FR2594613A1 - TRANSMISSION CENTER, IN PARTICULAR IN DECAMETRIC WAVES - Google Patents

Abstract

The present invention relates to transmission centers comprising transmitters associated with antennas dispersed over a given area and operating, for example, in HF. The transmission center comprises a building Bj comprising the necessary energy sources, a central building B intended to manage the operation of the transmission center and the transmission units Uel, Ue2 distributed on the ground. These transmitting units, all similar, each comprise a rotating antenna A1, A2 at the foot of which is arranged a room b1, b2 housing a transmitter E1, E2 associated with the antenna. Application, in particular, to HF transmission centers. (CF DRAWING IN BOPI)

Description

I

  Broadcast center, especially HF.

  The present invention relates to a transmission center provided, for example, to operate in HF and comprising transmitters associated with antennas distributed in a given space constituting

  what is generally called a field of antennas.

  Such centers are known, they include fixed antennas,

  transmitters grouped together in a central building and a complicated interconnection

  between transmitters and antennas with switching means,

  impedance transformation, distributed radiofrequency energy

  in the field with the disadvantages of construction, protection and exploitation that entails. In addition, such a center is practically frozen from its conception because modifications and extensions are often very uncomfortable. The present invention aims to avoid or, at the very least, to

  reduce the disadvantages mentioned above.

  This is achieved, in particular, by the use of rotating antennas

  and thanks to the systematic juxtaposition antenna-transmitter.

  According to the invention, a transmission center, in particular in HF, comprising a central building with its central unit designed to manage the operation of the whole of the center and n (n positive integer) antennas distributed on a ground to form a antenna field, is characterized in that the antennas are rotary antennas and in that the center comprises n transmitters respectively associated with the n antennas in an invariable one-to-one relationship, and n premises arranged respectively

  at the foot of the n antennas, to serve as shelter to the transmitter.

  The present invention will be better understood and other characteristics

  ticks will appear using the following description and figures

  which represent: - Figure 1, an HF transmission center according to the known art, - Figure 2, a transmission center comparable to that of Figure 1

but according to the invention.

  As a convention and to facilitate the understanding of

  the lines supplying the energy necessary for the radiation of

  They have been drawn in continuous lines in Figures I and 2, while the edges of the buildings have been drawn in broken lines. In addition, to simplify the drawings, with some exceptions, the lines

  other than radiofrequency have not been shown.

  FIG. 1 represents a HF emission center according to the known art. This center comprises, in particular, a central building B ', fixed antennas Afl1, Af2 ... formed of radiating doublets and distributed on the ground, and an energy supply building, Bj, also called "sub-station energy". It should be noted that for the convenience and clarity of the drawing, only two antennas and two transmitters have been shown in FIGS. 1 and 2, in fact the transmission centers having served as an example for

  description would include, for Figure 1, four transmitters

  and twenty antennas and, for Figure 2, four transmitters and four antennas.

  The low frequency energy of the substation is supplied to a power distribution circuit, 3, located in the central building, B ', and is distributed, still in the central building, between the transmitters E1, E2 to give the radiofrequency energy to be emitted and between two circuits Jc and Jb intended to respectively supply the energy necessary for the switching of the radiating elements inside each antenna and the necessary energy

  night lighting of pylons serving as supports for fixed antennas.

  The central building comprises, in addition to the transmitters and the circuits used to distribute the energy, a central unit, Uc, consoles, Cs, Cel, Ce2, Cm, Ca, two control cabinets Cdm and Cda and two matrices of

breakdown Ma and Mr.

  The central unit, Uc, has a computer; it is meant to

  manage the operation of the entire issuing center.

  The consoles each have a control panel and serve to define: - for the audio console, Cs, to which transmitters must be switched,

  by the distribution matrix Ma, the various audiofre-

quence, Sa, to emit,

  - for the transmitter consoles, Cel, Ce2,1st operating conditions-

  The transmitters E1 and E2, particularly with regard to the power and the transmission frequency, are used for the matrix console Cm, to which antenna is connected one or the other of the transmitters, the Cm console providing for this purpose control to the matrix control cabinet Cdm so as to ensure the desired links in the matrix Mr, - for the antenna console, Ca, what are the signals to send to

  the Cda antenna switching control cabinet for

  kill the shooting axis switching remote control in each of the antennas. In return the console Ca receives the remote signaling from the antenna with, in particular, the return signals of the safety chains whose path to go consists of lines which follow paths parallel to the paths of the radio frequency energy between the transmitters and the antennas to which these

  transmitters are connected; these parallel paths including

  mechanically coupled to the contactors crossed by the radiofrequency energy, make it possible to check whether the links

  desired have been established.

  The radiofrequency power lines, in strong lines, which connect the central building B 'to the antennas Af 1, Af 2 through sets T 1, T2 having in series a balun and an impedance transformer; the balun allows the passage of a coaxial line transmission matrix side Mr to a symmetrical line transmission antenna side, and the

  impedance transformer provides impedance matching, with a ratio

  stationary wave port as close to I as possible to the transmitter side.

  The fixed antennas Af 1, Af 2 are associated with housings of

  switching which, under the control of the Cda cabinet itself,

  by the antenna console, Ca, allow to modify the firing axis of

  antennas, by phase shift line switching.

  It should be noted that the central building B4, by the amount of means it houses, is large (more than 60 meters long in the example described) and therefore poses problems of implementation as well as regards its construction proper that its air conditioning. As will appear in the following, the transmitting center according to FIG. 2 does not pose such problems because the central building is much smaller in size, and the ancillary buildings associated with each antenna are all identical, of small size. size, have the same elements and therefore lend themselves to a realization in the form of a shelter manufactured in factory and transported by

  truck, with all the elements which it must contain, at the places of

  tion. FIG. 2 represents a HF emission center according to the invention. This center comprises, in particular, a central building, B, rotating antennas, A1, A2, associated with premises, b1, b2, to form emission units, Uel, Ue2, and a supply building.

  of energy, Bj, also called "energy substation".

  The low frequency energy of the substation is directly

  undermined by supply lines to premises bl, b2. It should be noted that the transport of this energy, because it is low-frequency energy, is much easier and causes much less losses than the radiofrequency energy between the central building and the antennas. center according to Figure 1; in fact, this transport can be carried out by flexible cables laid on the ground or buried while, in the case of Figure 1, the transport of radiofrequency energy was done by symmetrical lines, suspended at a height of several meters beyond- above ground

  thanks to poles and insulators.

  The central building B of FIG. 2, compared to the building B 'of FIG. 1, contains only a central unit, U, consoles, Cs, CI, C2 and

a distribution matrix Ma.

  The central unit, U, has a computer; it is intended to manage the operation of the entire transmission center. This is a simplified version of the central unit according to FIG. 1 since, as will appear in the following, it does not have to manage the operation of a switching matrix between the transmitters and the antennas; indeed the matrix Mr according to Figure 1 has completely disappeared in the center

transmission according to FIG.

  The console Cs is identical to the console Cs of FIG. 1, it is an audio console intended to define which transmitters must be switched,

  by the matrix Ma the different audio-frequency signals to be transmitted.

  The consoles C and C2 relate respectively to the emission units Uel and Ue2; they group together the elements of the consoles Cel, Ce2 of Figure I and the means for generating control signals of the light signaling of the antenna and control signals of the angular position of the antenna; these means are produced in the same way, but in a simpler way (sending a number of bits corresponding to the angle of rotation to be obtained), than the part of the antenna console Ca of FIG. signals for switching control

angle of fire.

  The rotating antennas AI and A2 are shown schematically.

  only on top of Figure 2. At their foot are located the premises bl and b2

  which has been discussed further in this description. These premises are,

  in the example described, made from prefabricated panels and mounted on a concrete slab cast at the foot of each antenna at the same time as

the base of the antenna.

  The premises b1, b2 each contain a transmitter, E1, E2, identical to the emitters of FIG. 1, with, at the output, a balun and an impedance transformer which are therefore grouped in the same premises as the transmitter and either scattered in the field as in the case of Figure 1; the transmitters receive the audio frequency signals of the matrix Ma and supply on the one hand the radiofrequency energy to the antenna and on the other hand

  receive CI consoles, C2 remote control information and provide

  in return the remote signaling information that is sent to the consoles CI, C2. An antenna rotation control cabinet located in the foot of the antenna is controlled by the remote control information received by the transmitter. In the example described, the antennas A1 and A2 are two vertical loop antennae of doublets allowing, between them, an operation of 6 to 26 MHz. It should be noted that it is intended to provide a transmission center according to FIG. 2 but in which the antennas will comprise means for feeding only a portion of the doublets in order to modify the antenna radiation pattern; in this other transmission center it is also planned to place the energy substation in the

central building.

  The present invention is not limited to the example described and can be applied, in particular, to the case of centers having only one rotating antenna.

Claims (2)

  1. Transmitting center, in particular HF,   carrying a central building (B) with its central unit (U) designed to manage the operation of the whole center and n (n positive integer) antennas (AI, A2) distributed over a field to form an antenna field, characterized in that the antennas (AI, A2) are rotary antennas and in that the center comprises n transmitters (E1, E2) associated respectively with the n antennas in an invariable one-to-one relationship, and n local (b1, b2) arranged respectively at the foot of the n antennas, to serve as a shelter for the transmitter (E1, E2).   2. Transmission center according to claim 1, characterized in that   the premises (bl, b2) and their contents are all identical.