Abstract: A pointing system for reflector type antennas providing a high degree of accuracy with low loss over wide scan areas, including a fixed illuminator retained in fixed position at the focal point of the reflector of the antenna. Surrounding the illuminator is a Cardanic joint which acts as a spherical hinge capable of radial rotation around the illuminator. Attached to the Cardanic joint is a support arm which is connected to the reflector. The reflector is therefore freely movable in a spherical path defined around the illuminator with the illuminator coinciding with the center of the sphere. The illuminator is kept within the focal point of the reflector regardless of the position of the reflector as it spherically rotates around the illuminator. Tension springs in the Cardanic joint and guide wires controlled by motors are provided for finely positioning the support arm and reflector in any given position along the spherical rotative path through which the reflector is able to move.

Abstract: An integrated antenna system for signal error tracking and correction capable of performing a mechanical conical scan. The mechanical conical scan imposes a modulation upon a received RF signal. This modulation is in turn imposed on an AGC circuit in the receiver of the antenna system, which modulates the AGC signal of the receiver in accord with the modulation imposed on the RF signal by the conical scan. This modulated AGC signal is compared in a detector circuit to a reference sinusoidal signal generated by a local oscillator in the system. This detector circuit outputs an error signal which is added to a reference sinusoidal signal which in combination drive an actuator. This actuator is responsible for imparting nutative motion to the antenna, for the purposes of producing the conical scan pattern.

Abstract: A method and apparatus for grounding multi-layer insulations (MLI) by electric contact, of either of each layer with the other or of all the layers with the underlying structure by means of one or more points of attachment of mechanical type. This makes it possible to simplify the construction procedure and increase the reliability.This method is essentially carried out in the following manner: The layers (FIG. 1) which form the multi-layer insulations (6), (7) (8) are metalized on both faces and have holes (9) which are also metalized. All layers are contacted with each other and with a part of the attachment system (3) which is also electrically conductive.The other part of the attachment system (2) is positioned on the structure (1) in such a manner as to permit the passage of electric charges. By contacting the two parts of the attachment system (2) (3), the multi-layer insulation is grounded with the structure.

Abstract: Adaptive phase and amplitude distributor for use with satellite antennae which require distribution of transmitter-generated microwave power over many elementary radiators having predetermined amplitude and phase characteristics thus achieving required radiation patterns. It consists essentially of two polarizers three circular waveguide rotating joints, all interconnected in a joint-to-polarizer-to-joint-to-polarizer-to-joint relation and followed by an orthomode.TM. transducer output which serves to separate the orthogonal components of the electromagnetic field. By rotating the two polarizers around the waveguide axis independently and by suitable choice of the rotating angles, it is possible to distribute the power entering at one port, say in the TE.sub.11 mode, on the two orthogonal components, still in TE.sub.11, with any amplitude and phase relationship at the output. The two components are separated by the orthomode.TM. transducer.

Abstract: A fine tracking radio frequency sensor system capable of locating ground beacons within an angular field which is substantially larger than -3dB antennae beamwidth beams, to be used preferably on board artificial telecommunication satellites equipped with single or multiple beam antennae.

Abstract: A controller is provided for a baseband switching matrix with one space switching stage. The matrix supplies the controller with a number of service channels (IOTS, CH) of the uplink frames, which channels comprise encoded commands that are decoded by the controller which generates service channels (IOTD, FMC) for the downlink frames and sends them towards the matrix. The controller is subdivided into three functional units: a preprocessing unit (PREL) which decodes uplink frame service channels; a processing unit (ELAB), which receives the commands decoded by the preprocessing unit and/or by a telecontrol station with which it performs a bidirectional dialogue and generates control signals comprising the matrix switching states; and an interface unit (INTM) comprising two memories (MEMA, MEMB) alternatively operating as active or backup memory, which store the switching states supplied by the processing unit and send them to the matrix.

Abstract: A direct-sequence digital spread spectrum modem in which the given functions are implemented by software algorithms utilizing a microprocessor architecture. The modem is especially effective for telesurveillance, teledetection, telemonitoring, telecontrol and telecommunications generally.

Abstract: A radar system for primary and secondary airspace surveillance, and especially for the detection and tracking of moving targets, consisting of a number of elementary satellites connected to nonrigid structures and of a main satellite, which performs accurate measurement of the position and altitude of elementary satellites and real-time adaptive combination of radar signals coming from them, so as to provide a large-phased array operating in the microwave band. This system overcomes the limitations on dimensioned large space-bound antennae found in the literature, minimizing the incidence and effects of undesired echoes and interference and assuring high detection accuracy. The fact that the elementary satellites are all the same (modular) makes possible gradual assembly of the system with possible expansion in time and assures particularly high operating availability.

Abstract: A digital signal to be transmitted (TXSG) is encoded through an external code device (EXCD); digital signal TXSG' so obtained (with a bit rate greater than TXSG) is used to modulate, through modulator MOD 1, a transmission carrier later amplified by transmitter TEQ 1 and radiated by antenna ANT1. The RF carrier sent by the transmitter is received by an intermediate transponder through antenna ANT2, receiver REQ2 and demodulator DEM1, which reconstitutes signal TXSG', save for transmission errors. The signal so received is once again encoded by internal coder INCD, obtaining a new digital signal TXSG", which has a bit rate even higher than TXSG'. This TXSG" signal is then used to modulate a second RF carrier by means of MOD2 modulator. The resulting signal is amplified by TEQ2 and radiated by antenna ANT3.

Abstract: Improvement to satellite telecommunication systems using SS-TDMA (Satellite Switch Time Domain Multiple Access) technique equipped with on board regenerative repeaters consisting of: 1. Transmitting from ground to the satellite a signal (CM) with high frequency stability and in harmonic relationship with digital data rate by modulating the carrier sent by a beacon station for fine tracking of on-board antennas. The signal (CM) being synchronized to the plesiochronous clock (CPL) common to all ground stations is used for: a. on board bit re-synchronization of the data stream after demodulation and re-generation on board of the asynchronous data arriving at the satellite; b. synchronization of reference words related to start of frames sent by the satellite. 2. Modulating the signal CM with digital signals, to be used as high speed telecommand which operate in a totally independent way of the telecommand system usually adopted for satellite control.

Abstract: A pulse-width-modulated inverter-converter for generating a direct current output from a direct current supply which utilizes a power inverter having smoothed trapezoidal waveform at the inverter output. A nonlinear inductive element, e.g. a reactor, is provided in series with the center tap of the primary winding of the power transformer which is connected to the power transistors of the inverter to allow storage in a capacitor upstream of this inductor of energy during the recovery times of the transistors.

Abstract: An oscillator circuit for generating a square wave output for space or terrestrial applications comprising a main oscillator and a saturable transformer forming the feedback loop of the power inverter. According to the invention, a synchronization circuit comprises transistors for shortcircuiting respective branches of the primary winding of this transformer upon detection of signal from differentiators connected to the main oscillator. Means connects a main limiting resistor to the center tap of the primary winding so that flux inversion is effected in the saturable transformer at the end of a power inverter recovery time.

Abstract: A solid state relay for aerospace applications utilize a transistor circuit for selectively short-circuiting and open-circuiting a secondary winding of a current transformer whose primary winding is in series with an alternating current source and an alternating current load.

Abstract: Differential phase-shifter operating in a wide frequency band, with constant differential phase shifting. This device is characterized by the fact that it produces a differential phase shift between two perpendicular polarizations, with constant frequency. This way, differential phase shifters with the desired flatness in the band can be obtained, either of 180.degree. (polarizers for systems of linear polarization) or of 90.degree. (polarizer for transforming the circular polarization into linear polarization and vice versa). Such a phase shifter can be used generally in antenna systems.