JP2004023534A

JP2004023534A - Communication terminal

Info

Publication number: JP2004023534A
Application number: JP2002177099A
Authority: JP
Inventors: Takehiko Suyama; 巣山　武彦
Original assignee: Kenwood KK
Current assignee: Kenwood KK
Priority date: 2002-06-18
Filing date: 2002-06-18
Publication date: 2004-01-22
Anticipated expiration: 2022-06-18
Also published as: JP3830097B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a smaller-sized, low-cost communication terminal which can transmit and receive signals of a plurality of frequency bands and has advanced features with improved transmission/reception characteristics. <P>SOLUTION: A communication terminal 100 comprises a transmitting unit 101 and a receiving unit 102 which are each equipped with an antenna and a duplexer independently. Namely, in the communication terminal 100, the transmitting unit 101 is equipped with an antenna 111 and a duplexer 131 and the receiving unit 102 is equipped with an antenna 112 and a duplexer 132, respectively. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は通信端末に関する。
【０００２】
【従来の技術】
近時、ＰＤＣ（Ｐｅｒｓｏｎａｌ　Ｄｉｇｉｔａｌ　Ｃｅｌｌｕｌａｒ）方式やＷ−ＣＤＭＡ（Ｗｉｄｅ　ｂａｎｄ−Ｃｏｄｅ　Ｄｉｖｉｓｉｏｎ　Ｍｕｌｔｉｐｌｅ　Ａｃｃｅｓｓ）方式等の複数の周波数帯域の通信方式で音声やデータ等の信号の送受信が行える携帯電話等のマルチバンド通信端末が考案されている。ＰＤＣ方式（１．５ＧＨｚ帯）の周波数帯域は、送信信号が１４２９〜１４５３ＭＨｚであり、受信信号が１４７７〜１５０１ＭＨｚとなっている。またＷ−ＣＤＭＡ方式の周波数帯域は、送信信号が１９２０〜１９８０ＭＨｚであり、受信信号が２１１０〜２１７０ＭＨｚとなっている。なおＰＤＣ方式やＷ−ＣＤＭＡ方式以外にＧＳＭ（Ｇｌｏｂａｌ　Ｓｙｓｔｅｍ　ｆｏｒ　Ｍｏｂｉｌｅ　Ｃｏｍｍｕｎｉｃａｔｉｏｎｓ）方式やＤＣＳ（Ｄｉｇｉｔａｌ　Ｃｏｍｍｕｎｉｃａｔｉｏｎ　Ｓｙｓｔｅｍ）方式等、他の通信方式も存在する。
【０００３】
上記通信端末の一例として、二つの通信方式（例えば、ＰＤＣ方式及びＷ−ＣＤＭＡ方式であり、以下、それぞれ通信方式Ａ、通信方式Ｂという）に基づいて音声やデータ等の信号の送受信を行う携帯端末２００の主要構成のブロック図を図２に示す。携帯電話２００は、一つのアンテナ２０１のみを用いて、二つの異なる通信方式Ａ及びＢに基づく音声やデータ等の信号の送受信を行う。
【０００４】
図２に示すように、通信端末２００は、アンテナ２０１、送信出力監視回路２０２、デュプレクサ（ＤＰＵ；ＤＵＰｌｅｘｅｒ）２０３、２０４ａ、２０４ｂ、送信装置２０５ａ、２０５ｂ、受信装置２０６ａ、２０６ｂ等を備えて構成される。通信方式Ａに基づく送信装置２０５ａ及び受信装置２０６ａと、通信方式Ｂに基づく送信装置２０５ｂ及び受信装置２０６ｂとは、三つのデュプレクサ２０４ａ、２０４ｂ及び２０３と一つの送信出力監視回路２０２とを介して一本のアンテナ２０１に接続されている。すなわちアンテナ２０１は送信受信共用アンテナである。
【０００５】
この場合、同一通信方式における送信信号と受信信号の各周波数帯域は互いに近接しているので、通信方式Ａにおける送信信号と受信信号とを分離するデュプレクサ２０４ａと、通信方式Ｂにおける送信信号と受信信号とを分離するデュプレクサ２０４ｂとは共にシャープな（すなわち、互いに近接する周波数の送信信号と受信信号とを正確に分離可能な）減衰特性を有する高性能なデュプレクサでなければならない。
【０００６】
また上記通信端末の他の一例として、二つの通信方式Ａ及びＢに基づいて音声やデータ等の信号の送受信を行う通信端末３００の主要構成のブロック図を図３に示す。通信端末３００は、二つのアンテナ、すなわち通信方式Ａ用のアンテナ３０１ａ及び通信方式Ｂ用のアンテナ３０１ｂを用いて二つの異なる通信方式Ａ及びＢに基づく音声やデータ等の信号の送受信を行う。
【０００７】
図３に示すように、通信端末３００は、アンテナ３０１ａ、デュプレクサ３０２ａ、送信出力監視回路３０３ａ、送信装置３０４ａ及び受信装置３０５ａ（以上、通信方式Ａに基づく）と、アンテナ３０１ｂ、デュプレクサ３０２ｂ、送信出力監視回路３０３ｂ、送信装置３０４ｂ及び受信装置３０５ｂ（以上、通信方式Ｂに基づく）とを備えて構成される。すなわち、通信方式Ａに基づく送信装置３０４ａ及び受信装置３０５ａは、通信方式Ａに基づく送信出力監視回路３０３ａとデュプレクサ３０２ａとを介して通信方式Ａ用のアンテナ３０１ａに接続され、通信方式Ｂに基づく送信装置３０４ｂ及び受信装置３０５ｂは、通信方式Ｂに基づく送信出力監視回路３０３ｂとデュプレクサ３０２ｂとを介して通信方式Ｂ用のアンテナ３０１ｂに接続されている。すなわちアンテナ３０１ａは通信方式Ａの送信受信共用アンテナであり、アンテナ３０１ｂは通信方式Ｂの送信受信共用アンテナである。
【０００８】
この場合、同一通信方式における送信信号と受信信号の各周波数帯域は互いに近接しているので、通信方式Ａにおける送信信号と受信信号とを分離するデュプレクサ３０２ａと、通信方式Ｂにおける送信信号と受信信号とを分離するデュプレクサ３０２ｂとは共にシャープな（すなわち、互いに近接する周波数の送信信号と受信信号とを正確に分離可能な）減衰特性を有する高性能なデュプレクサでなければならない。
【０００９】
【発明が解決しようとする課題】
しかし、上記従来の通信端末２００及び３００には、以下に示す問題点がある。
送信信号を通過させるデュプレクサは送信信号の通過に必要な耐電力を確保するの為に大型なものとなっている。このようなデュプレクサを計三つ（デュプレクサ２０３、２０４ａ及び２０４ｂ）備える通信端末２００と、計二つ（デュプレクサ３０２ａ及び３０２ｂ）備える通信端末３００とは、共に回路の規模が大きくなり通信端末の小型化を図ることが困難となる。
また通信端末２００では、通信方式Ａ及びＢの送受信信号が何れも二つのデュプレクサ（通信方式Ａ側ではデュプレクサ２０３とデュプレクサ２０４ａ、通信方式Ｂ側ではデュプレクサ２０３とデュプレクサ２０４ｂ）を経なければならず、この為、送信信号の通過ロスが増大して送受信特性の低下（電流増、Ｎ／Ｆ値増）を招くこととなる。この場合、上記増大した通過ロスに対応できる送信系終段増幅器は少数の限られたタイプのみとなり、当該送信系終段増幅器の選択肢の幅が狭まれることとなる。
また通信端末２００では、送信出力監視回路２０２がアンテナ２０１とデュプレクサ２０３との間に設けられている為に受信特性に対する送信出力監視回路２０２の影響を回避するのが困難となり、また通信端末３００では、二つの送信出力監視回路３０３ａ及び３０３ｂが用いられている為に回路の規模が大きくなり通信端末の小型化を図ることが困難となる。
また、通信端末２００及び３００に用いるデュプレクサ（デュプレクサ２０４ａ、２０４ｂ、３０２ａ及び３０２ｂ）は、互いに近接する周波数帯域にある同一通信方式に基づく送信信号と受信信号とを正確に分離しなければならず、シャープな減衰特性を有する高性能なデュプレクサが必要となり、この為コスト高となる。
【００１０】
本発明の課題は、複数の周波数帯域の信号の送受信が可能な通信端末において、送受信特性を向上させて高機能化を図ると共に小型化及び低コスト化を図ることである。
【００１１】
【課題を解決するための手段】
上記課題を解決するため、本発明は、
送信専用のアンテナを具備し、該送信専用のアンテナを介して複数の通信方式に基づく送信信号を送信する送信部と、
受信専用のアンテナを具備し、該受信専用のアンテナを介して前記複数の通信方式に基づく受信信号を受信する受信部と、
を備えたことを特徴とする。
【００１２】
更に、前記送信部は、
前記複数の通信方式に各々対応する複数の送信装置と、
前記複数の送信装置から送信される前記複数の通信方式に基づく送信信号を統合して前記送信専用のアンテナに出力する送信信号統合部とを具備し、
前記受信部は、
前記複数の通信方式に各々対応する複数の受信装置と、
前記受信専用のアンテナを介して受信される信号を前記通信方式毎に弁別して各々対応する通信方式の前記受信装置に出力する受信信号弁別部とを具備するのが好ましい。
【００１３】
また上記課題を解決するため、本発明は、
送信専用のアンテナを具備し、該送信専用のアンテナを介して複数の周波数帯域の送信信号を送信する送信部と、
受信専用のアンテナを具備し、該受信専用のアンテナを介して前記複数の周波数帯域の受信信号を受信する受信部と、
を備えたことを特徴とする。
【００１４】
更に、前記送信部は、
前記複数の周波数帯域に各々対応する複数の送信装置と、
前記複数の送信装置から送信される前記複数の周波数帯域の送信信号を統合して前記送信専用のアンテナに出力する送信信号統合部とを具備し、
前記受信部は、
前記複数の周波数帯域に各々対応する複数の受信装置と、
前記受信専用のアンテナを介して受信される信号を前記周波数帯域毎に弁別して各々対応する周波数帯域の前記受信装置に出力する受信信号弁別部とを具備するのが好ましい。
【００１５】
【発明の実施の形態】
以下、図１を参照して本発明の実施の形態における通信端末１００について詳細に説明する。
【００１６】
図１は、通信端末１００の主要構成を示すブロック図である。通信端末１００は、二つの通信方式Ａ及びＢ（例えば、ＰＤＣ方式及びＷ−ＣＤＭＡ方式等）に基づいて音声やデータ等の信号の送受信を行う。
【００１７】
図１に示すように、通信端末１００は、信号を送信する送信部１０１と信号を受信する受信部１０２とを各々独立して備える。なお、図示及び説明簡略化の為、通信端末１００の通信処理を制御する制御部等についての図示及び説明を省略する。
【００１８】
まず送信部１０１の構成を説明する。送信部１０１はアンテナ１１１、送信出力監視回路１２０、デュプレクサ１３１、送信装置１４０ａ及び１４０ｂ等を備える。ここで、送信部１０１は本発明の請求項に記載された送信部が有する機能を実現し、アンテナ１１１は送信専用のアンテナが有する機能を実現し、デュプレクサ１３１は送信信号統合部が有する機能を実現し、デュプレクサ１３２は受信信号弁別部が有する機能を実現し、送信装置１４０ａ及び１４０ｂは複数の送信装置が有する機能を実現する。
【００１９】
アンテナ１１１は送信専用のアンテナであり、送信出力監視回路１２０及びデュプレクサ１３１を介して通信方式Ａに基づく送信装置１４０ａと通信方式Ｂに基づく送信装置１４０ｂとに接続されている。送信出力監視回路１２０は、アンテナ１１１から外部に送信される送信信号の出力の低下を防止する為の回路である。
【００２０】
デュプレクサ１３１は、誘電体フィルタ等により構成され、送信装置１４０ａから出力される通信方式Ａに基づく送信信号Ａと、送信装置１４０ｂから出力される通信方式Ｂに基づく送信信号Ｂとを統合して後段に配設された送信出力監視回路１２０に出力する。この場合デュプレクサ１３１は、上記送信信号Ａ及びＢの周波数帯域の外にある周波数の信号を阻止及び抑圧して当該送信信号Ａ及びＢのみを通過させる。
【００２１】
この場合、送信信号Ａ及びＢの周波数帯域は互いに十分隔離している（例えば、通信方式ＡをＰＤＣ（１．５ＧＨｚ帯）方式に、通信方式をＷ−ＣＤＭＡ方式に設定した場合、ＰＤＣ方式（１．５ＧＨｚ帯）の送信信号の周波数帯域は１４２９〜１４５３ＭＨｚであり、Ｗ−ＣＤＭＡ方式の送信信号の周波数帯域は１９２０〜１９８０ＭＨｚであり、互いに十分離隔している）ので、デュプレクサ１３１は、送信信号Ａ及びＢのみ統合して容易に通過させることができる。
【００２２】
送信装置１４０ａは送信信号Ａを出力する通信方式Ａに基づく送信処理を行い、送信装置１４０ｂは送信信号Ｂを出力する通信方式Ｂに基づく送信処理を行う。
【００２３】
次に受信部１０２の構成を説明する。受信部１０２はアンテナ１１２、デュプレクサ１３２、受信装置１４１ａ及び１４１ｂ等を備える。ここで、受信部１０２は本発明の請求項に記載された受信部が有する機能を実現し、アンテナ１１２は受信専用のアンテナが有する機能を実現し、デュプレクサ１３２は受信信号弁別部が有する機能を実現し、受信装置１４１ａ及び１４１ｂは複数の受信装置が有する機能を実現する。
【００２４】
アンテナ１１２は受信専用のアンテナであり、デュプレクサ１３２を介して通信方式Ａに基づく受信装置１４１ａと通信方式Ｂに基づく受信装置１４１ｂとに接続されている。
【００２５】
デュプレクサ１３２は、表面弾性波フィルタ等により構成され、アンテナ１１２により受信された受信信号から通信方式Ａに基づく受信信号Ａと通信方式Ｂに基づく受信信号Ｂとを分離して当該受信信号Ａを受信装置１４１ａに出力すると共に当該受信信号Ｂを受信装置１４１ｂに出力する。この場合デュプレクサ１３２は、上記受信信号Ａ及びＢの周波数帯域の外にある周波数の信号を阻止及び抑圧して当該受信信号Ａ及びＢのみを通過させる。
【００２６】
ここで、受信信号Ａ及びＢの周波数帯域は互いに十分隔離している（例えば、通信方式ＡをＰＤＣ（１．５ＧＨｚ帯）方式に、通信方式をＷ−ＣＤＭＡ方式に設定した場合、ＰＤＣ方式（１．５ＧＨｚ帯）の受信信号の周波数帯域は１４７７〜１５０１ＭＨｚであり、Ｗ−ＣＤＭＡ方式の受信信号の周波数帯域は２１１０〜２１７０ＭＨｚであり、互いに十分離隔している）ので、デュプレクサ１３２は、受信信号Ａ及び受信信号Ｂの弁別が容易に行える。
【００２７】
受信装置１４１ａは受信信号Ａを受信する通信方式Ａに基づく受信処理を行い、受信装置１４１ｂは受信信号Ｂを受信する通信方式Ｂに基づく受信処理を行う。
【００２８】
以上説明したように、通信端末１００は、送信部１０１と受信部１０２とを独立して備え、送信部１０１では送信専用のアンテナ１１１がデュプレクサ１３１を介して送信装置１４０ａ及び１４０ｂに接続され、受信部１０２では受信専用のアンテナ１１２がデュプレクサ１３２を介して受信装置１４１ａ及び１４１ｂに接続される。
【００２９】
従って、受信部１０２のデュプレクサ１３２は、受信専用となっており送信信号を通過させるものではないので、受信信号を通過させる際に必要な耐電力を低く設計できる。この為、デュプレクサ１３２には小さなデュプレクサが利用でき、その結果、通信端末１００の小型化が可能になる。
【００３０】
また、送信部１０１のデュプレクサ１３１は互いに周波数帯域が離隔した通信方式Ａ及びＢの送信信号を通過させ、受信部１０２のデュプレクサ１３２も互いに周波数帯域が離隔した通信方式Ａ及びＢの受信信号を通過させるので、これらデュプレクサ１３１及び１３２は共にシャープな減衰特性を有する必要がない。この為、生産性（歩止まり）の向上と生産コストの削減が可能となる。
この場合、デュプレクサ１３１及び１３２における送信信号及び受信信号の通過ロスが低減化されるので、送受信特性の低下（電流増、Ｎ／Ｆ値増）が回避され、送信装置１４０ａ及び１４０ｂの電流低減化、低歪化や、受信装置１４１ａ及び１４１ｂのＮ／Ｆ値の改善、受信感度の改善等の効果が実現できる。
更にこの場合、デュプレクサ１３１における送信信号の通過ロスが低減化されるので、送信系終段増幅器の選択肢が増えることとなり、その結果、設計の自由度が向上し、より安価なデバイスを選択することができてコストの低減化が可能となる。また、デュプレクサ１３２における受信信号の通過ロスが低減化されるので、受信系初段増幅器の選択肢が増えることとなり、その結果、設計の自由度が向上し、より安価なデバイスを選択することができると共にコストの低減化が実現できる
【００３１】
また、送信部１０１と受信部１０２が互いに独立して設けられているので、送信信号と受信信号とが確実に分離できる。
【００３２】
また、送信専用のアンテナ１１１と受信専用のアンテナ１１２とが各々独立して設けられているので、送受信で各々好適な指向性や利得、或いは設置場所等を自由に設定できる。
【００３３】
すなわち、複数の周波数帯域の信号の送受信が可能な通信端末１００によれば、送受信特性が向上して高機能化が図られると共に小型化及び低コスト化が図られる。
【００３４】
なお、本実施の形態における記述は、本発明に係る通信端末の一例を示すものであり、これに限定されるものではない。本実施の形態の通信端末１００の細部構成及び詳細動作に関しては、本発明の趣旨を逸脱しない範囲で適宜変更可能である。
【００３５】
例えば、通信端末１００を、二つの通信方式Ａ及びＢ（例えば、ＰＤＣ方式やＷ−ＣＤＭＡ方式等の通信方式）に基づくデュアルバンドの通信端末としたが、これに限らず、アンテナ及びデュプレクサを送信部１０１と受信部１０２とで各々独立して設ける本発明の技術思想は、ＧＳＭ（Ｇｌｏｂａｌ　Ｓｙｓｔｅｍ　ｆｏｒ　Ｍｏｂｉｌｅ　Ｃｏｍｍｕｎｉｃａｔｉｏｎｓ）方式やＤＣＳ（Ｄｉｇｉｔａｌ　Ｃｏｍｍｕｎｉｃａｔｉｏｎ　Ｓｙｓｔｅｍ）方式等の他の通信方式を含めた三種類以上の通信方式で信号の送受信を行う通信端末に対しても適用可能である。
【００３６】
【発明の効果】
本発明によれば、複数の周波数帯域の信号の送受信が可能な通信端末において、送受信特性が向上して高機能化が図られると共に小型化及び低コスト化が図られる。
【図面の簡単な説明】
【図１】本発明を適用した通信端末の主要構成を示すブロック図である。
【図２】従来の通信端末の主要構成の一例を示すブロック図である。
【図３】従来の通信端末の主要構成の他の一例を示すブロック図である。
【符号の説明】
１００　通信端末
１０１　送信部
１０２　受信部
１１１、１１２　アンテナ
１２０　送信出力監視回路
１３１、１３２　デュプレクサ
１４０ａ、１４０ｂ　送信装置
１４１ａ、１４１ｂ　受信装置[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a communication terminal.
[0002]
[Prior art]
2. Description of the Related Art Recently, a multi-band such as a mobile phone that can transmit and receive signals such as voice and data using a communication system of a plurality of frequency bands such as a PDC (Personal Digital Cellular) system and a W-CDMA (Wide band-Code Division Multiple Access) system. Communication terminals have been devised. In the frequency band of the PDC system (1.5 GHz band), a transmission signal is 1429 to 1453 MHz, and a reception signal is 1477 to 1501 MHz. In the frequency band of the W-CDMA system, a transmission signal is 1920 to 1980 MHz, and a reception signal is 2110 to 2170 MHz. In addition to the PDC system and the W-CDMA system, there are other communication systems such as a GSM (Global System for Mobile Communications) system and a DCS (Digital Communication System) system.
[0003]
As an example of the communication terminal, a portable terminal that transmits and receives signals such as voice and data based on two communication schemes (for example, a PDC scheme and a W-CDMA scheme, hereinafter referred to as a communication scheme A and a communication scheme B, respectively). FIG. 2 is a block diagram of a main configuration of the terminal 200. The mobile phone 200 transmits and receives signals such as voice and data based on two different communication systems A and B using only one antenna 201.
[0004]
As shown in FIG. 2, the communication terminal 200 includes an antenna 201, a transmission output monitoring circuit 202, a duplexer (DPU; DUPlexer) 203, 204a, 204b, transmitting devices 205a, 205b, receiving devices 206a, 206b, and the like. You. The transmitting device 205a and the receiving device 206a based on the communication system A and the transmitting device 205b and the receiving device 206b based on the communication system B are connected to each other via three duplexers 204a, 204b and 203 and one transmission output monitoring circuit 202. It is connected to the antenna 201 of the book. That is, the antenna 201 is a shared antenna for transmission and reception.
[0005]
In this case, since the frequency bands of the transmission signal and the reception signal in the same communication scheme are close to each other, the duplexer 204a that separates the transmission signal and the reception signal in the communication scheme A, and the transmission signal and the reception signal in the communication scheme B The duplexer 204b must be a high-performance duplexer having sharp attenuation characteristics (that is, capable of accurately separating transmission signals and reception signals of frequencies close to each other).
[0006]
As another example of the communication terminal, FIG. 3 shows a block diagram of a main configuration of a communication terminal 300 that transmits and receives signals such as voice and data based on two communication systems A and B. The communication terminal 300 transmits and receives signals such as voice and data based on two different communication systems A and B using two antennas, that is, an antenna 301a for the communication system A and an antenna 301b for the communication system B.
[0007]
As shown in FIG. 3, the communication terminal 300 includes an antenna 301a, a duplexer 302a, a transmission output monitoring circuit 303a, a transmission device 304a, and a reception device 305a (hereinafter, based on the communication system A), an antenna 301b, a duplexer 302b, It comprises a monitoring circuit 303b, a transmitting device 304b and a receiving device 305b (above, based on the communication system B). That is, the transmitting device 304a and the receiving device 305a based on the communication system A are connected to the antenna 301a for the communication system A via the transmission output monitoring circuit 303a based on the communication system A and the duplexer 302a, and transmit based on the communication system B. The device 304b and the receiving device 305b are connected to an antenna 301b for the communication system B via a transmission output monitoring circuit 303b based on the communication system B and a duplexer 302b. That is, the antenna 301a is a shared transmission and reception antenna of the communication system A, and the antenna 301b is a shared transmission and reception antenna of the communication system B.
[0008]
In this case, since the frequency bands of the transmission signal and the reception signal in the same communication scheme are close to each other, the duplexer 302a that separates the transmission signal and the reception signal in the communication scheme A, and the transmission signal and the reception signal in the communication scheme B The duplexer 302b that separates the signals must be a high-performance duplexer having sharp attenuation characteristics (that is, capable of accurately separating transmission signals and reception signals of frequencies close to each other).
[0009]
[Problems to be solved by the invention]
However, the conventional communication terminals 200 and 300 have the following problems.
A duplexer that allows a transmission signal to pass through is large in order to ensure the withstand power required to pass the transmission signal. The communication terminal 200 including three such duplexers (duplexers 203, 204a, and 204b) and the communication terminal 300 including two total (duplexers 302a and 302b) both have a large circuit scale and a small communication terminal. Is difficult to achieve.
In the communication terminal 200, both transmission / reception signals of the communication schemes A and B must pass through two duplexers (the duplexer 203 and the duplexer 204a on the communication scheme A side, and the duplexers 203 and 204b on the communication scheme B side). For this reason, the transmission loss of the transmission signal increases, and the transmission / reception characteristics deteriorate (current increase, N / F value increase). In this case, only a limited number of transmission system final stage amplifiers can cope with the increased passing loss, and the range of options for the transmission system final stage amplifier is narrowed.
Further, in the communication terminal 200, since the transmission output monitoring circuit 202 is provided between the antenna 201 and the duplexer 203, it is difficult to avoid the influence of the transmission output monitoring circuit 202 on the reception characteristics. Since the two transmission output monitoring circuits 303a and 303b are used, the scale of the circuit is increased, and it is difficult to reduce the size of the communication terminal.
In addition, the duplexers (duplexers 204a, 204b, 302a, and 302b) used for the communication terminals 200 and 300 must accurately separate a transmission signal and a reception signal based on the same communication scheme in frequency bands close to each other. A high-performance duplexer having a sharp attenuation characteristic is required, which increases the cost.
[0010]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a communication terminal capable of transmitting and receiving signals in a plurality of frequency bands, to improve transmission / reception characteristics to achieve high functionality, and to reduce the size and cost.
[0011]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides:
A transmission unit that includes a transmission-only antenna and transmits transmission signals based on a plurality of communication schemes via the transmission-only antenna,
A receiving unit that includes a reception-only antenna and receives a reception signal based on the plurality of communication schemes via the reception-only antenna,
It is characterized by having.
[0012]
Further, the transmitting unit includes:
A plurality of transmission devices respectively corresponding to the plurality of communication schemes,
A transmission signal integration unit that integrates transmission signals based on the plurality of communication systems transmitted from the plurality of transmission devices and outputs the integrated transmission signals to the transmission-only antenna,
The receiving unit,
A plurality of receiving devices respectively corresponding to the plurality of communication schemes,
It is preferable that a reception signal discriminator that discriminates a signal received via the reception-only antenna for each communication method and outputs the signal to the receiving device of the corresponding communication method is provided.
[0013]
In order to solve the above problems, the present invention provides
A transmission unit that includes a transmission-only antenna and transmits transmission signals in a plurality of frequency bands via the transmission-only antenna,
A receiving unit that includes a reception-only antenna and receives the reception signals of the plurality of frequency bands via the reception-only antenna,
It is characterized by having.
[0014]
Further, the transmitting unit includes:
A plurality of transmission devices respectively corresponding to the plurality of frequency bands,
A transmission signal integration unit that integrates the transmission signals of the plurality of frequency bands transmitted from the plurality of transmission devices and outputs the integrated signal to the transmission-only antenna,
The receiving unit,
A plurality of receiving devices respectively corresponding to the plurality of frequency bands,
It is preferable that a reception signal discriminator that discriminates a signal received via the reception-only antenna for each of the frequency bands and outputs the signal to the reception device in a corresponding frequency band is provided.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the communication terminal 100 according to the embodiment of the present invention will be described in detail with reference to FIG.
[0016]
FIG. 1 is a block diagram showing a main configuration of communication terminal 100. The communication terminal 100 transmits and receives signals such as voice and data based on two communication schemes A and B (for example, PDC scheme and W-CDMA scheme).
[0017]
As shown in FIG. 1, a communication terminal 100 includes a transmitting unit 101 for transmitting a signal and a receiving unit 102 for receiving a signal, each of which is independently provided. For simplicity of illustration and description, illustration and description of a control unit and the like for controlling communication processing of the communication terminal 100 are omitted.
[0018]
First, the configuration of the transmission unit 101 will be described. The transmission unit 101 includes an antenna 111, a transmission output monitoring circuit 120, a duplexer 131, transmission devices 140a and 140b, and the like. Here, the transmitting unit 101 implements the function of the transmitting unit described in the claims of the present invention, the antenna 111 implements the function of the antenna dedicated to transmission, and the duplexer 131 implements the function of the transmitting signal integrating unit. The duplexer 132 implements the function of the received signal discriminating unit, and the transmitting devices 140a and 140b implement the functions of a plurality of transmitting devices.
[0019]
The antenna 111 is a transmission-only antenna, and is connected to the transmission device 140a based on the communication system A and the transmission device 140b based on the communication system B via the transmission output monitoring circuit 120 and the duplexer 131. The transmission output monitoring circuit 120 is a circuit for preventing a reduction in the output of a transmission signal transmitted from the antenna 111 to the outside.
[0020]
The duplexer 131 is configured by a dielectric filter or the like, integrates a transmission signal A based on the communication system A output from the transmission device 140a, and a transmission signal B based on the communication system B output from the transmission device 140b, and integrates the latter. Is output to the transmission output monitoring circuit 120 disposed at In this case, the duplexer 131 blocks and suppresses a signal having a frequency outside the frequency band of the transmission signals A and B, and passes only the transmission signals A and B.
[0021]
In this case, the frequency bands of the transmission signals A and B are sufficiently separated from each other (for example, when the communication system A is set to the PDC (1.5 GHz band) system and the communication system is set to the W-CDMA system, the PDC system ( The frequency band of the transmission signal (1.5 GHz band) is 1429 to 1453 MHz, and the frequency band of the transmission signal of the W-CDMA system is 1920 to 1980 MHz, which are sufficiently separated from each other. Only A and B can be integrated and easily passed.
[0022]
The transmission device 140a performs a transmission process based on the communication system A that outputs the transmission signal A, and the transmission device 140b performs a transmission process based on the communication system B that outputs the transmission signal B.
[0023]
Next, the configuration of the receiving unit 102 will be described. The receiving unit 102 includes an antenna 112, a duplexer 132, receiving devices 141a and 141b, and the like. Here, the receiving unit 102 realizes the function of the receiving unit described in the claims of the present invention, the antenna 112 realizes the function of the receiving-only antenna, and the duplexer 132 performs the function of the receiving signal discriminating unit. The receiving devices 141a and 141b implement the functions of a plurality of receiving devices.
[0024]
The antenna 112 is a reception-only antenna, and is connected to a receiving device 141a based on the communication system A and a receiving device 141b based on the communication system B via the duplexer 132.
[0025]
The duplexer 132 is configured by a surface acoustic wave filter or the like, and separates a reception signal A based on the communication scheme A and a reception signal B based on the communication scheme B from a reception signal received by the antenna 112 to receive the reception signal A. The signal is output to the device 141a and the received signal B is output to the receiving device 141b. In this case, the duplexer 132 blocks and suppresses a signal having a frequency outside the frequency band of the reception signals A and B, and passes only the reception signals A and B.
[0026]
Here, the frequency bands of the received signals A and B are sufficiently separated from each other (for example, when the communication method A is set to the PDC (1.5 GHz band) method and the communication method is set to the W-CDMA method, the PDC method ( The frequency band of the received signal (1.5 GHz band) is 1477 to 1501 MHz, and the frequency band of the received signal of the W-CDMA system is 2110 to 2170 MHz, which are well separated from each other.) A and the received signal B can be easily distinguished.
[0027]
The receiving device 141a performs a receiving process based on the communication system A for receiving the received signal A, and the receiving device 141b performs a receiving process based on the communication system B for receiving the received signal B.
[0028]
As described above, the communication terminal 100 includes the transmission unit 101 and the reception unit 102 independently. In the transmission unit 101, the transmission-only antenna 111 is connected to the transmission devices 140a and 140b via the duplexer 131, In the unit 102, the reception-only antenna 112 is connected to the reception devices 141 a and 141 b via the duplexer 132.
[0029]
Accordingly, since the duplexer 132 of the receiving unit 102 is dedicated to reception and does not pass a transmission signal, it is possible to design the withstand power required for passing a reception signal low. For this reason, a small duplexer can be used for the duplexer 132, and as a result, the communication terminal 100 can be downsized.
[0030]
In addition, the duplexer 131 of the transmitting unit 101 allows transmission signals of the communication systems A and B having frequency bands separated from each other, and the duplexer 132 of the receiving unit 102 also has the reception signals of communication systems A and B having frequency bands separated from each other. Therefore, both the duplexers 131 and 132 need not have sharp attenuation characteristics. Therefore, it is possible to improve the productivity (yield) and reduce the production cost.
In this case, the transmission loss of the transmission signal and the reception signal in the duplexers 131 and 132 is reduced, so that the deterioration of the transmission / reception characteristics (increase in current and increase in N / F value) is avoided, and the current in the transmission devices 140a and 140b is reduced. In addition, effects such as low distortion, improvement of the N / F value of the receiving devices 141a and 141b, improvement of the receiving sensitivity, and the like can be realized.
Further, in this case, the transmission loss of the transmission signal in the duplexer 131 is reduced, so that the number of choices of the final amplifier in the transmission system is increased. As a result, the degree of freedom in design is improved, and a cheaper device can be selected. And the cost can be reduced. In addition, since the passing loss of the received signal in the duplexer 132 is reduced, the options of the receiving-system first-stage amplifier are increased, and as a result, the degree of freedom in design is improved, and a cheaper device can be selected. Cost reduction can be realized.
Further, since the transmission unit 101 and the reception unit 102 are provided independently of each other, the transmission signal and the reception signal can be reliably separated.
[0032]
Further, since the transmission-only antenna 111 and the reception-only antenna 112 are provided independently of each other, it is possible to freely set appropriate directivity, gain, installation location, and the like for transmission and reception.
[0033]
That is, according to the communication terminal 100 capable of transmitting and receiving signals in a plurality of frequency bands, the transmission and reception characteristics are improved, the function is enhanced, and the size and cost are reduced.
[0034]
Note that the description in the present embodiment shows an example of the communication terminal according to the present invention, and the present invention is not limited to this. The detailed configuration and operation of communication terminal 100 of the present embodiment can be appropriately changed without departing from the spirit of the present invention.
[0035]
For example, the communication terminal 100 is a dual-band communication terminal based on two communication systems A and B (for example, a communication system such as a PDC system and a W-CDMA system). However, the communication terminal 100 is not limited to this and transmits an antenna and a duplexer. The technical idea of the present invention, which is provided independently for each of the unit 101 and the receiving unit 102, is that three or more types of communication systems including other communication systems such as a GSM (Global System for Mobile Communications) system and a DCS (Digital Communication System) system. The present invention is also applicable to a communication terminal that transmits and receives a signal by a communication method.
[0036]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, in the communication terminal which can transmit and receive the signal of a several frequency band, a transmission / reception characteristic is improved, high functionality is achieved, and size reduction and cost reduction are achieved.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a main configuration of a communication terminal to which the present invention has been applied.
FIG. 2 is a block diagram illustrating an example of a main configuration of a conventional communication terminal.
FIG. 3 is a block diagram showing another example of a main configuration of a conventional communication terminal.
[Explanation of symbols]
REFERENCE SIGNS LIST 100 Communication terminal 101 Transmitter 102 Receiver 111, 112 Antenna 120 Transmission output monitoring circuit 131, 132 Duplexer 140a, 140b Transmitter 141a, 141b Receiver

Claims

A transmission unit that includes a transmission-only antenna and transmits transmission signals based on a plurality of communication schemes via the transmission-only antenna,
A receiving unit that includes a reception-only antenna and receives a reception signal based on the plurality of communication schemes via the reception-only antenna,
A communication terminal comprising:

The transmitting unit includes:
A plurality of transmission devices respectively corresponding to the plurality of communication schemes,
A transmission signal integration unit that integrates transmission signals based on the plurality of communication systems transmitted from the plurality of transmission devices and outputs the integrated transmission signals to the transmission-only antenna,
The receiving unit,
A plurality of receiving devices respectively corresponding to the plurality of communication schemes,
The reception signal discrimination unit according to claim 1, further comprising: a reception signal discrimination unit that discriminates a signal received via the reception-only antenna for each communication method and outputs the signal to the reception device of the corresponding communication method. Communication terminal.

A transmission unit that includes a transmission-only antenna and transmits transmission signals in a plurality of frequency bands via the transmission-only antenna,
A receiving unit that includes a reception-only antenna and receives the reception signals of the plurality of frequency bands via the reception-only antenna,
A communication terminal comprising:

The transmitting unit includes:
A plurality of transmission devices each corresponding to the plurality of frequency bands,
A transmission signal integration unit that integrates the transmission signals of the plurality of frequency bands transmitted from the plurality of transmission devices and outputs the integrated signal to the transmission-only antenna,
The receiving unit,
A plurality of receiving devices respectively corresponding to the plurality of frequency bands,
The reception signal discrimination unit according to claim 3, further comprising a reception signal discrimination unit that discriminates a signal received via the reception-only antenna for each of the frequency bands and outputs the signal to the reception device in a corresponding frequency band. Communication terminal.