Thomson-csf

Thomson Composants Microondes

Thomson Hybrides Et Microondes

Thomson-lgt Laboratoire General Des Telecommunications

Alain Bert

Gerard Kantorowicz

Didier Kaminsky

Narguise Mamodaly

Marc Camiade

Yves Archambault

Pierre Guillon

Bernard Le Clerc

Henri Derewonko

Juan Obregon

Claude Cluniat

Guy Bessonneau

Narquise Mamodaly

Serge Malbe

Pascal Colin

Luis Bermudez

Marguise Mamodaly

Pierre Savary

Jean-Paul Mutzig

Bernard Leclerc

System for receiving TV signals retransmitted by satellites

A microwave resonator for operation in the whispering-gallery mode is constituted by a resonant element included in a flat disk having a diameter (2a) which is considerably larger than its thickness (2d). An electromagnetic wave which propagates within the disk is confined between the periphery of this latter and a so-called caustic surface having a smaller radius (a.sub.c). The wave does not radiate to the exterior and the resonator can be placed on a dielectric or metallic substrate. The disk can be hollowed-out within the caustic surface. A resonator can be simulated within the thickness of a dielectric substrate by at least one metallic ring which forms a magnetic short-circuit with the ground plane. Excitation is produced by microstrips or by dielectric image waveguides.

Microwave resonator for operation in the whispering-gallery mode

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.

Frequency-doubling oscillator, tuned by varactors

The invention relates to a compact combiner for ultra-high frequency semiconductor devices, such as negative resistance diodes (Gunn - Impatt). The combiner according to the invention combines on a base: at least one semiconductor pellet or a plurality of semiconductor devices integrated into a single pellet at the center of the base, a first ring of capacitors as located elements, a second dielectric material ring metallized on two opposite planar faces, forming both a second capacitor and part of the encapsulation box of the combiner; and metal tapes ensuring the connections between the active components and the capacitors and simultaneously forming non-located element chokes. A metal cover welded to the outer ring seals the box and supplies the bias. The compact combiner may be used in applications of ultra-high frequency amplifiers and oscillators.

Compact combiner for semiconductor devices operating in the ultra-high

An ultra high frequency circuit constructed in hybrid or integrated form whose parasite capacities are greatly reduced. The ultra high frequency circuit has, besides the components, at least one component fixing metallization and at least one microstrip formed by a metal track, on a first face of a dielectric substrate and, a ground plane metallization on a second face of the substrate. The ultra high frequency circuit is fixed to the base of a case. In order to reduce the parasite capacities formed between metallizations, the second metallized face of the substrate is locally demetallized, in line with the fixing metallization, and an air layer is introduced between the demetallized substrate and the base of the case.

Ultra high frequency circuit with low parasite capacities

The invention pertains to a doubling oscillator with low noise in the vicinity of the carrier frequency. The doubling oscillator of the invention is of the 'push-push' type comprising two parallel-mounted transistors. The gates of these two transistors have a common oscillating circuit comprising two microstrip lines, two resistors and a common dielectric resonator positioned between the two microstrip lines. To reduce the low-frequency noise in the vicinity of the carrier near the load, the non-correlated low frequency noise sources of the transistors are either placed in series by means of a choke and two capacitances mounted at the ends of the microstrips or loaded at an infinite impedance through two capacitances mounted at the ends of the microstrips. This oscillator has applications in ultra-high frequency systems, radars and telecommunications.

Frequency doubling oscillator working at ultra-high frequencies

The invention concerns a negative resistance hyperfrequency oscillator, operating in the millimetric band, comprising a waveguide delimited on one side by an iris and a useful load and on the other side by a supplementary load, wherein a Gunn or Impatt diode is polarized and coupled to the waveguide by means of an aerial, the resonator cavity of this oscillator being delimited by the iris and by a dielectric resonator placed in the waveguide between the aerial and the supplementary load, and double coupling being provided between the resonator and the guide and between the diode to the guide to produce a stable and relatively noiseless oscillator. The invention can be applied to hyperfrequency systems, for synchronizing hyperfrequency sources and conjugating their power.

Hyperfrequency oscillator operating in the millimetric band

A metallic support supports a number of semi-conductor devices surrounded by an annular dielectric substrate which in turn supports a circuit including at least two microstrip lines and a metallic circular output element. The small thickness and high dielectric constant of the substrate are selected to permit a reduction in width and in length of the microstrip lines which are folded-back in a curvelinear fashion and placed on the substrate along circular arcs which are concentric with the output element.

Compact combiner for use with semiconductor devices in the microwave

The invention relates to an ultra-high frequency oscillator operating in the X band. The oscillator circuit comprises a common gate-connected field effect transistor. The source connected tuning circuit comprises a variable capacitor of the varactor type controlled by a voltage and a choke in parallel. The control voltage is decoupled from earth by a capacitor. According to the invention, the transistor, the varactor and the capacitor are integrated into the same box or case in the form of a micromodule. The capacitor acts as a base for the transistor and the varactor, which are welded in juxtaposed manner. The length of the connection between the varactor and the source of the transistor has a minimum value, which makes it possible to broaden the linear frequency band as a function of the control voltage.

Variable capacitor-controlled transistorized ultra-high frequency

The invention relates to an ultra-high frequency oscillator (11-14 GHz) having a plurality of transistors, stabilized on at least one of their electrodes by a microstrip line coupled to a dielectric resonator. The oscillator according to the invention groups the transistors on the periphery of an insulating substrate, which centrally supports a single dielectric resonator common to all the transistors. The microstrip lines have two end portions, which are not coupled and are parallel to the field lines of the resonator, and a coupled central portion, perpendicular to the field lines. The transistors and microstrip lines are coplanar. The output is by a coaxial cable at the center of the substrate or by a microstrip line coplanar to the substrate.

Low noise oscillator operating in the ultra-high frequency range

A power oscillator for transmitter equipment operating at hyperfrequencies such as microwave links and radar. A plurality of elementary oscillators are coupled in parallel. Each elementary oscillator comprises a field effect transistor (FET) (11) connected in the common drain configuration with a first microstrip (51) connected to its gate and a second (21) connected to its source. Adjacent gates are interconnected by first resistances (R1) and adjacent sources by second resistances (R2). The resistances serve to balance the oscillators and to suppress parasitic oscillation. The free ends of the gate microstrips (21) are interconnected to synchronize the oscillators and the free ends of the source microstrips (51) are interconnected to constitute the oscillator outlet. The FETs may be disposed in a line or in a ring.

Hyperfrequency power oscillator

An ultra-high frequency oscillator having a very high thermal stability using a transistor coupled by a microstrip-type transmission line to a dielectric resonator with a very low temperature coefficient. It incorporates a field effect or bipolar transistor and an insulating substrate metallized or formed of metal on one face forming the ground plane. The latter projects over the substrate at a point close to two microstrip lines deposited on the face of the substrate opposite to the ground plane, the transistor being welded to said projecting point of the ground plane and to the microstrip lines. The assembly forms a compact hybrid circuit.

Ultra-high frequency oscillator with dielectric resonator of the compact

A device combining a certain number of elementary amplifiers formed on the same semiconductor wafer having a very high frequency (about 10 GHz), thus obtaining a monolithic amplifier with a high power and a wide pass band. This amplifier comprises at the input a first transmission line of the microstrip type, bent in such a way that it has an input branch and a tap branch where the waves reflected as a result of mismatches are absorbed in a resistive load. The bent region of line is connected to a row of elements of the impedance transformation lines passing to the gates (case of field effect transistors). It comprises at the output a second microstrip line parallel to the first and bias connected to a row of elements identical to those of the amplifier input.

Monolithic amplifier comprising a power division and recombination

The invention relates to a radio power distributor. The distributor comprises a plurality of dividers D(i-1), D(i) . . . mounted in cascade-like manner and each having a primary branch A(i-1, A(i) . . . which is divided up into secondary branches, whereof one, the main secondary branch B(i-1) is connected to the primary branch A(i) of the following and whereof the others (C) are terminated on the utilization points. All the branches (C) are connected to the same point a of the line B of the same rank i by resistance members. This makes it possible to absorb the reflected powers in these lines when mismatchings occur, even when the latter are identical. A phase changer .phi. is optionally placed in the primary branch.

Radio power distributor and radio equipment using such a distributor,

A solid state microwave source placed within a rectangular waveguide, whose one end is short-circuited. The microwave source incorporates a negative resistance diode system placed on the inner wider wall of the waveguide and perpendicularly with respect to the waveguide transmission direction, a resonant microband line suspended by means of a dielectric substrate, a connecting means between the diode system and the resonant line, and means for connecting to an external polarization source.

Growing community of inventors

Paris, France

Alain Bert