JP3594796B2

JP3594796B2 - Satellite signal receiving system and signal distribution switching device

Info

Publication number: JP3594796B2
Application number: JP10275798A
Authority: JP
Inventors: 通上村; 知幸國澤; 利之廣田
Original assignee: Ｄｘアンテナ株式会社
Priority date: 1998-04-14
Filing date: 1998-04-14
Publication date: 2004-12-02
Anticipated expiration: 2018-04-14
Also published as: JPH11298809A

Description

【０００１】
【発明の属する技術分野】
本発明は、例えば放送衛星や通信衛星からの信号を受信して、複数の端末に分配する衛星信号受信システムに関する。
【０００２】
【従来の技術】
衛星信号受信システムは、例えば放送衛星や通信衛星からの衛星信号を、各端末においてそれぞれ受信可能とするために使用される。しかし、或る通信衛星から、異なる偏波であるが、周波数帯が少なくとも一部で重複している少なくとも２波の電波を送信し、別の通信衛星から、上記の２波とそれぞれ偏波及び周波数帯が同一の少なくとも２波の電波を送信することがある。
【０００３】
また、上記２基の通信衛星からの電波をそれぞれ受信するアンテナには、コンバータがそれぞれ付属している。これらコンバータが、受信した通信衛星信号を中間周波信号に変換する。しかし、コンバータ内の局部発振器の発振周波数がいずれの通信衛星用のコンバータでも、同一周波数であるので、各コンバータから出力される中間周波信号の周波数帯は、ほぼ同一である。従って、同じ伝送線路によってこれら中間周波信号を伝送した場合、各端末側では、これら各中間周波信号を分離することができない。
【０００４】
従来、各衛星通信中間周波信号を、それぞれ別の伝送線路を介して各端末に伝送する別配線方式が提案されている。
【０００５】
【発明が解決しようとする課題】
しかし、上記の別配線方式では、各端末までそれぞれ個別の伝送線路を設けなければならず、伝送線路の配線が複雑になる。
【０００６】
本発明は、周波数帯が少なくとも一部で重複している衛星からの信号であっても、各端末まで少ない伝送線路で伝送することができる衛星信号受信システムを提供することを目的とする。また、このようなシステムにおいて使用する信号分配切換装置と、増幅器を提供することを目的とする。
【０００７】
【課題を解決するための手段】
上記の課題を解決するために、請求項１記載の発明は、第１の直流電圧が供給されたとき、第１の静止衛星から送信されている第１の衛星信号を、第１衛星中間周波信号に変換し、第２の直流電圧が供給されたとき、第１の静止衛星から送信され第１の衛星信号と周波数帯が一部重複し、かつ異なる偏波を有する第２衛星信号を第２衛星中間周波信号に変換する第１の変換手段と、第１の直流電圧が供給されたとき、第２の静止衛星から送信され、第１の衛星信号と同一の周波数帯と偏波を有する第３の衛星信号を第１衛星中間周波信号と同一周波数帯の第３中間周波信号に変換し、第２の直流電圧が供給されたとき、第２の衛星信号と同一の周波数帯と偏波を有する第４の衛星信号を、第２衛星中間周波信号と同一周波数帯の第４衛星中間周波信号に変換する第２の変換手段と、第１または第２衛星中間周波信号を複数の第１分配出力に分配する通電型の第１の分配手段と、第３または第４衛星中間周波信号を、第１分配出力と同数の第２分配出力に分配する通電型の第２の分配手段と、第１及び第２の分配出力がそれぞれ供給され、切換信号に応じて第１及び第２の分配出力の一方を出力する複数の切換手段と、これら切換手段と第１及び第２の衛星中間周波信号を受信復調する複数の受信手段との間にそれぞれ介在し、前記切換手段からの出力信号を前記受信手段に供給すると共に、前記受信手段から前記切換信号を前記切換手段に供給する第１の端子とを、有している。前記切換信号は、前記第１または第２直流電圧に、第１及び第２衛星中間周波信号よりも周波数が低い交番信号が重畳または非重畳されているものであり、前記切換手段は、前記交番信号の重畳の有無に基づいて第１及び第２の分配出力の一方を選択し、選択された分配出力を出力している分配手段に、そのとき第１の端子に供給されている前記直流電圧を供給する。
【００１２】
請求項２記載の発明は、請求項１または２記載の衛星信号受信システムにおいて、第３の静止衛星から送信された第５の衛星信号を第３の衛星中間周波信号に変換する第３の変換手段と、第３の変換手段からの第３の衛星中間周波信号と、地上波テレビジョン放送信号またはＣＡＴＶ信号とを混合する混合手段と、この混合手段の混合出力を複数の分配出力に分配する第３の分配手段と、第３の分配手段の各分配出力が供給され、上記各第１の端子とそれぞれ対応して設けられている第２の端子とを、具備している。
【００１３】
請求項２記載の発明によれば、第３の衛星中間周波信号と地上波信号との混合信号が、第３の分配手段を介して第２の端子に供給されている。従って、第２の端子を、地上波またはＣＡＴＶと第３の衛星中間周波信号とを復調可能なテレビジョン受像機に接続することによって、これらも視聴可能となる。
【００１４】
請求項３記載の発明は、第１の直流電圧が供給された第１変換手段が第１の静止衛星から送信された第１の衛星信号を変換した第１衛星中間周波信号または、第２の直流電圧が供給された第１変換手段が第１の静止衛星から送信され第１の衛星信号と周波数帯が少なくとも一部で重複し異なる偏波を有する第２の衛星信号を第１衛星中間周波信号と周波数帯が非重複の第２衛星中間周波信号を、複数の第１分配出力に分配する通電型の第１の分配手段と、第１の直流電圧が供給された第２変換手段が第２の静止衛星から送信され第１の衛星信号と同一の周波数帯と偏波を有する第３の衛星信号を変換した第１衛星中間周波信号と同一の周波数帯の第３衛星中間周波信号または、第２の直流電圧が供給された第２変換手段が第２の静止衛星から送信され第２の衛星信号と同一の周波数帯と偏波を有する第４の衛星信号変換した第２衛星中間周波信号と同一周波数帯の第４衛星中間周波信号を、第１分配出力と同数の第２分配出力に分配する通電型の第２の分配手段と、第１及び第２の分配出力がそれぞれ供給され、第１及び第２の分配出力の一方を、それぞれが１本の伝送線路に出力する複数の切換手段とを、有している。これら切換手段は、接続されている前記伝送線路において、第１乃至第４衛星中間周波信号よりも周波数の低い交番信号が第１または第２直流電圧に重畳されているか否かに基づいて第１及び第２の分配出力の一方を前記伝送線路に出力すると共にそのとき前記伝送線路に供給されている第１または第２直流動作電圧を前記一方の分配出力を生じている分配手段に供給する。
【００１８】
【発明の実施の形態】
本発明の１実施の形態の衛星信号受信システムは、一般家庭における複数の部屋において、２基の通信衛星からの信号と、１基の放送衛星からの信号と、ＵＨＦ及びＶＨＦの地上波信号と、必要によりＣＡＴＶ信号を視聴するためのものである。
【００１９】
図１に示すように、この衛星信号受信システムは、ＵＨＦ及びＶＨＦ帯の地上波テレビジョン信号を受信するためのＵ・Ｖアンテナ２を有している。さらに、この衛星信号受信システムは、放送衛星から送信されている衛星放送信号を受信する衛星放送受信用アンテナ４を有している。この衛星放送信号は、衛星放送受信用アンテナ４に付属している第３の変換手段、例えばコンバータ６によって、予め定められた１ＧＨｚ帯の衛星放送中間周波信号に変換される。
【００２０】
この衛星放送中間周波信号と、ＵＨＦ及びＶＨＦ帯の地上波テレビジョン信号とは、混合手段、例えば混合器８によって混合される。或る場合には、この混合器８にＣＡＴＶ施設からのＣＡＴＶ信号も供給されることがある。この混合器８の出力信号は、増幅器１０によって増幅された後、第３の分配手段、例えば分配器１２に供給され、複数、例えば４つの分配出力に分配される。
【００２１】
これら４つの分配出力は、一般家庭の例えば異なる部屋にそれぞれ設けられた第２の端子、例えば端子１４１、１４２、１４３、１４４にそれぞれ１本の伝送線路、例えばそれぞれ１本の同軸ケーブルを介して供給される。これら端子１４１乃至１４４には、それぞれテレビジョン受像機が接続されている。図１では、代表として、端子１４１にテレビジョン受像機１６が接続されている状態を示している。なお、コンバータ６への動作用直流電圧は、例えば衛星放送受信用チューナ内蔵の各テレビジョン受像機のいずれかから供給されている。そのため、端子１４１乃至１４４、分配器１２、増幅器１０、混合器８は通電型のものである。
【００２２】
これらＵ・Ｖアンテナ２、衛星放送受信用アンテナ４、コンバータ６、混合器８、増幅器１０、分配器１２、端子１４１、１４２、１４３、１４４は、新設してもよいが、既存の設備であってもよい。
【００２３】
この衛星信号受信システムは、さらに第１の通信衛星からの衛星通信信号を受信する衛星通信受信用アンテナ１８を有している。第１の通信衛星は、図２（ａ）に示すように、例えば１２．４９３ＧＨｚから１２．７３３ＧＨｚの周波数帯で垂直偏波の第１の衛星通信信号ＣＳ１（Ｖ）と、１２．５０８ＧＨｚから１２．７４８ＧＨｚの周波数帯で水平偏波の第２の衛星通信信号ＣＳ１（Ｈ）とを送信している。
【００２４】
第１の変換手段、例えば衛星通信受信用アンテナ１８に付属しているコンバータ２０は、１０．６７８ＧＨｚの局部発振信号を発生する局部発振器と、１１．２ＧＨｚの局部発振信号を発生する局部発振器とを備えている。このコンバータ２０は、後述するように＋１１Ｖの直流電圧が供給されたとき、第１の衛星通信信号ＣＳ１（Ｖ）を１２９３ＭＨｚから１５３３ＭＨｚの第１の衛星通信中間周波信号ＣＳ１−ＩＦ（Ｖ）に周波数変換する。また、このコンバータ２０は、＋１５Ｖの直流電圧が供給されたとき、第２の衛星通信信号ＣＳ１（Ｈ）を１８３０ＭＨｚから２０７０ＭＨｚの第２衛星通信中間周波信号ＣＳ１−ＩＦ（Ｈ）に周波数変換する。
【００２５】
この衛星信号受信システムには、第２の通信衛星からの衛星通信信号を受信する衛星通信受信用アンテナ２２も設けられている。第２の通信衛星も、図２（ｂ）に示すように、例えば１２．４９３ＧＨｚから１２．７３３ＧＨｚの周波数帯で垂直偏波の第３の衛星通信信号ＣＳ２（Ｖ）と、１２．５０８ＧＨｚから１２．７４８ＧＨｚの周波数帯で水平偏波の第４の衛星通信信号ＣＳ２（Ｈ）とを送信している。
【００２６】
第２の変換手段、例えば衛星通信受信用アンテナ２２に付属しているコンバータ２４も、１０．６７８ＧＨｚの局部発振信号を発生する局部発振器と、１１．２ＧＨｚの局部発振信号を発生する局部発振器とを備えている。このコンバータ２４も、＋１１Ｖの直流電圧が供給されたとき、第３の衛星通信信号ＣＳ２（Ｖ）を１２９３ＭＨｚから１５３３ＭＨｚの第３の衛星通信中間周波信号ＣＳ２−ＩＦ（Ｖ）に周波数変換する。また、このコンバータ２４も、＋１５Ｖの直流電圧が供給されたとき、第４の衛星通信信号ＣＳ２（Ｈ）を１８３０ＭＨｚから２０７０ＭＨｚの第４衛星通信中間周波信号ＣＳ２−ＩＦ（Ｈ）に周波数変換する。
【００２７】
このように第１の衛星通信信号ＣＳ１（Ｖ）と第３の衛星通信信号ＣＳ２（Ｖ）とは、同一周波数、同一偏波の信号であり、第２の衛星通信信号ＣＳ１（Ｈ）と第４の衛星通信信号ＣＳ２（Ｈ）とは、同一周波数、同一偏波の信号である。そして、第１の衛星通信信号ＣＳ１（Ｖ）、第３の衛星通信信号ＣＳ２（Ｖ）と、第２の衛星通信信号ＣＳ１（Ｈ）、第４の衛星通信信号ＣＳ２（Ｈ）とは、周波数帯が一部重複している。
【００２８】
従って、もし、コンバータ２０、２２の局部発振信号の周波数が１種類だけであると、ほぼ周波数帯が同一の４つの衛星通信中間周波信号が生成されることになる。しかし、この衛星信号受信システムでは、コンバータ２０、２４の局部発振周波数を２種類にしているので、同一の衛星からの衛星通信信号は、異なる周波数の中間周波信号に変換されている。なお、この各衛星通信中間周波信号の周波数は、衛星放送中間周波信号と周波数が完全に異なっている。
【００２９】
第１の衛星通信中間周波信号ＣＳ１−ＩＦ（Ｖ）と第２の衛星通信中間周波信号ＣＳ１−ＩＦ（Ｈ）とは、混合器２６において混合される。以下、この混合出力を、第１衛星中間周波信号ＣＳ１−ＩＦと称する。第３の衛星通信中間周波信号ＣＳ２−ＩＦ（Ｖ）と第４の衛星通信中間周波信号ＣＳ２−ＩＦ（Ｈ）も、混合器２８において混合される。以下、この混合出力を、第２衛星中間周波信号ＣＳ２−ＩＦと称する。なお、第１及び第２衛星中間周波信号の周波数帯は、衛星放送中間周波信号ＢＳ−ＩＦと一部で重複している。
【００３０】
第１衛星中間周波信号ＣＳ１−ＩＦは、増幅器３０の第１の増幅部３０ａによって増幅され、第１の分配手段、例えば４分配器３２に供給される。第２衛星中間周波信号ＣＳ２−ＩＦは、増幅器３０の第２の増幅部３０ｂによって増幅され、第２の分配手段、例えば４分配器３４に供給される。増幅器３０は、第１及び第２の増幅部３０ａ、３０ｂを１つの筐体内に収容した２入力２出力の増幅器である。
【００３１】
図３に示すように、筐体内に設けられた定電圧回路３０ｃが外部から供給された商用交流電圧を整流、平滑、定電圧化した直流電圧によって、第１及び第２の増幅部３０ａ、３０ｂは動作する。また、これら第１及び第２の増幅部３０ａ、３０ｂの入出力間には、直流電圧をバイパスするための高周波阻止コイル３０ｄ、３０ｅが設けられ、また、第１及び第２の増幅部３０ａ、３０ｂの入力側、出力側には、それぞれ直流阻止コンデンサ３０ｆ、３０ｇ、３０ｈ、３０ｉが設けられている。即ち、これら第１及び第２の増幅部３０ａ、３０ｂは、通電型のものである。
【００３２】
４分配器３２の各分配出力は、切換手段、例えばトーン切換器３６、３８、４０、４２に供給されている。同様に、４分配器３４の各分配出力も、トーン切換器３６、３８、４０、４２に供給されている。トーン切換器３６、３８、４０、４２の出力は、１本の伝送線路、例えば同軸ケーブル４４、４６、４８、５０を介して第１の端子である端子５２１、５２２、５２３、５２４にそれぞれ接続されている。
【００３３】
各端子５２１、５２２、５２３、５２４は、端子１４１、１４２、１４３、１４４とそれぞれ対に設けられており、受信手段、例えばレシーバを介してテレビジョン受像機に接続されている。図１では、代表としてレシーバ５４とテレビジョン受像機１６を示している。
【００３４】
レシーバ５４は、第１衛星中間周波信号ＣＳ１−ＩＦまたは第２衛星中間周波信号ＣＳ２−ＩＦが端子５２１を介して供給されると、これをテレビジョン受像機１６によって受信可能に復調する。また、レシーバ５４は、切換信号を生成可能に形成されている。即ち、図４（ａ）に示すような直流電圧または、同図（ｂ）に示すようなこの直流電圧に交番電圧、例えば３２ｋＨｚ乃至５３ｋＨｚのパルス電圧（トーン信号）が重畳された電圧を、生成可能に形成されている。これら電圧のいずれか一方は、端子５２１、伝送線路４４を介してトーン切換器３６に供給される。なお、直流電圧としては、＋１１Ｖと＋１５Ｖとがある。
【００３５】
トーン切換器３６、３８、４０、４２は、例えば図５に示すように、端子５２１、５２２、５２３または５２４に接続される出力端子５７と、分配器３２の分配出力（第１衛星中間周波信号ＣＳ１−ＩＦの分配出力）が供給される入力端子５６と、分配器３４の分配出力（第２衛星中間周波信号ＣＳ２−ＩＦの分配出力）が供給される入力端子５８とを有している。
【００３６】
入力端子５６に切換スイッチ６０の接点６０ａが接続され、入力端子５８に切換スイッチ６０の接点６０ｂが接続され、切換スイッチ６０の接触子６０ｃが出力端子５７に接続されている。この切換スイッチ６０は、切換信号が供給されていない状態で、接触子６０ｃを接点６０ａに接続し、切換信号が供給されたとき、接触子６０ｃを接点６０ｂに接続する。
【００３７】
出力端子５７には、トーンフィルタ６２が設けられている。これは、上述したトーン信号が直流電圧に重畳されているとき、これを検出し、所定の電圧を発生するものである。このトーンフィルタ６２の出力は、比較器６４に供給される。比較器６４は、トーンフィルタ６２の出力が、基準電圧源６６からの予め定めた基準電圧（上記所定電圧よりも小さい値）よりも大きな値のとき、切換信号を切換スイッチ６０に供給し、接触子６０ｃを接点６０ａに接触させ、トーン信号が検出されないとき、接触子６０ｃを接点６０ｂに接触させる。
【００３８】
従って、レシーバ５４が図４（ｂ）に示すトーン信号が重畳された直流電圧（＋１１Ｖでも＋１５Ｖでもかまわない）を発生しているとき、トーン切換器３６は、４分配器３２から供給されている第１衛星中間周波信号ＣＳ１−ＩＦをレシーバ５４に供給する。よって、レシーバ５４が、第１衛星中間周波信号ＣＳ１−ＩＦを復調し、テレビジョン受像機１６に供給することによって、第１の通信衛星からの衛星通信信号をテレビジョン受像機１６によって視聴できる。
【００３９】
なお、このとき＋１１Ｖの直流電圧が供給されていると、第１衛星中間周波信号ＣＳ１−ＩＦとして、コンバータ２０は、第１衛星通信中間周波信号ＣＳ１−ＩＦ（Ｖ）を生成する。また＋１５Ｖの直流電圧が供給されていると、第１衛星中間周波信号ＣＳ１−ＩＦとして、コンバータ２０は、第２衛星通信中間周波信号ＣＳ１−ＩＦ（Ｈ）を生成する。
【００４０】
また、レシーバ５４が図４（ａ）に示す直流電圧のみを発生しているとき、トーン切換器３６は、４分配器３４から供給されている第２衛星中間周波信号ＣＳ２−ＩＦをレシーバ５４に供給する。従って、レシーバ５４が、第２衛星中間周波信号ＣＳ２−ＩＦを復調し、テレビジョン受像機１６に供給することによって、第２の通信衛星からの衛星通信信号をテレビジョン受像機１６によって視聴できる。
【００４１】
なお、このとき＋１１Ｖの直流電圧が供給されていると、第２衛星中間周波信号ＣＳ２−ＩＦとして、コンバータ２４は、第３衛星通信中間周波信号ＣＳ２−ＩＦ（Ｖ）を生成する。また＋１５Ｖの直流電圧が供給されていると、第２衛星中間周波信号ＣＳ２−ＩＦとして、コンバータ２０は、第４衛星通信中間周波信号ＣＳ２−ＩＦ（Ｈ）を生成する。
【００４２】
なお、レシーバ５４から供給された図４（ｂ）の電圧は、切換スイッチ６０、４分配器３２、増幅器３０の高周波阻止コイル３０ｄ、混合器２６を介してコンバータ２０に供給され、コンバータ２０は、上述したように第１または第２の衛星中間周波信号ＣＳ１−ＩＦ（Ｖ）、ＣＳ１−ＩＦ（Ｈ）を生成する。同様に、レシーバ５４から供給された図４（ａ）の電圧は、切換スイッチ６０、４分配器３４、増幅器３０の高周波阻止コイル３０ｅ、混合器２８を介してコンバータ２４に供給され、コンバータ２４は上述したように第３または第４の衛星中間周波信号ＣＳ２−ＩＦ（Ｖ）、ＣＳ２−ＩＦ（Ｈ）を生成する。
【００４３】
従って、レシーバ３６は、トーン切換器を切り換えるために、コンバータ２０、２４の動作電圧以外に、特別な電圧を発生させる必要はない。無論、第１及び第２の増幅部３０ａ、３０ｂと同様に、分配器３２、３４、混合器２６、２８もコンバータ２０、２４に＋１１Ｖまたは＋１５Ｖの電圧（トーン信号が重畳されている場合もある。）を供給するために、通電型とされている。
【００４４】
このようにレシーバ５４から供給される直流電圧を１５Ｖまたは１１Ｖとするか、この１５Ｖまたは１１Ｖの電圧にパルス電圧を重畳するか否かによって、トーン切換器３６の切換と、コンバータ２０、２４が周波数変換する衛星通信信号の選択とが同時に行われる。なお、分配器３２、３４、トーン切換器３６、２８、４０、４２は、１つの筐体内に収容されて、信号分配切換器５５を構成している。分配器３２、３４とトーン切換器３６、２８、４０、４２は接近して配置されているので、分配器３２からトーン切換器３６、３８、４０、４２への配線と、分配器３４からトーン切換器３６、３８、４０、４２への配線とは、短くできる。
【００４５】
また、２基の通信衛星２０、２２からの４波の衛星通信信号をレシーバ５４において受信するにもかかわらず、レシーバ５４に接続されている端子５２１とトーン切換器３６との間には、１本の伝送線路４４が存在するだけである。
【００４６】
また、増幅器３０は、１つの筐体内に第１及び第２の増幅部３０ａ、３０ｂを有するものであるので、増幅器３０を配置し、その入力側に混合器２６、２８の出力側に接続し、その出力側を信号切換分配器５５の分配器３２、３４の入力側に接続する工事をするだけで、増幅器３０の設置が終了する。また、信号切換分配器５５も上記のように増幅器３０に接続すると共に、トーン切換器３６、３８、４０、４２の出力側を各端子５２１、５２２、５２３、５２４に接続するだけで、信号切換分配器５５の設置工事も終了する。従って、この受信システムの各部品の設置工事は容易である。
【００４７】
上記の実施の形態では、２基の通信衛星からそれぞれ送信される垂直偏波の信号は、周波数が同一で、同じく水平偏波の信号も周波数が同一で、垂直偏波と水平偏波の衛星通信信号同士は、少なくとも一部で重複するものであったが、例えば３基の通信衛星からそれぞれ送信される垂直偏波の信号は、周波数が同一で、同じく水平偏波の信号も周波数が同一で、垂直偏波と水平偏波の衛星通信信号同士は、少なくとも一部で重複するものの場合にも同様に、本発明を実施できる。但し、その場合、分配器をもう１組追加し、トーン切換器は、３つの入力端子に供給された中間周波信号のうち１つを選択するものとする必要がある。この場合、切換信号として、例えばトーン信号を含まないもの、３２ｋＨｚのトーン信号を含むもの、または５３ｋＨｚのトーン信号を含むものの３種類をレシーバ側から生成すればよい。
【００４８】
上記の実施の形態では、４つの端子に第１及び第２の衛星通信中間周波信号を切換供給するようにしたが、４つに限ったものでなく、状況に応じてその数を増減することができる。その場合、分配器３２、３４の分配数と、トーン切換器の台数とを変更する必要がある。
【００４９】
上記の実施の形態では、各レシーバから信号切換分配器を介して＋１１Ｖまたは＋１５Ｖの直流電圧をコンバータ２０、２４に供給して、これらを動作させたが、コンバータ２０を例えば＋１１Ｖの直流電圧が供給されたとき、第１及び第２の衛星通信中間周波信号ＣＳ１−ＩＦ（Ｖ）、ＣＳ１−ＩＦ（Ｈ）を生成するように構成し、かつコンバータ２４を例えば＋１１Ｖの直流電圧が供給されたとき、第３及び第４の衛星通信中間周波信号ＣＳ２−ＩＦ（Ｖ）、ＣＳ２−ＩＦ（Ｈ）を生成するように構成し、増幅器３０内に＋１１Ｖの直流電圧を生成する直流電源回路を設け、この電源回路から常時混合器２６を介してコンバータ２０へ、混合器２８を介してコンバータ２４へ、常時＋１１Ｖの直流電圧をそれぞれ供給するようにしてもよい。この場合、トーン切換器３６、３８、４０、４２から＋１１Ｖまたは＋１５Ｖの直流電圧が分配器３２、３４へ供給されないように、トーン切換器３６、３８、４０、４２において直流カットする。
【００５０】
【発明の効果】
以上のように、請求項１記載及び３記載の発明によれば、複数の衛星通信のうち任意に選択したものを、受信手段で視聴することができることを確保した上に、切換手段から端子までの間に布設する伝送線路を１本とすることができるので、その設置工事を容易にすることができる。また切換手段に切換に使用する信号が、変換手段の動作電圧を利用したものであるので、切換手段に対して切換信号の伝送用の線路を別途布設する必要がなく、設置工事を容易にすることができる。
【００５２】
請求項２記載の発明によれば、第１及び第２の静止衛星からの信号の他に、第３の静止衛星からの信号と地上波信号またはＣＡＴＶ信号も視聴可能である。
【図面の簡単な説明】
【図１】本発明の１実施の形態の衛星信号受信システムのブロック図である。
【図２】図１の衛星信号受信システムの各部の周波数関係を示す図である。
【図３】図１の衛星信号受信システムの増幅器のブロック図である。
【図４】図１の衛星信号受信システムで使用する切換信号を示す図である。
【図５】図１の衛星信号受信システムのトーン切換器のブロック図である。
【符号の説明】
２０コンバータ（第１の変換手段）
２４コンバータ（第２の変換手段）
３２３４分配器（分配手段）
３６３８４０４２トーン切換器（切換手段）
５２１、５２２、５２３、５２４端子
５４レシーバ（受信手段）[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a satellite signal receiving system that receives a signal from, for example, a broadcasting satellite or a communication satellite and distributes the signal to a plurality of terminals.
[0002]
[Prior art]
The satellite signal receiving system is used, for example, to enable each terminal to receive a satellite signal from a broadcasting satellite or a communication satellite. However, a certain communication satellite transmits at least two radio waves having different polarizations but overlapping at least in part in the frequency band, and from another communication satellite, the above two waves and the polarization and At least two waves having the same frequency band may be transmitted.
[0003]
Further, converters are attached to the antennas for receiving the radio waves from the two communication satellites, respectively. These converters convert the received communication satellite signal into an intermediate frequency signal. However, since the oscillation frequency of the local oscillator in the converter is the same in all converters for communication satellites, the frequency band of the intermediate frequency signal output from each converter is substantially the same. Therefore, when these intermediate frequency signals are transmitted through the same transmission line, each terminal cannot separate these intermediate frequency signals.
[0004]
2. Description of the Related Art Conventionally, another wiring method has been proposed in which each satellite communication intermediate frequency signal is transmitted to each terminal via a different transmission line.
[0005]
[Problems to be solved by the invention]
However, in the above separate wiring method, individual transmission lines must be provided to each terminal, and wiring of the transmission lines becomes complicated.
[0006]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a satellite signal receiving system capable of transmitting signals from satellites having at least partially overlapping frequency bands to each terminal with a small number of transmission lines. It is another object of the present invention to provide a signal distribution switching device and an amplifier used in such a system.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention according to claim 1 is characterized in that when a first DC voltage is supplied, a first satellite signal transmitted from a first geostationary satellite is converted to a first satellite intermediate frequency. When the second DC voltage is supplied to the second satellite signal, the second satellite signal transmitted from the first geostationary satellite and having a frequency band partially overlapping the first satellite signal and having a different polarization is converted to a second satellite signal. First conversion means for converting into a two-satellite intermediate frequency signal, and, when supplied with a first DC voltage, transmitted from a second geostationary satellite and having the same frequency band and polarization as the first satellite signal The third satellite signal is converted into a third intermediate frequency signal in the same frequency band as the first satellite intermediate frequency signal, and when a second DC voltage is supplied, the same frequency band and polarization as the second satellite signal are supplied. A fourth satellite signal having the same frequency band as that of the second satellite intermediate frequency signal. Second converting means for converting the first or second satellite intermediate frequency signal into a plurality of first distribution outputs, and a third or fourth satellite intermediate frequency signal. Are distributed to the same number of second distribution outputs as the first distribution output, and the first and second distribution outputs are supplied, respectively, and the first and second distribution outputs are supplied according to the switching signal. A plurality of switching means for outputting one of the divided outputs; and a plurality of receiving means for receiving and demodulating the first and second satellite intermediate frequency signals. And a first terminal for supplying the switching signal from the receiving means to the switching means. The switching signal is obtained by superimposing or not superimposing an alternating signal having a lower frequency than the first and second satellite intermediate frequency signals on the first or second DC voltage. One of the first and second distribution outputs is selected based on the presence or absence of superposition of the signal, and the DC voltage supplied to the first terminal at that time is supplied to the distribution means that outputs the selected distribution output. Supply.
[0012]
According to a second aspect of the present invention, in the satellite signal receiving system according to the first or second aspect, a third conversion for converting a fifth satellite signal transmitted from a third geostationary satellite into a third satellite intermediate frequency signal. Means, a mixing means for mixing the third satellite intermediate frequency signal from the third conversion means and a terrestrial television broadcast signal or a CATV signal, and a mixed output of the mixing means is distributed to a plurality of distributed outputs. It has a third distribution means and a second terminal to which each distribution output of the third distribution means is supplied and which is provided corresponding to each of the first terminals.
[0013]
According to the invention described in claim 2 , the mixed signal of the third satellite intermediate frequency signal and the terrestrial signal is supplied to the second terminal via the third distribution means. Therefore, by connecting the second terminal to a television receiver capable of demodulating a terrestrial or CATV signal and a third satellite intermediate frequency signal, these can also be viewed.
[0014]
According to a third aspect of the present invention, a first satellite intermediate frequency signal obtained by converting a first satellite signal transmitted from a first geostationary satellite by a first converter supplied with a first DC voltage or a second satellite intermediate frequency signal. The first converting means supplied with the DC voltage transmits the second satellite signal transmitted from the first geostationary satellite and having a polarization different from that of the first satellite signal at least in part in a frequency band to the first satellite intermediate frequency. A first distribution means of an energization type for distributing a second satellite intermediate frequency signal whose frequency band does not overlap with the signal to a plurality of first distribution outputs, and a second conversion means supplied with a first DC voltage are provided by a second conversion means. A third satellite intermediate frequency signal in the same frequency band as the first satellite intermediate frequency signal converted from a third satellite signal transmitted from two geostationary satellites and having the same frequency band and polarization as the first satellite signal, or The second converting means to which the second DC voltage is supplied from the second geostationary satellite A fourth satellite intermediate frequency signal in the same frequency band as the second satellite intermediate frequency signal converted and transmitted by the fourth satellite signal having the same frequency band and polarization as that of the second satellite signal is transmitted in the same number as the first distribution output. Second distribution means of an energizing type for distributing to the second distribution output, and the first and second distribution outputs are respectively supplied, and one of the first and second distribution outputs is connected to one transmission line. And a plurality of switching means for outputting. These switching means are configured to determine whether the alternating signal having a frequency lower than that of the first to fourth satellite intermediate frequency signals is superimposed on the first or second DC voltage in the connected transmission line. And one of the second divided outputs is output to the transmission line, and the first or second DC operating voltage supplied to the transmission line at that time is supplied to the distribution means generating the one distributed output.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
A satellite signal receiving system according to an embodiment of the present invention includes a signal from two communication satellites, a signal from one broadcast satellite, a UHF and VHF terrestrial signal in a plurality of rooms in a general home. , For viewing the CATV signal as required.
[0019]
As shown in FIG. 1, this satellite signal receiving system has a U / V antenna 2 for receiving terrestrial television signals in UHF and VHF bands. Furthermore, this satellite signal receiving system has a satellite broadcast receiving antenna 4 for receiving a satellite broadcast signal transmitted from a broadcast satellite. This satellite broadcast signal is converted into a predetermined 1 GHz band satellite broadcast intermediate frequency signal by a third converter, for example, a converter 6 attached to the satellite broadcast receiving antenna 4.
[0020]
The satellite broadcast intermediate frequency signal and the terrestrial television signal in the UHF and VHF bands are mixed by mixing means, for example, a mixer 8. In some cases, the mixer 8 may also be supplied with a CATV signal from a CATV facility. After the output signal of the mixer 8 is amplified by the amplifier 10, it is supplied to third distribution means, for example, a distributor 12, and distributed to a plurality of, for example, four distribution outputs.
[0021]
These four distributed outputs are connected to second terminals, for example, terminals 141, 142, 143, 144 provided respectively in, for example, different rooms of a general household via one transmission line, for example, one coaxial cable. Supplied. A television receiver is connected to each of these terminals 141 to 144. FIG. 1 shows a state where the television receiver 16 is connected to the terminal 141 as a representative. The operating DC voltage to the converter 6 is supplied, for example, from one of the television receivers having a built-in tuner for receiving satellite broadcasting. Therefore, the terminals 141 to 144, the distributor 12, the amplifier 10, and the mixer 8 are of a conduction type.
[0022]
The U / V antenna 2, the satellite broadcast receiving antenna 4, the converter 6, the mixer 8, the amplifier 10, the distributor 12, the terminals 141, 142, 143, and 144 may be newly provided, but are existing equipment. You may.
[0023]
This satellite signal receiving system further has a satellite communication receiving antenna 18 for receiving a satellite communication signal from the first communication satellite. As shown in FIG. 2A, the first communication satellite includes, for example, a vertically polarized first satellite communication signal CS1 (V) in a frequency band from 12.493 GHz to 12.733 GHz and a frequency band from 12.508 GHz to 12 It transmits the horizontally polarized second satellite communication signal CS1 (H) in the frequency band of .748 GHz.
[0024]
The first converter, for example, the converter 20 attached to the satellite communication receiving antenna 18 includes a local oscillator that generates a local oscillation signal of 10.678 GHz and a local oscillator that generates a local oscillation signal of 11.2 GHz. Have. When a DC voltage of +11 V is supplied as described later, the converter 20 converts the first satellite communication signal CS1 (V) into a first satellite communication intermediate frequency signal CS1-IF (V) from 1293 MHz to 1533 MHz. Convert. When a DC voltage of +15 V is supplied, converter 20 converts the frequency of second satellite communication signal CS1 (H) from 1830 MHz to a second satellite communication intermediate frequency signal CS1-IF (H) of 2070 MHz.
[0025]
This satellite signal receiving system is also provided with a satellite communication receiving antenna 22 for receiving a satellite communication signal from the second communication satellite. As shown in FIG. 2B, the second communication satellite also has a vertically polarized third satellite communication signal CS2 (V) in a frequency band of, for example, 12.493 GHz to 12.733 GHz and a frequency of 12.508 GHz to 12 The base station transmits a horizontally polarized fourth satellite communication signal CS2 (H) in a frequency band of .748 GHz.
[0026]
The second converter, for example, the converter 24 attached to the satellite communication receiving antenna 22 also includes a local oscillator that generates a local oscillation signal of 10.678 GHz and a local oscillator that generates a local oscillation signal of 11.2 GHz. Have. The converter 24 also converts the frequency of the third satellite communication signal CS2 (V) from 1293 MHz to the third satellite communication intermediate frequency signal CS2-IF (V) of 1533 MHz when a DC voltage of +11 V is supplied. When a DC voltage of +15 V is supplied, the converter 24 also converts the frequency of the fourth satellite communication signal CS2 (H) from 1830 MHz to the fourth satellite communication intermediate frequency signal CS2-IF (H) of 2070 MHz.
[0027]
As described above, the first satellite communication signal CS1 (V) and the third satellite communication signal CS2 (V) are signals having the same frequency and the same polarization, and the second satellite communication signal CS1 (H) and the second satellite communication signal CS1 (H). The satellite communication signal CS2 (H) of No. 4 is a signal having the same frequency and the same polarization. The first satellite communication signal CS1 (V), the third satellite communication signal CS2 (V), the second satellite communication signal CS1 (H), and the fourth satellite communication signal CS2 (H) The belts are partially overlapping.
[0028]
Therefore, if the local oscillation signals of converters 20 and 22 have only one type of frequency, four satellite communication intermediate frequency signals having substantially the same frequency band will be generated. However, in this satellite signal receiving system, since the local oscillation frequencies of the converters 20 and 24 are two types, satellite communication signals from the same satellite are converted into intermediate frequency signals of different frequencies. The frequency of each satellite communication intermediate frequency signal is completely different from the frequency of the satellite broadcasting intermediate frequency signal.
[0029]
The first satellite communication intermediate frequency signal CS1-IF (V) and the second satellite communication intermediate frequency signal CS1-IF (H) are mixed in the mixer 26. Hereinafter, this mixed output is referred to as a first satellite intermediate frequency signal CS1-IF. The third satellite communication intermediate frequency signal CS2-IF (V) and the fourth satellite communication intermediate frequency signal CS2-IF (H) are also mixed in the mixer 28. Hereinafter, this mixed output is referred to as a second satellite intermediate frequency signal CS2-IF. The frequency bands of the first and second satellite intermediate frequency signals partially overlap the satellite broadcast intermediate frequency signal BS-IF.
[0030]
The first satellite intermediate frequency signal CS1-IF is amplified by the first amplifier 30a of the amplifier 30, and is supplied to first distribution means, for example, a four distributor 32. The second satellite intermediate frequency signal CS2-IF is amplified by the second amplifying unit 30b of the amplifier 30, and is supplied to second distribution means, for example, a four distributor 34. The amplifier 30 is a two-input two-output amplifier in which the first and second amplifying units 30a and 30b are housed in one housing.
[0031]
As shown in FIG. 3, a constant voltage circuit 30c provided in the housing rectifies, smoothes, and converts a commercial AC voltage supplied from the outside to a first and second amplifying units 30a and 30b by using a DC voltage. Works. In addition, between the input and output of the first and second amplifiers 30a and 30b, high-frequency blocking coils 30d and 30e for bypassing a DC voltage are provided, and the first and second amplifiers 30a and 30b are provided. DC blocking capacitors 30f, 30g, 30h, and 30i are provided on the input side and the output side of 30b, respectively. That is, the first and second amplifying units 30a and 30b are of a conduction type.
[0032]
Each output of the four distributor 32 is supplied to switching means, for example, tone switches 36, 38, 40 and 42. Similarly, the respective divided outputs of the four divider 34 are also supplied to the tone switches 36, 38, 40, 42. The outputs of the tone switches 36, 38, 40, 42 are connected to first terminals 521, 522, 523, 524 via one transmission line, for example, coaxial cables 44, 46, 48, 50, respectively. Have been.
[0033]
The terminals 521, 522, 523, and 524 are provided in pairs with the terminals 141, 142, 143, and 144, respectively, and are connected to a television receiver via a receiving unit, for example, a receiver. FIG. 1 shows the receiver 54 and the television receiver 16 as representatives.
[0034]
When the first satellite intermediate frequency signal CS1-IF or the second satellite intermediate frequency signal CS2-IF is supplied via the terminal 521, the receiver 54 demodulates the signal so that the television receiver 16 can receive it. The receiver 54 is formed so as to be able to generate a switching signal. That is, a DC voltage as shown in FIG. 4A or an alternating voltage, for example, a voltage in which a pulse voltage (tone signal) of 32 kHz to 53 kHz is superimposed on this DC voltage as shown in FIG. It is formed to be possible. One of these voltages is supplied to the tone switch 36 via the terminal 521 and the transmission line 44. Note that the DC voltage includes + 11V and + 15V.
[0035]
For example, as shown in FIG. 5, the tone switches 36, 38, 40, and 42 include an output terminal 57 connected to terminals 521, 522, 523, and 524, and a distribution output of the distributor 32 (first satellite intermediate frequency signal). It has an input terminal 56 to which a distributed output of CS1-IF is supplied, and an input terminal 58 to which a distributed output of distributor 34 (a distributed output of second satellite intermediate frequency signal CS2-IF) is supplied.
[0036]
The contact 60a of the switch 60 is connected to the input terminal 56, the contact 60b of the switch 60 is connected to the input terminal 58, and the contact 60c of the switch 60 is connected to the output terminal 57. The changeover switch 60 connects the contact 60c to the contact 60a when no switching signal is supplied, and connects the contact 60c to the contact 60b when the switching signal is supplied.
[0037]
The output terminal 57 is provided with a tone filter 62. This is to detect when the tone signal described above is superimposed on the DC voltage and generate a predetermined voltage. The output of the tone filter 62 is supplied to a comparator 64. When the output of the tone filter 62 is higher than a predetermined reference voltage (a value smaller than the predetermined voltage) from the reference voltage source 66, the comparator 64 supplies a switch signal to the switch 60, and The contact 60c is brought into contact with the contact 60a, and when no tone signal is detected, the contact 60c is brought into contact with the contact 60b.
[0038]
Accordingly, when the receiver 54 is generating a DC voltage (either +11 V or +15 V) on which the tone signal shown in FIG. 4B is superimposed, the tone switch 36 is supplied from the four distributor 32. The first satellite intermediate frequency signal CS1-IF is supplied to the receiver 54. Therefore, the receiver 54 demodulates the first satellite intermediate frequency signal CS1-IF and supplies the demodulated signal to the television receiver 16, so that the satellite communication signal from the first communication satellite can be viewed by the television receiver 16.
[0039]
When a DC voltage of +11 V is supplied at this time, converter 20 generates first satellite communication intermediate frequency signal CS1-IF (V) as first satellite intermediate frequency signal CS1-IF. When a DC voltage of +15 V is supplied, converter 20 generates second satellite communication intermediate frequency signal CS1-IF (H) as first satellite intermediate frequency signal CS1-IF.
[0040]
When the receiver 54 is generating only the DC voltage shown in FIG. 4A, the tone switch 36 sends the second satellite intermediate frequency signal CS2-IF supplied from the four distributor 34 to the receiver 54. Supply. Therefore, the receiver 54 demodulates the second satellite intermediate frequency signal CS2-IF and supplies the demodulated signal to the television receiver 16, so that the satellite communication signal from the second communication satellite can be viewed by the television receiver 16.
[0041]
When a DC voltage of +11 V is supplied at this time, the converter 24 generates the third satellite communication intermediate frequency signal CS2-IF (V) as the second satellite intermediate frequency signal CS2-IF. When a DC voltage of +15 V is supplied, converter 20 generates fourth satellite communication intermediate frequency signal CS2-IF (H) as second satellite intermediate frequency signal CS2-IF .
[0042]
The voltage of FIG. 4B supplied from the receiver 54 is supplied to the converter 20 via the changeover switch 60, the four divider 32, the high-frequency blocking coil 30d of the amplifier 30, and the mixer 26. As described above, the first or second satellite intermediate frequency signals CS1-IF (V) and CS1-IF (H) are generated. Similarly, the voltage shown in FIG. 4A supplied from the receiver 54 is supplied to the converter 24 via the changeover switch 60, the four divider 34, the high-frequency blocking coil 30e of the amplifier 30, and the mixer 28. As described above, the third or fourth satellite intermediate frequency signals CS2-IF (V) and CS2-IF (H) are generated.
[0043]
Therefore, the receiver 36 does not need to generate a special voltage other than the operating voltage of the converters 20 and 24 to switch the tone switch. Of course, like the first and second amplifying units 30a and 30b, the distributors 32 and 34 and the mixers 26 and 28 also have a voltage of +11 V or +15 V (a tone signal may be superimposed on the converters 20 and 24). ) Is supplied with electricity.
[0044]
Depending on whether the DC voltage supplied from the receiver 54 is 15 V or 11 V, or whether a pulse voltage is superimposed on the 15 V or 11 V voltage, the switching of the tone switch 36 and the conversion of the converters 20 and 24 The selection of the satellite communication signal to be converted is performed at the same time. Note that the distributors 32 and 34 and the tone switches 36, 28, 40 and 42 are housed in one housing and constitute a signal distribution switch 55. Since the distributors 32, 34 and the tone switches 36, 28, 40, 42 are arranged close to each other, the wiring from the distributor 32 to the tone switches 36, 38, 40, 42 and the tone from the distributor 34 The wiring to the switches 36, 38, 40, 42 can be shortened.
[0045]
Further, although four satellite communication signals from the two communication satellites 20 and 22 are received by the receiver 54, one terminal is connected between the terminal 521 connected to the receiver 54 and the tone switch 36. There are only transmission lines 44.
[0046]
Further, since the amplifier 30 has the first and second amplifying units 30a and 30b in one housing, the amplifier 30 is arranged and connected to the output side of the mixers 26 and 28 at its input side. The installation of the amplifier 30 is completed simply by connecting the output side to the input sides of the distributors 32 and 34 of the signal switching distributor 55. The signal switching distributor 55 is connected to the amplifier 30 as described above, and the signal switching is performed only by connecting the output sides of the tone switches 36, 38, 40 and 42 to the terminals 521, 522, 523 and 524. The installation work of the distributor 55 is also completed. Therefore, installation work of each component of the receiving system is easy.
[0047]
In the above embodiment, the vertically polarized signals transmitted from the two communication satellites have the same frequency, the horizontally polarized signal has the same frequency, and the vertically polarized and horizontally polarized satellites have the same frequency. The communication signals overlap at least in part. For example, vertically polarized signals transmitted from three communication satellites have the same frequency, and similarly horizontally polarized signals have the same frequency. The present invention can be similarly applied to the case where the vertically and horizontally polarized satellite communication signals overlap at least partially. However, in that case, it is necessary to add another pair of distributors, and the tone switch should select one of the intermediate frequency signals supplied to the three input terminals. In this case, three types of switching signals, for example, a signal not including a tone signal, a signal including a 32 kHz tone signal, and a signal including a 53 kHz tone signal may be generated from the receiver side.
[0048]
In the above embodiment, the first and second satellite communication intermediate frequency signals are switched and supplied to the four terminals. However, the number is not limited to four, and the number may be increased or decreased according to the situation. Can be. In that case, it is necessary to change the number of distributors 32 and 34 and the number of tone switches.
[0049]
In the above-described embodiment, a DC voltage of +11 V or +15 V is supplied from each receiver to the converters 20 and 24 via the signal switching distributor, and these converters are operated. However, the DC voltage of +11 V is supplied to the converter 20, for example. The first and second satellite communication intermediate frequency signals CS1-IF (V) and CS1-IF (H) are generated when the converter 24 is supplied with a DC voltage of, for example, + 11V. , A third and fourth satellite communication intermediate frequency signals CS2-IF (V), CS2-IF (H), and a DC power supply circuit for generating a DC voltage of + 11V in the amplifier 30; A DC voltage of +11 V may always be supplied from the power supply circuit to the converter 20 via the mixer 26 and to the converter 24 via the mixer 28. . In this case, the DC is cut in the tone switches 36, 38, 40, 42 so that the DC voltage of +11 V or +15 V is not supplied from the tone switches 36, 38, 40, 42 to the distributors 32, 34.
[0050]
【The invention's effect】
As described above, according to the first and third aspects of the present invention, it is possible to ensure that the arbitrarily selected one of the plurality of satellite communications can be viewed and received by the receiving means, and that the switching means to the terminal are provided. Since only one transmission line can be laid between them, the installation work can be facilitated. Further, since the signal used for switching in the switching means utilizes the operating voltage of the conversion means, there is no need to separately lay a transmission signal transmission line for the switching means, which facilitates installation work. be able to.
[0052]
According to the second aspect of the present invention, in addition to the signals from the first and second geosynchronous satellites, the signals from the third geosynchronous satellite and the terrestrial signal or the CATV signal can be viewed.
[Brief description of the drawings]
FIG. 1 is a block diagram of a satellite signal receiving system according to an embodiment of the present invention.
FIG. 2 is a diagram showing a frequency relationship of each part of the satellite signal receiving system of FIG. 1;
FIG. 3 is a block diagram of an amplifier of the satellite signal receiving system of FIG. 1;
FIG. 4 is a diagram showing a switching signal used in the satellite signal receiving system of FIG. 1;
FIG. 5 is a block diagram of a tone switch of the satellite signal receiving system of FIG. 1;
[Explanation of symbols]
20 converter (first conversion means)
24 converter (second conversion means)
32 34 Distributor (distribution means)
36 38 40 42 Tone switch (switching means)
521, 522, 523, 524 Terminal 54 Receiver (receiving means)

Claims

When the first DC voltage is supplied, the first satellite signal transmitted from the first geosynchronous satellite is converted into a first satellite intermediate frequency signal, and when the second DC voltage is supplied, the first satellite signal is transmitted. First conversion means for converting a second satellite signal transmitted from one geostationary satellite, the frequency band of which partially overlaps with the first satellite signal, and having a different polarization into a second satellite intermediate frequency signal;
When the first DC voltage is supplied, the third satellite signal transmitted from the second geostationary satellite and having the same frequency band and polarization as the first satellite signal is converted to the same frequency as the first satellite intermediate frequency signal. And converting the fourth satellite signal having the same frequency band and polarization as that of the second satellite signal into a second satellite intermediate frequency signal when a second DC voltage is supplied. A second converting means for converting into a fourth satellite intermediate frequency signal in the same frequency band as:
Energized first distribution means for distributing the first or second satellite intermediate frequency signal to a plurality of first distribution outputs;
Conducting second distributing means for distributing the third or fourth satellite intermediate frequency signal to the same number of second distributed outputs as the first distributed output;
A plurality of switching means to which the first and second distribution outputs are respectively supplied and which outputs one of the first and second distribution outputs in response to the switching signal;
These switching means are interposed between the plurality of receiving means for receiving and demodulating the first and second satellite intermediate frequency signals, and output signals from the switching means are supplied to the receiving means. A first terminal for supplying the switching signal to the switching means;
Wherein the switching signal is obtained by superimposing or not superimposing an alternating signal having a frequency lower than that of the first and second satellite intermediate frequency signals on the first or second DC voltage. One of the first and second distribution outputs is selected based on the presence or absence of the alternating signal, and the selected distribution output is supplied to the first terminal at that time. A satellite signal receiving system for supplying the DC voltage ;

The satellite signal receiving system according to claim 1,
Third conversion means for converting a fifth satellite signal transmitted from a third geostationary satellite into a third satellite intermediate frequency signal;
Mixing means for mixing the third satellite intermediate frequency signal from the third conversion means and a terrestrial television broadcast signal or CATV signal;
Third distribution means for distributing the mixed output of the mixing means to a plurality of distribution outputs;
Each of the divided outputs of the third distributing means is supplied, and the second terminals provided in correspondence with the first terminals, respectively,
Satellite signal receiving system provided.

The first converting means to which the first DC voltage is supplied converts the first satellite signal transmitted from the first geostationary satellite to the first satellite intermediate frequency signal or the first to which the second DC voltage is supplied. The converting means converts a second satellite signal transmitted from the first geostationary satellite, which has a frequency band at least partially overlapped with the first satellite signal and has a different polarization, to a signal whose frequency band is not overlapped with the first satellite intermediate frequency signal. Energizing first distribution means for distributing the second satellite intermediate frequency signal to a plurality of first distribution outputs;
A first satellite intermediate frequency converted from a second satellite supplied with the first DC voltage and converted from a third satellite signal transmitted from the second geostationary satellite and having the same frequency band and polarization as the first satellite signal. A third satellite intermediate frequency signal in the same frequency band as the signal or a second converter supplied with a second DC voltage is transmitted from the second geostationary satellite and transmitted in the same frequency band and polarization as the second satellite signal. Second distribution means for distributing the fourth satellite intermediate frequency signal in the same frequency band as the converted second satellite intermediate frequency signal having the fourth satellite signal to the same number of second distribution outputs as the first distribution output When,
A plurality of switching means to which the first and second distribution outputs are supplied, respectively, and which outputs one of the first and second distribution outputs to one transmission line, wherein the switching means comprises: In the connected transmission line, first and second distributions are performed based on whether an alternating signal having a lower frequency than the first to fourth satellite intermediate frequency signals is superimposed on the first or second DC voltage. Then the transmission line was first or being supplied to the satellite signal reception system is supplied to the distributing means occurring distribution output of the one of the second DC operating voltage outputs one of the outputs to the transmission line Signal distribution switching device.