JPH05251909A - Dual lnb - Google Patents
Dual lnbInfo
- Publication number
- JPH05251909A JPH05251909A JP4094662A JP9466292A JPH05251909A JP H05251909 A JPH05251909 A JP H05251909A JP 4094662 A JP4094662 A JP 4094662A JP 9466292 A JP9466292 A JP 9466292A JP H05251909 A JPH05251909 A JP H05251909A
- Authority
- JP
- Japan
- Prior art keywords
- waveguide
- adjusting screw
- screw
- waveguides
- coaxial waveguide
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Landscapes
- Waveguide Switches, Polarizers, And Phase Shifters (AREA)
- Input Circuits Of Receivers And Coupling Of Receivers And Audio Equipment (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、衛星放送や衛星通信に
用いられ、２種類の偏波の受信信号に周波数変換を施す
とともに一方の受信信号を択一的に出力することができ
るデュアルＬＮＢに関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in satellite broadcasting and satellite communications, and is capable of performing frequency conversion on received signals of two types of polarized waves and outputting one of the received signals alternatively. It is about.
【０００２】[0002]
【従来の技術】従来より、衛星放送や衛星通信におい
て、周波数の有効利用を図るために、同一周波数の電波
について異なる偏波の電波を用いて異なる情報を伝送す
る通信方法が利用されている。たとえば、円偏波であれ
ば右回り偏波と左回り偏波とで異なる情報を伝送し、直
線偏波であれば水平偏波と垂直偏波とで異なる情報を伝
送するのである。したがって、２種類の偏波を分離する
ためにデュアルＬＮＢが用いられる。2. Description of the Related Art Conventionally, in satellite broadcasting and satellite communication, in order to effectively utilize frequencies, communication methods of transmitting different information by using radio waves of different polarization for radio waves of the same frequency have been used. For example, circularly polarized wave transmits different information between right-handed polarized wave and left-handed polarized wave, and linear polarized wave transmits different information between horizontal polarized wave and vertical polarized wave. Therefore, a dual LNB is used to separate the two types of polarized waves.
【０００３】デュアルＬＮＢ（低雑音の帯域ダウンコン
バータ）には、アンテナで受信された各偏波の受信信号
が入力される。デュアルＬＮＢは、受信信号の周波数を
下げるように周波数変換を施すとともに、周波数変換を
行った各偏波の受信信号を択一的に出力する。具体的に
は、たとえば図６に示すような構成を有する。すなわ
ち、アンテナで受信した各偏波を伝送する各別の導波管
２ａ，２ｂを備えた一対の同軸導波管変換器１ａ，１ｂ
を有し、各同軸導波管変換器１ａ，１ｂより出力された
各偏波ごとの受信信号をそれぞれ端子３ａ，３ｂを介し
て高周波増幅回路４ａ，４ｂに入力し増幅する。高周波
増幅回路４ａ，４ｂによって増幅された両偏波の受信信
号は、合成器５を通して高周波増幅回路６で増幅され、
帯域フィルタ７で影像帯域周波数が除去された後、ミキ
サ８において局部発振回路９からの局部発振信号と混合
されて周波数変換がなされる。すなわち、ミキサ８およ
び局部発振回路９によって周波数変換手段が構成され
る。周波数変換が施された後の受信信号は中間周波数増
幅回路１０によって増幅されて出力される。ここにおい
て、高周波増幅回路４ａ，４ｂは選択回路１１を通して
択一的に給電され、いずれか一方のみが動作することに
よって、２種類の偏波の受信信号の一方のみが合成器５
を通過するようになっている。すなわち、選択回路１１
は一方の偏波を選択する選択手段として機能する。A received signal of each polarization received by an antenna is input to a dual LNB (low noise band down converter). The dual LNB performs frequency conversion so as to lower the frequency of the received signal, and alternatively outputs the frequency-converted received signal of each polarization. Specifically, for example, it has a configuration as shown in FIG. That is, a pair of coaxial waveguide converters 1a and 1b having different waveguides 2a and 2b for transmitting the respective polarized waves received by the antenna.
The received signals for the respective polarized waves output from the coaxial waveguide converters 1a and 1b are input to the high frequency amplifier circuits 4a and 4b via the terminals 3a and 3b, respectively, and are amplified. The received signals of both polarizations amplified by the high frequency amplification circuits 4a and 4b are amplified by the high frequency amplification circuit 6 through the combiner 5,
After the image band frequency is removed by the bandpass filter 7, the mixer 8 mixes the image with the local oscillation signal from the local oscillation circuit 9 to perform frequency conversion. That is, the mixer 8 and the local oscillation circuit 9 constitute frequency conversion means. The received signal after the frequency conversion is amplified by the intermediate frequency amplifier circuit 10 and output. Here, the high-frequency amplifier circuits 4a and 4b are selectively supplied with power through the selection circuit 11, and only one of them operates so that only one of the reception signals of the two types of polarized waves is combined.
Is supposed to pass through. That is, the selection circuit 11
Functions as a selection unit that selects one polarized wave.
【０００４】ところで、この種の周波数変換手段を備え
た回路では、局部発振回路９からの局部発振信号の一部
が入力側および出力側に漏洩するのが避けられないもの
である。外部への影響を考えると、このような漏洩電力
を極力少なくすることが望ましく、とくに入力側への漏
洩信号はアンテナを介して空中に放射されるから十分に
抑制する必要がある。By the way, in the circuit provided with this kind of frequency conversion means, it is inevitable that a part of the local oscillation signal from the local oscillation circuit 9 leaks to the input side and the output side. Considering the influence on the outside, it is desirable to reduce such leakage power as much as possible, and in particular, the leakage signal to the input side is radiated into the air via the antenna, so it is necessary to sufficiently suppress it.
【０００５】この種のデュアルＬＮＢではマイクロスト
リップ線路を用いており、局部発振信号は、マイクロス
トリップ線路を通して入力側に漏洩するほかに、空間を
伝搬することによっても入力側に漏洩することが知られ
ている。したがって、高周波増幅回路６、帯域フィルタ
７、ミキサ８、局部発振回路９の各回路間に金属製の仕
切を設けるなどして空間を複数に区切ることによって、
空間を伝搬する局部発振信号を抑制しているのが現状で
ある。This type of dual LNB uses a microstrip line, and it is known that the local oscillation signal leaks to the input side through the microstrip line and also to the input side by propagating in space. ing. Therefore, by partitioning the space into a plurality of spaces by providing a partition between each of the high frequency amplifier circuit 6, the bandpass filter 7, the mixer 8, and the local oscillator circuit 9,
The current situation is suppressing local oscillation signals propagating in space.
【０００６】[0006]
【発明が解決しようとする課題】ところで、高周波増幅
回路４ａ，４ｂは、一方が択一的に動作し、他方は給電
されずに非動作状態になっている。一般に、高周波増幅
回路４ａ，４ｂは、動作時と非動作時とでは逆方向の信
号伝達特性が変化することが知られている。出力側から
入力側へと逆方向に伝達される信号について、動作時で
は反射が大きく入力側には信号がほとんど伝達されない
が、非動作時では動作時に比較して入力側に伝達される
信号が増加するのである。したがって、上述した２種類
の偏波の一方を選択するデュアルＬＮＢでは、非動作で
ある一方の高周波増幅回路４ａ，４ｂを通して局部発振
信号がアンテナに漏洩するという問題が生じる。By the way, one of the high-frequency amplifier circuits 4a and 4b operates as an alternative, and the other is not operated without power supply. It is generally known that the high-frequency amplifier circuits 4a and 4b have opposite signal transfer characteristics when operating and when not operating. Regarding the signal transmitted in the reverse direction from the output side to the input side, the signal is transmitted to the input side in the non-operating state as compared with the signal in the non-operating state, although the reflection is large and the signal is hardly transmitted to the input side. It will increase. Therefore, in the dual LNB that selects one of the above-mentioned two types of polarized waves, there arises a problem that the local oscillation signal leaks to the antenna through the inoperative high-frequency amplifier circuits 4a and 4b.
【０００７】このような問題を回避するために、伝送路
の近傍に電波吸収体等を設けることも考えられている
が、高周波信号の伝送特性が悪化するという問題が生じ
る。本発明は上記問題点の解決を目的とするものであ
り、比較的簡単な構成ながら高周波信号の伝送特性を損
なうことなく、アンテナへの局部発振信号の漏洩電力を
低減することができるデュアルＬＮＢを提供しようとす
るものである。In order to avoid such a problem, it has been considered to provide a radio wave absorber or the like in the vicinity of the transmission line, but there arises a problem that the transmission characteristic of the high frequency signal is deteriorated. An object of the present invention is to solve the above problems, and to provide a dual LNB capable of reducing the leakage power of a local oscillation signal to an antenna without compromising the transmission characteristics of a high frequency signal with a relatively simple structure. It is the one we are trying to provide.
【０００８】[0008]
【課題を解決するための手段】本発明では、上記目的を
達成するために、２種類の偏波を受信するアンテナに接
続されて各偏波をそれぞれ伝送する導波管を備えた一対
の同軸導波管変換器と、各同軸導波管変換器より出力さ
れる受信信号の一方を択一的に通過させる選択手段と、
受信信号に周波数変換を施す周波数変換手段とを具備し
たデュアルＬＮＢにおいて、各同軸導波管変換器は導波
管のＥ面に平行となるように一方のＨ面に螺合した調節
ねじを備え、調節ねじは導波管内への挿入長が調節可能
とされているのである。According to the present invention, in order to achieve the above object, a pair of coaxial circuits provided with a waveguide connected to an antenna for receiving two kinds of polarized waves and transmitting each polarized wave. A waveguide converter, and a selection means for selectively passing one of the received signals output from each coaxial waveguide converter,
In a dual LNB equipped with frequency conversion means for frequency converting a received signal, each coaxial waveguide converter is provided with an adjusting screw screwed on one H surface so as to be parallel to the E surface of the waveguide. The adjusting screw has an adjustable insertion length into the waveguide.
【０００９】また、調節ねじは、導波管内に挿入される
端部を導波管に螺合する部位よりも細径に形成するのが
望ましい。Further, it is desirable that the adjusting screw is formed to have a diameter smaller than that of a portion where the end portion inserted into the waveguide is screwed into the waveguide.
【００１０】[0010]
【作用】上記構成によれば、同軸導波管変換器を介して
アンテナを接続しているのであって、同軸導波管変換器
は帯域阻止フィルタとしての特性を有しているから、阻
止帯域の中心周波数を局部発振信号の周波数に一致させ
ることによって、入力端から導波管への局部発振信号の
漏洩を阻止することが可能になる。同軸導波管変換器の
帯域阻止フィルタとしての特性は、非常に狭い帯域幅で
あり、しかも、減衰量が大きいから、受信信号は通過さ
せるが局部発振信号はほとんど通過させないように調節
することが可能になるのである。ここに、導波管のＥ面
に平行となるように一方のＨ面に螺合した調節ねじを設
け、調節ねじの導波管への挿入量を調節可能としている
ので、調節ねじがいわゆるトラップ周波数調整器として
機能し、調節ねじの挿入量を調節することによって同軸
導波管変換器の阻止帯域の中心周波数を調節することが
できるのである。すなわち、調節ねじの挿入量の調節に
よって局部発振信号の導波管への漏洩を大幅に低減させ
ることができ、局部発振信号のアンテナからの放射を防
止することになる。また、同軸導波管変換器は局部発振
信号を阻止する帯域阻止フィルタとして機能するだけで
あるから、目的とする受信信号の伝送特性には影響がな
く、簡単な構成ながら高周波信号の伝送特性を損なわず
にアンテナへの局部発振信号の漏洩を低減できるのであ
る。また、設計的には調節ねじの位置や径を適宜設定す
ることによって、同軸導波管変換器の阻止帯域の中心周
波数の調節が可能である。According to the above construction, since the antenna is connected through the coaxial waveguide converter, and the coaxial waveguide converter has a characteristic as a band stop filter, the stop band is reduced. It is possible to prevent the local oscillation signal from leaking from the input end to the waveguide by matching the center frequency of the signal with the frequency of the local oscillation signal. The characteristics of the coaxial waveguide converter as a band elimination filter are such that the bandwidth is extremely narrow and the amount of attenuation is large. Therefore, it can be adjusted so that the received signal is passed but the local oscillation signal is hardly passed. It will be possible. An adjusting screw screwed on one H surface so as to be parallel to the E surface of the waveguide is provided here, and the amount of insertion of the adjusting screw into the waveguide can be adjusted. The center frequency of the stop band of the coaxial waveguide converter can be adjusted by functioning as a frequency adjuster and adjusting the insertion amount of the adjusting screw. That is, by adjusting the insertion amount of the adjusting screw, the leakage of the local oscillation signal to the waveguide can be significantly reduced, and the emission of the local oscillation signal from the antenna can be prevented. Further, since the coaxial waveguide converter only functions as a band elimination filter that inhibits the local oscillation signal, it does not affect the transmission characteristics of the target reception signal, and the transmission characteristics of the high frequency signal can be achieved with a simple configuration. The leakage of the local oscillation signal to the antenna can be reduced without damaging it. Further, in design, the center frequency of the stop band of the coaxial waveguide converter can be adjusted by appropriately setting the position and diameter of the adjusting screw.
【００１１】さらに、導波管内に挿入される端部を導波
管に螺合する部位よりも細径に形成した調節ねじを用い
れば、導波管への螺合部位の径が同じであるとして、径
が均一な調節ねじを用いる場合に比較すると、ねじの進
退量に対する阻止帯域の中心周波数の変化が小さくなる
から、中心周波数の微調整が可能になる。また、中心周
波数の調節範囲の長さだけねじ部を設ければよいのであ
って、調節ねじの導波管に対するがたつきを防止するた
めにねじ部に樹脂を塗布した場合に、径が均一な調節ね
じを用いる場合に比較すると、調節ねじの進退に伴って
発生しねじ溝に詰まる樹脂粉の量を大幅に低減できるか
ら、樹脂粉の目詰まりによって調節ねじの回転が困難に
なるということがないのである。すなわち、調節ねじの
ねじ部に塗布した樹脂は、調節ねじの回転量が多いほど
ねじ溝に詰まる量が多くなるのであって、径が均一な調
節ねじを用いて樹脂を調節ねじの全体に塗布していると
すれば、調節ねじを所望の位置まで挿入するための回転
量が多くなり、当然ながらねじ溝に詰まる樹脂粉の量が
多くなる。これに対して、導波管に挿入する先端部を導
波管に螺合する部位よりも細径にした調節ねじを用いれ
ば、導波管内に調節ねじの端部をある程度挿入してから
調節ねじを導波管に螺合させることになるから、調節ね
じを所望の位置まで挿入するための回転量が少なくな
り、樹脂粉によるねじ溝の目詰まりが少なくなるのであ
る。その結果、調節ねじをがたつきなく滑らかに回転さ
せることができ、調節作業が容易になるのである。Further, if an adjusting screw having an end inserted into the waveguide and having a diameter smaller than that of the portion screwed into the waveguide is used, the diameter of the portion screwed into the waveguide is the same. As compared with the case where the adjusting screw having a uniform diameter is used, the change in the center frequency of the stop band with respect to the amount of advance and retreat of the screw becomes small, and thus the center frequency can be finely adjusted. In addition, since it is sufficient to provide the threaded portion only for the length of the adjustment range of the center frequency, when the resin is applied to the threaded portion to prevent the adjustment screw from rattling with respect to the waveguide, the diameter is uniform. The amount of resin powder that is generated as the adjustment screw moves back and forth and that clogs the screw groove can be significantly reduced compared to the case where a large adjustment screw is used, which makes it difficult to rotate the adjustment screw due to clogging of the resin powder. There is no. In other words, the amount of resin applied to the threaded portion of the adjusting screw will increase as the amount of rotation of the adjusting screw increases, and the amount of resin that gets stuck in the thread groove increases. If so, the amount of rotation for inserting the adjusting screw to a desired position increases, and naturally, the amount of resin powder clogging the screw groove increases. On the other hand, if you use an adjusting screw that has a smaller diameter than the part that is inserted into the waveguide and that is screwed into the waveguide, adjust the adjustment screw after inserting the end of the adjusting screw to some extent in the waveguide. Since the screw is screwed into the waveguide, the amount of rotation for inserting the adjusting screw to a desired position is reduced and clogging of the screw groove due to the resin powder is reduced. As a result, the adjusting screw can be smoothly rotated without rattling, which facilitates the adjusting work.
【００１２】[0012]
【実施例】（実施例１）本実施例の回路構成は従来の技
術で説明したものと同様である。すなわち、図６に示す
ように、平面アンテナ等のアンテナの出力は、導波管２
ａ，２ｂを備えた同軸導波管変換器１ａ，１ｂを介して
高周波増幅回路４ａ，４ｂに入力される。同軸導波管変
換器１ａ，１ｂは、各偏波に対応する各導波管２ａ，２
ｂにそれぞれ挿入した同軸プローブ１２ａ，１２ｂを有
し、同軸プローブ１２ａ，１２ｂが回路部を実装した回
路基板１４に接続されるのである（図１参照）。(Embodiment 1) The circuit configuration of this embodiment is similar to that described in the prior art. That is, as shown in FIG. 6, the output of an antenna such as a planar antenna is
It is input to the high frequency amplifier circuits 4a and 4b via the coaxial waveguide converters 1a and 1b provided with a and 2b. The coaxial waveguide converters 1a and 1b include the waveguides 2a and 2 corresponding to the respective polarized waves.
The coaxial probes 12a and 12b are respectively inserted in b, and the coaxial probes 12a and 12b are connected to the circuit board 14 on which the circuit section is mounted (see FIG. 1).
【００１３】ところで、同軸導波管変換器１ａ，１ｂ
は、図１に示すように、導波管２ａ，２ｂに先端部が挿
入された調節ねじ１３ａ，１３ｂを備えている。導波管
２ａ，２ｂとしては、たとえば日本電子機械工業会規格
のＷＲＪ−１２０を用いることができ、Ｅ面に平行とな
るように一方のＨ面に調節ねじ１３ａ，１３ｂを螺合さ
せることによって、図２に示すような伝送特性に設定す
ることが可能である。すなわち、調節ねじ１３ａ，１３
ｂの導波管２ａ，２ｂへの挿入量を調節することによっ
て、図２における阻止帯域の中心周波数を調節すること
が可能になるのであって、中心周波数を局部発振信号Ｌ
0 に一致させれば、受信信号ＲＦの伝送特性にはほとん
ど影響を与えることなく、局部発振信号Ｌ0 のみを３０
ｄＢ程度減衰させることができることがわかる。このよ
うにして、受信信号ＲＦの伝送特性に影響を与えないよ
うにしながらも、局部発振信号Ｌ0 のアンテナへの漏洩
を阻止することができるのである。また、同軸導波管変
換器１ａ，１ｂの導波管２ａ，２ｂに調節ねじ１３ａ，
１３ｂを螺合させるだけの簡単な構成であって、容易に
実現できるものである。By the way, the coaxial waveguide converters 1a, 1b.
As shown in FIG. 1, each of the waveguides 2a and 2b is provided with adjusting screws 13a and 13b whose tip portions are inserted. As the waveguides 2a and 2b, for example, WRJ-120 of Japan Electronic Machinery Manufacturers Association Standard can be used, and by adjusting screws 13a and 13b on one H surface so as to be parallel to the E surface, It is possible to set the transmission characteristics as shown in FIG. That is, the adjusting screws 13a, 13
It is possible to adjust the center frequency of the stop band in FIG. 2 by adjusting the insertion amount of b into the waveguides 2a and 2b.
If brought into match zero, without giving little effect on the transmission characteristics of the reception signal RF, only local oscillation signal L 0 30
It can be seen that it can be attenuated by about dB. In this way, it is possible to prevent the local oscillation signal L 0 from leaking to the antenna while not affecting the transmission characteristics of the reception signal RF. In addition, the adjustment screws 13a are attached to the waveguides 2a and 2b of the coaxial waveguide converters 1a and 1b.
It has a simple structure in which 13b is screwed together, and can be easily realized.
【００１４】（実施例２）本実施例は、請求項２の発明
に対応するものであって、調節ねじ１３ａ，１３ｂを図
３および図４に示すような形状に形成した点が実施例１
と相違する。すなわち、調節ねじ１３ａ，１３ｂは、導
波管２ａ，２ｂに挿入される端部が、導波管２ａ，２ｂ
に螺合するねじ部１３1 よりも細径（たとえば、直径１
〜１．５ｍｍに設定する）である細径部１３2 になった
ものである。導波管２ａ，２ｂに調節ねじ１３ａ，１３
ｂを螺合させる際には、ねじ部１３1 に樹脂を塗布して
導波管２ａ，２ｂに対する調節ねじ１３ａ，１３ｂのが
たつきが防止されるとともに防水性が保たれるようにす
る。(Embodiment 2) This embodiment corresponds to the invention of claim 2 and is that the adjusting screws 13a and 13b are formed in the shapes shown in FIGS. 3 and 4.
Is different from. That is, in the adjusting screws 13a and 13b, the ends inserted into the waveguides 2a and 2b have the waveguides 2a and 2b.
Smaller than the threaded portion 13 1 that is screwed into
Is set to 1.5 mm) in which it was a small diameter portion 13 2. Adjusting screws 13a, 13 on the waveguides 2a, 2b
When screwing b, resin is applied to the threaded portion 13 1 so that the adjustment screws 13a and 13b are prevented from rattling with respect to the waveguides 2a and 2b and the waterproofness is maintained.
【００１５】このような調節ねじ１３ａ，１３ｂを用い
れば、細径部１３2 が導波管２ａ，２ｂにある程度挿入
されてからねじ部１３1 が導波管２ａ，２ｂに螺合する
ことになるから、調節ねじ１３ａ，１３ｂを導波管２
ａ，２ｂに対して所望位置まで挿入する際の調節ねじ１
３ａ，１３ｂの回転量を少なくすることができ、導波管
２ａ，２ｂに設けたねじ孔のねじ溝に詰まる樹脂粉の量
が少なくなり、調節ねじ１３ａ，１３ｂをがたつきなく
滑らかに回転させることができるのである。If the adjusting screws 13a and 13b are used, the small diameter portion 13 2 is inserted into the waveguides 2a and 2b to some extent, and then the screw portion 13 1 is screwed into the waveguides 2a and 2b. Therefore, adjust the adjusting screws 13a and 13b to the waveguide 2
Adjustment screw 1 when inserting to the desired position with respect to a and 2b
The amount of rotation of 3a, 13b can be reduced, the amount of resin powder clogging the thread grooves of the screw holes provided in the waveguides 2a, 2b is reduced, and the adjustment screws 13a, 13b can be smoothly rotated without rattling. It can be done.
【００１６】また、導波管２ａ，２ｂにねじ部１３1 よ
りも細径である細径部１３2 を挿入しているから、ねじ
部１３1 の径を、加工が容易で導波管２ａ，２ｂに対す
るがたつきを少なくする程度に設定しても、ねじ部１３
1 の径が同じであって径が均一な調節ねじに比較すれ
ば、調節ねじ１３ａ，１３ｂの回転量に対する特性変化
を小さくすることができるのであって微調整が可能にな
るのである。また、調整した後には外部振動などによっ
て調節値が大きくずれることがなく、安定した動作が期
待できるのである。さらに、図５に示すように、調節ね
じ１３ａ，１３ｂの挿入位置や挿入角度が多少ずれたと
しても、細径部１３2 を設けていることによって、径が
均一な調節ねじ１３1 ，１３2 を用いる場合に比較すれ
ば、伝送特性に与える影響が小さくなる。調節ねじ１３
ａ，１３ｂの挿入量を調節した後は、接着剤を用いて調
節ねじ１３ａ，１３ｂを導波管２ａ，２ｂに固定する。
他の構成は実施例１と同様である。Further, since the small diameter portion 13 2 having a smaller diameter than the threaded portion 13 1 is inserted into the waveguides 2a and 2b, the diameter of the threaded portion 13 1 can be easily machined and the waveguide 2a can be processed. , 2b is set to such an extent that rattling with respect to
Compared with an adjusting screw having the same diameter 1 and a uniform diameter, the characteristic change with respect to the rotation amount of the adjusting screws 13a and 13b can be reduced, and fine adjustment can be performed. Further, after the adjustment, the adjustment value does not largely deviate due to external vibration, etc., and stable operation can be expected. Furthermore, as shown in FIG. 5, the adjustment screw 13a, even if the insertion position and insertion angle of 13b was slightly shifted, the small-diameter portion 13 by which 2 provided, diameter uniform adjusting screw 13 1, 13 2 Compared with the case of using, the influence on the transmission characteristics is reduced. Adjustment screw 13
After adjusting the insertion amounts of a and 13b, the adjusting screws 13a and 13b are fixed to the waveguides 2a and 2b using an adhesive.
Other configurations are similar to those of the first embodiment.
【００１７】[0017]
【発明の効果】本発明は上述のように、同軸導波管変換
器を介してアンテナを接続しているのであり、同軸導波
管変換器は帯域阻止フィルタとしての特性を有している
から、阻止帯域の中心周波数を局部発振信号の周波数に
一致させることによって、入力端から導波管への局部発
振信号の漏洩を阻止することが可能になる。ここに、導
波管のＥ面に平行となるように一方のＨ面に螺合した調
節ねじを設け、調節ねじの導波管への挿入量を調節可能
としているので、調節ねじの挿入量を調節することによ
って同軸導波管変換器の阻止帯域の中心周波数を調節す
ることができる。すなわち、局部発振信号の導波管への
漏洩を大幅に低減させることができ、局部発振信号のア
ンテナからの放射を防止することができるという効果を
奏するのである。また、同軸導波管変換器は局部発振信
号を阻止する帯域阻止フィルタとして機能するだけであ
るから、目的とする受信信号の伝送特性には影響がな
く、簡単な構成ながら高周波信号の伝送特性を損なうこ
となくアンテナへの局部発振信号の漏洩を低減できると
いう利点がある。As described above, according to the present invention, the antenna is connected through the coaxial waveguide converter, and the coaxial waveguide converter has characteristics as a band elimination filter. By matching the center frequency of the stop band with the frequency of the local oscillation signal, it becomes possible to prevent the leakage of the local oscillation signal from the input end to the waveguide. An adjustment screw screwed on one H surface so as to be parallel to the E surface of the waveguide is provided here, and the amount of the adjustment screw inserted into the waveguide can be adjusted. Can be adjusted to adjust the center frequency of the stopband of the coaxial waveguide converter. That is, it is possible to significantly reduce the leakage of the local oscillation signal to the waveguide, and to prevent the emission of the local oscillation signal from the antenna. Further, since the coaxial waveguide converter only functions as a band elimination filter that inhibits the local oscillation signal, it does not affect the transmission characteristics of the target reception signal, and the transmission characteristics of the high frequency signal can be achieved with a simple configuration. There is an advantage that the leakage of the local oscillation signal to the antenna can be reduced without damage.
【００１８】さらに、導波管内に挿入される端部を導波
管に螺合する部位よりも細径に形成した調節ねじを用い
れば、導波管への螺合部位の径が同じであるとして、径
が均一な調節ねじを用いる場合に比較すると、ねじの進
退量に対する阻止帯域の中心周波数の変化が小さくなる
から、中心周波数の微調整が可能になるという効果があ
る。また、中心周波数の調節範囲の長さだけねじ部を設
ければよいのであって、調節ねじの導波管に対するがた
つきを防止するためにねじ部に樹脂を塗布した場合に、
径が均一な調節ねじを用いる場合に比較すれば、調節ね
じの進退に伴って生じてねじ溝に詰まる樹脂粉の量を大
幅に低減できるから、調節ねじをがたつきなく滑らかに
回転させることができ、調節作業が容易になるという利
点を有する。Further, if an adjusting screw having an end inserted into the waveguide and having a diameter smaller than that of the portion screwed into the waveguide is used, the diameter of the portion screwed into the waveguide is the same. As compared with the case where the adjusting screw having a uniform diameter is used, the change in the center frequency of the stop band with respect to the amount of advance and retreat of the screw becomes small, and thus there is an effect that the center frequency can be finely adjusted. Further, it is only necessary to provide the screw portion for the length of the adjustment range of the center frequency, and when resin is applied to the screw portion in order to prevent the adjustment screw from rattling with respect to the waveguide,
Compared with the case of using an adjusting screw with a uniform diameter, the amount of resin powder that accompanies the advancing / retreating of the adjusting screw and clogs the screw groove can be greatly reduced, so the adjusting screw should rotate smoothly without rattling. This has the advantage that the adjustment work can be facilitated.
【図１】実施例１を示し、（ａ）は導波管の開口面側か
らの正面図、（ｂ）は同軸導波管変換器の要部の断面図
である。1A and 1B show a first embodiment, FIG. 1A is a front view from the opening surface side of a waveguide, and FIG. 1B is a sectional view of a main part of a coaxial waveguide converter.
【図２】実施例１の動作特性を示す説明図である。FIG. 2 is an explanatory diagram showing operating characteristics of the first embodiment.
【図３】実施例２の導波管の開口面側からの一部破断正
面図である。FIG. 3 is a partially cutaway front view of the waveguide of Example 2 from the opening surface side.
【図４】実施例２に用いる調節ねじの正面図である。FIG. 4 is a front view of an adjusting screw used in a second embodiment.
【図５】実施例２の動作説明図である。FIG. 5 is an operation explanatory diagram of the second embodiment.
【図６】本発明に係るデュアルＬＮＢを示すブロック回
路図である。FIG. 6 is a block circuit diagram showing a dual LNB according to the present invention.
１ａ 同軸導波管変換器 １ｂ 同軸導波管変換器 ２ａ 導波管 ２ｂ 導波管 ８ ミキサ ９ 局部発振回路 １１ 選択回路 １３ａ 調節ねじ １３ｂ 調節ねじ １３1 ねじ部 １３2 細径部1a coaxial waveguide converter 1b coaxial waveguide converter 2a waveguide 2b waveguide 8 mixer 9 local oscillation circuit 11 selection circuit 13a adjusting screw 13b adjusting screw 13 1 screw portion 13 2 small diameter portion
─────────────────────────────────────────────────────
─────────────────────────────────────────────────── ───
【手続補正書】[Procedure amendment]
【提出日】平成４年６月１日[Submission date] June 1, 1992
【手続補正１】[Procedure Amendment 1]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００１１[Correction target item name] 0011
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【００１１】さらに、中心周波数の調節範囲の長さだけ
ねじ部を設ければよいのであって、調節ねじの導波管に
対するがたつきを防止するためにねじ部に樹脂を塗布し
た場合に、径が均一な調節ねじを用いる場合に比較する
と、調節ねじの進退に伴って発生しねじ溝に詰まる樹脂
粉の量を大幅に低減できるから、樹脂粉の目詰まりによ
って調節ねじの回転が困難になるということがないので
ある。すなわち、調節ねじのねじ部に塗布した樹脂は、
調節ねじの回転量が多いほどねじ溝に詰まる量が多くな
るのであって、径が均一な調節ねじを用いて樹脂を調節
ねじの全体に塗布しているとすれば、調節ねじを所望の
位置まで挿入するための回転量が多くなり、当然ながら
ねじ溝に詰まる樹脂粉の量が多くなる。これに対して、
導波管に挿入する先端部を導波管に螺合する部位よりも
細径にした調節ねじを用いれば、導波管内に調節ねじの
端部をある程度挿入してから調節ねじを導波管に螺合さ
せることになるから、調節ねじを所望の位置まで挿入す
るための回転量が少なくなり、樹脂粉によるねじ溝の目
詰まりが少なくなるのである。その結果、調節ねじをが
たつきなく滑らかに回転させることができ、調節作業が
容易になるのである。 Furthermore, there than may be provided by the length threaded portion of the adjustment range of the center frequency, when the resin is applied to the threaded portion in order to prevent rattling against the waveguide of the adjustment screw As compared with the case of using an adjusting screw with a uniform diameter, the amount of resin powder that is generated as the adjusting screw advances and retracts and clogs the screw groove can be greatly reduced, making it difficult to rotate the adjusting screw due to clogging of the resin powder. It never becomes. That is, the resin applied to the thread of the adjusting screw is
The greater the amount of rotation of the adjusting screw, the greater the amount of clogging in the thread groove.If the resin is applied to the entire adjusting screw using the adjusting screw with a uniform diameter, adjust the adjusting screw to the desired position. As a result, the amount of rotation required to insert into the screw groove increases, and naturally, the amount of resin powder that clogs the thread groove increases. On the contrary,
If you use an adjusting screw with a tip that is inserted into the waveguide smaller than the part that is screwed into the waveguide, insert the end of the adjusting screw into the waveguide to some extent and then insert the adjusting screw into the waveguide. Therefore, the amount of rotation for inserting the adjusting screw to a desired position is reduced and clogging of the screw groove due to the resin powder is reduced. As a result, the adjusting screw can be smoothly rotated without rattling, which facilitates the adjusting work.
【手続補正２】[Procedure Amendment 2]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００１６[Correction target item name] 0016
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【００１６】また、調整した後には外部振動などによっ
て調節値が大きくずれることがなく、安定した動作が期
待できるのである。さらに、図５に示すように、調節ね
じ１３ａ，１３ｂの挿入位置や挿入角度が多少ずれたと
しても、細径部１３2 を設けていることによって、径が
均一な調節ねじ１３1 ，１３2 を用いる場合に比較すれ
ば、伝送特性に与える影響が小さくなる。調節ねじ１３
ａ，１３ｂの挿入量を調節した後は、接着剤を用いて調
節ねじ１３ａ，１３ｂを導波管２ａ，２ｂに固定する。
他の構成は実施例１と同様である。 Further, after the adjustment has never deviate greatly adjusted value by an external vibration, stable operation is to be expected. Furthermore, as shown in FIG. 5, the adjustment screw 13a, even if the insertion position and insertion angle of 13b was slightly shifted, the small-diameter portion 13 by which 2 provided, diameter uniform adjusting screw 13 1, 13 2 Compared with the case of using, the influence on the transmission characteristics is reduced. Adjustment screw 13
After adjusting the insertion amounts of a and 13b, the adjusting screws 13a and 13b are fixed to the waveguides 2a and 2b using an adhesive.
Other configurations are similar to those of the first embodiment.
【手続補正３】[Procedure 3]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００１８[Correction target item name] 0018
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【００１８】さらに、中心周波数の調節範囲の長さだけ
ねじ部を設ければよいのであって、調節ねじの導波管に
対するがたつきを防止するためにねじ部に樹脂を塗布し
た場合に、径が均一な調節ねじを用いる場合に比較すれ
ば、調節ねじの進退に伴って生じてねじ溝に詰まる樹脂
粉の量を大幅に低減できるから、調節ねじをがたつきな
く滑らかに回転させることができ、調節作業が容易にな
るという利点を有する。 Furthermore, there than may be provided by the length threaded portion of the adjustment range of the center frequency, when the resin was applied to the threaded portion in order to prevent rattling against the waveguide of the adjustment screw Compared to the case of using an adjusting screw with a uniform diameter, the amount of resin powder that accompanies the advancing / retreating of the adjusting screw and clogs the screw groove can be significantly reduced, so that the adjusting screw rotates smoothly without rattling. This has the advantage that adjustment work is facilitated.
Claims (2)
されて各偏波をそれぞれ伝送する導波管を備えた一対の
同軸導波管変換器と、各同軸導波管変換器より出力され
る受信信号の一方を択一的に通過させる選択手段と、受
信信号に周波数変換を施す周波数変換手段とを具備した
デュアルＬＮＢにおいて、各同軸導波管変換器は導波管
のＥ面に平行となるように一方のＨ面に螺合した調節ね
じを備え、調節ねじは導波管内への挿入長が調節可能で
あることを特徴とするデュアルＬＮＢ。1. A pair of coaxial waveguide converters, each of which is connected to an antenna for receiving two kinds of polarized waves and has a waveguide for transmitting each polarized wave, and outputs from each coaxial waveguide converter. In the dual LNB including selection means for selectively passing one of the received signals and frequency conversion means for performing frequency conversion on the received signal, each coaxial waveguide converter is located on the E surface of the waveguide. A dual LNB, which is provided with an adjusting screw screwed on one H surface so as to be parallel to each other, and the adjusting screw has an adjustable insertion length into the waveguide.
が導波管に螺合する部位よりも細径に形成されているこ
とを特徴とする請求項１記載のデュアルＬＮＢ。2. The dual LNB according to claim 1, wherein the adjusting screw is formed to have a smaller diameter than a portion where an end portion inserted into the waveguide is screwed into the waveguide.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| EP19920201921 EP0523770B1 (en) | 1991-07-15 | 1992-06-29 | Low-noise-block downconverter for use with flat antenna receiving dual polarized electromagnetic waves |
| DE1992630048 DE69230048T2 (en) | 1991-07-15 | 1992-06-29 | Low noise down converter block for use in a plane antenna for double polarized electromagnetic waves |
| US08/353,050 US5630226A (en) | 1991-07-15 | 1994-12-09 | Low-noise downconverter for use with flat antenna receiving dual polarized electromagnetic waves |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP226492 | 1992-01-09 | ||
| JP4-2264 | 1992-01-09 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05251909A true JPH05251909A (en) | 1993-09-28 |
| JP3072183B2 JP3072183B2 (en) | 2000-07-31 |
Family
ID=11524517
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP04094662A Expired - Fee Related JP3072183B2 (en) | 1991-07-15 | 1992-04-15 | Dual LNB |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3072183B2 (en) |
-
1992
- 1992-04-15 JP JP04094662A patent/JP3072183B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JP3072183B2 (en) | 2000-07-31 |
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