DE4243967A1 - Change=over switching appts. for satellite broadcast reception systems - Google Patents

Abstract

The horizontally polarised waves (h) and vertically polarised waves (v) are switched to separate branches (1',1") of the circuit contg. wideband SHF preamplifiers (V1, V2) whose outputs are combined (4) on to a single line feeding an intermediate amplifier (7), a mixer (9) and an output amplifier (11).For programmes radiated in a band broader than that of the IF plane, an extended comparator (21) is provided for switching the local oscillators (L01,L02) and preamplifiers by selection among two positive and two negative supply voltages.

Description

The invention relates to a switching device for satellite Lite reception systems according to the preamble of the claim 1.

In the book publication DE-Z "Thurl / Ilsanker: antennas for satellite reception ", 1991, Francis-Verlag GmbH, Munich are different feeding systems for satellites receiving systems, namely for individual receiving systems as also described for community facilities. With these Satellite receiving systems can differ from those Most satellite programs and frequency broadcasts rich are received.

The Astra 1 A and Astra 1 B satellites have become very important on the consumer side. Both satellites emit both horizontally and vertically polarized waves on different frequency bands.

To receive the differently polarized waves as is known, a polarization switch (OMT) is inserted  sets, following the outputs for the horizon tal and the vertically polarized signals each Preamplifier is turned on.

In the case of a single reception system, you can then use the two switchable preamplifiers received signals summarized again on a derivation and ver strengthens and be implemented in the ZF area. Here only one preamplifier can be in operation at a time. Of the Switching from one preamp to the other follows via a switchable switchable from the receiver Supply voltage, which is usually at 14 volts or 18 volts lies.

In addition to converter circuits with a switchable front Converter circuits with switchable amplifiers are also amplifiers ren local oscillator frequencies become known. This switchable converters are used for alternate reception of two different frequency bands, which is why the emp catch signals in the IF frequency plane on a lead tion can be fed. In this case, too Switching from one local oscillator to another using a comparator responsive to 14 volts or 18 volts respectively.

In the case of community antenna systems, if the IF frequency bandwidth is insufficient, the emp catch horizontally and vertically polarized waves of the different satellite frequency ranges in the IF Level fed into several derivatives, about which the Consumers can receive the individual programs.

However, there is now the problem, for example after the geostationary positioning of the third Astra satellite 1 C and other planned satellites, that the total frequency spectrum emitted by all Astra satellites is so wide that implementation with only one local oscillator frequency in the intermediate frequency with the usual intermediate frequency range of 0.95 GHz to 1.75 GHz is not possible. Depending on the use of a particular local oscillator, either an upper or lower band spectrum of all three Astra satellites is cut off in the intermediate frequency level (IF level) and is therefore not receivable for the connected consumers.

To nevertheless give consumers the opportunity all also broadcast by other Astra satellites To be able to receive programs must therefore be at single temp a switch from a local oscillator to another, in combination with a polarization switch over the preamplifier and in the case of general systems switch from a derivative to a next one can be made, in each case once upper or lower band from the satellites blasted programs once regarding the horizontal and secondly, regarding vertical polarization can be received.

So there is also a switch with respect to the horizontal and of vertically polarized waves, a fourfold changeover is therefore necessary in total. The pro now exists for single reception systems blem that switching between the two converters, d. H. usually between the two different ones Preamplifiers once to receive the horizontal and the vertically polarized waves and a switchover between only the two local oscillators required with a supply voltage comprising two voltage levels Switching device from 14 volts to 18 volts not to be is working. About the control options of a conventional receivers can be switched by the voltage from 14 volts to 18 volts only either switching  from one to the other preamplifier of the converter (or from one to the other converter at all) or alternatively, switching from a local oszilla can be made on the other.

The same applies in principle to a community antenna plant, in which four derivatives via a secondary Matrix switched on the individual consumers once those in a vertical or horizontal polarization programs broadcast and one each of them can receive the upper as a lower band. Here too a fourfold switch must be made, whereby also the one provided by the receiver Two voltage level switch of 14 volts / 18 Volt only allows simple switching.

The object of the present invention is therefore the To overcome disadvantages according to the prior art and to create a way with comparatively simple Chen means an expanded, at least fourfold order Switching option for receiving different programs enable me / frequency spectra.

The task is according to the invention in accordance with solved claim 1 reproduced features. Beneficial Embodiments of the invention are in the subclaims specified.

The present invention is extremely economical Measures and means a very useful additional Switching possibility created.

Basically, it would be quite conceivable to assume that a simple switching option continues through a Switching from, for example, 14 volts to 18 volts on Receiver made and by an appropriate Kompara  then a switching of the preamplifier (Kon verter) or the two available lo Kal oscillators featured in the case of single receiving systems can be taken. The second order still required circuit could for example have an additional Control device are carried out by means of a broadcast sound fed in at a certain frequency follows. In other words, should have a derivative certain frequency signal are fed in, via what a detection circuit then made the switch becomes. A sound signal switching from 0 heart to example as 400 KHz could be used as a switching signal for switching from one local oscillator frequency to the other localos zillator frequency serve. But this would be an additional one Transmitter unit for generating and feeding the sound signal and require appropriate evaluation electronics. The like frequency signals can also add Impairment, reducing the quality of reception can be fundamentally impaired.

The invention proposes a completely different way here in front.

According to the invention it is namely provided that a fourfold Switching while already maintaining the on the receiver existing two-voltage level switching of example as 14 volts to 18 volts and vice versa. An extension to achieve a fourfold switchover is made possible only by the fact that now this Switching available food or tax voltages of 14 volts and 18 volts in the negative Be are richly "mirrored", so that an additional two Voltage level or control signals of -14 volts and -18 Volts are available. On the receivers, the Be provision of these two further negative voltage pe gel can be made easily. But also the Auswer  device for switching in the converters is comparative simply possible. Above all, it is important that one further switching only by applying a span no further technical problems in terms of reception quality.

The principle of the invention can basically be Use single reception systems where a switchover for the reception of horizontally and vertically polarized Waves and for switching an upper one to a lower band by switching from a local Oscillator frequency on the other is feasible.

The invention is equally in the case of a Community antenna system with z. B. four participants possible, in which the consumer by switching from consumer-dependent switches / amplifiers the example wise at four leads different TV programs can optionally receive.

In a preferred embodiment of the invention for example, the converter circuits then in reverse semiconductor technology, d. H. once based on NPN transistors and semiconductor junctions and vice versa executed on PNP transistors. I.e. when creating positive tensions is automatically the one Converter branch in operation and the other switched off, being by applying the mirrored negative voltage an automatic switchover takes place.

In a preferred embodiment of the invention it is but also an extended converter circuit possible to provide what about the one derivative also fed the supply voltage used for switching is evaluated and processed accordingly. Is to a converter branch is provided, in the case of  negative supply voltages of, for example, -14 volts / -18 Volts through "a downstream chopper and equal always judge the corresponding positive supply voltage conditions for operating the converter preamplifiers and / or the Local Social Generators is generated.

In the case of a locally fed community antenna system A simple logic evaluation electronics is sufficient, because here the voltage levels fed in by the receiver only as switching and control signals and not at the same time also serve as supply voltage.

Further advantages, details and features of the invention follow from the drawings illustrated embodiments. Show in the individual:

Fig. 1 is a single installation of the invention for receiving satellite programs with a four-fold change-over;

FIG. 2 shows a corresponding circuit diagram for an expanded comparator circuit for four-way switching of the individual reception system shown in FIG. 1;

Fig. 3 shows an embodiment of a community satellite reception system with four derivatives; and

Fig. 4 one of the community satellite reception system shown in FIG. 3 downstream Ma trix for individual consumers.

In the following, reference is made to FIG. 1.

In this circuit arrangement for an individual reception system, the programs broadcast by one or more satellites, for example the Astra satellites 1 A to 1 C, are received in a known manner via a satellite antenna, not shown. Via a downstream polarizing switch, the horizontally polarized waves h are fed into the first branch 1 'and the vertically polarized waves v into the second branch 1 ''. A broadband SHF amplifier V1 or V2 is connected in each branch. The outputs of the two SHF amplifier stages V1, V2 are fed via a distributor 4 to a single line 5 , in which, for example, an intermediate amplifier 7 , a mixer 9 and an output amplifier 11 are connected. From the outlet 13 leads a derivative 14 to the consumer.

The mixer 9 is connected to the two local oscillators LO1 and LO2 via a distributor 15 . Therefore only one oscillator may be in operation at a time.

In a departure from the exemplary embodiment shown, the signals preamplified by the two SHF amplifiers V1 / V2 could also be processed in two separate branches via mixers arranged separately in each separate branch and operated via a local oscillator assigned to them, and only on the output side via a diplexer are given to a common output 13 and fed into a common derivative 14 .

An extended comparator circuit 21 is also indicated in FIG. 1.

Via a receiver, not shown, the connected consumer of this single satellite receiving system can generate corresponding supply voltages of +14 volts, +18 volts, -14 volts, -18 volts and feed it as feed and control voltage into the lead 14 in the opposite direction . About the extended Komperatorschal device 21 is, for example, by switching from +14 volts / + 18 volts to -14 volts / -18 volts a switch from the first local oscillator frequency to the second local oscillator frequency and by selecting +14 volts or +18 volts a switchover from the operation of the first pre-amplifier V1 to the operation of the second pre-amplifier V2.

Referring to Fig. 2, the advanced comparator circuit 21 is shown in greater detail.

A consumer or receiver supplies the positive and negative voltage level supply voltages fed in by the derivation 14 via a control line 29 at a branch point 25 in branch lines 27 a and 27 b.

In the first branch line 27 a after the branch point 25, a first diode 31 a is connected, which switches through in the case of a positive supply voltage. Via a downstream voltage regulator generating voltage regulator 33 , a desired supply voltage is generated for example for the operation of the local oscillator LO1.

In contrast, if a negative voltage of, for example, -14 volts or -18 volts is applied, the first diode 31 a blocks and switches the oppositely connected second diode 31 b in the second branch line 27 b to pass. In this branch line, the diode 31 b is followed by a voltage inverter 35 , which also generates a positive supply voltage again at its output, which corresponds in principle to the positive output supply voltage in the first branch line 27 a, if the consumer does not have a negative, but a positive voltage level supply voltage is switched on.

The voltage inverter 35 consists in principle of a chopper 35 'and a connected rectifier 35 ''.

As can also be seen from FIG. 2, the two supply and control voltage output lines 39 a and 39 b are each connected via a diode 41 a, 41 b connected to a common supply voltage output line 43 with a positive voltage in the flow direction. The supply voltage required for the operation of the further module of the converter, ie the SHF amplifier or IF preamplifier, is provided.

Fig. 2 also shows that each of the two branch line 27 a and 27 b connected to the derivative 14 is also equipped with two branch lines 27 c and 27 d each comprising an operational amplifier 45 a or 45 b. Via the operational amplifier in the network shown in FIG. 2, with the respective diode 41 c and 41 d connected downstream, the supply or control voltage for the SHF- is respectively connected to the two further supply and control voltage output lines 39 c and 39 d. Amplifier VI or V2 of the converter generated.

For this purpose, the converter supply voltage line 43 is connected via line 48 and from the voltage divider circuit shown in FIG. 2 to the second input of the respective operational amplifier 45 a and 45 b, respectively.

The circuit arrangement is such that when a positive voltage +14 volts or +18 volts always the Loka loszillator LO1 and when a negative voltage is applied -14 volts or -18 volts only the local oscillator LO2  is operated.

Depending on the amount of either positive or negative tive supply voltage level of ± 14 volts or ± 18 volts but then alternately becomes either the first or the second Preamplifier V1 or V2 switched on or off, what from the shaft attached at the end of the description is.

The corresponding switchover with respect to the SHF amplifier V1 / V2 then also takes place as a function of the input voltage on the further operational amplifier 51 arranged in the second control or supply voltage output line 39 d.

In another table, examples are given for the transmission frequencies of the Astra satellites and for two possible local oscillator frequencies, from which the so-called upper and lower band in the intermediate frequency level can be seen, which after switching from a local oscillator Frequency on the second can be received. By additional switching from the first branch 1 'to the second branch 1 ''by switching the corresponding amplifier V1 / V2 can then with respect to the upper and lower band once the horizontally polarized and secondly the vertically polarized signals and thus the corresponding programs be received.

In FIGS. 3 and 4 is a corresponding circuit arrangement shown for a Shared satellite receiving system.

In Fig. 3, the respective downstream SHF amplifier V1 for receiving the horizontally polarized signals h is a distributor 4 'or 4 '', where a further splitting over a line 57 a and 57 b for an upper or lower frequency band (oB, uB). The frequency signals converted into the intermediate frequency are passed to an output amplifier 11 a or 11 b and above each to an output 13 a or 13 b, of which two derivatives 14 a and 14 b are received, via a downstream mixer 9 a and 9 b of the horizontally polarized waves are fed in once with the upper band, ie with the higher band, and once with the lower band, ie with the lower band.

One mixer 9 a is always operated via the local oscillator LO2 and the second mixer 9 b is always operated via the local oscillator LO1.

The frequencies radiated with vertical polarization v are split via the non-illustrated polarization switch via the second branch 1 '' and the downstream diplexer 4 '' to the two other mixers 9 c and 9 d and implemented in each case in an IF plane and amplified via likewise downstream output amplifiers 11 c and 11 d and fed to the further outputs 13 c and 13 d as well as the leads 14 c and 14 d coming therefrom.

Here too, the corresponding mixer is replaced by the each operated a local oscillator assigned to them ben.

Only the two illustrated local oscillators LO1 and LO2 are for the whole converter circuit is provided which via a switch 53 and 54, each having a zugeord Neten mixer 9 a and 9 c, 9 b and 9 d connected in the respective branch are such that the upper and lower frequency bands received by the consumer are the same for the horizontal and vertical polarizations.

From Fig. 4 it can be seen that via the four leads 14 a to 14 d via the downstream 4 × 4 matrix 65 each of the four leads to an extended converter circuit 21 ', what each consumer a to d connected via four receive lines 67 is. Here each consumer a to d can switch one of the switches 71 a to 71 d (which can also represent an amplifier circuit) depending on the voltage by feeding in a control voltage of +14 volts, +18 volts, -14 volts or -18 volts that one of the four program or frequency spectra h, oB, h, uB, v, oB or v, uB can be received, for which "h" for horizontal polarization and "v" for vertical polarization and "oB" for a upper band and "uB" stand for a lower band.

In the case of communal systems, all that is required is an extended converter circuit in the sense of a logic evaluation circuit, which, depending on the positive or negative 14 volt or 18 volt voltage level, leads the corresponding switching from one of the four leads to one of the four to each consumer the reception lines 67 enables. Since such logic evaluation circuits are at the discretion of the person skilled in the art, a further exemplary embodiment is ignored. In the case of the common antenna system, the different voltages only serve as control voltages, since the various converter and amplifier stages, local oscillators etc. are always supplied with a corresponding supply voltage and current and are operated in parallel.

Table 1

Table 2

Claims (9)

1.Switching device for satellite reception systems for receiving at least four different frequency bands and / or four different polarizations, in particular for receiving vertically and horizontally polarized transmission signals emitted at two mutually offset frequency bands, with an expanded comparator circuit ( 21, 21 ' ), the extended comparator gate circuit ( 21 , 21 ') by two positive offset and two negative offset voltage levels can be operated by the consumer so that at least four different frequency bands and / or polarization-dependent transmission spectra can be received. 2. Switching device according to claim 1, characterized records that the two are offset from each other positive voltage level and the two ver sets the negative voltage level to ground have the same absolute size.   3. Switching device according to claim 1 or 2, characterized in that in the case of a single satellite Emp reception system via the extended comparator circuit ( 21 ) sign and voltage level-dependent one of two for the gain once the horizontal as well the vertically polarized received waves in two separate branches provided amplifier stages (V1, V2) and one of two provided local oscillators (LO1, LO2) can be operated. 4. Switching device according to claim 3, characterized in that the extended comparator circuit ( 21 ) for alternative control of the SHF amplifier (V1, V2) or for alternative control of one of the two local oscillators (LO1, LO2) one with Derivation ( 14 ) on the consumer side connected branch line ( 27 a, 27 b) comprises, in one of the two branches of the branch line ( 27 a, 27 b) a voltage inverter circuit ( 35 ) is provided such that independent of positive or negative voltage level supply and control signals always a positive supply and control voltage for the operation of the amplifier (V1, V2) and / or the local oscillators (LO1, LO2) can be generated. 5. Switching device according to claim 4, characterized in that the voltage inverter circuit ( 35 ) consists of a chopper ( 35 ') and a voltage rectifier ( 35 ''). 6. Switching device according to one of claims 3 to 5, characterized in that the two branch lines ( 27 a, 27 b) on the input side each have a reverse-connected device ( 31 a, 31 b). 7. Switching device according to one of claims 3 to 6, characterized in that each of the two branch lines ( 27 a, 27 b) is each connected to a further branch line ( 27 c, 27 d), via which a supply and control voltage for voltage level alternative control of one or the other amplifier (V1, V2) is seen before. 8. Switching device according to claim 1 or 2, characterized ge indicates that the converter or amplifier (V1, V2) in reverse semiconductor technology with npn transistors or semiconductor junctions and pnp semiconductor junctions or transistors work and therefore dependent of the consigned with different signs alternatively be are drivable. 9. Switching device according to claim 1 or 2, characterized in that in the case of a community satellite receiving system with at least four derivatives ( 14 a to 14 d) one of the number of downstream consumers dependent matrix ( 65 ) is connected, each to closed consumers (a to d) an extended comparator circuit ( 21 ') can be controlled via two voltage level stages, each with two different signs, depending on the consumer, by means of which the different programs pending at the four derivatives ( 14 a to 14 d) are dependent the voltage level and the associated sign can be switched by.