DE4335616C2 - Satellite receiving system - Google Patents

Description

The invention relates to a satellite receiving system the preamble of claim 1.

The offer of broadcast via geostationary satellites programs is constantly growing. Especially those about Programs broadcast by Astra satellites are enjoying themselves of great popularity. The number of over the Astra-Sa telliten broadcast programs is due to the new incoming Astra satellites 1C have become even larger. He Another Satelli station is also waiting ten Astra 1D and Astra 1E.

As is well known, the received signals, d. H. which are usually polarized horizontally and vertically electromagnetic waves via suitable converters north gates implemented in an intermediate frequency level. Con Verteranrangungen are for example from DE 42nd 01 649 A1 and DE 39 29 824 C2 have become known.

Already in geostationary position in space located Astra satellites 1A to 1C radiate today Programs already on a frequency spectrum of 10.95 GHz up to 11.70 GHz. The fifth Astra- Satellite Astra 1E is then supposed to be in an upper one Broadcast programs from 11.70 GHz to 12.50 GHz. It is thought that in the mentioned upper frequency band from 11.70 to 12.50 GHz all programs for radio as well as television radio in Digi valley technology can be broadcast.  

An increasingly larger overall frequency band is required of course - if as many of the offered as possible Programs to be received - also correspond to one de Adaptation of the receivers and receivers, which then ent speaking broadband must be interpreted.

In the case of such a broadband spectrum of for example 10.70 GHz to 12.50 GHz (in the case of five Astra satellites 1A to 1E) could do this basically mean that the entire frequency spectrum once for the vertically polarized waves in one and for the horizontally polarized waves in a second Branch, for example, using a local oscillator frequency from 10.50 GHz to the intermediate frequency level becomes. This means that in both converter branches the received vertically or horizontally polarized waves in an intermediate frequency range from 0.30 to 2.00 GHz would be set.

Then, according to the usual reception systems for example for a community antenna system that corresponding programs implemented in the ZF areas, over two antenna cables or leads and given if a downstream switching matrix corresponds to the the receiver-side receiver can be connected with Then the entire program package is the same can be received in time.

However, the reception of broadcasts in digital technical problems. Processing the digitized Data, in the corresponding, up to the connected Leading line systems is very disturbing sensitive.

The object of the present invention is a To create satellite reception system, which is especially for the reception of a very broadband frequency spectrum and in turn for the reception of programs in digital technology is suitable.

The task is according to the invention in accordance with solved claim 1 specified features. Favorable off designs of the invention are in the subclaims specified.

The solution according to the invention stands out above all by from that with comparatively simple means Opportunity is created, not just a broad fre frequency spectrum and thus program package different Most programs broadcast via satellite at all to be able to receive, but above all a reception of programs in digital technology with high quality and To enable goodness and low susceptibility to faults.

According to the invention, this can be achieved in that at least in one of the two, for receiving the horizon Valley and / or vertically polarized waves provided Converter branches, an implementation of the upcoming frequency does not band overall into an intermediate frequency level, but instead a frequency-selective one Split into two sub-branches or sub-branches in which a separate conversion to an intermediate frequency is carried out. The Implemented such that the preferred for the Digital radio provided upper frequency band in a counter intermediate frequencies lower than the other frequency band quenz level is converted. Because it has been shown that in particular broadcasts in digital technology in one lower frequency range with low susceptibility to interference in can be transmitted to the antenna distribution systems.  

In a particularly preferred embodiment, the above frequency intended for digital radio band, with a local oscillator frequency in the IF range mixed, which is preferably even above the highest in the IF level to be converted lies.

This surprising solution leads to the difference the local oscillator frequencies and a multiple thereof in both frequency branches definitely above the highest frequency is in the intermediate frequency range. With in other words, all possible interference products are in the Intermediate frequency level outside the Fre to be received frequency range, whereby the quality and quality of the received This program again clearly with simple means is improved.

According to the invention, the implementation in the second, for the Digital radio range intended sub-branch or sub-branch, with a single mixer or with a double or cas Kaden mixer arrangement, i.e. a second, subsequent Mixer can be made. The first mixer can do this the same local oscillator frequency as in the other Have converter branch, with the second mixer the preferred reverse mix or reflection in the low rigorous frequency range is performed.

Another is then preferred on the receiver side others that reverse the reversal mixture or return it rende, reverse mixing performed.

The invention is based on an embodiment example explained in more detail. The individual shows:

Fig. 1 shows a satellite reception system according to the invention (feed system);

Figure 2 is a detailed circuit arrangement for an appropriate example for the reception of vertically or horizontally polarized wave converter circuit having an inverted position mixture. and

Fig. 3 is a receiver-side circuit arrangement for a reversing position mixture.

In Fig. 1 the schematic basic structure of a feed system with a broadband converter according to the invention (hereinafter also called LNC) is explained.

This satellite receiving system includes a horn 1, about which receive the vertically and horizontally polarized waves and an OMT, a polarization filter 3, and two branch lines 4 that is _v or 4 _h in the two converter circuits 5 _v and fed _h. 5 In each of these branches a Kon verterschalt 7 _v or 7 _{h is} provided.

If, for example, circularly polarized waves are also received on the left and right, the polarization switch 3 can also be preceded by a so-called polarization converter, by means of which circularly polarized waves can be converted into linearly polarized waves.

Referring to Fig. 2 will now be further explained in detail, each of the two converter circuits 5 and 5 _{h v} comprises a frequency selective splitting.

In Fig. 2, the converter arrangement is explained using a converter circuit 5 _v or 5 _h , wherein - since the structure in these two converter circuits is the same in itself - the index "v" or "h" for the implementation of the vertically polarized as well as the horizontally polarized waves is omitted in the following.

From Fig. 2 it can be seen that each of the two converter circuit 5, for example, a preamplifier 13 to which a crossover 15 is connected downstream.

In the embodiment shown, the frequency crossover 15 is used to split the entire frequency band into a partial frequency band for transmission corresponding to the programs, in particular in analog technology, and a second partial frequency band, in particular for transmitting programs in digital technology.

The exemplary embodiment explained takes place for the case of the Astra satellites 1A to 1E, with the frequency soft 15 splitting, for example, into a frequency band from 10.70 GHz to 11.70 GHz (Astra satellite 1A to 1D) and a further frequency band from 11 , 70 GHz to 12.70 GHz (Astra satellite 1E). The frequency-selective splitting takes place in a first converter branch 17 'and a second converter branch 17 '', which are also referred to below as sub-branches 17 ' and 17 ''.

In each of the two frequency branches 17 'and 17 ''is a mixer 19 ' and 19 '', each a mixer driving local oscillator 21 'and 21 ''and one of the mixer downstream intermediate frequency amplifier 23 ' and 23 '' is arranged . The outputs of the intermediate frequency amplifiers are fed via a frequency-selective switch 25 to a derivative or an antenna cable 27 .

In the selected embodiment, for example, in the first frequency branch 17 'the local oscillator operates at 9.65 GHz, which can be used to convert to an IF band from 1.05 to 2.05 GHz.

In the other branch, a local oscillator frequency is now used, which is above the highest frequency to be received of 12.50 GHz. In the exemplary embodiment shown, the local oscillator 21 '' operates at a frequency of 12.70 GHz. As a result, the frequency band provided for digital radio and separated by the crossover 15 from, for example, 11.70 to 12.50 GHz is converted to a frequency band of 0.2 to 1.0 GHz in the sense of a reverse mix.

The digitized ones can be digitized in the lower frequency band received programs much less susceptible to interference transmitted to the following receivers. But especially is the difference between the two local oscillator frequencies in the selected embodiment at 3.05 GHz, meaning German Lich above the highest frequency to be transmitted in IF frequency range of 2.05 GHz. This also means all interference products and multiples thereof outside of receiving frequency range.

The two corresponding converted into the IF level frequency bands are passed over said network 25 and the antenna cable 27 _v and 27 _h to the connected receiver.

The structure explained above applies, for example, to the converter circuit 5 _v for implementing the vertically polarized waves. The second converter circuit 5 _h is constructed accordingly. The signals processed in this way are thus forwarded to the receiver 29 via a second antenna cable or a second derivative. In other words, the programs ultimately going back to the vertically polarized waves are forwarded via an antenna cable 27 _v and the waves polarized orthogonally to them after conversion in the second converter circuit via the second antenna cable 27 _h to the connected subscribers 29 ( FIG . 1).

For the sake of completeness, it is also noted that, in principle, only one of the two converter circuits 5 can be provided, for example, if only one subscriber or receiver 29 is connected. In this case, the connected subscriber could actuate a polarization switch, for example, by switching a control voltage from 14 volts to 18 volts, so that either the horizontally or the vertically polarized programs are received and implemented in the downstream converter arrangement.

As shown in FIG. 3, an input circuit 30 (which comprises two circuit branches 30 _v and 30 _h ), such as that via a frequency-selective switch 31 _v or 31 _h , is now split into two frequency branches on the receiver or receiver side 35 'and 35 ''instead. The frequency-selective splitting in the relevant Wei surface 31 is again carried out in such a way that in one branch the frequency band previously mirrored in the converter branch 5 is transformed again by a further mixer 37 _v or 37 _h in the sense of an inverted mixture so that the between Frequency band from 0.95 GHz to 2.05 GHz. In the exemplary embodiment shown, the local oscillator 39 _v or 39 _{h in question} , which drives the mixer 37 _v or 37 _h , operates with a local oscillator frequency of, for example, 2.25 GHz. That is, the signal in the band from 0.2 GHz to 1.2 GHz in the branch comprising the mixer 37 _v or 37 _h send 35 '' is now in the correct non-ge mirrored frequency band of z. B. 1.25 GHz to 2.05 GHz ge mixed.

Thus, it is clear from the overall structure that each of the shown in Fig. 1 two converter circuits 7 _v and 7 _h, an internal division of the received frequency band is carried out, wherein a in the respective two sub-branches 17 'and 17' 'with a different Loka loszillator frequency different implementation takes place. A reversal mixture is carried out in one volume.

_V via the two lines 27 and 27 _h are then fed with the mixed in the IF-level frequency bands of the recei generally in FIG. 1 and in Fig. 3 in the concrete shown verseitigen reception circuit 30. In the two, to the antenna transmission line 27 _v and 27 _h and the subsequent crossovers 31 _v and 31 _h at closing branches 35 '', each of a previously reflected frequency band is reversed mixed again.

In each of the two branches 35 'and 35 '', provided for the reception of the vertically and horizontally polarized waves, is then in the receiving circuit 30 on the output side via a corresponding switch 45 _v and 45 _h and one of the two switches 45 _v and 45 _{h bringing} together further switch 47 the band in question to a receiver 29 via a line 49 .

The aforementioned switch 47 can be connected directly upstream of the receiver 29 or integrated in the receiver. The receiver 27 can be switched, for example, by means of a DC switch from 14 to 18 volts and vice versa. This switches over to receive either the vertically or horizontally polarized waves. By switching on a transmission pulse of 22 KHz, for example, a switch is made from switch 45 _v to switch 45 _h and vice versa. In this way, it can be decided on the subscriber side which sub-frequency band can be received in the branch connected in each case via the switch 45 _v or 45 _h .

If more than one subscriber, ie receiver 29 , is to be connected, then the receiver-side input circuit or electronics 30 would be preceded by a corresponding 2 × 4 or, for example, 4 × 4 or another switching matrix. This is equipped on the input side with two connections for connecting both the one antenna cable 27 _v and the other antenna cable 27 _h . On the output side, the input circuit or electronics 30 can then be connected to the relevant receiver via one or two connecting lines (depending on the type of receiver). In a receiver with two inputs, switch 47 is then usually integrated in the receiver.

Claims (10)

1. Satellite receiving system with a converter circuit ( 7 _v , 7 _h ), in which the radiated from satellites, in particular vertically or horizontally polarized electromagnetic waves at least in one, preferably in two converter circuits ( 5 _v , 5 _h ) in an intermediate frequency level are implemented, characterized in that in the at least one converter circuit ( 5 _v , 5 _h ) the received frequency band is frequency-selectively split into two frequency bands, each in an assigned converter branch ( 17 ′, 17 ′ ′) by means of a single or multi-stage frequency conversion in two offset intermediate frequency bands are implemented, the local oscillator frequency in the case of a one-stage, or the sum of the local oscillator frequencies in the case of a multi-stage frequency conversion in the one converter branch ( 17 ') has a value which is below the in this converter branch ( 17 ') in the intermediate frequency level converted frequency band, and the Lokalos zillatorfrequenz in the case of a one-stage or the sum of the local oscillator frequencies in the case of a multi-stage frequency conversion in the second converter branch ( 17 '') has a value which is above the lowest frequency of the in this converter branch ( 17 '') frequency band converted into the intermediate frequency level, and that the frequency band provided for digital radio in the second converter branch ( 17 '') is converted into an intermediate frequency band which is converted below the intermediate frequency band implemented in the other converter branch ( 17 ''). Band lies. 2. Satellite reception system according to claim 1, characterized in that in the one converter branch ( 17 '') implemented implementation of the received frequency band in an intermediate frequency level can be carried out such that in the case of a one-stage implementation, the frequency of a local oscillator or in In the case of a multi-stage implementation, the sum of these local oscillator frequencies lies above the highest satellite frequency to be received. 3. Satellite receiving system according to claim 1 or 2, characterized in that in the second converter branch ( 17 '') the frequency of one or the sum of several local oscillators is selected so that the verter branch in this con ( 17 '') to the intermediate frequency -Level converted frequency band is reversed. 4. Satellite reception system according to one of claims 1 to 3, characterized in that in each converter circuit ( 5 _v , 5 _h ) in each of the two converter branches ( 17 ', 17 '') each because a one-stage mixer arrangement ( 19 ', 19 '' ) is provided. 5. Satellite reception system according to one of claims 1 to 3, characterized in that in each case in the second converter branch ( 17 ''), in which the received frequency band is implemented in the sense of a reversal mix in an inter mediate frequency level, this implementation by means of one is carried out twice in succession by means of two mixers, one of the two mixers operating at the same local oscillator frequency as the mixer ( 19 ') in the other converter branch ( 17 '). 6. Satellite reception system according to one of claims 1 to 5, characterized in that the outputs of the two converter branches ( 17 ', 17 '') are preferably combined via a switch ( 25 ) on an antenna line ( 27 _v , 27 _h ). 7. Satellite reception system according to one of claims 1 to 6, characterized in that on the subscriber side a Reverse layer mix, reversing reverse mix is feasible. 8. Satellite reception system according to claim 7, characterized in that the device in a relevant antenna line ( 27 _v , 27 _h ) pending and converted into the respective intermediate frequency level received signals via a frequency-selective switch ( 31 _v , 31 _h ) can be split , in which in each case one branch ( 35 '') by means of a mixer arrangement ( 37 _v , 37 _h ) one of the reversing-position mixture which was previously carried out in the associated converter branch ( 17 '') can be recycled. 9. Satellite reception system according to claim 7 or 8, characterized in that after carrying out the reverse reversal positions, the first carried out reversal mix, the receivable in this mixer branch ( 35 '') Fre frequency band together with the upcoming in the parallel frequency branch ( 35 ') Frequency band preferably via a crossover ( 45 _v , 45 _h ) on a common to one or more participants ( 29 ) leading output ( 51 _v , 51 _h ) are merged. 10. Satellite reception system according to one of claims 1 to 9, characterized in that a switchover matrix is provided on the receiver side for the parallel connection of a plurality of subscribers ( 29 ).