JP3565677B2 - Down converter for receiving satellite broadcasting - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a down converter for receiving satellite broadcasting, which is equipped with a coaxial waveguide converter for receiving two types of independent linearly polarized signals and mounted on an outdoor antenna device.
[0002]
[Prior art]
6 and 7 are views for explaining this type of downconverter. FIG. 6 is a sectional view of a main part, and FIG. 7 is a block diagram.
[0003]
In these figures, the downconverter 41 is formed by integrally forming a waveguide 42 and a circuit board housing (hereinafter simply referred to as a housing) 43, and both of them have a substantially L-shape. Both ends are open and formed in a cylindrical shape. A circuit board 44 housed in a housing 43 extends through the rear opening 42a, and a metal case having a flange 45a at the bottom. Reference numeral 45 is provided via the circuit board 44 so as to close the rear opening 42a of the waveguide 42. In the waveguide 42, a substantially L-shaped first linearly polarized wave (for example, a horizontally polarized wave) for detecting a first linearly polarized wave (for example, a horizontally polarized wave) is located at a position one quarter wavelength before the received radio wave from the circuit board 44 behind the waveguide 42. A first probe 46 is located.
[0004]
The base end of the first probe 46 is connected to the circuit board 44, and a portion extending linearly from the base end is covered with an insulating member 47 such as Teflon to form a groove in the waveguide 42. After being incorporated in the waveguide 42b, the tip side is projected into the waveguide 42 by a predetermined dimension.
[0005]
Of the front and back surfaces of the circuit board 44 orthogonal to the axial direction of the waveguide 42, the surface on the first probe 46 side reflects the first linearly polarized wave to the first A short-circuit pattern 47 for detection by the probe 46 is provided, and a second linear polarization (for example, a vertical polarization) orthogonal to the first linear polarization is provided on the other surface. ) Is patterned. Also, the inner bottom surface of the metal case 45 is formed as a short-circuit surface 45b for reflecting the second linearly polarized wave and detecting it by the second probe 48, and the second probe 48 is connected to the metal case. The distance from the short-circuit surface 45b, which is the inner bottom surface of the negative electrode 45, is also set to 1/4 wavelength of the received radio wave.
[0006]
The circuit board 44 is provided with a frequency conversion circuit for converting the frequency of the signals detected by the first probe 46 and the second probe 48. As shown in FIG. 7, two frequency conversion circuits are provided corresponding to the first and second linearly polarized waves, and high-frequency amplification circuits 51h and 51v, band-pass filters 52h and 52v, a mixing circuit 53h, 53v, the number of intermediate frequency amplifying circuits 54h and 54v, and the local oscillation signal from the common local oscillation circuit 55 is distributed by the distribution circuit 56 and supplied to the mixing circuits 53h and 53v to perform frequency conversion. I have. A first probe 46 for detecting the first linear polarization is connected to one high-frequency amplifier circuit 51h of the frequency conversion circuit, and a second probe 48 for detecting the second linear polarization is provided. It is connected to the other high-frequency amplifier circuit 51v.
[0007]
The frequencies of the first and second linearly polarized signals detected by the first and second probes are 10.7 GHz to 11.7 GHz, and the frequency is converted by a local oscillation signal of 9.75 GHz. Therefore, the intermediate frequency amplification circuits 54h and 54v output intermediate frequency signals (band 1 GHz) whose frequencies have been converted to 0.95 GHz to 1.95 GHz, respectively. The intermediate frequency signal is transmitted to an indoor receiver via respective coaxial cables (not shown) connected to two connectors 49 attached to the housing 43.
[0008]
[Problems to be solved by the invention]
In the above-mentioned conventional down-converter 41, when the frequency band of satellite broadcasting is expanded and the number of frequency conversion circuits is increased accordingly, the size of the circuit board 44 must be increased. However, there is a problem that the shape of the downconverter 41 must be increased. That is, at present, the frequency used for satellite broadcasting is about 10.7 HGz to 11.7 GHz as described above, but there is a movement to expand this to 10.7 GHz to 12.75 GHz and to broaden the frequency band to about twice. is there.
[0009]
However, even when the frequency band is expanded in this way, the receivable band of the indoor receiver is limited to about 1 GHz as in the conventional case, so that the output frequency band of the downconverter for receiving satellite broadcasts is also set to approximately 1 GHz. There is a need. For this reason, the band of the reception frequency is divided into a lower band, for example, 10.7 GHz to 11.7 GHz and a higher band, for example, 11.7 GHz to 12.75 GHz. It is conceivable to make the frequencies approximately the same. As a result, as described above, the number of frequency conversion circuits is doubled, and the circuit board 44 and the down converter 41 are both increased in size.
[0010]
In addition, since the frequency band of the divided frequency band is converted and the respective intermediate frequencies are made substantially the same, the number of local oscillation circuits also increases, and since their transmission frequencies are different, the local oscillation frequencies interfere with each other and generate an interference signal. Also occurs.
[0011]
Therefore, in the present invention, it is possible to cope with an increase in the number of frequency conversion circuits without increasing the size of the circuit board or the shape of the down converter, and furthermore, a novel down converter that does not cause interference between local oscillation signals. -Data is provided.
[0012]
[Means for Solving the Problems]
In order to solve the above problems, a down converter for receiving satellite broadcasting according to the present invention has a rectangular bottom wall, a side wall rising from the periphery of the bottom wall, and an opening on a side facing the bottom wall. A metal housing, and a metal waveguide that projects vertically outward from the bottom wall and is formed integrally with the housing with a rear opening communicating with the inside of the housing. A partition wall protruding into the housing along the rear opening is provided, the height of the partition wall is made lower than the side wall, and a step is formed on the side wall located in the housing, A metal plate is bridged between the upper end of the wall and the step portion, and a first compartment located on the bottom wall side partitioned by the metal plate in the housing and located on the opening side in the housing and a second compartment provided, wherein the first compartment a first attached to the metal plate With arranging the road substrate, wherein the second compartment is disposed a second circuit board mounted on said metal plate, one of said first or second on one of the circuit board of the reception frequency band A first frequency conversion circuit unit for converting the frequency of the received signal in the low frequency band is configured, and the other of the first and second circuit boards performs frequency conversion on the received signal in the high frequency band of the received frequency band. A second frequency conversion circuit section was configured.
[0013]
Further, a probe for extending the second circuit board and closing the rear opening, and detecting a received radio wave input to the waveguide in an area of the second circuit board that closes the rear opening is provided. Configured.
[0014]
Further, another side wall connected to the side wall provided with the step portion and an end face of the metal plate are electrically connected via a conductive elastic member.
[0015]
Further, the conductive elastic member is constituted by an elastic member and a conductive cloth member provided on an outer surface of the elastic member.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of a satellite broadcast receiving downconverter according to the present invention will be described below with reference to FIGS. FIG. 1 is a cross-sectional view of a main part of a down converter for receiving satellite broadcasting according to the present invention, FIG. 2 is a cross-sectional view of a main part along line AA of FIG. 1 , and FIG. 3 is a down converter of the present invention. FIG. 4 is a perspective view of an assembly of a circuit board and a metal plate housed in a housing, FIG. 4 is a cross-sectional view taken along line BB of FIG. 3, and FIG. FIG.
[0017]
First, in FIG. 1 and FIG. 2, a down converter 1 for receiving satellite broadcasting according to the present invention has a waveguide 2 and a rectangular parallelepiped housing 3 for accommodating a circuit board integrally formed of metal. The waveguide 2 is formed in a tubular shape with both ends opened, and the rear opening 2 a is located in the housing 3. The housing 3 has a bottom wall 3a and side walls 3b, 3c, 3d, 3e rising from around four sides of the bottom wall 3a and interconnecting. The waveguide 2 projects vertically outward from the bottom wall of the housing 3 and is open. The bottom wall 3a is provided with a partition wall 3f projecting into the housing 3 along the rear opening 2a, and the rear opening 2a is separated from the one side wall 3d by the partition wall 3f. The side wall 3d is provided with a step 3g. The height of the step 3g is the same as the height of the partition wall 3f, and is lower than the surface of the opening.
[0018]
Then, the metal plate 6 having the first and second circuit boards 4 and 5 attached to both sides thereof is mounted on the partition wall 3f and the stepped portion 3g in a bridging manner. The first compartment 7 located on the side of the bottom wall 3a to be formed is closed by the metal plate 6. As a result, a second compartment 8 is formed on the opening side above the metal plate 6, the first circuit board 4 is disposed in the first compartment 7, and the second circuit board 5 is , And both substrates 5 and 6 are housed in the housing 3. The metal plate 6 is fixed to the partition wall 3f and the step 3g with screws (not shown) or the like.
[0019]
A second circuit board 5 disposed in the second compartment 8 extends to the rear opening 2a of the waveguide 2 and a metal case 9 having a bottom and a flange 9a is attached to the second circuit board 5. The waveguide 2 is installed through the substrate 5 so as to close the rear opening 2a. Further, in the waveguide 2, a substantially linear polarization (for example, a horizontal polarization) for detecting a first linear polarization (for example, a horizontal polarization) is located at a position that is １ ／ wavelength behind the received radio wave from the second circuit board 5 behind the waveguide 2. A first probe 10 having a letter shape is arranged. The base end of the first probe 10 is connected to the second circuit board 5, and a portion extending linearly from the base end is covered with an insulating member 11 such as Teflon to form a waveguide 2 And the tip side is projected into the waveguide 2 by a predetermined dimension.
[0020]
The portion of the second circuit board 5 perpendicular to the axial direction of the waveguide 2 corresponding to the rear opening 2a is provided on the surface on the first probe 10 side of the front and back surfaces. Is provided with a short-circuit pattern 12 for reflecting the first linearly polarized wave and detecting the first linearly polarized wave, and the other surface has a short-circuit pattern for the first linearly polarized wave. And a second probe 13 for detecting a second orthogonal linearly polarized wave (for example, vertically polarized wave) is patterned (see also FIG. 3). The inner bottom surface of the metal case 9 serves as a short-circuit surface 9b for reflecting the second linearly polarized wave and detecting the second linearly polarized wave by the second probe 13. The distance from the short-circuit surface 9b which is the inner bottom surface of the metal case 9 is also set to １ ／ wavelength of the received radio wave.
[0021]
2 and 3, first and second circuit boards 4 and 5 are previously attached to both surfaces of the metal plate 6 by screws or the like (not shown). A conductive elastic member 16 provided with a conductive cloth member 15 such as a polyester cloth is adhered to an outer surface of an elastic member 14 such as a foam, and the metal plate 6 is mounted in the housing 3 as shown in FIG. As shown in FIG. 2, the metal plate 6 and the side walls 3b and 3c of the housing 3 are in close contact with and electrically connected to the conductive elastic member 16, and as a result, the two circuit boards 4 and 5 are The plate 6, the partition wall 3f, the side walls 3b, 3c, 3d, and the conductive elastic member 16 completely shield the plate. The cover 17 is engaged with the opening of the housing 3 in which the circuit boards 4 and 5 are stored, and the down converter 1 for receiving satellite broadcasting is completed.
[0022]
As the conductive elastic member 16, conductive rubber or the like can be used. However, when the metal plate 6 to which the first and second circuit boards 4 and 5 are attached is housed in the housing 3, the side wall 3b of the housing 3 The conductive elastic member 16 using the conductive cloth member 15 shown in FIG. 4 with little friction with the surface 3c is preferable.
[0023]
The circuit boards 4 and 5 and the metal plate 6 are formed of a multilayer substrate, and a foil-shaped metal plate formed between two insulating substrates is used instead of the metal plate 6 shown in FIGS. It is also possible. In this case, since the foil-shaped metal plate is so thin that it is difficult to adhere to the conductive elastic member 16 alone, the conductive elastic member 16 is adhered to the end surfaces of the two insulating substrates and the foil-shaped metal plate is attached. What is necessary is just to make it electrically connected to a metal plate.
[0024]
FIG. 5 shows a frequency conversion circuit formed on the first and second circuit boards 4 and 5. Each of the first linearly polarized signal and the second linearly polarized signal has a frequency band of 10.7 GHz to 12.75 GHz, and the bandwidth is approximately twice as wide as that of the related art. These polarized signals are amplified by the high-frequency amplifier circuits 21h and 21v, respectively, and then, in the duplexers 22h and 22v, the lower band, for example, 10.7 GHz to 11.7 GHz (hereinafter referred to as low band) is higher. , For example, from 11.7 GHz to 12.75 GHz (hereinafter referred to as a high band). After the low-band signals of the first and second linearly polarized signals have passed through the low-band bandpass filters 23hl and 23vl, respectively, the low-band signals from the common low-band local oscillation circuit 24l, for example, 9 The low frequency mixing circuit 25hl, 25vl supplied with the local oscillation signal of 0.75GHz converts it to an intermediate frequency of 0.95GHz to 1.95GHz and outputs from the low band intermediate frequency amplifying circuits 26hl, 26vl, respectively. It has become.
[0025]
On the other hand, the high-band signals of the first and second linearly polarized signals pass through the high-band bandpass filters 23hh and 23vh, respectively, and then output from the common high-band local oscillation circuit 24h, for example, at 10.6 GHz. The local oscillation signal is converted to an intermediate frequency of 1.1 GHz to 2.15 GHz by the supplied high band mixing circuits 25 hh and 25 vh, and output from the high band intermediate frequency amplifier circuits 26 hh and 26 vh, respectively. I have. As a result, the intermediate frequency ranges from about 1 GHz to about 2 GHz, which can be almost the same as the conventional band.
[0026]
The second circuit board 5 includes high-frequency amplifier circuits 21h and 21v, duplexers 22h and 22v, low-band bandpass filters 23hl and 23vl, a low-band local oscillation circuit 24l, and a low-band local oscillation circuit 24l. A low-band frequency conversion circuit 271 composed of band mixing circuits 25hl and 25vl and low-band intermediate frequency amplifier circuits 26hl and 26vl is configured. On the other hand, the first circuit board 4 includes high-band bandpass filters 23hh and 23vh, a high-band local oscillation circuit 24h, high-band mixing circuits 25hh and 25vh, and high-band intermediate frequency amplifier circuits 26hh and 26vh. The high-band frequency conversion circuit unit 27h is configured, and the duplexers 22h and 22v configured on the second circuit board 5 and the high-band bandpass filters 23hh and 23vh configured on the first circuit board 4 are Are connected by terminals (not shown) penetrating the first and second circuit boards 4 and 5 and the metal plate 6 respectively.
[0027]
As described above, since the frequency conversion circuit units 271 and 27h that perform frequency conversion of the reception frequencies having different frequency bands are separately provided on the two circuit boards 4 and 5, interference between the frequency conversion circuit units can be prevented. A downconverter for receiving satellite broadcasting with a wide frequency band can be constructed.
[0028]
The first linear polarization (for example, horizontal polarization) and the second linear polarization (vertical polarization) signals detected by the first probe 10 and the second probe 13 are respectively The signals are input to the high frequency amplifier circuits 21h and 21v by the extraction patterns 18 and 19 (see FIG. 3) formed on the second circuit board 5, respectively , and are output from the four intermediate frequency amplifier circuits 26hl, 26vl, 26hh and 26vh. The intermediate frequency signal is transmitted from four connectors 20 attached to the housing 3 to an indoor receiver via a coaxial cable (not shown).
[0029]
【The invention's effect】
As described above, the down converter for receiving satellite broadcasting according to the present invention comprises a first compartment located on the bottom wall side partitioned by a metal plate and a second compartment located on the opening side in a housing. And a first compartment is provided with a first circuit board attached to a metal plate in the first compartment , and a second circuit board attached to the metal plate is arranged in the second compartment, One of the first or second circuit board constitutes a first frequency conversion circuit unit for frequency-converting a received signal in a lower frequency band of the reception frequency band, and the other of the first or second circuit board. Since the second frequency conversion circuit configured to frequency-convert a received signal in a high frequency band of the reception frequency band is configured, the size can be reduced even if the reception frequency band is expanded. By simply bridging the metal plate between the partition walls and the steps, two compartments can be easily formed in the housing, and the circuit boards mounted on the metal plates are arranged in the upper and lower compartments sandwiching the metal plate. Therefore, the circuit board is fixed by the metal plate. In addition, even when the reception frequency band is expanded, a necessary circuit can be configured without increasing the planar area of the housing. In addition, there is obtained an effect that interference between circuits formed on the two circuit boards can be prevented by the metal plate.
[0030]
In addition, since the second circuit board is extended to close the rear opening, and a probe for detecting the received radio wave input to the waveguide is configured in a region that closes the rear opening of the second circuit board, The second circuit board can be used efficiently.
[0031]
Since the other side wall connected to the side wall provided with the step portion and the end face of the metal plate were electrically connected via the conductive elastic member, the two circuit boards were formed of the metal plate, the conductive elastic member, and the partition. The chambers and the side walls are completely shielded from each other, so that interference between circuits formed on the respective substrates can be completely prevented.
[0032]
In addition, since the conductive elastic member is constituted by the elastic member and the conductive cloth member provided on the outer surface of the elastic member, when the metal plate on which the circuit board is mounted is housed in the housing, the conductive elastic member and the housing are separated from each other. There is little friction with the inner wall surface and it is easy to store.
[Brief description of the drawings]
FIG. 1 is a side sectional view of a main part of a down converter for receiving satellite broadcasting according to the present invention.
FIG. 2 is a sectional view of an essential part taken along line AA of FIG. 1;
FIG. 3 is a perspective view of an assembly of a circuit board and a metal plate housed in a housing of the down converter for receiving satellite broadcasting according to the present invention.
FIG. 4 is a sectional view taken along line BB of FIG. 3;
FIG. 5 is a block diagram of a down converter for receiving satellite broadcasting according to the present invention.
FIG. 6 is a sectional view of a main part of a conventional down converter for receiving satellite broadcasting.
FIG. 7 is a block diagram of a conventional down converter for receiving satellite broadcasting.
[Explanation of symbols]
1 down converter for receiving satellite broadcasting 2 waveguide 2a rear opening 2b concave groove 3 housing 3a bottom wall 3b. 3c. 3d. 3e Side wall 3f Partition wall 3g Step 4 First circuit board 5 Second circuit board 6 Metal plate 7 First compartment 8 Second compartment 9 Metal case 9a Flange 9b Short-circuit surface 10 First Probe 11 Insulating member 12 Short-circuit pattern 13 Second probe 14 Elastic member 15 Conductive member 16 Conductive elastic member 17 Cover
18.19 Drawer pattern 20 Connector

Claims (4)

A metal housing having a rectangular bottom wall and a side wall rising from the periphery of the bottom wall, having an opening on a side facing the bottom wall, and vertically projecting outward from the bottom wall, and a rear opening is provided in the housing. A metal waveguide integrally formed with the housing in a state communicating with the inside, and a partition wall protruding into the housing along the rear opening is provided on the bottom wall; The height is made lower than the side wall, and a step is formed on the side wall located in the housing, and a metal plate is bridged between the upper end of the partition wall and the step to form the housing. A first compartment located on the bottom wall side partitioned by the metal plate and a second compartment located on the opening side are provided, and the first compartment is provided on the metal plate. with placing the first circuit board which is mounted, wherein the second compartment mounting et al to the metal plate And the second circuit board are arranged, it constitutes the first frequency converting circuit for frequency converting the received signal of the first or second on one of the circuit board of the low frequency band among the reception frequency band, The other of the first and second circuit boards has a second frequency conversion circuit for frequency-converting a received signal in a higher frequency band of the reception frequency band, and a satellite broadcast reception downconverter. . A probe for extending the second circuit board and closing the rear opening, and configuring a probe for detecting a received radio wave input to the waveguide in a region of the second circuit board that closes the rear opening was configured. 2. The down converter for receiving satellite broadcasting according to claim 1, wherein: 3. The satellite according to claim 1, wherein another side wall connected to the side wall provided with the step portion and an end face of the metal plate are electrically connected via a conductive elastic member. Down converter for broadcast reception. 4. The down converter for receiving satellite broadcasting according to claim 3, wherein said conductive elastic member comprises an elastic member and a conductive cloth member provided on an outer surface of said elastic member. No change in the actual content of the statement

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