JPH07273682A - Intermediate frequency generating system - Google Patents
Intermediate frequency generating systemInfo
- Publication number
- JPH07273682A JPH07273682A JP6060795A JP6079594A JPH07273682A JP H07273682 A JPH07273682 A JP H07273682A JP 6060795 A JP6060795 A JP 6060795A JP 6079594 A JP6079594 A JP 6079594A JP H07273682 A JPH07273682 A JP H07273682A
- Authority
- JP
- Japan
- Prior art keywords
- frequency signal
- mixer
- transmission
- local oscillator
- reception
- 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.)
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- Transceivers (AREA)
- Superheterodyne Receivers (AREA)
- Noise Elimination (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、通信機や放送受信機な
どとして用いられるＴＤＭＡ（Time Division Multiple
x Access：時分割多元接続）通信方式やＴＤＤ（Time D
ivision Duplex）通信方式の無線部における中間周波数
発生方式に関するものである。ＴＤＭＡ通信方式は、送
信すべき信号の周波数帯として各局とも同一周波数帯を
用い、時間軸上で各局が送信すべき時間を分割して使用
する方式である。ＴＤＤ通信方式は、送信すべき信号と
受信すべき信号の周波数帯として同一周波数帯を用い、
送信周波数信号と受信周波数信号とを時分割して送受信
する方式である。BACKGROUND OF THE INVENTION The present invention relates to a TDMA (Time Division Multiplexer) used as a communication device or a broadcast receiver.
x Access: Time division multiple access (TD) communication method and TDD (Time D)
ivision Duplex) The present invention relates to an intermediate frequency generation method in a wireless part of a communication method. The TDMA communication system is a system in which each station uses the same frequency band as a frequency band of a signal to be transmitted and the time to be transmitted by each station is divided and used on the time axis. The TDD communication system uses the same frequency band as a frequency band of a signal to be transmitted and a signal to be received,
This is a method of transmitting and receiving a transmission frequency signal and a reception frequency signal in a time division manner.
【０００２】[0002]
【従来の技術】従来のＴＤＭＡ通信方式の無線部におけ
る中間周波数発生方式として、図３，図４，図５に示す
３つの方式が代表的なものとして挙げられる。2. Description of the Related Art As a conventional intermediate frequency generation method in a radio section of a conventional TDMA communication method, three methods shown in FIGS. 3, 4 and 5 are representative.
【０００３】これら各図において、１は信号を電波とし
て送信したり電波を受信したりする送受信アンテナ、２
はアンテナ１が送受信を共用していることから送信時に
は送信ブロックへ接続し受信時には受信ブロックへ接続
する送受切換スイッチ、３は受信時に微小な信号を増幅
する受信系アンプ、４は受信する希望周波数の信号を通
過させその他の周波数信号を減衰させるバンドパスフィ
ルタ、５は受信した周波数信号を第１の局部発振器１６
の局発周波数信号とミキシングして周波数を下げ第１中
間周波数信号を作る第１のミキサー、６および８は送信
時と受信時とで信号の経路を切り換える切換スイッチ、
７は第１中間周波数信号だけを通過させその他の周波数
信号を減衰させるバンドパスフィルタ、９は第１中間周
波数信号と第２の局部発振器１１の局発周波数信号をミ
キシングして周波数を下げ第２中間周波数信号を作る第
２のミキサー、１０は第２中間周波数信号だけを通過さ
せその他の周波数信号を減衰させるバンドパスフィル
タ、１１はＶＣＯ部，ＰＬＬ部よりなり第２局発周波数
信号を発生させる第２の局部発振器、１２は第２の局部
発振器１１からの第２局発周波数信号および第２中間周
波数信号と同一の周波数信号をミキシングして第１中間
周波数信号と同一周波数の信号を作る第３のミキサー
（アップコンバータ）、１３は第２中間周波数信号と同
一周波数信号により送信信号に対してπ／４シフトＱＰ
ＳＫの変調をかける直交変調器、１４は第２中間周波数
信号だけを通過させその他の周波数信号を減衰させるバ
ンドパスフィルタ、１５は第１の局部発振器１６からの
第１局発周波数信号および第１中間周波数信号と同一の
周波数信号をミキシングして送信周波数信号を作る第４
のミキサー（アップコンバータ）、１６はＶＣＯ部，Ｐ
ＬＬ部よりなり第１局発周波数信号を発生させる第１の
局部発振器、１７は送信周波数信号だけを通過させその
他の周波数信号を減衰させるバンドパスフィルタ、１８
は送信周波数信号を増幅する送信系アンプである。In each of these figures, 1 is a transmitting / receiving antenna for transmitting and receiving signals as radio waves, and 2
Since the antenna 1 shares transmission and reception, the transmission / reception switch that connects to the transmission block during transmission and connects to the reception block during reception, 3 is a reception system amplifier that amplifies a minute signal during reception, and 4 is the desired frequency to be received Is a band-pass filter that passes the signal of FIG. 4 and attenuates other frequency signals, and 5 receives the received frequency signal from the first local oscillator 16
A first mixer for mixing with the local frequency signal to lower the frequency to produce a first intermediate frequency signal, 6 and 8 are changeover switches for switching the signal path between transmission and reception,
Reference numeral 7 is a band-pass filter that passes only the first intermediate frequency signal and attenuates other frequency signals, and 9 is a second lowering frequency by mixing the first intermediate frequency signal and the local oscillation frequency signal of the second local oscillator 11. A second mixer 10 for producing an intermediate frequency signal, 10 a band pass filter for passing only the second intermediate frequency signal and attenuating the other frequency signals, 11 a VCO section, a PLL section for generating a second local frequency signal A second local oscillator, 12 is a second local oscillator for mixing a frequency signal that is the same as the second local oscillator frequency signal and the second intermediate frequency signal from the second local oscillator 11 to generate a signal that has the same frequency as the first intermediate frequency signal. A mixer (up converter) 3 and a π / 4 shift QP for the transmission signal by the same frequency signal as the second intermediate frequency signal 13
A quadrature modulator for modulating SK, 14 is a band-pass filter that passes only the second intermediate frequency signal and attenuates other frequency signals, and 15 is the first local oscillator frequency signal from the first local oscillator 16 and the first local oscillator signal. Fourth, mixing the same frequency signal as the intermediate frequency signal to create a transmission frequency signal
Mixer (up converter), 16 is a VCO section, P
A first local oscillator composed of an LL section for generating a first local frequency signal, 17 is a bandpass filter for passing only a transmission frequency signal and attenuating other frequency signals, 18
Is a transmission system amplifier that amplifies a transmission frequency signal.
【０００４】図３に示す第１の従来例においては、受信
時に、送受信アンテナ１から受信された信号は、送受切
換スイッチ２、受信系アンプ３、バンドパスフィルタ４
を通り、第１のミキサー５で第１の局部発振器１６から
の第１局発周波数信号とミキシングされて第１中間周波
数信号となり、この第１中間周波数信号は、切換スイッ
チ６、バンドパスフィルタ７、切換スイッチ８を通り、
第２のミキサー９で第２の局部発振器１１からの第２局
発周波数信号とミキシングされて第２中間周波数信号と
なり、バンドパスフィルタ１０を通ってデモジュレータ
へ導かれる。In the first conventional example shown in FIG. 3, at the time of reception, the signal received from the transmission / reception antenna 1 is used as a transmission / reception changeover switch 2, a reception system amplifier 3, a bandpass filter 4.
And is mixed with the first local oscillator frequency signal from the first local oscillator 16 by the first mixer 5 to form a first intermediate frequency signal. The first intermediate frequency signal is transferred to the changeover switch 6 and the band pass filter 7. , Through the changeover switch 8,
The second mixer 9 mixes the second local oscillator frequency signal from the second local oscillator 11 into a second intermediate frequency signal, which is guided to the demodulator through the bandpass filter 10.
【０００５】送信時には、直交変調器１３において送信
信号に対して第２中間周波数信号と同一の周波数信号で
変調をかけ、バンドパスフィルタ１４によりスプリアス
を除き、第３のミキサー１２で第２の局部発振器１１か
らの第２局発周波数信号とミキシングされて第１中間周
波数信号となり、切換スイッチ８、バンドパスフィルタ
７、切換スイッチ６を通り、第４のミキサー１５で第１
の局部発振器１６からの第１局発周波数信号とミキシン
グされて送信周波数信号となり、バンドパスフィルタ１
７を通り、送信系アンプ１８で増幅され、送受切換スイ
ッチ２を通り、送受信アンテナ１から送信される。During transmission, the quadrature modulator 13 modulates the transmission signal with the same frequency signal as the second intermediate frequency signal, the bandpass filter 14 removes spurious signals, and the third mixer 12 produces a second local signal. The first local frequency signal is mixed with the second local oscillator frequency signal from the oscillator 11, passes through the changeover switch 8, the bandpass filter 7 and the changeover switch 6, and is passed through the fourth mixer 15 to the first intermediate frequency signal.
Is mixed with the first local oscillator frequency signal from the local oscillator 16 to become a transmission frequency signal, and the band pass filter 1
7, the signal is amplified by the transmission system amplifier 18, passes through the transmission / reception changeover switch 2, and is transmitted from the transmission / reception antenna 1.
【０００６】図４に示す第２の従来例においては、受信
時の動作は図３の場合と同様である。送信時には、直交
変調器１３において送信信号に対して第２の局部発振器
１１からの第２局発周波数信号で変調をかけて第１中間
周波数信号となし、切換スイッチ８、バンドパスフィル
タ７、切換スイッチ６を通って第４のミキサー１５に至
り、その後は図３の場合と同様にしてバンドパスフィル
タ１７、送信系アンプ１８、送受切換スイッチ２を通っ
て送受信アンテナ１から送信される。In the second conventional example shown in FIG. 4, the operation at the time of reception is the same as in the case of FIG. At the time of transmission, the quadrature modulator 13 modulates the transmission signal with the second local oscillation frequency signal from the second local oscillator 11 to obtain the first intermediate frequency signal, and the changeover switch 8, the bandpass filter 7, the changeover switch The signal reaches the fourth mixer 15 through the switch 6, and thereafter, the signal is transmitted from the transmission / reception antenna 1 through the bandpass filter 17, the transmission system amplifier 18, and the transmission / reception changeover switch 2 as in the case of FIG.
【０００７】図５に示す第３の従来例においては、切換
スイッチ６，８がないだけで、受信時の動作は図３の場
合と同様に行われる。送信時については、直交変調器１
３において送信信号に対して第２の局部発振器１１から
の第２局発周波数信号で変調をかけて第１中間周波数信
号となし、バンドパスフィルタ１４を通って第４のミキ
サー１５に至り、その後は図３の場合と同様にしてバン
ドパスフィルタ１７、送信系アンプ１８、送受切換スイ
ッチ２を通って送受信アンテナ１から送信される。In the third conventional example shown in FIG. 5, only the changeover switches 6 and 8 are omitted, and the receiving operation is performed in the same manner as in the case of FIG. For transmission, quadrature modulator 1
In 3, the transmission signal is modulated with the second local oscillator frequency signal from the second local oscillator 11 to obtain a first intermediate frequency signal, which passes through the bandpass filter 14 to the fourth mixer 15 and then Is transmitted from the transmission / reception antenna 1 through the bandpass filter 17, the transmission system amplifier 18, and the transmission / reception changeover switch 2 in the same manner as in FIG.
【０００８】[0008]
【発明が解決しようとする課題】図５の従来例の場合、
回路規模的に最も簡単であるが、ＴＤＭＡ通信方式とす
るには、〔送信周波数〕＝〔受信周波数〕となるため、
第２中間周波数信号の周波数差を、第１の局部発振器１
６と第２の局部発振器１１とのいずれか一方において周
波数切り換えで対応しなければならず、特に、ＴＤＭＡ
通信方式，ＴＤＤ通信方式においては、この切り換え時
間はかなり短い時間となってしまい、局部発振器にＰＬ
Ｌ回路などを用いていると、切り換えが困難なものとな
る。また、その短い時間で切り換えを行うようにする
と、局部発振器の回路構成が非常に大規模なものになっ
てしまう。In the case of the conventional example of FIG. 5,
This is the simplest in terms of circuit scale, but in order to use the TDMA communication system, [transmission frequency] = [reception frequency]
The frequency difference of the second intermediate frequency signal is calculated as the first local oscillator 1
6 or the second local oscillator 11 must be supported by frequency switching.
In the communication system and the TDD communication system, this switching time becomes a very short time, and the
If an L circuit or the like is used, switching becomes difficult. Further, if the switching is performed in the short time, the circuit configuration of the local oscillator becomes very large.
【０００９】図４の従来例の場合、図３の従来例に比べ
て部品点数が少なくより簡単に構成できるが、第２の局
部発振器１１の発振周波数を受信時と送信時とで切り換
えなければならず、わずらわしい。また、図５の従来例
と比べると、バンドパスフィルタ７を送信と受信とで共
用化しているが、直交変調器１３によって変調をかけた
後、バンドパスフィルタ７を通るため、変調がπ／４シ
フトＱＰＳＫのときにバンドパスフィルタ７が狭帯域で
あるため、群遅延特性が悪化し、変調精度が悪くなって
しまう。バンドパスフィルタ７の帯域を広げると、逆
に、受信時の選択度特性の悪化を引き起こす。In the case of the conventional example of FIG. 4, the number of parts is smaller than that of the conventional example of FIG. 3 and the configuration can be simplified. However, the oscillation frequency of the second local oscillator 11 must be switched between reception and transmission. No, it's annoying. Further, compared with the conventional example of FIG. 5, the bandpass filter 7 is commonly used for transmission and reception. However, after being modulated by the quadrature modulator 13, it passes through the bandpass filter 7, so that the modulation is π /. In the case of 4-shift QPSK, since the bandpass filter 7 has a narrow band, the group delay characteristic is deteriorated and the modulation accuracy is deteriorated. If the band of the bandpass filter 7 is widened, conversely, the selectivity characteristic at the time of reception is deteriorated.
【００１０】図３の従来例の場合、図４の従来例に比べ
て第２の局部発振器１１の発振周波数の切り換えをしな
くてもよいが、回路規模が複雑になってしまう。また、
狭帯域のバンドパスフィルタ７を送信時と受信時とで共
用するため、図４の従来例と同様に変調精度悪化の問題
を有している。In the case of the conventional example of FIG. 3, it is not necessary to switch the oscillation frequency of the second local oscillator 11 as compared with the conventional example of FIG. 4, but the circuit scale becomes complicated. Also,
Since the narrow-band bandpass filter 7 is shared during transmission and reception, there is a problem of deterioration in modulation accuracy as in the conventional example of FIG.
【００１１】本発明は、このような事情に鑑みて創案さ
れたものであって、局部発振周波数の切り換えは不要と
し、回路構成を簡単化するとともに変調精度を良好に確
保できるようにすることを目的としている。The present invention was devised in view of such circumstances, and it is not necessary to switch the local oscillation frequency, and it is possible to simplify the circuit configuration and ensure good modulation accuracy. Has an aim.
【００１２】[0012]
【課題を解決するための手段】本発明に係る請求項１の
中間周波数発生方式は、ＴＤＭＡ通信方式またはＴＤＤ
通信方式における無線部の中間周波数発生方式であっ
て、送信・受信で共通のバンドパスフィルタの一側に第
１局発周波数信号による第１のミキサーを設けるととも
に、他側に第２局発周波数信号による第２のミキサーを
設ける一方、前記共通のバンドパスフィルタの他側に第
２局発周波数信号による第３のミキサーを設けるととも
に、一側に第１局発周波数信号による第４のミキサーを
設け、前記第３のミキサーにおいては第２局発周波数信
号および第２中間周波数信号と同一の周波数信号をミキ
シングするように構成し、前記共通のバンドパスフィル
タと前記第４のミキサーとの間に送信信号を第１中間周
波数信号によって変調する直交変調器を挿入してあるこ
とを特徴とするものである。An intermediate frequency generating system according to claim 1 of the present invention is a TDMA communication system or TDD.
An intermediate frequency generation method of a radio unit in a communication method, wherein a first mixer for the first station frequency signal is provided on one side of a bandpass filter common to transmission and reception, and a second station frequency is provided on the other side. While providing a second mixer for the signal, a third mixer for the second local oscillator frequency signal is provided on the other side of the common bandpass filter, and a fourth mixer for the first local oscillator frequency signal is provided on one side. The third mixer is configured to mix the same frequency signal as the second local oscillator frequency signal and the second intermediate frequency signal, and is provided between the common bandpass filter and the fourth mixer. It is characterized in that a quadrature modulator for modulating the transmission signal by the first intermediate frequency signal is inserted.
【００１３】本発明に係る請求項２の中間周波数発生方
式は、送受信アンテナに接続された送受切換スイッチ
と、送受切換スイッチの受信側に接続された受信系アン
プとバンドパスフィルタと第１のミキサーとの直列回路
と、前記第１のミキサーに第１局発周波数信号を与えて
第１中間周波数信号を生成する第１の局部発振器と、両
端にそれぞれ切換スイッチを有する送受信で共通のバン
ドパスフィルタと、第２のミキサーとバンドパスフィル
タとの直列回路と、前記第２のミキサーに第２局発周波
数信号を与えて第２中間周波数信号を生成する第２の局
部発振器と、前記第２の局部発振器からの第２局発周波
数信号および第２中間周波数信号と同一の周波数信号を
ミキシングして第１中間周波数信号を生成する第３のミ
キサーと、前記第３のミキサーからの第１中間周波数信
号に基づいて送信信号に変調をかける直交変調器と、前
記直交変調器に接続されたバンドパスフィルタと、この
バンドパスフィルタに接続され前記第１の局部発振器か
らの第１局発周波数信号をミキシングして送信周波数信
号を生成する第４のミキサーと、前記第４のミキサーと
前記送受切換スイッチとの間に挿入されたバンドパスフ
ィルタと送信系アンプとの直列回路とからなり、前記第
１のミキサーの出力側と前記直交変調器の入力側とが前
記共通のバンドパスフィルタの一端の切換スイッチに接
続され、前記第２のミキサーの入力側と前記第３のミキ
サーの出力側とが前記共通のバンドパスフィルタの他端
の切換スイッチに接続されていることを特徴とするもの
である。An intermediate frequency generating system according to a second aspect of the present invention is a transmission / reception changeover switch connected to a transmission / reception antenna, a reception system amplifier, a bandpass filter and a first mixer connected to the reception side of the transmission / reception changeover switch. , A first local oscillator for applying a first local oscillator frequency signal to the first mixer to generate a first intermediate frequency signal, and a bandpass filter common to both transmission and reception, each having a changeover switch at both ends. A series circuit of a second mixer and a bandpass filter, a second local oscillator for applying a second local oscillator frequency signal to the second mixer to generate a second intermediate frequency signal, and the second local oscillator. A third mixer for generating a first intermediate frequency signal by mixing the same frequency signal as the second local oscillator frequency signal and the second intermediate frequency signal from the local oscillator; A quadrature modulator that modulates a transmission signal based on a first intermediate frequency signal from a mixer, a bandpass filter connected to the quadrature modulator, and a bandpass filter connected to the bandpass filter from the first local oscillator. A fourth mixer that mixes the first station-originated frequency signal to generate a transmission frequency signal, and a series circuit of a bandpass filter and a transmission system amplifier that are inserted between the fourth mixer and the transmission / reception changeover switch. The output side of the first mixer and the input side of the quadrature modulator are connected to a changeover switch at one end of the common bandpass filter, and the input side of the second mixer and the third side An output side of the mixer is connected to a changeover switch at the other end of the common bandpass filter.
【００１４】[0014]
【作用】第３のミキサーにおいて第２局発周波数信号お
よび第２中間周波数信号と同一の周波数信号をミキシン
グして第１中間周波数信号を生成し、かつ、変調をかけ
る前の搬送波の状態で狭帯域のバンドパスフィルタを通
し、その後、直交変調器で変調をかけるように構成して
あるので、第２局発周波数信号の周波数を送信時と受信
時とで切り換える必要がなくなり、第２の局部発振器の
構成を簡単化することができる。In the third mixer, the same frequency signal as the second local frequency signal and the second intermediate frequency signal is mixed to generate the first intermediate frequency signal, and the first intermediate frequency signal is narrowed in the carrier state before being modulated. Since it is configured to pass through the band pass filter of the band and then to be modulated by the quadrature modulator, there is no need to switch the frequency of the second local oscillator frequency signal between transmission and reception, and the second local part The configuration of the oscillator can be simplified.
【００１５】また、第１中間周波数信号を生成する第３
のミキサーは、まだ低い周波数の段階でミキシングする
ので、トランジスタやダイオードなどの簡単な部品で構
成することができる。送信・受信の切り換えもスイッチ
ング動作を行うことで切り換えることができるため、送
受の切り換え時間もごく短いものとできる。A third intermediate frequency signal generating third intermediate frequency signal is generated.
The mixer still mixes at low frequency stages, so it can consist of simple components such as transistors and diodes. Since switching between transmission and reception can be performed by performing a switching operation, the switching time between transmission and reception can be extremely short.
【００１６】さらに、共通のバンドパスフィルタは、送
信時に搬送波しか通さないため、受信特性のみで設計し
た狭帯域のバンドパスフィルタを採用できる。また、Ｔ
ＤＭＡ通信方式，ＴＤＤ通信方式において変調精度も悪
化しない。Further, since the common bandpass filter allows only the carrier wave to pass at the time of transmission, a narrowband bandpass filter designed only with the reception characteristic can be adopted. Also, T
The modulation accuracy does not deteriorate in the DMA communication system and the TDD communication system.
【００１７】[0017]
【実施例】以下、本発明に係る中間周波数発生方式の一
実施例を図面に基づいて詳細に説明する。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an intermediate frequency generating system according to the present invention will be described below in detail with reference to the drawings.
【００１８】図１はＴＤＭＡ通信方式の無線部における
中間周波数発生方式の構成を示す回路図である。FIG. 1 is a circuit diagram showing a configuration of an intermediate frequency generation system in a radio section of the TDMA communication system.
【００１９】図１に示すように、信号を電波として送信
したり電波を受信したりする送受信アンテナ１に、送信
時には送信ブロックへ接続し受信時には受信ブロックへ
接続する送受切換スイッチ２が接続され、この送受切換
スイッチ２の受信側端子に受信系アンプ３とバンドパス
フィルタ４と第１のミキサー５とが直列に接続されてい
る。受信系アンプ３は受信時の微小な信号を増幅するも
のであり、バンドパスフィルタ４は受信する希望周波数
の信号を通過させその他の周波数信号を減衰させるもの
であり、第１のミキサー５は受信した周波数信号を第１
の局部発振器１６の局発周波数信号とミキシングして周
波数を下げ第１中間周波数信号を作るものである。第１
の局部発振器１６はＶＣＯ部，ＰＬＬ部よりなり第１局
発周波数信号を発生させるものである。As shown in FIG. 1, a transmission / reception switch 2 that connects to a transmission block during transmission and connects to a reception block during reception is connected to a transmission / reception antenna 1 that transmits and receives signals as radio waves. A reception system amplifier 3, a bandpass filter 4, and a first mixer 5 are connected in series to a reception side terminal of the transmission / reception changeover switch 2. The reception system amplifier 3 amplifies a minute signal at the time of reception, the band pass filter 4 passes a signal of a desired frequency to be received and attenuates other frequency signals, and the first mixer 5 receives the signal. Frequency signal
Is mixed with the local oscillation frequency signal of the local oscillator 16 to lower the frequency to produce a first intermediate frequency signal. First
The local oscillator 16 is composed of a VCO section and a PLL section and generates a first local oscillation frequency signal.
【００２０】切換スイッチ６とバンドパスフィルタ７と
切換スイッチ８からなる直列回路を介して第１のミキサ
ー５が第２のミキサー９に接続されている。切換スイッ
チ６，８は送信時と受信時とで信号の経路を切り換える
ものであり、バンドパスフィルタ７は第１中間周波数信
号だけを通過させその他の周波数信号を減衰させるもの
である。第２のミキサー９は第１中間周波数信号と第２
の局部発振器１１の局発周波数信号をミキシングして周
波数を下げ第２中間周波数信号を作るものである。第２
のミキサー９に接続されたバンドパスフィルタ１０は第
２中間周波数信号だけを通過させその他の周波数信号を
減衰させるものである。第２の局部発振器１１はＶＣＯ
部，ＰＬＬ部よりなり第２局発周波数信号を発生させる
ものである。The first mixer 5 is connected to the second mixer 9 via a series circuit composed of the changeover switch 6, the bandpass filter 7 and the changeover switch 8. The changeover switches 6 and 8 are for switching the signal path between transmission and reception, and the bandpass filter 7 is for passing only the first intermediate frequency signal and attenuating the other frequency signals. The second mixer 9 receives the first intermediate frequency signal and the second intermediate frequency signal.
This is to mix the local oscillation frequency signal of the local oscillator 11 to lower the frequency to produce a second intermediate frequency signal. Second
The band-pass filter 10 connected to the mixer 9 of FIG. 3 passes only the second intermediate frequency signal and attenuates other frequency signals. The second local oscillator 11 is a VCO
And a PLL unit to generate a second local oscillator frequency signal.
【００２１】第２の局部発振器１１からの第２局発周波
数信号および第２中間周波数信号と同一の周波数信号を
ミキシングして第１中間周波数信号と同一の周波数信号
を作る第３のミキサー（アップコンバータ）１２が設け
られ、この第３のミキサー１２が切換スイッチ８を介し
て送受信に共通なバンドパスフィルタ７に接続されてい
る。バンドパスフィルタ７に接続の切換スイッチ６の一
端は第１のミキサー５に接続されているが、他端は直交
変調器１３に接続されている。すなわち、第１中間周波
数信号により送信信号に対してπ／４シフトＱＰＳＫの
変調をかける直交変調器１３が、第３のミキサー１２に
対して切換スイッチ８とバンドパスフィルタ７と切換ス
イッチ６の直列回路を介して接続されている。A third mixer (up) for mixing the second local oscillator frequency signal from the second local oscillator 11 and the same frequency signal as the second intermediate frequency signal to produce the same frequency signal as the first intermediate frequency signal. A converter) 12 is provided, and this third mixer 12 is connected via a changeover switch 8 to a bandpass filter 7 common to transmission and reception. One end of the changeover switch 6 connected to the bandpass filter 7 is connected to the first mixer 5, but the other end is connected to the quadrature modulator 13. That is, the quadrature modulator 13 that modulates the transmission signal by π / 4 shift QPSK with the first intermediate frequency signal is connected to the third mixer 12 in series with the changeover switch 8, the bandpass filter 7, and the changeover switch 6. It is connected through a circuit.
【００２２】直交変調器１３の出力側はバンドパスフィ
ルタ１４を介して第４のミキサー１５に接続されてい
る。バンドパスフィルタ１４は第１中間周波数信号だけ
を通過させその他の周波数信号を減衰させるものであ
る。第４のミキサー１５は第１の局部発振器１６からの
第１局発周波数信号および第１中間周波数信号と同一の
周波数信号をミキシングして送信周波数信号を作るアッ
プコンバータである。第４のミキサー１５はバンドパス
フィルタ１７と送信系アンプ１８を介して送受切換スイ
ッチ２の送信側端子に接続されている。バンドパスフィ
ルタ１７は送信周波数信号だけを通過させその他の周波
数信号を減衰させるものであり、送信系アンプ１８は送
信周波数信号を増幅するものである。The output side of the quadrature modulator 13 is connected to a fourth mixer 15 via a bandpass filter 14. The bandpass filter 14 passes only the first intermediate frequency signal and attenuates other frequency signals. The fourth mixer 15 is an up-converter that mixes the first local oscillation frequency signal and the first intermediate frequency signal from the first local oscillator 16 to generate a transmission frequency signal. The fourth mixer 15 is connected to the transmission-side terminal of the transmission / reception changeover switch 2 via a bandpass filter 17 and a transmission system amplifier 18. The bandpass filter 17 passes only the transmission frequency signal and attenuates other frequency signals, and the transmission system amplifier 18 amplifies the transmission frequency signal.
【００２３】次に、動作を説明する。Next, the operation will be described.
【００２４】第２の局部発振器１１が発生する第２局発
周波数信号の周波数は送信時と受信時とで同一であり、
切り換える必要はない。The frequency of the second local oscillator frequency signal generated by the second local oscillator 11 is the same during transmission and during reception,
No need to switch.
【００２５】送信時において、第３のミキサー１２で
は、第２の局部発振器１１からの一定の第２局発周波数
信号および第２中間周波数信号と同一の周波数信号をミ
キシングさせて第１中間周波数信号となし、切換スイッ
チ８を通ってバンドパスフィルタ７に至り、バンドパス
フィルタ７でスプリアスが除去される。そして、切換ス
イッチ６を通って直交変調器１３に至り、直交変調器１
３で送信信号が第１中間周波数信号と同一の周波数信号
で変調をかけられる。次いで、広帯域のバンドパスフィ
ルタ１４を通って第４のミキサー１５に至る。第４のミ
キサー１５では、第１の局部発振器１６からの第１局発
周波数信号とミキシングされて送信周波数信号となり、
バンドパスフィルタ１７を通り、送信系アンプ１８で増
幅され、送受切換スイッチ２を通り、送受信アンテナ１
から送信される。At the time of transmission, the third mixer 12 mixes a frequency signal that is the same as the constant second local oscillator frequency signal and the second intermediate frequency signal from the second local oscillator 11 to mix the first intermediate frequency signal. Then, the changeover switch 8 is passed to reach the bandpass filter 7, and spurious is removed by the bandpass filter 7. Then, it passes through the changeover switch 6 to reach the quadrature modulator 13, and the quadrature modulator 1
At 3, the transmitted signal is modulated with the same frequency signal as the first intermediate frequency signal. Then, the light passes through the wideband bandpass filter 14 and reaches the fourth mixer 15. The fourth mixer 15 mixes with the first local oscillator frequency signal from the first local oscillator 16 to form a transmission frequency signal,
It passes through the band pass filter 17, is amplified by the transmission system amplifier 18, passes through the transmission / reception changeover switch 2, and the transmission / reception antenna 1
Sent from.
【００２６】受信時には、送受信アンテナ１から受信さ
れた信号は、送受切換スイッチ２、受信系アンプ３、バ
ンドパスフィルタ４を通り、第１のミキサー５で第１の
局部発振器１６からの第１局発周波数信号とミキシング
されて第１中間周波数信号となり、この第１中間周波数
信号は、切換スイッチ６、バンドパスフィルタ７、切換
スイッチ８を通り、第２のミキサー９で第２の局部発振
器１１からの第２局発周波数信号とミキシングされて第
２中間周波数信号となり、バンドパスフィルタ１０を通
ってデモジュレータへ導かれる。At the time of reception, the signal received from the transmission / reception antenna 1 passes through the transmission / reception changeover switch 2, the reception system amplifier 3, and the bandpass filter 4, and is passed through the first mixer 5 to the first station from the first local oscillator 16. The first intermediate frequency signal is mixed with the source frequency signal, and the first intermediate frequency signal passes through the changeover switch 6, the bandpass filter 7, and the changeover switch 8 and is transmitted from the second local oscillator 11 by the second mixer 9. Is mixed with the second locally-generated frequency signal to form a second intermediate frequency signal, which is guided to the demodulator through the bandpass filter 10.
【００２７】以上のように、第３のミキサー１２におい
て、第２の局部発振器１１からの第２局発周波数信号お
よび第２中間周波数信号と同一の周波数信号をミキシン
グして第１中間周波数信号を生成するようにしている。
また、変調をかける前の搬送波の状態で、送受信で共通
な狭帯域のバンドパスフィルタ７を通しておき、その
後、直交変調器１３で変調をかけるようにしてある。As described above, in the third mixer 12, the same frequency signals as the second local oscillator frequency signal and the second intermediate frequency signal from the second local oscillator 11 are mixed to generate the first intermediate frequency signal. I am trying to generate.
In addition, the carrier wave before being modulated is passed through a bandpass filter 7 having a narrow band common to transmission and reception, and then the quadrature modulator 13 is used for modulation.
【００２８】上記のように構成することで、第２局発周
波数信号の周波数を送信時と受信時とで切り換える必要
がなくなり、第２の局部発振器１１の構成を簡単化する
ことができる。With the above configuration, it is not necessary to switch the frequency of the second local oscillator frequency signal between transmission and reception, and the configuration of the second local oscillator 11 can be simplified.
【００２９】また、第１中間周波数信号を生成するため
の第３のミキサー１２は、まだ低い周波数（無変調波）
の段階でミキシングを行うものであるので、トランジス
タやダイオードなどで簡単に構成することができる。そ
の一例を図２に示す。送信・受信の切り換えについても
スイッチング動作を行うことで切り換えることができる
ため、送受の切り換え時間もごく短時間ですむ。The third mixer 12 for generating the first intermediate frequency signal has a low frequency (unmodulated wave).
Since mixing is performed at the stage of, it can be easily configured with transistors, diodes, and the like. An example thereof is shown in FIG. Switching between sending and receiving can also be done by performing a switching operation, so switching time between sending and receiving is extremely short.
【００３０】さらに、第１中間周波数信号の周波数が送
信時と受信時で同じであるため、バンドパスフィルタ７
が共通化できて、部品点数少なく安価に構成できる。Furthermore, since the frequency of the first intermediate frequency signal is the same during transmission and during reception, the bandpass filter 7
Can be shared, and the number of parts can be reduced and the cost can be reduced.
【００３１】共通のバンドパスフィルタ７は、送信時に
搬送波しか通さないため、ＴＤＭＡ通信方式，ＴＤＤ通
信方式において変調精度も悪化せず、π／４シフトＱＰ
ＳＫなどのような群遅延特性のきびしい変調方式にも対
応できる。そして、受信特性のみで設計した狭帯域のバ
ンドパスフィルタも採用できる。Since the common bandpass filter 7 passes only the carrier wave at the time of transmission, the modulation accuracy does not deteriorate in the TDMA communication system and the TDD communication system, and the π / 4 shift QP
It can also be applied to modulation systems with severe group delay characteristics such as SK. A narrow band bandpass filter designed only with reception characteristics can also be used.
【００３２】以上のように、本実施例によれば、第１か
ら第３までのすべての従来例の問題点を解消している。As described above, according to this embodiment, the problems of all the first to third conventional examples are solved.
【００３３】[0033]
【発明の効果】第３のミキサーにおいて第２局発周波数
信号および第２中間周波数信号と同一の周波数信号をミ
キシングして第１中間周波数信号を生成するようにし、
かつ、変調をかける前の搬送波の状態で狭帯域のバンド
パスフィルタを通し、その後、直交変調器で変調をかけ
るように構成してあるので、第２局発周波数信号の周波
数を送信時と受信時とで切り換える必要がなくなり、第
２の局部発振器の構成を簡単化することができる。In the third mixer, the same frequency signal as the second local frequency signal and the second intermediate frequency signal is mixed to generate the first intermediate frequency signal,
In addition, the carrier wave before modulation is passed through a narrow band pass filter and then modulated by a quadrature modulator, so that the frequency of the second station-originated frequency signal is transmitted and received. There is no need to switch between time and time, and the configuration of the second local oscillator can be simplified.
【００３４】また、第１中間周波数信号を生成する第３
のミキサーは、まだ低い周波数の段階でミキシングする
ので、トランジスタやダイオードなどで簡単に構成する
ことができ、送信・受信の切り換えもスイッチング動作
を行うことで切り換えることができるため、送受の切り
換え時間もごく短いものとできる。A third intermediate frequency signal generating third intermediate frequency signal is generated.
Since the mixer does not mix at a low frequency stage yet, it can be easily configured with transistors, diodes, etc., and switching between transmission and reception can also be performed by performing a switching operation, so the switching time between transmission and reception is also reduced. Can be very short.
【００３５】さらに、共通のバンドパスフィルタは、送
信時に搬送波しか通さないため、ＴＤＭＡ通信方式，Ｔ
ＤＤ通信方式において変調精度も悪化せず、π／４シフ
トＱＰＳＫなどのような群遅延特性のきびしい変調方式
にも対応することができる。Further, since the common bandpass filter allows only the carrier wave to pass during transmission, the TDMA communication system, T
In the DD communication system, the modulation accuracy does not deteriorate, and it is possible to support a modulation system having severe group delay characteristics such as π / 4 shift QPSK.
【図１】本発明の一実施例に係る中間周波数発生方式の
構成を示す回路図である。FIG. 1 is a circuit diagram showing a configuration of an intermediate frequency generation system according to an embodiment of the present invention.
【図２】実施例における第３のミキサーの具体例を示す
回路図である。FIG. 2 is a circuit diagram showing a specific example of a third mixer in the embodiment.
【図３】第１の従来例に係る中間周波数発生方式の構成
を示す回路図である。FIG. 3 is a circuit diagram showing a configuration of an intermediate frequency generation system according to a first conventional example.
【図４】第２の従来例に係る中間周波数発生方式の構成
を示す回路図である。FIG. 4 is a circuit diagram showing a configuration of an intermediate frequency generation system according to a second conventional example.
【図５】第３の従来例に係る中間周波数発生方式の構成
を示す回路図である。FIG. 5 is a circuit diagram showing a configuration of an intermediate frequency generation system according to a third conventional example.
１……送受信アンテナ ２……送受切換スイッチ ３……受信系アンプ ４……バンドパスフィルタ ５……第１のミキサー ６……切換スイッチ ７……送受信で共通のバンドパスフィルタ ８……切換スイッチ ９……第２のミキサー １０……バンドパスフィルタ １１……第２の局部発振器 １２……第３のミキサー １３……直交変調器 １４……バンドパスフィルタ １５……第４のミキサー １６……第１の局部発振器 １７……バンドパスフィルタ １８……送信系アンプ 1 ... Transmission / reception antenna 2 ... Transmission / reception switch 3 ... Reception system amplifier 4 ... Bandpass filter 5 ... First mixer 6 ... Changeover switch 7 ... Bandpass filter common for transmission and reception 8 ... Changeover switch 9 ... Second mixer 10 ... Bandpass filter 11 ... Second local oscillator 12 ... Third mixer 13 ... Quadrature modulator 14 ... Bandpass filter 15 ... Fourth mixer 16 ... First local oscillator 17 ... Band pass filter 18 ... Transmission system amplifier
Claims (2)
における無線部の中間周波数発生方式であって、送信・
受信で共通のバンドパスフィルタの一側に第１局発周波
数信号による第１のミキサーを設けるとともに、他側に
第２局発周波数信号による第２のミキサーを設ける一
方、前記共通のバンドパスフィルタの他側に第２局発周
波数信号による第３のミキサーを設けるとともに、一側
に第１局発周波数信号による第４のミキサーを設け、前
記第３のミキサーにおいては第２局発周波数信号および
第２中間周波数信号と同一の周波数信号をミキシングす
るように構成し、前記共通のバンドパスフィルタと前記
第４のミキサーとの間に送信信号を第１中間周波数信号
によって変調する直交変調器を挿入してあることを特徴
とする中間周波数発生方式。1. A method of generating an intermediate frequency of a radio unit in a TDMA communication method or a TDD communication method,
The common bandpass filter is provided on one side of the common bandpass filter for reception, while the first mixer based on the first local oscillator frequency signal is provided on the other side, and on the other side is provided with the second mixer based on the second local oscillator frequency signal. The other side is provided with a third mixer based on the second local oscillator frequency signal, and the one side is provided with a fourth mixer based on the first local oscillator frequency signal. A quadrature modulator configured to mix the same frequency signal as the second intermediate frequency signal and which modulates the transmission signal with the first intermediate frequency signal is inserted between the common bandpass filter and the fourth mixer. The intermediate frequency generation method characterized in that
イッチと、送受切換スイッチの受信側に接続された受信
系アンプとバンドパスフィルタと第１のミキサーとの直
列回路と、前記第１のミキサーに第１局発周波数信号を
与えて第１中間周波数信号を生成する第１の局部発振器
と、両端にそれぞれ切換スイッチを有する送受信で共通
のバンドパスフィルタと、第２のミキサーとバンドパス
フィルタとの直列回路と、前記第２のミキサーに第２局
発周波数信号を与えて第２中間周波数信号を生成する第
２の局部発振器と、前記第２の局部発振器からの第２局
発周波数信号および第２中間周波数信号と同一の周波数
信号をミキシングして第１中間周波数信号を生成する第
３のミキサーと、前記第３のミキサーからの第１中間周
波数信号に基づいて送信信号に変調をかける直交変調器
と、前記直交変調器に接続されたバンドパスフィルタ
と、このバンドパスフィルタに接続され前記第１の局部
発振器からの第１局発周波数信号をミキシングして送信
周波数信号を生成する第４のミキサーと、前記第４のミ
キサーと前記送受切換スイッチとの間に挿入されたバン
ドパスフィルタと送信系アンプとの直列回路とからな
り、前記第１のミキサーの出力側と前記直交変調器の入
力側とが前記共通のバンドパスフィルタの一端の切換ス
イッチに接続され、前記第２のミキサーの入力側と前記
第３のミキサーの出力側とが前記共通のバンドパスフィ
ルタの他端の切換スイッチに接続されていることを特徴
とする中間周波数発生方式。2. A transmission / reception changeover switch connected to a transmission / reception antenna, a series circuit of a reception system amplifier, a bandpass filter and a first mixer connected to the reception side of the transmission / reception changeover switch, and the first mixer. A first local oscillator for generating a first intermediate frequency signal by giving a first local oscillation frequency signal; a bandpass filter common to both transmission and reception, each having a changeover switch at both ends; a second mixer and a bandpass filter; A series circuit; a second local oscillator for applying a second local oscillator frequency signal to the second mixer to generate a second intermediate frequency signal; a second local oscillator frequency signal from the second local oscillator; A third mixer for generating a first intermediate frequency signal by mixing the same frequency signal as the second intermediate frequency signal, and a first intermediate frequency signal from the third mixer A quadrature modulator that modulates a transmission signal, a bandpass filter connected to the quadrature modulator, and a first local oscillator frequency signal from the first local oscillator that is connected to the bandpass filter and is mixed and transmitted. The output of the first mixer comprises a fourth mixer for generating a frequency signal, and a series circuit of a bandpass filter and a transmission system amplifier inserted between the fourth mixer and the transmission / reception changeover switch. Side and an input side of the quadrature modulator are connected to a changeover switch at one end of the common bandpass filter, and an input side of the second mixer and an output side of the third mixer are the common bandpass. An intermediate frequency generation method characterized in that it is connected to a changeover switch at the other end of the filter.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP06060795A JP3084545B2 (en) | 1994-03-30 | 1994-03-30 | Intermediate frequency generation method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP06060795A JP3084545B2 (en) | 1994-03-30 | 1994-03-30 | Intermediate frequency generation method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH07273682A true JPH07273682A (en) | 1995-10-20 |
| JP3084545B2 JP3084545B2 (en) | 2000-09-04 |
Family
ID=13152609
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP06060795A Expired - Fee Related JP3084545B2 (en) | 1994-03-30 | 1994-03-30 | Intermediate frequency generation method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3084545B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100463648B1 (en) * | 1997-12-10 | 2005-04-06 | 주식회사 팬택앤큐리텔 | Intermediate frequency test signal generator of wireless subscriber network system |
| JP2008228196A (en) * | 2007-03-15 | 2008-09-25 | Matsushita Electric Works Ltd | Communication equipment |
| US9106491B2 (en) | 2011-03-28 | 2015-08-11 | Nec Corporation | Receiver circuit and filtering method used therein |
-
1994
- 1994-03-30 JP JP06060795A patent/JP3084545B2/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100463648B1 (en) * | 1997-12-10 | 2005-04-06 | 주식회사 팬택앤큐리텔 | Intermediate frequency test signal generator of wireless subscriber network system |
| JP2008228196A (en) * | 2007-03-15 | 2008-09-25 | Matsushita Electric Works Ltd | Communication equipment |
| US9106491B2 (en) | 2011-03-28 | 2015-08-11 | Nec Corporation | Receiver circuit and filtering method used therein |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3084545B2 (en) | 2000-09-04 |
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|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |