch in which slides a sub-assembly carrying a radiating module containing an oscillating diode. The position of the module affects the power and the frequency of oscillation of the source and the position of the movable piston acts on the power emitted by the radiating horn.

Abstract: A device facilitating the design and adjustment of millimeter wave sources comprising an active component of quasi-microscopic dimensions which has to be coupled with extreme accuracy to the input of a directional antenna having relatively large dimensions. In various embodiments the device exhibits the following common features: an assembly incorporating a solid-state active component, a resonant cavity, means for coupling said cavity to a directional antenna, adjusting means and a directional antenna, said assembly being fitted in such a manner that a simultaneous adjustment of the position of said component in said cavity and of said coupling means, is made possible by acting upon said adjusting means.

Abstract: A method for manufacturing semiconductor devices and the devices so made, having two components with differing internal structures of very small dimension on a common heat-dissipating support, wherein the two components are obtained by suitable ion implants in two separate regions of a single block of silicon by alternately protecting each region with a mask. After welding the structure to a metallic support, a pair of diodes or mounds is relieved by ion machining or chemical etching. The assembly is then insulated and provided with the necessary power connections by the alternate application of insulating and conductive materials, the latter being separate metallic layers enabling the two components to be discretely biased.

Abstract: A structure consisting of a semiconductive device e.g. an IMPATT diode destined to transmit high frequency electromagnetic waves through a radial waveguide integral with the structure, forming a "easy to handle" unit. A fabrication process allowing a large number of units to be made utilizing batch processing techniques, is provided. The process includes forming a plurality of mesa diodes on a semiconductor wafer, coating the wafer with a first insulating layer (filling the intervals between the mesa tables), then depositing on the wafer a plate of a solid dielectric with openings for access to the upper part of diodes. The diodes are spaced enough to allow forming around each of them a radial waveguide using a portion of the solid dielectric for propagation medium and for walls, on one hand a metallization extending the biassing electrodes of the upper parts of diode, and on the other hand, a metallic base supporting the assembly after grinding of the substrate of the wafer.

Abstract: The present invention relates to microwave circuits for operating on microwave radiations. It consists in combining a dielectric resonator and a microwave diode in a hybrid or integrated circuit, in order to provide a circuit which will operate without any external elements other than a direct current supply for the transmitter and a local microwave radiation for the receiver.

Abstract: A NOR or a NAND gate of integrated circuit type, having a fan-out of at least three and with a propagation time in the order of 1 nanosecond for a power consumption of a fraction of a milliwatt, is provided. The gate comprises an inverter stage supplied by a saturable load, and an amplifier stage injecting into a diode and into a saturable load connected in such a fashion as to effect a voltage shift. At the input, there are field-effect transistors of low threshold voltage (-0.2 volts), drawing two microamps at zero gate voltage. For the remainder of the circuit, field-effect transistors having a higher absolute threshold voltage (-0.6 volts) are used, these being designed to draw a very low current at a supply voltage of 1.5 volt.