JPH0448825A - Cellular receiver - Google Patents
Cellular receiverInfo
- Publication number
- JPH0448825A JPH0448825A JP15825790A JP15825790A JPH0448825A JP H0448825 A JPH0448825 A JP H0448825A JP 15825790 A JP15825790 A JP 15825790A JP 15825790 A JP15825790 A JP 15825790A JP H0448825 A JPH0448825 A JP H0448825A
- Authority
- JP
- Japan
- Prior art keywords
- high frequency
- frequency amplifier
- detection circuit
- reception
- circuit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 230000001413 cellular effect Effects 0.000 title claims description 13
- 238000001514 detection method Methods 0.000 claims abstract description 25
- 230000005684 electric field Effects 0.000 claims abstract description 16
- 230000035945 sensitivity Effects 0.000 abstract description 8
- 230000015556 catabolic process Effects 0.000 abstract 1
- 238000006731 degradation reaction Methods 0.000 abstract 1
- 238000010586 diagram Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 230000006866 deterioration Effects 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000010295 mobile communication Methods 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
Landscapes
- Noise Elimination (AREA)
- Mobile Radio Communication Systems (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は移動通信装置等に関し、特に相互変調特性を改
善することが可能なセルラー受信機に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to mobile communication devices and the like, and particularly to a cellular receiver capable of improving intermodulation characteristics.
従来のこの種のセルラー受信機を第２図に示す。 A conventional cellular receiver of this type is shown in FIG.
同図のように、送受信アンテナ１、送受分波器２、高周
波増幅器３、高周波フィルタ４、第１ミキサー５、第１
局発回路６、ＩＦフィルタ７、第２ミキサー８、第２局
発回路９、ＩＦ増幅器１０、復調回路１１、受信電界強
度検出回路１２、低周波増幅器１３、ＳＡＴ信号検出回
路１４、スピーカ１５で構成されている。As shown in the figure, a transmitting/receiving antenna 1, a transmitting/receiving splitter 2, a high frequency amplifier 3, a high frequency filter 4, a first mixer 5, a first
Local oscillator circuit 6, IF filter 7, second mixer 8, second local oscillator circuit 9, IF amplifier 10, demodulation circuit 11, received field strength detection circuit 12, low frequency amplifier 13, SAT signal detection circuit 14, and speaker 15. It is configured.
すなわち、アンテナ１より入力された受信入力波は、送
受分波器２にて受信波のみ通過され、高周波増幅器３に
て受信波を増幅し、高周波フィルタ４により受信周波数
帯以外の減衰特性を補う。That is, the received input wave inputted from the antenna 1 is passed through the transmitter/receiver splitter 2, the received wave is amplified by the high frequency amplifier 3, and the attenuation characteristics other than the received frequency band are compensated for by the high frequency filter 4. .
また、第１ミキサー５と第１局発回路６で１次の周波数
を変換を行い、ＩＦフィルタ７を通した後、第２ミキサ
ー８と第２局発回路９で２次の周波数を変換を行って１
１周波数にし、ＩＦ増幅器１０にて復調回路１１が動作
するレベルまで利得を上げる。そして、復調後、低周波
増幅器１３で復調信号を増幅しスピーカ１５を鳴らして
いる。In addition, the first mixer 5 and the first local oscillator circuit 6 convert the first-order frequency, and after passing it through the IF filter 7, the second mixer 8 and the second local oscillator circuit 9 convert the second-order frequency. Go 1
1 frequency, and the IF amplifier 10 increases the gain to a level at which the demodulation circuit 11 operates. After demodulation, the demodulated signal is amplified by the low frequency amplifier 13 and the speaker 15 is sounded.
なお、この種のセルラー受信機には受信入力波の電界強
度を電圧に変換する回路１２が備えられ、受信入力電界
強度を監視している。また、基地局から送られてくるＳ
ＡＴ信号をＳＡＴ信号検出回路１４により検出し、基地
局との間で通話状態にあることを常時判定している。Note that this type of cellular receiver is equipped with a circuit 12 that converts the electric field strength of received input waves into voltage, and monitors the received input electric field strength. Also, the S sent from the base station
The AT signal is detected by the SAT signal detection circuit 14, and it is constantly determined that a call is being made with the base station.
上述した従来のセルラー受信機では、高周波増幅器３を
設けているため受信機全体の利得が高く受信感度特性に
すぐれている。しかし、他からの妨害波によって高周波
増幅器３と第１ミキサー５とで起こる相互歪のため相互
変調特性を悪化させるという問題がある。In the conventional cellular receiver described above, since the high frequency amplifier 3 is provided, the gain of the entire receiver is high and the receiving sensitivity characteristics are excellent. However, there is a problem in that intermodulation characteristics are deteriorated due to mutual distortion occurring between the high frequency amplifier 3 and the first mixer 5 due to interference waves from other sources.
このため、高周波増幅器３を省略することで、第１ミキ
サー５に入力される妨害波のレベルを抑制し、相互歪を
低減して相互変調特性を改善するようにした受信機が提
案されているが、高周波増幅器を省略したことで、高周
波利得が無くなり、受信感度特性が悪いという問題があ
る。For this reason, a receiver has been proposed in which the level of interference waves input to the first mixer 5 is suppressed, mutual distortion is reduced, and intermodulation characteristics are improved by omitting the high-frequency amplifier 3. However, by omitting the high frequency amplifier, there is a problem that there is no high frequency gain and the reception sensitivity characteristics are poor.
本発明の目的は、受信感度特性を高める一方で相互変調
特性を改善したセルラー受信機を提供することにある。An object of the present invention is to provide a cellular receiver that improves intermodulation characteristics while increasing receiving sensitivity characteristics.
本発明のセルラー受信機は、受信入力波を高周波増幅器
に入力させる状態と、該受信入力波を高周波増幅器をバ
イパスして次段へ入力させる状態とで切り換え可能な高
周波切換スイッチを設け、受信入力電界強度がある一定
レベル以上で、かつＳＡＴ信号を検出できないときにこ
の高周波切換スイッチを高周波増幅器をバイパスさせる
状態に切り換えるように構成している。The cellular receiver of the present invention is provided with a high-frequency changeover switch that can switch between a state in which a received input wave is input to a high-frequency amplifier and a state in which the received input wave is inputted to the next stage bypassing the high-frequency amplifier. When the electric field strength exceeds a certain level and the SAT signal cannot be detected, the high frequency changeover switch is configured to bypass the high frequency amplifier.
例えば、一方の入力端に受信電圧強度検出回路の出力が
入力され、他方の入力端にＳＡＴ信号検出回路の出力が
入力される論理回路を設け、この論理回路の出力により
高周波切換スイッチを切り換え制御するように構成する
。For example, a logic circuit is provided in which the output of the received voltage strength detection circuit is input to one input terminal and the output of the SAT signal detection circuit is input to the other input terminal, and the high frequency changeover switch is switched and controlled by the output of this logic circuit. Configure it to do so.
本発明によれば、受信入力電界が一定レベル以下のとき
には受信入力波を高周波増幅器に入力させることで受信
感度特性の劣化を防止し、妨害波が存在するときには高
周波増幅器をバイパスさセることで相互変調特性を改善
する。According to the present invention, when the received input electric field is below a certain level, the received input wave is input to the high frequency amplifier to prevent deterioration of the receiving sensitivity characteristics, and when interference waves are present, the high frequency amplifier is bypassed. Improve intermodulation characteristics.
〔実施例］ 次に、本発明を図面を参照して説明する。〔Example] Next, the present invention will be explained with reference to the drawings.
第１図は本発明の一実施例を示すブロック図であり、第
２図に示した従来構成と同一部分には同一符号を付しで
ある。すなわち、送受信アンテナｌ、送受分波器２、高
周波増幅器３、高周波フィルタ４、第１ミキサー５、第
１局発回路６、ＩＦフィルタ７、第２ミキサー８、第２
局発回路９、ＩＦ増幅器１０、復調回路１１、受信電界
強度検出回路１２、低周波増幅器１３、ＳＡＴ信号検出
回路１４、スピーカ１５を備えている。FIG. 1 is a block diagram showing an embodiment of the present invention, and the same parts as the conventional configuration shown in FIG. 2 are given the same reference numerals. That is, a transmitting/receiving antenna 1, a transmitting/receiving splitter 2, a high frequency amplifier 3, a high frequency filter 4, a first mixer 5, a first local oscillator circuit 6, an IF filter 7, a second mixer 8, a second
It includes a local oscillation circuit 9, an IF amplifier 10, a demodulation circuit 11, a received field strength detection circuit 12, a low frequency amplifier 13, a SAT signal detection circuit 14, and a speaker 15.
これに加えて、前記高周波増幅器３の前段に、この高周
波増幅器３を短絡させる高周波切換スイッチ１６を設け
、この高周波切換スイッチ１６をナンド回路１７の出力
により切り換え動作させるように構成している。このナ
ンド回路１７の一方の入力端には、受信電界強度検出回
路１２の出力が入力され、他方の入力端にはＳＡＴ信号
検出回路１４の出力がノット回路１８を介して入力され
ている。In addition, a high frequency changeover switch 16 for short-circuiting the high frequency amplifier 3 is provided at the front stage of the high frequency amplifier 3, and the high frequency changeover switch 16 is configured to be switched and operated by the output of a NAND circuit 17. The output of the received field strength detection circuit 12 is inputted to one input terminal of the NAND circuit 17, and the output of the SAT signal detection circuit 14 is inputted to the other input terminal via the NOT circuit 18.
なお、受信電界強度検出回路Ｉ２は、ある一定レベル以
上の受信電界を検出したときに高レベル“′Ｈ”を出力
する。また、ＳＡＴ信号検出回路１４ではＳＡＴ信号を
検出した場合に“Ｈ”′を出力する。また、高周波切換
スイッチ１６は、ナンド回路１７から”Ｈ”が出力され
たときに受信信号が高周波増幅器３を通過するように接
続され、ナンド回路１７から低レベル“Ｌ”が出力され
たときに高周波増幅器３を短絡して受信信号を直接高周
波フィルタ４に入力させるように構成している。Note that the received electric field strength detection circuit I2 outputs a high level "'H" when detecting a received electric field of a certain level or higher. Further, the SAT signal detection circuit 14 outputs "H"' when detecting the SAT signal. Further, the high frequency selector switch 16 is connected so that the received signal passes through the high frequency amplifier 3 when the NAND circuit 17 outputs "H", and when the NAND circuit 17 outputs a low level "L" The configuration is such that the high frequency amplifier 3 is short-circuited and the received signal is input directly to the high frequency filter 4.
この構成のセルラー受信機によれば、例えば、受信入力
電界が弱い場合には、受信電界強度検出回路１２より“
°Ｌ”が出力されるため、ナンド回路１７では、ＳＡＴ
信号検出回路１４の出力にかかわらず“Ｈ”を出力し、
高周波切換スイッチ１６によって、アンテナで受信した
受信信号を高周波増幅器３を通過させる。これにより、
高い受信感度での受信が可能となる。According to the cellular receiver having this configuration, for example, when the received input electric field is weak, the received electric field strength detection circuit 12 detects “
°L" is output, the NAND circuit 17 outputs SAT
Outputs "H" regardless of the output of the signal detection circuit 14,
The high frequency changeover switch 16 causes the received signal received by the antenna to pass through the high frequency amplifier 3. This results in
Reception with high reception sensitivity becomes possible.
逆に、受信入力電界が強いが、一方で妨害波が入力され
ることでＳＡＴ信号波形が乱れてＳＡＴ信号検出回路１
４でＳＡＴ信号が検出できない場合には、受信電界強度
検出回路１２から“Ｈ”が出力され、ＳＡＴ信号検出回
路１４からは“Ｌ”が出力される。そして、このＳＡＴ
信号検出回路１４からの“Ｌ”は、ノット回路１８で反
転されてＨ”としてナンド回路１７に入力されるため、
結果としてナンド回路１７からは“Ｌ”が出力され、高
周波切換えスイッチ１６を切り換えて高周波増幅器３を
短絡する。これにより、受信信号は高周波増幅器３を通
過することな（次段の高周波フィルタ４へ入力される。On the other hand, although the received input electric field is strong, the SAT signal waveform is disturbed due to interference waves being input, and the SAT signal detection circuit 1
If the SAT signal cannot be detected in step 4, the received field strength detection circuit 12 outputs "H" and the SAT signal detection circuit 14 outputs "L". And this SAT
Since the "L" from the signal detection circuit 14 is inverted by the NOT circuit 18 and inputted as "H" to the NAND circuit 17,
As a result, "L" is output from the NAND circuit 17, and the high frequency changeover switch 16 is switched to short-circuit the high frequency amplifier 3. As a result, the received signal does not pass through the high frequency amplifier 3 (it is input to the next stage high frequency filter 4).
これにより、他からの妨害波が存在するときには高周波
増幅器３を短絡することで、第１ミキサー５に入力され
る妨害波レベルを高周波増幅器３の利得分だけ小さくす
ることができ、第１ミキサー５における相互歪を小さく
し、結果として受信機の相互変調特性を改善することが
できる。As a result, by short-circuiting the high frequency amplifier 3 when interference waves from other sources are present, the level of interference waves input to the first mixer 5 can be reduced by the gain of the high frequency amplifier 3, and the first mixer 5 As a result, the intermodulation characteristics of the receiver can be improved.
以上説明したように本発明は、受信入力電界が一定レベ
ル以下のときには受信入力波を高周波増幅器に入力させ
ることで受信感度特性の劣化を防止し、妨害波が存在す
るときには受信入力波を高周波増幅器をバイパスさせて
次段に入力させることで相互変調特性を改善することが
できる効果がある。As explained above, the present invention prevents deterioration of reception sensitivity characteristics by inputting the received input wave to a high-frequency amplifier when the received input electric field is below a certain level, and inputs the received input wave to the high-frequency amplifier when interference waves are present. By bypassing the signal and inputting it to the next stage, there is an effect that the intermodulation characteristics can be improved.
第１図は本発明のセルラー受信機の一実施例のブロック
図、第２図は従来のセルラー受信機の一例のブロック図
である。
１・・・アンテナ、２・・・送受分波器、３・・・高周
波増幅器、４・・・高周波フィルタ、５・・・第１ミキ
サー・・・第１局発回路、７・・・ＩＦフィルタ、８・
・・第２キサ−１９・・・第２局発回路、１０・・・Ｉ
Ｆ増幅器、１・・・復調回路、１２・・・受信電界強度
検出回路、３・・・低周波増幅器、１４・・・ＳＡＴ信
号検出回路、５・・・スピーカ、１６・・・高周波切換
スイッチ、７・・・ナンド回路、１８・・・ノット回路
。FIG. 1 is a block diagram of an embodiment of a cellular receiver according to the present invention, and FIG. 2 is a block diagram of an example of a conventional cellular receiver. 1... Antenna, 2... Transmission/reception duplexer, 3... High frequency amplifier, 4... High frequency filter, 5... First mixer... First local oscillator circuit, 7... IF Filter, 8・
...Second kisser-19...Second local oscillator circuit, 10...I
F amplifier, 1... Demodulation circuit, 12... Received electric field strength detection circuit, 3... Low frequency amplifier, 14... SAT signal detection circuit, 5... Speaker, 16... High frequency changeover switch , 7...Nand circuit, 18...Knot circuit.
Claims (1)
検出する受信電界強度検出回路と、ＳＡＴ信号を検出す
るＳＡＴ信号検出回路とを有するセルラー受信機におい
て、受信入力波を前記高周波増幅器に入力させる状態と
、該受信入力波を高周波増幅器をバイパスして次段へ入
力させる状態とで切り換え可能な高周波切換スイッチを
有し、受信入力電界強度がある一定レベル以上で、かつ
ＳＡＴ信号を検出できないときに前記高周波切換スイッ
チを前記高周波増幅器をバイパスさせる状態に切り換え
るように構成したことを特徴とするセルラー受信機。 ２、一方の入力端に受信電圧強度検出回路の出力が入力
され、他方の入力端にＳＡＴ信号検出回路の出力が入力
される論理回路を有し、この論理回路の出力により高周
波切換スイッチを切り換え制御するように構成してなる
特許請求の範囲第１項記載のセルラー受信機。[Claims] 1. In a cellular receiver having at least a high frequency amplifier, a received field strength detection circuit for detecting the strength of a received input electric field, and a SAT signal detection circuit for detecting a SAT signal, the received input wave is It has a high frequency changeover switch that can switch between a state in which the received input wave is input to the high frequency amplifier and a state in which the received input wave is inputted to the next stage bypassing the high frequency amplifier. A cellular receiver characterized in that the high frequency changeover switch is configured to switch the high frequency selector switch to a state in which the high frequency amplifier is bypassed when a signal cannot be detected. 2. It has a logic circuit in which the output of the received voltage strength detection circuit is input to one input terminal and the output of the SAT signal detection circuit is input to the other input terminal, and the high frequency changeover switch is switched by the output of this logic circuit. A cellular receiver according to claim 1, which is configured to control.
Priority Applications (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2158257A JP3068159B2 (en) | 1990-06-16 | 1990-06-16 | Cellular receiver |
| CA002044774A CA2044774C (en) | 1990-06-16 | 1991-06-17 | Receiver for a cellular mobile radio communication system |
| DE69107698T DE69107698T2 (en) | 1990-06-16 | 1991-06-17 | Receiver for a cellular wireless communication system. |
| EP91305467A EP0462782B1 (en) | 1990-06-16 | 1991-06-17 | Receiver for a cellular mobile radio communication system |
| AU78467/91A AU646672B2 (en) | 1990-06-16 | 1991-06-17 | Receiver for a cellular mobile radio communication system |
| US08/340,814 US5513386A (en) | 1990-06-16 | 1994-11-17 | Receiver for a cellular mobile radio communication system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2158257A JP3068159B2 (en) | 1990-06-16 | 1990-06-16 | Cellular receiver |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0448825A true JPH0448825A (en) | 1992-02-18 |
| JP3068159B2 JP3068159B2 (en) | 2000-07-24 |
Family
ID=15667673
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2158257A Expired - Fee Related JP3068159B2 (en) | 1990-06-16 | 1990-06-16 | Cellular receiver |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3068159B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0563624A (en) * | 1991-08-28 | 1993-03-12 | Nec Corp | Cellular receiver |
| US5678214A (en) * | 1993-12-24 | 1997-10-14 | Nec Corporation | RF receiver using if amplifier operative during low level reception |
-
1990
- 1990-06-16 JP JP2158257A patent/JP3068159B2/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0563624A (en) * | 1991-08-28 | 1993-03-12 | Nec Corp | Cellular receiver |
| US5678214A (en) * | 1993-12-24 | 1997-10-14 | Nec Corporation | RF receiver using if amplifier operative during low level reception |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3068159B2 (en) | 2000-07-24 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |