Thomson-csf

Gerard Kantorowicz

Alain Bert

Didier Kaminsky

Bernard Epsztein

In a pulse compression device, the pulses to be compressed being frequency modulated, the device comprises at least one transmission line, the cut-off frequency of which varies along its axis of propagation and means for the separation of an incident wave and a reflected wave, loaded by the transmission line and receiving the pulses to be compressed which get reflected along the transmission line, the variation of the cut-off frequency and the frequency modulation of the pulses being matched with each other. Application: high power pulse compression in microwave transmission. FIG. 3a.

Method for the compression of pulses, notably in microwave transmission

A synthesizer apparatus is provided allowing very high speed switching while keeping phase continuity. It includes a plurality of cells, each with four mixers, a subtractor and an adder for obtaining at the output two in quadrature signals, of jump frequency .-+.n F.sub.r, n being an integer, from in quadrature signals of a basic frequency F.sub.r. These signals are then multiplied in a terminal circuit with two in quadrature signals relative to a carrier frequency Fc then added so as to produce the signal transposed to the frequency F.sub.c .-+.n F.sub.r desired for use.

Frequency synthesis method and a synthesizer apparatus using this method

A frequency divide-by-two circuit capable of operating from substantially DC up to the maximum operating frequency of the component devices. First and second mixer stages receive the signal to be divided and its antiphase complement. The mixer output signals are amplified and summed. A portion of the sum signal is fed back to the other inputs of the mixers. The mixing amplifying and summing functions can all be performed by two FETs each having two gates. The divider can be integrated on a single chip since it does not make use of a filter. It can be used at frequencies of up to about 25 GHz.

Analog and aperiodic frequency divide-by-two circuit

An oscillator including, a parametric amplifier which has three branches at the terminals of a non-linear capacitor C(V). In the pump branch there is a negative resistance dipole (D) which is able to oscillate at frequency f.sub.p. One of the two other branches is matched to a resonant circuit (C.sub.s) exhibiting a high Q factor at frequency f.sub.s, and the other branch is matched to a load impedance, namely that of resonant circuit (C.sub.o) at frequency f.sub.o .multidot.(f.sub.o =f.sub.p -f.sub.s). A high level output signal f.sub.o is thus provided.

Stabilized oscillator for microwaves with frequency conversion and its

The amplifier comprises two input and output transmission lines connected together by means of a plurality of active quadripoles mounted in parallel across the transmission lines, the elements for matching the quadripoles being inserted between the lines. In a solid state design, the active quadripoles are formed in a gallium arsenide substrate and the lines are constituted by metallic deposits formed on the substrate by means of the microstrip technique. The matching elements comprise inductance coils between which are placed coupling capacitors.

Distributed amplifier for microwave frequencies

A memory for non-volatile recording, lasting a long time, of fast signals. It comprises two storage stages: The first stage enables the input signal to be recorded by the production of depletion zones in a semiconductor; The second stage is formed by an MIIS type element whose charge is controlled by the extent of the preceding depletion zone, and ensures long recording of the signal.

Non-volatile memory for fast signals

A memory for the non-volatile, long recording of fast signals. It is formed by two memory stages:

Non-volatile long memory for fast signals

A negative differential mobility amplifier with a layer of semiconductor material of negative differential mobility. Two electrodes formed by two metallic combs are disposed on the free surface of the layer of semiconductor material. Overlapping fingers of the metallic combs are orthogonal to the propagation direction of the progressive wave and form an ohmic contact with the free surface of the semiconductor layer. The semiconductor layer is deposited onto a first surface of a dielectric substrate. A second surface of the dielectric substrate opposite to the first surface is provided with a metallic plate. The two electrodes are brought in operation to different electrical d.c. biassing potentials by a biassing source and to the high frequency potential of the progressive wave to be amplified. A line of asymetric parallel bands is formed by the metallic plate, the metallic combs, and the dielectric substrate.

Negative differential mobility amplifier for a progressive wave

A high frequency elastic bulk wave filter, using the variation as a function of frequency of the direction in which a bulk wave travelling through an elastic body is diffracted by a flat surface of that body, formed with a grating. The bulk wave beam corresponding to the signal to be filtered, impinges under normal incidence on the grating, the profile of which is designed to minimize the amount of energy contained in the non-dispersive beam specularly reflected by the grating. The filter further comprises a transducer to collect the diffracted wave, applied to an inclined surface, which is parallel to the wave plane of the diffracted wave.

Elastic bulk wave frequency filter

Solid-state diodes constituted by a semiconductor 3 and an insulated electrode 1 are aligned upon a piezoelectric substrate 4 at the surface of which there propagate the acoustic waves induced by the signals applied to transducers 7 and 8. With each diode there is associated a capacitor whose dielectric is constituted by a portion of the substrate 4; 9 designates the terminals of the electrodes 2 and 5 between which a voltage pulse is applied, in order to charge up the capacitors, after a first high frequency signal has been applied to the transducer 7. Thus, there is stored the high frequency signal at the terminals of the capacitor. During discharge of the capacitor, a second signal is applied to one of the transducers 7 or 8. At 9, there is picked off either the correlation or the convolution of the stored signal and the second signal.

Acoustic storage device for the correlation in particular of two high

The present invention relates to a storage device for high-frequency electrical signals. In the units employed for the storage of electrical signals and consisting of a capacitor in series with a diode constituted by an insulated electrode 10 applied to a semi-conductive substrate marked 3 arranged between the electrodes 2, 5, the invention utilises the piezo-electric substance 40 coupled to a transducer 7 to which they are applied the electrical signals for storage, and a network of diodes applied in the variant embodiment shown in the figure, to said substance and aligned in the direction of propagation of the acoustic waves. Voltage of opposite direction are alternately applied between the electrodes to effect storage and to effect read-out of the signal. Application to radio frequencies of the order of 100 MHz.

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Paris, France

Gerard Kantorowicz