Abstract: An omnidirectional, broad-band antenna for installation on a vertical mast. The antenna is formed of one or more superposed arrays of elementary antennas in the form of log-periodic alignments of vertical dipoles. Particularly for use in ground stations for ground-air communications.

Abstract: A switching network comprises a matrix of cross-point switches disposed in a pattern at selected ones of the cross-points in an array of mutually othogonal inlets and outlets. The pattern of selected cross-points is built up from a rectangular array of basic layouts each comprising eight cross-point switches distributed among the 16 cross-points which is formed by a group of four consecutive inlets crossing a row of four consecutive outlets. There are two types of basic layout: an A-type having its switches at the outer cross-points of its odd numbered lines and at the inner cross-points of its even numbered lines, and a B-type having its switches at the other cross-points. The basic layouts are disposed in a binary pattern over the matrix such that the matrix has a first line of alternating types of layout, a second line of alternating pairs of layout types etc.; each n-th line having its layouts in sets 2.sup.n-1 layouts of each type.

Abstract: The invention relates to the coding of analog signals. An analog signal is compared with a comparison signal increasing according to a given law, until equality with the analog signal is reached; then, the comparison signal remains constant during a predetermined time and resumes its original value. The transmission device includes a processing circuit at the transmission end and at the receiving end; at the transmission end, the processing circuit is preceded by a comparator receiving the analog signal, and the comparison signal supplied by a converter is fed thereto by the processing circuit; at the receiving end, the signal to be decoded is supplied to a forming circuit connected to the input of the processing circuit. The present invention is applicable to data transmission and to telephony in particular.

Abstract: A relay matrix which constitutes an array of switches providing connection points between a set of "horizontal" inputs and a set of "vertical" outputs, has n relays per column disposed in p columns. Each relay column is associated with a register which fulfills the functions of controlling and storing the state of the relays of the column. The invention can be applied to switching systems and in particular to automatic telecommunication exchanges.

Abstract: A concentrator for use in a PCM telephone network. The concentrator has conventional units such as line equipments, a space concentration network and a coder/decoder-PCM sampler and additionally includes a time cross-connection network and two different types of junctors, one type being a complete junctor and the other type (a simplified type) conducting only during the conversation part of a call. The concentrator therefore arranges firstly for a normal junctor to set a call up, then subsequently releases it, substituting it by a simplified junctor. This substitution causes a complementary modification of the time connection in the time connection network to keep the same connection channel with the exchange.

Abstract: Switching circuitry for transferring data from an input time-division multiplex system to an output time-division multiplex system includes a transfer circuit for temporarily storing the data received from the input-time-division multiplex system prior to its transfer to the output time-division multiplex system. For controlling the selective transfer of data from an input channel of the input time-division multiplex system to any one output channel of the output time-division multiplex system control circuitry is provided which controls the storage of the input channel data in a selected position of the transfer circuit with a timing corresponding to the respective time slots of the input channel and controls the transfer of that data from the selected position in the transfer circuit to the output time-division multiplex system with a timing corresponding to the respective time slot selected output channel.

Abstract: Demodulator assembly for m data trains, with differential phase modulation, comprising, for each train, an elementary demodulator dimensioned over a space of one bit, whereas the coding is effected over a space of n intermediate bits, comprising, for each train, a shift register having n+1 flip-flops in a functional connection with an adder.