摘要:
This element comprises a winding (4, 5) wound on a rectilinear magnetic core formed by various ferrite rods (1, 2, 3) placed side by side as in a bundle, and the winding is wound partly in one direction (9) and partly in the other (10). Application: Cable television distribution.
摘要:
A filter for treating a plurality of channels in a television signal cable distribution system comprises a plurality of paralel bandpass filters having a frequency which is individually controlled by frequency control voltages. A master filter provided with a filtering cell of a type identical to that used in a bandpass filter corresponds to each bandpass filter. For adjusting the central frequency of a master filter, a frequency is applied thereto by a frequency synthesizer and the cell is aligned with this frequency by acting on its frequency control voltage. This voltage is simultaneously applied to a bandpass filter for controlling the frequency, which is thus aligned with the frequency of the synthesizer simultaneously with that of the corresponding master filter. Each couple consisting of a bandpass filter and a corresponding master filter is realized by means of integration on the same semiconductor substrate (IC).
摘要:
A television signal distribution network includes respective distributor cables for signals from respective satellite antennas, one of such cables also being coupled to a terrestrial signal source and serving as a dual distribution cable for both satellite and terrestrial signals. A switching unit permits each user terminal to be selectively connected to any of the distributor cables for reception of a selected satellite signal. The user terminals are also all coupled to the dual cable via a filter which only passes the terrestrial signal band, whereby the terrestrial signal is distributed to all terminals from only a single cable, independently of the setting of the switching unit. Another of the distributor cables also serves as a return cable for upstream signals from the user terminals. The return path includes a filter which only passes an upstream frequency band below that of the terrestrial and satellite signals.
摘要:
The invention relates to the selection of a source from a plurality of sources by means of shunt switches and series switches, which are respectively turned on and mined off, and vice versa. For access to, for example, four sources the device has two intermediate terminals B.sub.1, B.sub.2), one series switch (SE.sub.a, SE.sub.b) is arranged between the user installation and each of the two intermediate terminals, and each of the intermediate terminals is coupled to two sources (IN.sub.1, IN.sub.2 or IN.sub.3, IN.sub.4) by each time one series switch (SE.sub.1, SE.sub.2, SE.sub.3, SE.sub.4). Moreover, each source (IN.sub.1, IN.sub.2, IN.sub.3, IN.sub.4) is a.c. coupled to earth by a matching impedance in series with a shunt switch (Z.sub.1, SH.sub.1, or Z.sub.2, SH.sub.2, or Z.sub.3, SH.sub.3, or Z.sub.4, SH.sub.4). The device is used in CATV.
摘要:
For switching, for example four satellite signal sources, there is a switch for each user. This switch selects a source as a function of the value of a control signal applied to its RF signal output and connects the selected source to this output. It is provided with a connection unit (75) for each user who has the disposal of a television apparatus (74) and a satellite decoder (84). This connection unit comprises an adjustable control signal generator (78) which is connected to the input (81) of the satellite decoder (84) via a signal-blocking inductance and to a two-wire connection (83) for the control current produced by the decoder and determines the control signal to be applied as a function of the value of the parameters generated by the satellite decoder.
摘要:
A splitter for passband signals up to several GHz has symmetrical transformer windings that are connected together at input ends and extend to output ends. An input resistor connects between an input terminal of the splitter and the connected input ends of the windings. A respective output resistor connects between each output end of the windings and a respective output terminal of the splitter. A respective shunt resistor connects between each output end of the windings and ground. A resistor and capacitor in series connect between two of the output ends of the windings.
摘要:
The receiver which comprises a flat picture screen (20) has an antenna which comprises two articulated main plates (4, 5) symmetrically disposed on either one of the two sides of the screen, and forming an angle with each other, as well as two plates (2, 3) parallel with the screen and symmetrical to each other relative to the median vertical plane (19) of the screen.
摘要:
A printed circuit board carrying active and/or passive components and provided with high-frequency lines is mounted parallel to a ground plane (4) of the housing. The printed circuit board is a single-sided one whose rear surface (11) without metallization is joined to the ground plane (4) of the housing, while spacer blocks are provided for maintaining a spacing between the rear surface (11) and the ground plane (4).
摘要:
A device for electrical connection of a cable provided with an electrically conductive core to a printed circuit secured in a case, using a tubular member which is longitudinally subdivided into several limbs wherebetween the conductive core of the cable passes, which tubular member is provided with a thread so as to screw thereon a threaded cap provided with a stud-like member which bears on the conductive core of the cable. In accordance with the invention, the printed circuit is provided with orifices to allow passage of the limbs of the tubular member, said orifices forming between themselves a bridge which extends between the limbs of the tubular member and on which there is provided at least one conductive track onto which said stud-like member presses the core of the cable.
摘要:
An antenna system (1) transmits return signals, for example, in the band Ka, based on signals received from a distribution network in the band from 2.5-3 GHz. The return signals are transmitted through the network from a user receiver (PC) with a frequency lying below 65 MHz, they are processed in a frequency converter (up-C) between the network and the antenna system so as to be delivered to the antenna system with a frequency lying in the 2.5-3 GHz band, and frequency management data received in the downstream channel are used in the frequency converter (up-C) for selecting the frequency in the 2.5-3 GHz band.