Abstract: The disclosed circuit decouples the aiming of an electronic scanning antenna from the motions of its platform which is assumed to be a moving body. It has two independent tracking channels which determine the direction cosines of the beam along pitch and yaw axes of a referential trihedron that is related to the platform and that has its roll axis colinear with the direction of orientation of the antenna. Each of these channels is decoupled from the motions of the platform by the introduction of a variable that is deduced, by a stabilization circuit, from the gyrometrical measurements of an inertial unit linked to the platform. This device makes it easy for the beam of the antenna to carry out a watch scanning operation or target-tracking operation that is independent of the motions of the platform. Should the electronic scanning antenna form part of a homing unit of the missile, it can easily be complemented by a proportional navigation guidance device.

Abstract: The method consists in mounting the armature of an motor in a bridge circuit and in injecting, at the input of a circuit for amplifying the supply of the bridge receiving the control voltage, an automatic control signal corresponding to the difference between the intensity feedback and the voltage feedback picked up at the terminals of the bridge. Upstream of the amplifier circuit, there is injected an AC voltage with a frequency greater than a cut-off frequency of the motor, the AC voltage generating an AC component of the above-mentioned automatic control signal representing a disequillibrium of the bridge due to a variation of the armature resistance. This AC component is used as a source of a control signal of the gain of an amplifier with adjustable gain of an intensity feedback present at one of the terminals of the bridge.

Abstract: A transceiver system of a frequency-agile Doppler radar comprises a transmission-side and a reception-side oscillator circuit both connected to a frequency-agility controller for concurrently varying their operating frequencies. Each of these oscillator circuits includes a high-frequency generator coupled via a frequency divider and a frequency multiplier to a pair of auxiliary mixers in a control loop of an associated microwave generator, the loop further including another frequency divider between the two mixers. The step-down ratios of the two frequency dividers of each oscillator circuit is adjustable by the frequency-agility controller. The microwave generator of the transmission-side oscillator circuit emits an outgoing signal to a duplexer connected to the radar antenna while incoming echoes are fed by the duplexer to a first principal mixer receiving a heterodyning signal from the microwave generator of the reception-side oscillator circuit.

Abstract: A device for generating a frequency-modulated signal according to a predetermined modulation law includes a digital generator that, from a clock signal, generates an output signal s(t) and a error signal (S.sub.e). The signal s(t) is a signal in which the duration of each alternance is an integer multiple of the clock period. The error signal (S.sub.e) represents the modulation errors of the output signal s(t) with respect to the theoretical output signal (S.sub.t) modulated according to the predetermined law. An error correction device receives the output signal s(t) and is controlled by the error signal (S.sub.e) and corrects the modulation errors and provides a corrected output signal.

Abstract: In an airborne frequency-modulation radar designed for the homing head of a guided missile, enhanced resolution both in distance and in velocity is obtained by making use of a solid-state transmitter in conjunction with a frequency-modulating oscillator and by means of a receiver comprising a controlled frequency-shift oscillator.

Abstract: The invention relates to missile-guidance systems of the semi-active homing type using the Doppler effect, designed for air-to-air, ground-to-air or ship-to-air installations. On the radar installation, a first illuminator comprising a directional antenna illuminates a target with a wave of first frequency F.sub.1. The wave reflected by the target is picked up by an antenna situated at the front of the missile. A second illuminator comprising a wide-beam antenna illuminates an antenna situated at the rear of the missile with a continuous wave of second frequency F.sub.2 coherent with the wave of frequency F.sub.1. The local oscillator in the receiver of the missile is phase-controlled in dependence upon the continuous wave of frequency F.sub.2.