Abstract: An electronic-scanning antenna composed of radiating elements each forming an active channel in which the signals arising from the channels are grouped together to form deviometry signals, each deviometry signal forming a deviometry channel, and are grouped together according to sectors to form a sector-based signal forming a sector channel, a computation-based beam being formed on the basis of the signals arising from each of the sectors, the method comprises the following steps: measuring the response to a calibration signal of each active channel at one and the same time on the sum deviometry channel and on the sector channel to which it belongs, the responses on the sum channel to obtain the calibration of the sum channel; computing, for each active channel, the disparity between the mean of the responses measured on the sum channel and the mean of the responses measured on the sector to which it belongs; in the operational phase, forming the beam by computation on the basis of the measurements of the sig

Abstract: An electronic-scanning antenna composed of radiating elements each forming an active channel in which the signals arising from the channels are grouped together to form deviometry signals, each deviometry signal forming a deviometry channel, and are grouped together according to sectors to form a sector-based signal forming a sector channel, a computation-based beam being formed on the basis of the signals arising from each of the sectors, the method comprises the following steps: measuring the response to a calibration signal of each active channel at one and the same time on the sum deviometry channel and on the sector channel to which it belongs, the responses on the sum channel to obtain the calibration of the sum channel; computing, for each active channel, the disparity between the mean of the responses measured on the sum channel and the mean of the responses measured on the sector to which it belongs; in the operational phase, forming the beam by computation on the basis of the measurements of the sig

Abstract: A device includes a test enclosure defining a cavity forming an anechoic chamber, having a test probe placed inside the cavity. The cavity comprises an aperture against which the radiating surface of antenna is positioned. The device includes a microwave-frequency test signal generator and a receiver for microwave-frequency signal emitted by the antenna under test and for measuring its amplitude and its phase in relation to a reference. Depending on the depth of the cavity and the dimensions of the radiation pattern of a test probe, the device comprises one or more test probes placed in fixed positions in the cavity or a mobile probe that can be positioned in various locations of the cavity, the probe or probes being configured and arranged to illuminate the whole active surface of the antenna and that the radiation pattern of each radiating element illuminates at least one test probe.

Abstract: A device includes a test enclosure defining a cavity forming an anechoic chamber, having a test probe placed inside the cavity. The cavity comprises an aperture against which the radiating surface of antenna is positioned. The device includes a microwave-frequency test signal generator and a receiver for microwave-frequency signal emitted by the antenna under test and for measuring its amplitude and its phase in relation to a reference. Depending on the depth of the cavity and the dimensions of the radiation pattern of a test probe, the device comprises one or more test probes placed in fixed positions in the cavity or a mobile probe that can be positioned in various locations of the cavity, the probe or probes being configured and arranged to illuminate the whole active surface of the antenna and that the radiation pattern of each radiating element illuminates at least one test probe.

Abstract: The present invention relates to new noncentrosymmetric crystal structures consisting of an optionally substituted 2-amino-5-nitropyridinium halide.It also relates to a process for the preparation of these crystal structures. Finally, it relates to a device with an electro-optical effect comprising said crystal structure.

Abstract: The present invention relates to new noncentrosymmetric crystal structures consisting of an optionally substituted 2-amino-5-nitropyridinium halide.It also relates to a process for the preparation of these crystal structures. Finally, it relates to a device with an electro-optical effect comprising said crystal structure.

Abstract: The present invention relates to new left-handed or right-handed monohydrogentartrate crystalline structures having nonlinear quadratic effects and a wide transparency range extending from the visible to the near infrared, consisting of optionally substituted 2-amino-5-nitropyridinium cations in combination with a polyanionic organic matrix formed of left-handed or right-handed monohydrogentartrate anions.It also relates to a process for the preparation of these crystalline structures consisting in mixing one mole of cation base with at least two moles of left-handed and/or right-handed tartaric acid. It finally relates to a device having an electrooptical effect containing said crystalline structure.

Abstract: Electric heating apparatus having at least one electrical heating resistor (24) arranged in a body (1) of sheet metal provided with an air inlet in its lower part and an air outlet in its upper part. The body (1) is formed by a double-walled hollow element in the form of a trough (2, 3) provided with end walls (14, 15) and at least one opening (12) for the entry of air and defining a first space (20) for the admission of air. The electrical resistor (24) is mounted on the concave part of the double-walled element in the form of a trough (2, 3) on the exterior of the latter. A perforated panel (30) is arranged on the concave wall and defines with the latter a second space (33) for the heating of the air by convection and for the direct radiation of the heat by the resistor through the perforations in the perforated panel.

Abstract: The process consists in guiding the missile firstly by an electromagnetic guidance by interferometric bases up to the proximity of the target, then by infrared guidance up to the target. Electromagnetic guidance is effected by maintaining constant the angle (.alpha.) between the velocity vector (V) of the missle (E) and the straight line (R") passing through the missile (E) and the projection (C") of the target (C) on the earth (S). The process is particularly applicable to the interception of targets travelling at low altitude above the sea.

Abstract: A passive homing system for missiles is provided having at least three interferometric bases each comprising two electromagnetic antennae disposed on the missile. Said three interferometric bases have respective mid-perpendicular planes which are inclined two by two at 120.degree. with respect to each other.