GB2233830A

GB2233830A - Antenna receiving arrangement

Info

Publication number: GB2233830A
Application number: GB8910456A
Authority: GB
Inventors: Norman Albert Cooper
Original assignee: Individual
Current assignee: Individual
Priority date: 1989-05-06
Filing date: 1989-05-06
Publication date: 1991-01-16
Also published as: GB8910456D0

Abstract

A receiving arrangement for satellite signals comprises an antenna dish and a module 16, which are preferably combined together to form an electronic board 10. The module 16 may include a tuner (R), an audio/video processor (S), a de-scrambler (T), a power supply circuit (U) and a loop-through modulator (V), figure 12. The board 10 can be interposed between a V.H.F./U.H.F. aerial 13 and a T.V. set (12), figure 1. <IMAGE>

Description

TELECOMMUNICATIONS EQUIPMENT Field of the Invention This invention relates to telecommunications equipment and is particularly concerned with the provision of improved forms of such equipment for not only domestic but also commercial and industrial use.

Summary of the Invention According to the present invention, there is provided telecommunications equipment comprising a dish receiver for the reception of satellite-transmitted signals and a module for the tuning and processing of such signals, which module is either mounted within or carried by the dish mounting or is formed as one unit with the dish.

The dish receiver and the module are preferably combined together to form an electronic board which can be interposed between a V.H.F./U.H.F. aerial and a TV set, the board being connected via a coaxial cable to both the aerial and the set or a power supply for the set.

In an alternative arrangement, the module is a separate item mounted on the support bracket for the dish. As a further alternative, the dish receiver and the module are combined in a unit which also includes a display screen.

Provision may be made for operation of the module functions under the control of a remote control which directs R.F. digital commands at the coaxial cable.

The circuitry within the module may be such that a received digital command pulse is directed to an interface which operates to command a processor to carry out appropriate switch or tuning functions.

The dish receiver preferably includes or carries a low noise block-down converter which receives reflected signals from the dish and feeds them to the module. The module preferably includes audio/video processor circuits for separation of the sound and vision sub-carriers of the input signals.

Brief Description of the Drawings Figure 1 is a diagrammatic illustration of a TV/Radio reception installation, Figure 2 shows the electronic board of the installation of Figure 1 and its connections, Figures 3, 4, 5 and 6 are front views of four different board configurations, Figures 7, 8, 9 and 10 are vertical sectional views of the board configurations shown in Figures 3 to 6, Figure 11 is a circuit diagram illustrating the functions of one typical unit, and Figure 12 is a circuit diagram illustrating the functions of a somewhat simpler form of unit.

Description of the Preferred Embodiments Referring first to the general outline schemes that are illustrated in Figures 1 and 2, these include an electronic board 10 mounted on the outside of an external wall of a building 11 within which is located a combined television and radio set 12. A VHF/UHF aerial 13 is mounted on the chimney 14 of the building 11 and this aerial 13 is connected to the set 12 by a coaxial cable 15, the electronic board 10 being inserted or multi-plexed in this cable 15 which provides the downlead to the set 12.

The board 10 includes a dish receiver contained within or forming part of a housing which includes a rearwardly facing recess within which an electronic module 16 is fitted. This electronic module 16 incorporates the whole of the control circuitry for the system. It includes a socket for reception of the input signal from aerial 13 and the power to operate the module functions is derived from a portable power plug 17 which energises the upward path coaxial cable to the internal power supply of the module 16 where various preset voltages to match the appropriate internal circuit functions are derived.

As shown in Figures 3 to 10, a number of different dish configurations can be employed. Figures 3 and 7 show what is commonly referred to as a planar dish but comprises a large number of parallel reflectors. Figures 4 and 8 show a prime focus reflector having an external L.N.B. Figures 5 and 9 show a "Cassigrain" reflector which has an internally located L.N.B.

Figures 6 and 10 show an offset dish reflector.

Regardless of the dish configuration which is adopted, the board 10 has a mounting arrangement to enable it to be positioned in a suitable South-facing location and to track the satellites from which programmes are to be received.

Turning now to the circuit diagram shown in Figure 11, this incorporates the various functions performed by the module 16 and includes a circuit function M which is activated upon switching on the power source. Function M is afforded by an integrated circuit and is a digital tuning function control processor. The control functions of this particular circuit are effected by an R.F. digital modulated carrier transmitted by a remote control source. The R.F. frequency could be at V.H.F.

but not within the normal U.H.F. TV bands, or can be within the infra-red frequency range and directed to the power supply source which could contain an infra-red digital receiver.

The digital commands are directed towards the U.H.F.

cable or to the infra-red receiver which, in turn, retransmits or conducts the signals which travel up to and then enter the electronic board common power source return signal module from which a received digital command pulse is directed to the digital R.F. receiver interface which, in turn, commands the processor to carry out the appropriate circuit switch or tuning function which has been selected by the user remote control.

The digital control tuning processor functions are such that signal paths are provided for the reception of satellite broadcasting downlinks contained within the frequency spectrum of 10.95 to 12.75 GHz in three bands.The R.F. frequency carriers or spot beams contain TV sound, vision and radio subcarriers. The electronic circuitry further contains a provision for receiving bands 89 to 108 MHz (Band 2) and U.H.F. TV 432 to 860 MHz, both of which bands are configured for multi-plexed wide-band loop-through. These are received by the provision of an input socket to modulator F.

Signal delivery frequency spectrum bands transmitted by closed circuit transmission using the common down-lead (coaxial cable) to the power supply contain the following: a) tunable satellite TV/sound channels received at FM 625 remodulated at PAL D with PAL I to G tunable sound filters, and b) radio filtered channels remodulated at V.H.F., the MAC format D/D2 MAC standards converted to PAL D at U.H.F.625 for the common interface coaxial cable to the TV receiver or, in the case of V.H.F., reception of remodulated satellite radio channels is by a standard V.H.F. radio set or by a combined TV and radio set.

Satellite TV /radio channel reception can be stereodecoded using, where appropriate, the PANDA or WEGNER formats for remodulation at 19.5 KHz. The sub-carrier can be used via the simulcast transmission method whereby the TV reception can be in mono while the radio hi-fi system can decode stereo reception. As an alternative, it is possible to have a TV set with a built-in stereo radio receiver. The system can also, if desired, be arranged to decode/receive information for passage to a teletext receiver.

Each of the electronic boards illustrated in Figures 3 to 10 includes a low noise block-down converter (L.N.C.) to which the signal is directed by the dish and which, in turn, feeds the appropriate tunable IF frequency of 950 / 1750 GHz (800 MHz tunable bandwidth) via tuner A to interface B. This signal is further fed to an audio/video processor circuit C where the appropriate circuit filters perform functions such as separation of the sound and vision sub-carriers to be presented to integrated circuit D which has a circuit function of amplifying, decoding and remodulating the radio and TV sound channels via an audio interface switching circuit E for presentation to the V.H.F./U.H.F. mixer modulator loop-through F.

The modules are formed as interchangeable plug-in units and, in order to perform the required descrambling functions, a de-emphasised base band frequency with appropriate band width is fed to either the PAL / SECAM descrambler I or the D / D2 descrambler H by automatic remote-controlled circuit functions.

Descrambled signals, in order of selection, are fed via an interface G to modulator F.

The circuitry can be such that all circuit commands are configured for visual identification. The visual identification can be by means of a liquid crystal display screen contained within the remote control. An appropriate recall memory display or menu is provided.

As an alternative, the digital tuning control processor M may be arranged to transmit signals to a function display character generator J with preprogrammed (EPROM) messages. This circuit component J can have a "white" matrixed output signal which has a timed and recalled over-ride displayed on the screen via modulator F.

Of course, a basic remote control with no liquid crystal display and no function display character generator would also work perfectly well and would be cheaper.The circuit may also be configured solely for mono reception to provide a basic or economy design.

The power plug 17 which affords the power supply required to drive the board may comprise a mains step-down transformer from 220/240 Volts A.C. with suitable isolation characteristics to BS 415. The module circuit is configured to have a 25 Volt D.C. coaxial cable supply to a power supply circuit K within the module. The supply circuit is of sufficient capability to supply 0.5 amps. while also containing the appropriate signal loop-through return path to both the radio and TV receivers via a built-in wall socket or loose fly lead.

In order to increase the security of the installation, a burglar alarm control circuit is shown in Figure 11 and is arranged to respond to an interruption in the up-link to operate an alarm which will normally be incorporated within the TV set.

Turning next to Figure 12, this shows an installation configured for single satellite reception with mono sound and using internal preset controls. The installation includes an electronic board having any one of the configurations shown in Figures 3 to 10 and the board is again mounted on an external wall in a generally South-facing location. The board is formed with a recess in which the module is fitted, the module including a tuner R, an audio/video processor S, a de-scrambler T, a power supply circuit U and a loop-through modulator V.

In alternative arrangements, (not shown in the drawings) the control module, instead of being inserted in a recess in the board, is carried by the mounting bracket or other support for the dish, the electronic control circuitry being contained within a weather-proof casing which is positioned adjacent the dish to simplify installation of the system.

The electronic board may be mounted using a motoroperated polar mount tracking system. Alternatively, and particularly for the more basic versions, the mounting may include a Bowden cable mechanism for enabling manual movement of the dish from one selected satellite orientation to another.

The installation may be used in hotels or in flat complexes to enable programmes to be directed from a single aerial installation to a plurality of TV receivers. The use of a single coaxial cable and the loop-through design arrangement ensures that the wiring requirement is minimised and the time taken to install the equipment of the present invention for a multiple reception arrangement will be considerably less than the installation times for those systems which are currently available.

The electronic board may be in the form of a portable unit for use when, for example, on holiday in a caravan with an alternative built-in multi-supply circuit for mains/battery use. The offset dish arrangement of Figures 6 and 10 will then be preferred and a carrying handle may then be provided the design of which is such as to facilitate mounting of the board on the roof of a caravan. The electronic board may alternatively be designed for use on an oilrig as part of a communications module.

In the various embodiments described above, the electronic board and the TV or radio receiver are two quite distinct and separate entities. It is, however, within the scope of the present invention to have a combined dish and TV screen unit. In such an arrangement, the rear of the electronic board is formed with a liquid crystal display energisation of which is effected under the control of control circuitry as described above in relation to Figures 11 and 12.

Such apparatus will have a range of commercial applications and will be of particular advantage if used in connection with very sharply focussed satellite transmissions of the frequency spectrum covering 30 to 100 GHz, for example, steerable down-link spot beams which are of the order of 100 meters in diameter and which can be used for the transmission of encrypted digital high speed narrow band data, for retrival as text or as a terrain survey to be displayed on a liquid crystal display screen, or as hard copy reproduced using an appropriate interface printer/plotter.

Claims

Claims:

1. Telecommunications equipment comprising a dish receiver for the reception of satellite-transmitted signals and a module for the tuning and processing of such signals, which module is either mounted within or carried by the dish mounting or is formed as one unit with the dish.

2. Telecommunications equipment according to Claim 1, in which the dish receiver and the module are combined to form an electronic board which can be interposed between a V.H.F./U.H.F aerial and a TV set.

3. Telecommunications equipment according to Claim 2, in which the board is connected via a coaxial cable to both the aerial and either the set or a power supply for the set.

4. Telecommunications equipment according to Claim 1, in which the module is a separate item mounted on a support bracket for the dish.

5. Telecommunications equipment according to Claim 1, in which the dish receiver and the module are combined in a unit which also includes a display screen.

6. Telecommunications equipment according to Claim 3, in which provision is made for operation of the module functions under the control of a remote control which directs R.F.

digital commands at the coaxial cable.

7. Telecommunications equipment according to Claim 1, in which the circuitry within the module is such that a received digital command pulse is directed to an interface which operates to command a processor to carry out appropriate tuning or switching functions.

8. Telecommunications equipment according to Claim 1, in which the dish receiver includes or carries a low noise blockdown converter which receives reflected signals from the dish and feeds them to the module, the module including audio/video processor circuits for separation of the sound and vision subcarriers of the input signals.

9. Telecommunications equipment substantially as hereinbefore described with reference to and as shown in Figures 1 to 10 of the accompanying drawings.

10. Telecommunications equipment having a control circuit substantially as hereinbefore described with reference to and as shown in Figure 11 or Figure 12 of the accompanying drawings.