JP2001267948A - Satellite signal transmission system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of frequency converters in a block converter used for a satellite signal transmission system. SOLUTION: A converter 8 frequency-converts a satellite broadcast signal into a satellite broadcast intermediate frequency signal BS-IF. Converters 4V, 4H frequency-convert horizontally and vertically polarized wave satellite communication signals into first and second satellite communication intermediate frequency signals CS-IF1, CS-IF2, respectively. The frequency bands of the signals CS-IF1, CS-IF2 are partly overlapping but not overlapping with the frequency band of the signal BS-IF and the signals can be transmitted through a transmission path. The block converter 20 receives the signals CS-IF1, CS-IF2 and the signal BS-IF. The converter 20 is provided with a frequency converter that frequency-converts the signal CS-IF1 into a third satellite communication intermediate frequency signal by using a first local oscillation signal and with a second frequency converter that frequency-converts the third satellite communication intermediate frequency signal into a fourth satellite communication intermediate frequency signal by using a second local oscillation signal, and the block converter 20 outputs the fourth satellite communication intermediate frequency signal with the second satellite communication intermediate frequency signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to receiving horizontal and vertical polarized satellite communication signals, converting the frequency into a satellite communication intermediate frequency signal, receiving the satellite broadcast signal, and converting the frequency into a satellite broadcast intermediate frequency signal. And a satellite signal transmission system for transmitting these via a transmission path.

[0002]

2. Description of the Related Art At present, in Japan, vertically polarized satellite communications are transmitted at 12.493 GHz to 12.733 GHz, and horizontally polarized satellite communications are transmitted at 12.508 GHz to 1 GHz.
Some transmit at 2.748 GHz. Some satellite broadcasts are transmitted in a frequency band of 11.713 GHz to 12.1313 GHz.

In general, vertical and horizontal polarization satellite communications are:
In a converter attached to a satellite communication receiving antenna, a vertically polarized satellite communication signal is converted to a 1293 MHz signal using a local oscillation signal of 11.2 GHz as shown in FIG.
Frequency conversion to a vertically polarized intermediate frequency signal of 1533 MHz to a horizontally polarized satellite communication signal of 11.2 GHz.
1308 MHz to 154 using the local oscillation signal of
2. Description of the Related Art Frequency conversion into a horizontally polarized satellite communication signal of 8 MHz and supply to a television receiver via a coaxial cable are performed.

Similarly, a satellite broadcast signal is converted to 10.678 by a converter attached to a satellite broadcast receiving antenna.
As shown in FIG. 9E, a local oscillation signal of GHz is used to convert the frequency into a satellite broadcast intermediate frequency signal of 1035 MHz to 1335 MHz and supply the signal to a television receiver via a coaxial cable. ing.

In this case, the frequency bands partially overlap between the satellite broadcast intermediate frequency signal and the vertical and horizontal polarization intermediate frequency signals. Therefore, the satellite broadcast intermediate frequency signal and the vertical and horizontal polarization intermediate frequency signals cannot be transmitted through the same coaxial cable. Therefore, a block converter is used. In the block converter, FIG.
The vertical polarization satellite communication intermediate frequency signal shown in FIG. 1 is temporarily changed to 337 MHz to 577 MHz in a frequency band different from that of the satellite broadcasting intermediate frequency signal as shown in FIG. The frequency is converted using a frequency converter having a frequency of 1870 MHz. Also, the horizontal polarization satellite communication intermediate frequency signal shown in FIG. 4A is converted to a local oscillation frequency of 1885 MHz shown in FIG.
The frequency is converted from 337 MHz to 577 MHz shown in FIG. Further, the frequency-converted vertically polarized intermediate frequency signal is converted into a 1385 MHz signal as shown in FIG.
To a frequency band of 1625 MHz to 1625 MHz. The frequency-converted horizontal polarization intermediate frequency signal is converted from a 1655 MHz to 1895 MHZ as shown in FIG.
The frequency is converted to the frequency band of z. As a result,
As shown in (e), the satellite broadcast intermediate frequency signal, the vertically and horizontally polarized satellite communication intermediate frequency signal twice frequency-converted, shall be transmitted via one coaxial cable without frequency duplication. Can be. Since UHF and VHF television broadcast signals have low frequency bands, they can be transmitted simultaneously using the same coaxial cable.

[0006]

However, in such a configuration, a total of four frequency converters are required for the frequency conversion of the satellite communication intermediate frequency signal, which increases the cost. Moreover, of the local oscillation signals used in these frequency converters, 1870 MHz and 1885 MHz exist in the frequency band of the horizontally polarized satellite communication intermediate frequency signal which has been frequency-converted twice. Susceptible to spurs. Therefore, the frequency converter
Attention must be paid to the shield so that spurious emission of the local oscillation signal does not easily occur.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a satellite signal transmission system using a block converter that reduces the number of frequency converters and is not affected by spurious local oscillation signals.

[0008]

SUMMARY OF THE INVENTION A satellite signal transmission system according to the present invention comprises: a satellite broadcast receiving converter for frequency-converting a satellite broadcast signal received by a satellite broadcast receiving antenna into a satellite broadcast intermediate frequency signal; Horizontal and vertical polarization satellite communication signals received by the antenna,
A satellite communication receiving converter for converting the frequency into first and second satellite communication intermediate frequency signals having a frequency band partially overlapping and having a frequency band not overlapping with the satellite broadcasting intermediate frequency signal; The satellite communication intermediate frequency signal and the satellite broadcasting intermediate frequency signal are input, and the first satellite communication intermediate frequency signal is located between the upper limit frequency of the satellite broadcasting intermediate frequency signal and the transmission upper limit frequency of the transmission path. Frequency conversion into a satellite communication intermediate frequency signal in a frequency band not overlapping with the second satellite communication intermediate frequency signal, mixing this with the satellite broadcasting intermediate frequency signal and the second satellite broadcasting intermediate frequency signal, And a block converter for outputting to the

In this satellite signal transmission system, the second satellite communication intermediate frequency signal is so-called pass-through without being frequency-converted by the block converter. Therefore, the only frequency conversion means used is the frequency conversion means for the first satellite communication intermediate frequency signal.

[0010] The satellite signal transmission system may include a satellite broadcast receiving antenna and a satellite communication receiving antenna.

Further, the block converter includes a first frequency conversion means for frequency-converting the first satellite communication intermediate frequency signal into a third satellite communication intermediate frequency signal lower than the satellite broadcasting intermediate frequency signal, and a third satellite communication. An intermediate frequency signal between the upper limit frequency of the satellite broadcast intermediate frequency signal and the transmission upper limit frequency of the transmission path, and a fourth satellite communication intermediate frequency in a frequency band not overlapping with the second satellite communication intermediate frequency signal; Second frequency conversion means for converting the frequency into a signal. In this case, the local oscillation frequencies of the first and second frequency converters are selected so as not to overlap with the frequencies of the satellite broadcast intermediate frequency signal and the second and fourth satellite communication intermediate frequency signals.

With this configuration, it is possible to prevent the generation of spurious.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A satellite signal transmission system according to a first embodiment of the present invention has a satellite communication receiving antenna 2 as shown in FIG. This satellite communication receiving antenna 2 transmits, for example, 12.493G transmitted from a communication satellite.
Hz to 12.733 GHz vertically polarized radio waves and 1
Receiving the horizontally polarized radio waves of 2.508 GHz to 12.748 GHz, respectively.

The received vertically polarized radio wave is transmitted to a vertically polarized wave receiving converter 4 attached to the satellite communication receiving antenna 2.
V, the first satellite communication intermediate frequency signal, for example, 16
The frequency is converted to a vertically polarized satellite communication intermediate frequency signal CS-IF1 (V) of 40 MHz to 1880 MHz. Similarly, the horizontally polarized radio wave received by the satellite communication receiving antenna 2 is converted by a horizontal polarized wave receiving converter 4H attached to the satellite communication receiving antenna 2 into a second satellite communication intermediate frequency signal, for example, 1650 MHz to 1650 MHz. 1895MH
z-polarized satellite communication intermediate frequency signal CS-IF2 (H)
Is frequency-converted. In order to perform the frequency conversion as described above, the vertical polarization reception converter 4V and the horizontal polarization reception converter 4H use a local oscillation signal of 10.853 GHz.

This satellite signal transmission system also has a satellite broadcast receiving antenna 6. The satellite broadcast receiving antenna 6 transmits, for example, 11.713 GHz transmitted from a broadcast satellite.
receiving radio waves of satellite broadcasts from z to 12.13 GHz;
The satellite broadcast receiving converter 8 attached to the satellite broadcast receiving antenna 6 uses 1035 MHz to 1335 MHz.
z is converted to a satellite broadcast intermediate frequency signal BS-IF. The satellite broadcast receiving converter 8 uses a local oscillation signal of 10.678 GHz for frequency conversion as described above. This satellite broadcast intermediate frequency signal BS-IF
The signal is amplified by a satellite broadcast intermediate frequency signal amplifier 10 and supplied to a mixer 12.

The satellite signal transmission system has a VHF receiving antenna 14 and a UHF receiving antenna 16 for receiving a VHF television broadcast signal and a UHF receiving signal respectively.
The HF television broadcast signal (hereinafter referred to as a terrestrial signal) has a frequency band of, for example, 76 MHz to 770 MHz, and is amplified by the UHF and VHF amplifier 18 and supplied to the mixer 12. This mixer 1
Reference numeral 2 denotes a broadband signal capable of mixing a satellite broadcast intermediate frequency signal BS-IF signal and a terrestrial signal.

Vertically polarized satellite communication intermediate frequency signal CS-IF
1 (V), horizontally polarized satellite communication intermediate frequency signal CS-IF2
(H), the satellite broadcast intermediate frequency signal BS-IF and the terrestrial signal are supplied to the block converter 20. As shown in FIG. 3E, the block converter 20 maintains the frequency bands of the terrestrial signal, the satellite broadcast signal BS-IF, and the horizontally polarized satellite communication intermediate frequency signal CS-IF2 (H) as they are, It is supplied to the output terminal. However, the vertically polarized satellite communication intermediate frequency signal CS-IF1 (V) is composed of the satellite broadcasting intermediate frequency signal BS-IF and the horizontally polarized satellite communication intermediate frequency signal C-IF1 (V).
1385 MHz to 1625 between S-IF2 (H)
To a terminal via a transmission path, for example, a coaxial cable, along with a terrestrial signal, a satellite broadcast signal BS-IF, and a horizontally polarized satellite communication intermediate frequency signal CS-IF2 (H). Transmitted. This coaxial cable is connected to a horizontally polarized satellite communication intermediate frequency signal CS-IF2.
The frequency slightly higher than the upper limit frequency of (H) is the highest transmittable frequency.

As shown in FIG. 2, the block converter 20 has an input terminal 22 for a vertically polarized satellite communication intermediate frequency signal.
And the vertical polarization satellite communication intermediate frequency signal CS-IF1 (V) supplied to the input terminal 22 is amplified by an amplification stage including an amplifier 24, a gain adjustment circuit 26, and an amplifier 28. The gain control circuit 26 can be constituted by an automatic gain control circuit or a manual gain control circuit.

The vertically polarized satellite communication intermediate frequency signal CS-IF1 (V) from the amplifier 28 is supplied to a first frequency converter 30.
Is supplied to the mixer 32. The mixer 32 has a first
The first local oscillation signal is supplied from the local oscillator 34 of the frequency converter 30 of FIG. The first local oscillation signal is shown in FIG.
The frequency is 2217 MHz as shown in FIG. The mixer 32 subtracts the frequency of the vertically polarized satellite communication intermediate frequency signal CS-IF1 (V) from the frequency of the local oscillation signal to the frequency of the vertically polarized satellite communication intermediate frequency signal CS-IF1 (V).
The frequency of (V) is converted. Accordingly, the third intermediate frequency signal CS-IF3 having a frequency of 337 MHz to 577 MHz is output from the mixer 32 as shown in FIG.
(V) is output.

This third intermediate frequency signal CS-IF3 (V)
Comprises an amplifier 36, a band-pass filter 38 and an amplifier 40
Are amplified by an amplification stage consisting of The band-pass filter 38 has a pass band of 337 MHz to 577 MHz and removes unnecessary frequency components other than the third intermediate frequency signal CS-IF3 (V).

The output of the amplifier 40 is supplied to a mixer 44 of a second frequency converter 42. The mixer 44 receives a signal from the local oscillator 46 of the second frequency
Are supplied. The second local oscillation signal has a frequency of 1962 MHz as shown in FIG. The mixer 44 converts the frequency of the third intermediate frequency signal CS-IF3 (V) into a frequency obtained by subtracting the frequency of the third intermediate frequency signal CS-IF3 (V) from the local oscillation frequency. Therefore, the frequency from the mixer 44 is 138.
5th to 1625 MHz fourth intermediate frequency signal CS−
IF4 (V) is output.

This fourth intermediate frequency signal CS-IF4 (V)
Is amplified by an amplification stage including an amplifier 48 and a band-pass filter 50, and then supplied to a one-way splitter 52.
The band-pass filter 48 has a pass band of 1385 MHz to 1625 MHz, and has a fourth intermediate frequency signal CS-I
This is for removing unnecessary frequency components other than F4 (V).

The band-pass filters 38 and 50 can be removed when unnecessary radiation is small, and the amplifiers 24, 28, 36, 40 and 48 and the gain control circuit 26 can be removed.
May not be necessary in some cases. The high-frequency blocking coil 51, one end of which is connected to the input terminal 22, is for supplying a DC voltage for operation to the satellite communication receiving converter 4V.

On the other hand, the horizontally polarized satellite communication intermediate frequency signal CS
The input terminal 54 for −IF2 (H) receives the horizontal polarization satellite communication intermediate frequency signal CS-IF2 (H). After this is amplified by the amplifier 24a, gain control is performed by a gain control circuit 26a similar to the gain control circuit 26. The horizontally-polarized satellite communication intermediate frequency signal CS-IF2 (H) on which gain control has been performed is amplified by the amplifier 28a, and the horizontally-polarized satellite communication intermediate frequency signal CS by a band-pass filter 38a having a pass band of 1655 MHz to 1895 MHz. Unnecessary frequency components other than -IF2 (H) are removed.

After the output of the band-pass filter 38a is amplified by the amplifier 48a, the cutoff frequency becomes 165.
After unnecessary low frequency components are removed by a high-pass filter 50 a of 5 MHz, the high-pass filter 50 a supplies the single-branch device 52. The high-frequency blocking coil 51a, one end of which is connected to the input terminal 54, is also for supplying a DC voltage for operation to the satellite communication receiving converter 4H.

A terrestrial signal and a satellite broadcast intermediate frequency signal input terminal 56 are supplied with a satellite broadcast intermediate frequency signal BS-IF and a terrestrial signal, which have cutoff frequencies of 1335.
After being supplied to the low-pass filter 50b of which frequency is higher than the upper limit frequency 1335MHz of the satellite broadcast intermediate frequency signal, unnecessary frequency components are removed.
Supplied to The high-frequency blocking coil 51b, one end of which is connected to the input terminal 56, is for supplying an operating DC voltage to the amplifier 10, the satellite broadcast receiving converter 8, and the amplifier 18. Note that amplification may be provided between the input terminal 56 and the low-pass filter 50b.

The output terminal of the one branch unit 52 is connected to the output terminal 58 of the block converter 20, and the branch terminal of the one branch unit 52 is connected to the monitor terminal 60. From the output terminal 58 and the monitor terminal 60, as shown in FIG. 3 (e), a terrestrial signal, a satellite broadcast intermediate frequency signal BS-IF,
The fourth satellite communication intermediate frequency signal CS-IF4 (V) and the second satellite communication intermediate frequency signal CS-IF2 (H) are output without overlapping frequency bands.

The block converter 20 performs a two-stage frequency conversion when converting the first satellite communication intermediate frequency signal CS-IF1 (V) into the fourth satellite communication intermediate frequency signal CS-IF4 (V). . For example, if the local oscillation frequency is 255 MHz, the first satellite communication intermediate frequency signal CS-IF1
(V) is the fourth satellite communication intermediate frequency signal CS-IF4 (V)
Can be frequency-converted. In that case, the local oscillation signal must be set to a frequency within the frequency band of the terrestrial signal, a filter must be provided so that the 255 MHz local oscillation signal does not cause unnecessary radiation, and its characteristics Must be steep, and care must be taken in its production.

On the other hand, in this block converter 20,
The frequency conversion is performed in two stages, and the frequency conversion also employs a method of frequency conversion to a value obtained by subtracting the frequency of the input signal from the local oscillation frequency. 1962 MHz and 22 higher than the upper limit frequency 1895 MHz transmitted by
It is 17 MH, and does not affect any of the signals transmitted by this transmission system due to spurious. Further, even if the third harmonic is generated from the local oscillation signal, it does not affect any of the signals transmitted by the transmission system.

The satellite communication receiving converters 4V, 4V
H. The frequency of the local oscillation signal at 10.853 GHz
Therefore, the frequency of the horizontally polarized satellite broadcasting intermediate frequency signal CS-IF2 (H), which is the second satellite communication intermediate frequency signal, is set to 1655 MHz to 1895 MHz, which does not require any frequency conversion.

The satellite signal transmission system according to the second embodiment of the present invention has the same configuration as that of the satellite signal transmission system shown in FIGS.
The frequencies of the local oscillation signals of V and 4H and the local oscillation signals of the local oscillators 34 and 46 of the block converter 20 are different from those of the above-mentioned satellite signal transmission system.

That is, the satellite communication receiving converters 4V, 4V
The local oscillation signal of H is selected at 11.108 GHz. Therefore, as shown in FIG. 4A, the vertically polarized satellite communication intermediate frequency signal CS-IF1 (V) is 1385 MHz.
The horizontal polarization satellite communication intermediate frequency signal CS-IF2 (H) has a frequency band of 1400 MHz to 1
It has a frequency band of 640 MHz.

The frequency conversion in the block converter 20 is performed by the vertical polarization satellite communication intermediate frequency signal C.
The horizontal polarization satellite communication intermediate frequency signal CS-IF2 (H) is supplied to the input terminal 22 in FIG. 2 instead of the S-IF1 (V). The oscillation frequency of the local oscillator 34 of the first frequency converter 32 is, as shown in FIG.
77 MHz, whereby the horizontal polarization satellite communication intermediate frequency signal CS-IF2 (H) as shown in FIG.
Is frequency-converted to a third intermediate frequency signal CS-IF3 (H) of 337 MHz to 577 MHz. Since the oscillation frequency of the local oscillator 46 of the second frequency converter 42 is selected to be 2232 MHz as shown in FIG. 4D, the third intermediate frequency signal CS-IF3 (H) is
As shown in (e), 1655 MHz to 1895 MH
The frequency is converted to the fourth intermediate frequency signal CS-IF4 (H) of z. In this case, a high-pass filter is used instead of the band-pass filter 50 of the first embodiment, and its cutoff frequency is 1655 MHz.

The input terminal 54 of the block converter 20 is connected to the horizontally polarized satellite communication intermediate frequency signal CS-IF2.
(H), not the vertically polarized satellite communication intermediate frequency signal CS-
IF1 (V) is input. In this case, the band-pass filter 38a has a pass band of 1385 MHz to 1625 MHz, and a band-pass filter is used instead of the high-pass filter 50a of the first embodiment, and the pass band is 1385 MHz to 1625 MHz. 1625 MHz.

As shown in FIG. 4E, the vertical polarization satellite communication intermediate frequency signal CS-IF2 (H) is frequency-converted from 1655 MHz to 1895 MHz, and the horizontal polarization satellite communication intermediate frequency signal CS-IF1 (V) is converted. Output at the same frequency. As a result, there is no overlap in the frequency bands of the terrestrial signal, the satellite broadcast intermediate frequency signal, the first intermediate frequency signal CS-IF1 (V), and the fourth intermediate frequency signal CS-IF4 (H). Moreover, the frequencies of the two local oscillation signals from the local oscillators 34 and 46 in the block converter 20 are also higher than the highest frequency in this satellite signal transmission system. Also, the vertical polarization satellite communication intermediate frequency signal CS-IF1 (V) may not be frequency converted,
This is because the local oscillation signals of the satellite communication receiving converters 4V and 4H are selected to be 11.108 GHz.

The satellite signal transmission system according to the third embodiment of the present invention has the same configuration as the satellite signal transmission system shown in FIGS. However, the frequencies of the local oscillation signals of the satellite communication reception converters 4V and 4H and the local oscillation signals of the local oscillators 34 and 46 of the block converter 20 are different.

That is, the satellite communication receiving converters 4V, 4V
The H local oscillation signal is selected to be 10.678 GHz, which is the same as the local oscillator of the satellite broadcast receiving converter 8.
Therefore, as shown in FIG. 5A, the vertically polarized satellite communication intermediate frequency signal CS-IF1 (V) has a frequency band of 1815 MHz to 2055 MHz, and the horizontally polarized satellite communication intermediate frequency signal CS-IF2 (H). ) Has a frequency band from 1830 MHz to 2070 MHz.

Also, the frequency converted by the block converter 20 is the vertically polarized satellite communication intermediate frequency signal CS-IF1 (V), as in the first embodiment.
This is supplied to the input terminal 22 of FIG. The oscillation frequency of the local oscillator 34 of the first frequency converter 30 is shown in FIG.
As shown in FIG. 5B, the frequency is 2392 MHz, and as shown in FIG. 5C, the vertically polarized satellite communication intermediate frequency signal CS-IF1 (V) is 337 MHz to 577 MHz.
The frequency is converted to a third intermediate frequency signal CS-IF3 (V) of MHz. The oscillation frequency of the local oscillator 46 of the second frequency converter 42 is 213 as shown in FIG.
7 MHz, the third intermediate frequency signal CS
−IF3 (V) is 1560, as shown in FIG.
MHz to 1800 MHz fourth intermediate frequency signal CS-I
The frequency is converted to F4 (V). In this case, the band pass filter 50 has a pass band of 1560 MHz to 1800 MHz.

An input terminal 54 of the block converter 20 is connected to the horizontal polarization satellite communication intermediate frequency signal CS-IF2.
(H) is input. In this case, the band-pass filter 38
a has a pass band of 1830 MHz to 2070 MHz, and the high-pass filter 50a has a cut-off frequency of 1830 MHz.

In this configuration, as shown in FIG. 5 (e), the vertically polarized satellite communication intermediate frequency signal CS-IF1 (V) is frequency-converted, and the horizontally polarized satellite communication intermediate frequency signal CS-IF is converted.
2 (H) is output at the same frequency. as a result,
The frequency bands of the signals generated at the output terminal 58 do not overlap. Moreover, the frequencies of the two local oscillation signals are also higher than the highest frequency in this satellite signal transmission system. Also, the horizontally polarized satellite communication intermediate frequency signal CS-IF2
The reason why the frequency conversion of (H) may not be performed is that the local oscillation signals of the satellite communication reception converters 4V and 4H are converted to 10.678.
This is because GHz is selected. Further, an oscillator having the same configuration as the local oscillator of the satellite broadcast receiving converter 8 is
Since it can be used for the satellite communication receiving converters 4V and 4H, the manufacture is easy.

The satellite signal transmission system according to the fourth embodiment of the present invention has the same configuration as the satellite signal transmission system shown in FIGS.
The frequencies of the local oscillation signals of V and 4H and the local oscillation signals of the local oscillators 34 and 46 of the block converter 20 are different.

That is, the satellite communication receiving converters 4V, 4V
As in the third embodiment, the local oscillation signal of H is the same as the local oscillator of the satellite broadcast reception converter 8, which is 10.67.
8 GHz is selected. Therefore, as shown in FIG. 6A, the vertically polarized satellite communication intermediate frequency signal CS-IF1
(V) has a frequency band of 1815 MHz to 2055 MHz, and has a horizontally polarized satellite communication intermediate frequency signal CS-IF2.
(H) has a frequency band of 1830 MHz to 2070 MHz.

As in the second embodiment, the frequency conversion by the block converter 20 is not the vertical polarization satellite communication intermediate frequency signal CS-IF1 (V), but the horizontal polarization satellite communication intermediate frequency signal CS-IF1 (V). −IF2 (H).
This is supplied to the input terminal 22 of FIG. The oscillation frequency of the local oscillator 34 of the first frequency converter 30 is as shown in FIG.
As shown in FIG. 6B, the frequency is 2407 MHz, whereby the horizontal polarization satellite communication intermediate frequency signal CS-IF2 (H) is 337 MHz to 577 MHz as shown in FIG.
The frequency is converted to a third intermediate frequency signal CS-IF3 (H) of MHz. The oscillation frequency of the local oscillator 46 of the second frequency converter 42 is set to 212 as shown in FIG.
2 MHz, the third intermediate frequency signal CS
−IF3 (H) is 1545 as shown in FIG.
MHz to 1785 MHz fourth intermediate frequency signal CS-I
The frequency is converted to F4 (H). In this case, the pass band of the band-pass filter 50 ranges from 1545 MHz to 1785.
MHz.

The input terminal 54 of the block converter 20 is connected to the horizontal polarization satellite communication intermediate frequency signal CS-IF2.
(H), not the vertically polarized satellite communication intermediate frequency signal CS-
IF1 (V) is input. In this case, the band-pass filter 38a has a pass band of 1815 MHz to 2055 MHz, and the high-pass filter 50a has a cut-off frequency of 1815 MHz.

In this configuration, as shown in FIG.
The vertical polarization satellite communication intermediate frequency signal CS-IF2 (H) is frequency-converted, and the horizontal polarization satellite communication intermediate frequency signal CS-I is converted.
F1 (V) is output at the same frequency. As a result, there is no overlap in the frequency bands of any of the signals. Moreover,
The frequencies of the two local oscillation signals are also higher than the highest frequency in this satellite signal transmission system. The reason why the vertical polarization satellite communication intermediate frequency signal CS-IF1 (V) may not be frequency-converted is that the local oscillation signals of the satellite communication receiving converters 4V and 4H are selected to be 10.678 GHz. Since the same oscillation circuit as the local oscillator of the satellite broadcast receiving converter 8 may be used for the satellite communication receiving converters 4V and 4H, manufacture is easy.

As shown in FIG. 7, a satellite signal transmission system according to a fifth embodiment of the present invention comprises a satellite communication receiving antenna 2, vertically and horizontally polarized satellite communication receiving converters 4V, 4H, and a satellite. Broadcast receiving antenna 6, satellite broadcast receiving converter 8, mixer 12, VHF receiving antenna 1
4. It has a UHF receiving antenna 16, a UHF and a VHF amplifier 18. These are the same as those used in the first embodiment.

Converter 4V for receiving vertically polarized satellite communications
Generates a first satellite communication intermediate frequency signal, for example, a vertically polarized satellite communication intermediate frequency signal CS-IF1 (V), and the horizontally polarized satellite communication receiving converter 4H outputs a second satellite communication intermediate frequency signal, For example, horizontally polarized satellite communication intermediate frequency signal CS
-Generate IF2 (H) and convert it to satellite broadcast receiving converter 8
Generates a satellite broadcast intermediate frequency signal BS-IF. VH
The F receiving antenna 14 and the UHF receiving antenna 16 generate a terrestrial signal. These are mixed by the mixer 62 and output via a transmission path, for example, a coaxial cable.

Vertically polarized satellite communication receiving converter 4V
Selects the frequency of the local oscillation signal to be 11.108 GHz, and converts the input vertical-polarized satellite communication signal of 12.493 GHz to 12.733 GHz to 1385 MHz.
To 1625 MHz vertically polarized satellite communication intermediate frequency signal C
The frequency is converted to S-IF1 (V). The horizontally polarized satellite communication receiving converter 4H selects the local oscillation signal frequency of 10.853 GHz, and outputs the horizontally polarized wave of 12.50.
8 GHz to 12.748 GHz satellite communication signal
The frequency is converted to a horizontally polarized satellite communication intermediate frequency signal CS-IF2 (H) of 655 MHz to 1895 MHz.

As described above, the vertically polarized satellite communication signal and the horizontally polarized satellite communication signal whose frequencies partially overlap each other are:
Vertically polarized satellite communication intermediate frequency signal CS without frequency overlap
-IF1 (V), horizontal polarization satellite communication intermediate frequency signal CS-
The frequency has been converted to IF2 (H). This is because the frequencies of the local oscillation signals of the vertically polarized satellite communication receiving converter 4V and the horizontally polarized satellite communication receiving converter 4H are different from each other.

The frequency of the satellite broadcast intermediate frequency signal BS-IF is set to 1035 MHz, as in the first embodiment.
z to 1335 MHz, and the local oscillation frequency of the satellite broadcast receiving converter 8 is also selected to be 10.678 GHz. The satellite broadcast intermediate frequency signal BS-IF and the terrestrial signal are mixed by the mixer 12.

These vertically polarized satellite communication intermediate frequency signals CS
-IF1 (V), horizontal polarization satellite communication intermediate frequency signal CS-
The IF2 (H) and the mixed output signal of the mixer 12 are supplied to the mixer 62.

As shown in FIG. 8, the mixer 62 has an input terminal 64 to which a horizontally polarized satellite communication intermediate frequency signal CS-IF2 (H) is input. Polarization satellite communication intermediate frequency signal CS-IF2 (H)
Is connected to a high-pass filter 66 set near the lowest frequency of 1655 MHz. Further, an input terminal 68 for inputting the vertically polarized satellite communication intermediate frequency signal CS-IF1 (V) is provided, and the input terminal 68 has a pass band having a frequency band 138 of the vertically polarized satellite communication intermediate frequency signal.
Bandpass filter 7 of 5 MHz to 1625 MHz
Connected to 0. Further, an input terminal 72 to which a mixed output signal from the mixer 12 is supplied is provided. The input terminal 72 is connected to a low-pass filter whose cut-off frequency is set near 1335 MHz which is the highest frequency of the mixed output signal. 74. The output side of each of these filters is connected to an output terminal 76, to which a transmission path such as a coaxial cable is connected.

With such a configuration, a terrestrial signal,
The satellite broadcasting intermediate frequency signal BS-IF, the vertically polarized satellite communication intermediate frequency signal CS-IF1 (V), and the horizontally polarized satellite communication intermediate frequency signal CS-IF2 (H) have no frequency duplication, and no block converter is required. It is. Since no block converter is provided, there is almost no spurious problem.

The frequencies of the local oscillation signals of the vertically and horizontally polarized satellite communication receiving converters 4V and 4H are not limited to those described above. When the frequency band of the satellite broadcast signal is changed, the satellite broadcast intermediate frequency signal BS-IF, vertically polarized wave, horizontally polarized satellite communication intermediate frequency signal CS-IF1 (V), CS is appropriately changed according to the change. -The frequency of IF2 (H) is changed so as to be non-overlapping.

In FIG. 7, DC power is supplied from the output side of the mixer 62, and the converter 4V for receiving vertically polarized satellite communications, the converter 4H for receiving horizontally polarized satellite communications, the converter 8 for receiving satellite broadcasting, and UHF and VHF amplifier 1
8 and the like can be supplied with operating power. In this case, an energizing circuit is provided between each of the input terminals 64, 68, 72 and the output terminal 76. The input terminals 64, 6
An energizing switch may be provided in the mixer 62 so that only a desired one of the power supplies 8 and 72 can output a DC power. Although the DC power is supplied to each input terminal from the output side, a power supply may be provided in the mixer 62, and the DC power may be output from this power supply to each input terminal. Although the mixer 12 is provided, the mixer 12 may be omitted, and the satellite broadcast intermediate frequency signal BS-IF and the terrestrial signal from the amplifier 18 may be directly input to the mixer 62. In this case, the satellite broadcast intermediate frequency signal BS-I is provided in the mixer 62.
What is necessary is just to provide a mixer of F and a terrestrial signal. Alternatively, the satellite broadcast intermediate frequency signal BS-IF, the UHF television broadcast signal, and the VHF television broadcast signal may be input to the mixer 62, respectively. In this case, a mixer for mixing these signals may be provided in the mixer 62. Further, an amplifier for amplifying each signal input into the mixer 62 may be provided.

[0056]

As described above, in the satellite signal transmission system according to the present invention, the number of frequency converters can be reduced, so that the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram of a satellite signal transmission system according to a first embodiment of the present invention.

FIG. 2 is a block diagram of a block converter used in the satellite signal transmission system of FIG.

FIG. 3 is a diagram showing a frequency relationship of each signal used in the satellite signal transmission system of FIG. 1;

FIG. 4 is a diagram illustrating a frequency relationship of each signal used in the satellite signal transmission system according to the second embodiment of the present invention.

FIG. 5 is a diagram showing a frequency relationship of each signal used in the satellite signal transmission system according to the third embodiment of the present invention.

FIG. 6 is a diagram illustrating a frequency relationship of signals used in a satellite signal transmission system according to a fourth embodiment of the present invention.

FIG. 7 is a block diagram of a satellite signal system according to a fifth embodiment of the present invention.

FIG. 8 is a block diagram of a mixer used in the satellite signal transmission system of FIG. 7;

FIG. 9 is a diagram showing a frequency relationship of each signal used in a conventional satellite signal transmission system.

[Explanation of symbols]

 4V 4H Converter for satellite communication reception 8 Converter for satellite broadcast reception 20 Block converter 30 First frequency converter (first frequency conversion means) 42 Second frequency converter (second frequency conversion means)

Claims (3)

[Claims] 1. A satellite broadcast receiving converter for frequency-converting a satellite broadcast signal received by a satellite broadcast receiving antenna into a satellite broadcast intermediate frequency signal, and a horizontally and vertically polarized satellite communication signal received by the satellite communication receiving antenna. , A frequency band partially overlapping and having a frequency band not overlapping with the satellite broadcasting intermediate frequency signal.
And a satellite communication receiving converter for converting the frequency into a second satellite communication intermediate frequency signal; a first and a second satellite communication intermediate frequency signal; The frequency signal is frequency-converted into a satellite communication intermediate frequency signal between the upper limit frequency of the satellite broadcasting intermediate frequency signal and the transmission upper limit frequency of the transmission path and not overlapping the second satellite communication intermediate frequency signal. A block converter that has frequency conversion means and mixes the satellite communication intermediate frequency signal with the satellite broadcasting intermediate frequency signal and the second satellite broadcasting intermediate frequency signal and outputs the mixed signal to the transmission path. . 2. A satellite broadcast receiving antenna, a satellite broadcast receiving converter for frequency-converting a satellite broadcast signal received by the satellite broadcast receiving antenna into a satellite broadcast intermediate frequency signal, a satellite communication receiving antenna, The first and second satellite communication intermediate frequencies having a frequency band partially overlapping the horizontal and vertical polarization satellite communication signals received by the communication receiving antenna and having a frequency band not overlapping with the satellite broadcasting intermediate frequency signal. A satellite communication receiving converter for converting a frequency into a signal; a first and a second satellite communication intermediate frequency signal; and the satellite broadcasting intermediate frequency signal, and converting the first satellite communication intermediate frequency signal into the satellite broadcasting intermediate frequency. Between the upper limit frequency of the signal and the transmission upper limit frequency of the transmission path, and the satellite communication intermediate frequency signal in a frequency band not overlapping with the second satellite communication intermediate frequency signal. A block converter that has frequency conversion means for converting the wave number, and mixes the satellite communication intermediate frequency signal with the satellite broadcast intermediate frequency signal and the second satellite broadcast intermediate frequency signal and outputs the mixed signal to the transmission path. Signal transmission system. 3. The satellite signal transmission system according to claim 1, wherein said frequency conversion means converts the first satellite communication intermediate frequency signal into a third satellite communication intermediate frequency signal lower than the satellite broadcasting intermediate frequency signal. A first frequency converting means for converting the frequency, a third satellite communication intermediate frequency signal between an upper limit frequency of the satellite broadcasting intermediate frequency signal and a transmission upper limit frequency of the transmission path, A second frequency conversion to a fourth satellite communication intermediate frequency signal in a frequency band not overlapping with the signal
Frequency conversion means, wherein the local oscillation frequencies of the first and second frequency conversion means are selected so as not to overlap with the frequencies of the satellite broadcast intermediate frequency signal and the second and fourth satellite communication intermediate frequency signals. Is a satellite signal transmission system.