JP2776063B2 - Satellite receiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a receiver for distribution and broadcasting of television signals by a communication satellite and BS broadcasting.

[0002]

2. Description of the Related Art In recent years, services using a communication satellite (CS) have been expanding. Since both CS broadcasting and BS using a communication satellite (CS) are transmitted using satellites, they are integrated. A receiver that can enjoy both media is conceivable. 12GHz radiated from broadcast satellite
After the radio wave of the band is converged by the parabolic antenna, the frequency is converted to the first intermediate frequency of the 1 GHz band by the low noise converter, and the signal is input to the indoor satellite receiver via the coaxial cable to receive the satellite broadcast. be able to. In a satellite receiver, one of the signals of several channels
After selecting a channel, FM demodulation is performed to obtain a video signal and an audio signal.

Hereinafter, a conventional example will be described with reference to the drawings. FIG. 6 shows an example of a block diagram of a conventional satellite broadcast receiver in which a BS receiver and a CS broadcast receiver are integrated. In FIG. 6, 211 is the first BS.
Input terminal for intermediate frequency signal. 212 is the first of BS
1035.98 which is a lower frequency band than the intermediate frequency band
MHz is attenuated, and the first intermediate frequency band of BS broadcasting is 1035.98 MHz to 1331.5 MHz.
Is a first high-pass filter that allows the signal of FIG. 2
Reference numeral 13 denotes an amplifier circuit for amplifying a signal in the first intermediate frequency band of the BS. Reference numeral 214 denotes an image frequency band component 1835 which is the sum of twice the first intermediate frequency and the second intermediate frequency of the BS.
This is a first image filter for removing the frequency band from MHz to 2131.5 MHz to prevent image interference. A high-frequency switching circuit 215 switches between the first intermediate frequency band of the BS and the first intermediate frequency band of the CS broadcast. 216 is an output terminal. 217 is an input terminal for the first intermediate frequency signal of CS. 218 is the first of CS broadcasting
1309.75 which is a lower frequency band than the intermediate frequency band.
This is a second high-pass filter that attenuates signals of 1 MHz or less and passes signals of 1309.75 MHz to 1548 MHz, which is the first intermediate frequency band of CS broadcasting. 219
Reference numeral 220 denotes an amplifier circuit for amplifying a signal in the first intermediate frequency band of the CS broadcast, and reference numeral 220 denotes an image frequency band component 21 which is the sum of twice the first intermediate frequency and the second intermediate frequency of the CS broadcast.
This is a second image filter that removes 09.75 MHz to 2348 MHz so as not to cause image interference (reference: satellite broadcast receiver, No. 1, published by Target Rated Radio Technology Association).

[0004] The operation of the input circuit of the satellite broadcast receiver configured as described above will be described. To the input terminal 211 of the first intermediate frequency signal of the BS, a 12 GHz band radio wave from a satellite received by an antenna is frequency-converted to a 1 GHz band by a down-converter and guided indoors by a coaxial cable to be applied. The BS stipulates that the local oscillation frequency of the down converter be 10.678 GHz. Therefore, the first intermediate frequency band of the BS is 1035.98.
MHz to 1331.5 MHz. The first high-pass filter 212 attenuates signals of 1050 MHz or less, which is a frequency band lower than the first intermediate frequency band. The BS first intermediate frequency amplifying circuit 213 is a broadband amplifying circuit for improving NF, such as a mixer circuit connected at a subsequent stage. The first image filter 214 has an image frequency band 1850-2348M which is twice the sum of the first intermediate frequency and the second intermediate frequency of the BS in order to prevent image interference.
It plays the role of removing the Hz signal. The first of CS
To the input terminal 217 for the intermediate frequency signal, a 12 GHz band radio wave from a satellite received by an antenna is frequency-converted to a 1 GHz band by a down-converter and guided indoors by a coaxial cable to be applied.

[0005] In CS broadcasting, the local oscillation frequency of the down converter is set to 11.2 GHz.
Therefore, the first intermediate frequency band of CS broadcasting is 1309.75.
MHz to 1548 MHz. The second high-pass filter 218 attenuates a signal of 1309.75 MHz or lower, which is a frequency band lower than the first intermediate frequency band of CS broadcasting. The CS broadcast first intermediate frequency amplifying circuit 219 is a wideband amplifying circuit for improving NF, such as a mixer circuit connected at a subsequent stage. The second image filter 220 converts a signal of an image frequency band 2115.31 MHz to 2353.56 MHz, which is the sum of twice the first intermediate frequency and the second intermediate frequency of the CS broadcast, in order to prevent image interference. Plays a role in removal. High frequency switching circuit 21
5 indicates that the first intermediate frequency band of the BS is 1035.98 MHz.
To 1331.5 MHz, the first intermediate frequency band of CS broadcasting is 1309.75 MHz to 1548 MHz,
Since there is a frequency at which the first intermediate frequency band of the BS and the first intermediate frequency band of the CS broadcast overlap, it plays a role of switching between the BS and the CS broadcast.

[0006]

As described above, the image frequency band of the CS broadcast and the image frequency band of the BS are adjacent to each other, and a satellite broadcast receiver in which each image filter is simplified can be considered.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to simplify each image filter for CS broadcast and BS in a satellite broadcast receiver.

[0008]

In order to solve the above-mentioned problems, a satellite broadcast receiver according to the present invention attenuates a signal of 1309.75 MHz or less which is a frequency band lower than the first intermediate frequency band of CS broadcasting, A first high-pass filter that passes without attenuating a signal of 1309.75 to 1548 MHz, which is a first intermediate frequency band of CS broadcasting, and an output signal of the first high-pass filter are input, and a first intermediate frequency of CS broadcasting is input. A first amplifier circuit for amplifying a signal of 1309.75 to 1548 MHz, which is a band, and an output signal of the first amplifier circuit, and a first intermediate frequency band of BS and a first intermediate frequency band of CS broadcasting are transmitted. A high-frequency switching circuit for switching, and an output signal of the high-frequency switching circuit, and an image frequency component that is a sum of twice the first intermediate frequency and the second intermediate frequency of the CS broadcast 115.31MHz~2353.5
A first image filter for removing the 6 MHz frequency band to prevent image interference, and 1035.9 which is a lower frequency band than the first intermediate frequency band of the BS.
A second high-pass filter that attenuates a signal of 8 MHz or less and passes a signal of 1035.98 MHz to 1331.5 MHz, which is the first intermediate frequency band of the BS, and an output signal of the second high-pass filter, and receives a first signal of the BS. A second amplifier circuit for amplifying the signal of the intermediate frequency band, and an output signal of the second amplifier circuit are input, and an image frequency component 1851.18 which is the sum of twice the first intermediate frequency and the second intermediate frequency of the BS.
Of the 54 MHz to 2137.06 MHz, a second image filter connected to a high frequency switching circuit for removing a frequency band that cannot be completely removed by the first image filter and preventing image interference is provided. Features.

[0009]

According to the present invention, the image filter for removing the image frequency component of the BS and the image filter for removing the image frequency component of the CS broadcast can also remove the high frequency band of the image frequency band of the BS by the above configuration. The configuration can be simplified, and the image filter in the satellite broadcast receiver can be simplified.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram of a satellite broadcast receiver according to one embodiment of the present invention. In FIG. 1, 1
Is an input terminal of the first intermediate frequency signal of the BS. 46 is C
S is an input terminal for the first intermediate frequency signal. 87 is an output terminal. 3, 4, 6, 7, 15, 16, 17, 18,
9, 20, 30, 31, 209, 210, 38, 48,
49, 51, 54, 52, 55, 56, 62, 63, 9
5,65,66,72,76,79,81,83,8
5,86 are chip capacitors. 2,5,12,
19, 25, 26, 32, 34, 36, 47, 50, 5
3, 59, 67, 70, 80, 82, 84 are microstrip lines. 8, 10, 13, 14, 21,
22, 23, 24, 28, 29, 39, 43, 57, 6
0,61,96,97,68,64,71,73,75
Is a chip resistor. 44 is a power supply terminal 1. 45 is a power supply terminal 2. Reference numerals 11, 24, 58 and 69 are high-frequency transistors. 40, 41, 42, 74, 77, 7
8 is a PIN diode.

Reference numeral 88 denotes a second high-pass filter that attenuates a signal lower than the first intermediate frequency band of the BS and passes the first intermediate frequency band of the BS broadcast. Reference numeral 89 denotes a second amplifier circuit for amplifying the first intermediate frequency band of the BS. 90
Is 1841.54 MHz of the image frequency component which is the sum of twice the first intermediate frequency and the second intermediate frequency of the BS.
This is a second image filter for removing a frequency band of 2000 MHz and preventing image interference. A high-frequency switching circuit 91 switches between the first intermediate frequency band of the BS and the first intermediate frequency band of the CS broadcast.
94 is the first intermediate frequency and the second intermediate frequency of the CS broadcast.
This is a first image filter for removing image frequency components that are double sums and preventing image interference. Reference numeral 92 denotes a first high-pass filter that attenuates a frequency band lower than the first intermediate frequency band of the CS broadcast and passes the first intermediate frequency band of the CS broadcast. 93 is a first amplifying circuit for amplifying the first intermediate frequency band of the CS broadcast.

FIG. 2 attenuates a signal of 1309.75 MHz or less, which is a lower frequency band than the first intermediate frequency band of the CS broadcast, and 130 attenuates the first intermediate frequency band of the CS broadcast.
9 shows frequency characteristics of a first high-pass filter that passes a signal of 9.75 to 1548 MHz without being attenuated.

FIG. 3 shows 18 of the image frequency components which are the sum of twice the first intermediate frequency and the second intermediate frequency of the BS.
It shows the frequency characteristic of the second image filter for removing the frequency band of 41.54 MHz to 2000 MHz and preventing image interference.

FIG. 4 shows a frequency of a first image filter for removing an image frequency band which is twice the sum of the first intermediate frequency and the second intermediate frequency of the CS broadcast and preventing image interference. It shows the characteristics.

FIG. 5 attenuates a signal of 1035.98 MHz or less, which is a lower frequency band than the first intermediate frequency band of the BS, and obtains 1035.98 which is the first intermediate frequency band of the BS.
9 shows frequency characteristics of a second high-pass filter that passes a signal of MHz to 1331.5 MHz without attenuating the signal.

The operation of the satellite broadcasting receiver configured as described above will be described below.

The input terminal 1 of the first intermediate frequency signal of the BS is used to convert the frequency of a 12-GHz band radio wave from a satellite received by an antenna into a 1-GHz band by a down-converter, and is guided indoors by a coaxial cable. A first intermediate frequency signal of a BS broadcast is applied. The signal input to the input terminal 1 of the first intermediate frequency signal of the BS attenuates a signal lower than the first intermediate frequency band of the BS shown in FIG. 5 by about 30 dB,
The signal is input to a second high-pass filter 88 that allows the first intermediate frequency band of the BS to pass therethrough.
The signal is amplified by an amplifier circuit 89 for amplifying 5 dB, and FIG.
1841.54M of the image frequency components which are the sum of twice the first intermediate frequency and the second intermediate frequency of the BS shown in FIG.
The frequency band of Hz to 2000 MHz is input to a second image filter 90 for attenuating the frequency band of about 50 dB to prevent image interference, and the first intermediate frequency band of BS and the first intermediate frequency band of CS broadcasting are separated. In order to attenuate the image frequency band which is twice the sum of the first intermediate frequency and the second intermediate frequency of the CS broadcast shown in FIG. Is input to the first image filter 94 and transmitted to the output terminal 87.

An input terminal 46 for the first intermediate frequency signal of the CS broadcast is connected to a 12 GHz signal from a satellite received by an antenna.
The band radio wave is converted into a frequency of 1 GHz by a down-converter, and a first intermediate frequency signal of CS broadcasting guided indoors by a coaxial cable is applied. C from input satellite
The S broadcast signal is input to the first high-pass filter 92 that attenuates a frequency band lower than the first intermediate frequency band of the CS broadcast shown in FIG. 2 by about 30 dB and passes the first intermediate frequency band of the CS broadcast, The first intermediate frequency band of CS broadcasting is about 1
Amplified by an amplification circuit 93 for amplifying 5 dB
The first intermediate frequency band of the BS and the first intermediate frequency band of the CS broadcast are input signals through the high frequency switching circuit 91 for switching between the first intermediate frequency band of the CS broadcast and the first intermediate frequency band of the CS broadcast, and are shown in FIG. The image frequency band, which is twice the sum of the first intermediate frequency and the second intermediate frequency of the CS broadcast, is removed, input to an image filter 94 for preventing image interference, and transmitted to an output terminal 87. .

As described above, the image filter for reducing the image frequency components of the CS broadcast and the BS is provided with an image frequency band component of 1835 MHz to 2000 MHz in the image frequency band component which is twice the sum of the first intermediate frequency and the second intermediate frequency of the BS. The frequency band is removed by the second image filter 90, and the first image filter 94 removes the second of the image frequency components that are twice the sum of the first intermediate frequency and the second intermediate frequency of the BS and CS broadcasts. It is possible to remove the frequency band that cannot be completely removed by the image filter 90,
The image filter can have a simple configuration, and the image filter can be simplified in the satellite broadcast receiver.

[0020]

As described above, according to the present invention, it is possible to simplify an image filter in a satellite broadcast receiver.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a satellite broadcast receiver according to an embodiment of the present invention.

FIG. 2 attenuates a signal of 1309.75 MHz or lower, which is a frequency band lower than a first intermediate frequency band of CS broadcasting,
1309.75-1, which is the first intermediate frequency band of CS broadcasting
Frequency characteristic diagram of a first high-pass filter that passes a 548 MHz signal without attenuating

FIG. 3 shows 1841.54M of an image frequency component that is twice the sum of a first intermediate frequency and a second intermediate frequency of a BS.
Frequency characteristic diagram of a second image filter for removing a frequency band of Hz to 2000 MHz and preventing image disturbance.

FIG. 4 is a frequency characteristic diagram of a first image filter for removing an image frequency band that is twice the sum of a first intermediate frequency and a second intermediate frequency of a CS broadcast to prevent image interference;

FIG. 5 attenuates signals below 1035.98 MHz, which is a frequency band lower than the first intermediate frequency band of the BS,
1035.98 MHz to 13 which is the first intermediate frequency band
Frequency characteristic diagram of a second high-pass filter that passes a 31.5 MHz signal without attenuating it

FIG. 6 is a block diagram of a satellite broadcast receiver in a conventional example.

[Explanation of symbols]

1 BS first intermediate frequency signal input terminal 46 CS broadcast first intermediate frequency signal input terminal 87 output terminal 3,4,6,7,9,15,16,17,18,20,
30, 31, 209, 210, 38, 48, 49, 5
1,54,52,55,56,62,63,95,6
5,66,72,76,79,81,83,85,86
Chip capacitors 2,5,12,19,25,26,32,34,36,
47, 50, 53, 59, 67, 70, 80, 82, 8
4 Microstrip line 8, 10, 13, 14, 21, 22, 23, 24, 2
8, 29, 39, 43, 57, 60, 61, 96, 9
7, 68, 64, 71, 73, 75 chip resistor 44 power supply terminal 1 45 power supply terminal 2 11, 24, 58, 69 high-frequency transistor 40, 41, 42, 74, 77, 78 PIN diode 88 First intermediate frequency of BS A second high-pass filter that attenuates signals lower than the band and passes the first intermediate frequency band of the BS 89 A second amplifier circuit that amplifies the first intermediate frequency band of the BS 90 The first intermediate frequency of the BS and the second intermediate frequency Intermediate frequency 2
1841.54 of the image frequency components that are the sum of doubles
A second image filter 91 for removing a frequency band from MHz to 2000 MHz and preventing image interference from occurring. A high frequency switching circuit 94 CS for switching between the first intermediate frequency band of the BS and the first intermediate frequency band of the CS broadcast. A first image filter for removing an image frequency band which is twice the sum of the first intermediate frequency and the second intermediate frequency of the broadcast to prevent image interference; A first high-pass filter that attenuates the lower intermediate frequency band and passes the first intermediate frequency band of the CS broadcast 93 a first amplifier circuit 211 that amplifies the first intermediate frequency band of the CS broadcast 211 The first intermediate frequency signal of the BS The input terminal 212 attenuates a signal of 1035.98 MHz or less, which is a frequency band lower than the first intermediate frequency band of the BS,
1035.98 MHz-1 which is the first intermediate frequency band of S
A first high-pass filter 213 that allows a signal of 331.5 MHz to pass therethrough A first amplifier circuit 214 that amplifies a signal in the first intermediate frequency band of the BS 214 The first amplifier frequency 214 and the second intermediate frequency 2 of the BS
1835MH which is the image frequency band component which is the sum of doubles
A first image filter 215 for removing z to 2131.5 MHz and preventing image interference from occurring High-frequency switching circuit 216 for switching between the first intermediate frequency band of BS and the first intermediate frequency band of CS broadcasting 216 Output terminal 217 Input terminal of first intermediate frequency signal of CS broadcast 218 Attenuates a signal of 1309.75 MHz or lower which is a lower frequency band than the first intermediate frequency band of CS broadcast, and 1309.1 is the first intermediate frequency band of CS broadcast. 75
A second high-pass filter that passes a signal of 1 MHz to 1548 MHz 219 A second amplifier circuit that amplifies a signal of the first intermediate frequency band of the CS broadcast 220 The sum of twice the first intermediate frequency and the second intermediate frequency of the CS broadcast 210 which is an image frequency band component
Second image filter for removing 9.75 MHz to 2348 MHz and preventing image interference

Claims (2)

(57) [Claims] 1. A signal having a frequency lower than 1309.75 MHz, which is a lower frequency band than the first intermediate frequency band of CS broadcasting, is attenuated, and 1309.75 of a first intermediate frequency band of CS broadcasting is attenuated.
A first high-pass filter that allows a signal of 〜1548 MHz to pass therethrough without attenuation, and an output signal of the first high-pass filter are input to amplify a signal of 1309.75 to 1548 MHz, which is a first intermediate frequency band of CS broadcasting. A first amplifier circuit, a high-frequency switching circuit that receives an output signal of the first amplifier circuit, and switches between a first intermediate frequency band of BS and a first intermediate frequency band of CS broadcasting, and an output signal of the high-frequency switching circuit. 215.31 MHz to 2353.56 MHz, which are image frequency components that are input and are the sum of twice the first intermediate frequency and the second intermediate frequency of the CS broadcast
, And a first image filter for eliminating image interference, and a frequency band of 1035.98 MHz lower than the first intermediate frequency band of the BS.
The following signals are attenuated, and a second high-pass filter that passes 1035.98 MHz to 1331.5 MHz, which is the first intermediate frequency band of the BS, and an output signal of the second high-pass filter are input, and the first intermediate signal of the BS is input. A second amplifying circuit for amplifying a signal in a frequency band, and an output signal of the second amplifying circuit are input, and an image frequency component 1851 which is a sum of twice the first intermediate frequency and the second intermediate frequency of the BS. .5
A second image filter connected to a high-frequency switching circuit for removing a frequency band that cannot be completely removed by the first image filter from 4 MHz to 2137.06 MHz and preventing image interference; Characteristic satellite broadcasting receiver. 2. A first series resonance device comprising: a first image filter, a first microstrip line connected to one terminal of a first capacitor, and the other terminal of the first capacitor grounded. Circuit, a second series resonance circuit having a configuration equivalent to the first series resonance circuit, and a third series resonance circuit having a configuration equivalent to the first series resonance circuit,
A second microstrip line connecting the first and second series resonance circuits to each other, and a connection between the second microstrip line and the first series resonance circuit connecting the first and second series resonance circuits to each other A third microstrip line connected to a point, a fourth microstrip line connecting the second and third series resonance circuits to each other, and a fourth microstrip line connecting the second and third series resonance circuits to each other. The fifth microstrip line is connected to the connection point between the stripline and the third series resonance circuit, and the second image filter is connected to one terminal of the second capacitor with the sixth microstrip line. A fourth series resonance circuit having the other terminal of the second capacitor grounded, and a fifth series resonance circuit having a configuration equivalent to that of the fourth series resonance circuit. A series resonance circuit, a seventh microstrip line connecting the fourth and fifth series resonance circuits to each other, a seventh microstrip line connecting the fourth and fifth series resonance circuits to each other, and a fourth series connection. An eighth microstrip line connected to a connection point with the resonance circuit, and a connection point between the seventh microstrip line and the fifth series resonance circuit connecting the fourth and fifth series resonance circuits to each other. The satellite broadcast receiver according to claim 1, wherein the satellite broadcast receiver comprises a ninth microstrip line.