JP3068159B2 - Cellular receiver - Google Patents
Cellular receiverInfo
- Publication number
- JP3068159B2 JP3068159B2 JP2158257A JP15825790A JP3068159B2 JP 3068159 B2 JP3068159 B2 JP 3068159B2 JP 2158257 A JP2158257 A JP 2158257A JP 15825790 A JP15825790 A JP 15825790A JP 3068159 B2 JP3068159 B2 JP 3068159B2
- Authority
- JP
- Japan
- Prior art keywords
- reception
- circuit
- frequency amplifier
- frequency
- detection 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.)
- Expired - Fee Related
Links
Landscapes
- Noise Elimination (AREA)
- Mobile Radio Communication Systems (AREA)
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。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to mobile communication devices and the like, and more 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。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1
2、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。FIG. 2 shows a conventional cellular receiver of this type. As shown in FIG. 1, 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 6, an IF filter 7, a second mixer 8, and a second local oscillator 9, IF amplifier 10, demodulation circuit 11, reception electric field strength detection circuit 1
2. It is composed of a low frequency amplifier 13, a SAT signal detection circuit 14, and a speaker 15.
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。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IF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。That is, the received input wave input from the antenna 1 is
Only the reception wave is passed through the transmission / reception splitter 2, and the high-frequency amplifier 3
And amplifies the received wave, and the high-frequency filter 4 compensates for attenuation characteristics outside the reception frequency band. The first mixer 5 and the first local oscillator 6 convert the primary frequency, and after passing through the IF filter 7, the second mixer 8 and the second local oscillator 9 convert the secondary frequency. Then, the IF frequency is set, and the gain is increased by the IF amplifier 10 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 sounds.
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SA
T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。This type of cellular receiver is provided with a circuit 12 for converting the electric field strength of a received input wave into a voltage, and monitors the received input electric field strength. Also, the SA sent from the base station
The T signal is detected by the SAT signal detection circuit 14, and it is always 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 above-described conventional cellular receiver, the high-frequency amplifier 3
Is provided, the gain of the entire receiver is high and the receiving sensitivity is excellent. However, there is a problem in that the intermodulation characteristics are deteriorated due to mutual distortion 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 high-frequency amplifier 3 is omitted to suppress the level of an interfering wave input to the first mixer 5 and reduce mutual distortion to improve the intermodulation characteristics. However, omitting the high-frequency amplifier causes a problem that high-frequency gain is lost and 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 having improved intermodulation characteristics while improving reception sensitivity characteristics.
本発明のセルラー受信機は、受信入力波を増幅可能な
高周波増幅器と、前記受信入力波から受信入力電界の強
度を検出し、検出した受信入力電界が所定レベル以上の
ときに高レベルを出力する受信電界強度検出回路と、前
記受信入力波からSAT信号を検出し、SAT信号を検出した
ときに高レベルを出力するSAT信号検出回路と、前記受
信入力波を前記高周波増幅器に入力させる状態と当該高
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と、前記SAT信号検出
回路の出力を反転する反転回路と、前記受信電界強度検
出回路の出力と前記反転回路の出力がそれぞれ高レベル
のときに前記高周波切換スイッチを前記高周波増幅器を
バイパスする側に切り換え制御する論理回路とを備え
る。A cellular receiver according to the present invention includes a high-frequency amplifier capable of amplifying a reception input wave, and detecting the intensity of a reception input electric field from the reception input wave, and outputting a high level when the detected reception input electric field is equal to or higher than a predetermined level. A reception electric field strength detection circuit, a SAT signal detection circuit that detects a SAT signal from the reception input wave, and outputs a high level when the SAT signal is detected, and a state in which the reception input wave is input to the high frequency amplifier. A high-frequency changeover switch that can be switched between a state in which the signal is input to the next stage by bypassing the high-frequency amplifier, an inversion circuit that inverts the output of the SAT signal detection circuit, an output of the reception field strength detection circuit, and an output of the inversion circuit. And a logic circuit for switching and controlling the high-frequency changeover switch to a side that bypasses the high-frequency amplifier when each is at a high level.
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せ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 the deterioration of the reception sensitivity characteristic, and when an interfering wave is present, the high-frequency amplifier is bypassed to thereby achieve the intermodulation. Improve properties.
次に、本発明を図面を参照して説明する。 Next, the present invention will be described 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
てある。すなわち、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を備えている。FIG. 1 is a block diagram showing one embodiment of the present invention.
The same parts as those in the conventional configuration shown in FIG. 2 are denoted by the same reference numerals. That is, the transmitting / receiving antenna 1, the transmitting / receiving splitter 2,
High frequency amplifier 3, high frequency filter 4, first mixer 5,
1st local oscillator 6, IF filter 7, 2nd mixer 8, 2nd
It includes a local oscillation circuit 9, an IF amplifier 10, a demodulation circuit 11, a reception electric 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1
4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 switch 16 for short-circuiting the high-frequency amplifier 3 is provided at a stage preceding the high-frequency amplifier 3, and the high-frequency switch 16 is configured to be switched by an output of the NAND circuit 17. One input terminal of the NAND circuit 17 is connected to the reception electric field strength detection circuit 12.
SAT signal detection circuit 1 is input to the other input terminal.
4 is input via the knot circuit 18.
なお、受信電界強度検出回路12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 reception electric field strength detection circuit 12 outputs a high level “H” when detecting a reception electric field of a certain level or more. When the SAT signal is detected, the SAT signal detection circuit 14 outputs “H”. In addition, the high-frequency switch 16
The reception circuit is connected so that the reception signal passes through the high-frequency amplifier 3 when “H” is output from the NAND circuit 17.
When a low level “L” is output from the high-frequency filter 3, the high-frequency amplifier 3 is short-circuited and the received signal is directly input 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 reception input electric field is weak, “L” is output from the reception electric field strength detection circuit 12, and the NAND circuit 17 outputs the “L” signal to the output of the SAT signal detection circuit 14. Regardless, "H" is output, and the received signal received by the antenna is passed through the high-frequency amplifier 3 by the high-frequency switch 16. This enables reception with high reception sensitivity.
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14でSA
T信号が検出できない場合には、受信電界強度検出回路1
2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を通過することなく次段の高周波フィルタ
４へ入力される。Conversely, although the reception input electric field is strong, the SAT signal waveform is disturbed by the
If the T signal cannot be detected, the reception electric field strength detection circuit 1
2 outputs “H”, and the SAT signal detection circuit 14 outputs “L”. The “L” from the SAT signal detection circuit 14 is inverted by the knot circuit 18 and input to the NAND circuit 17 as “H”. As a result, “L” is output from the NAND circuit 17 and The changeover switch 16 is switched to short-circuit the high-frequency amplifier 3. As a result, the received signal is input to the next-stage high-frequency filter 4 without passing through the high-frequency amplifier 3.
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。By short-circuiting the high-frequency amplifier 3 when there is another interfering wave, the level of the interfering wave input to the first mixer 5 can be reduced by the gain of the high-frequency amplifier 3. Can be reduced, and 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 described above, the present invention prevents the deterioration of the reception sensitivity characteristic by inputting a reception input wave to a high-frequency amplifier when a reception input electric field is equal to or lower than a certain level, and converts the reception input wave to a high-frequency amplifier when an interference wave exists. By bypassing and inputting to the next stage, there is an effect that the intermodulation characteristics can be improved.
また、本発明では受信電界強度検出回路は受信入力電
界強度が所定レベル以上のときに高レベルを出力し、ま
たSAT検出検出回路はSAT信号を検出したときに高レベル
を出力し、SAT信号検出回路の出力を反転回路により反
転し、論理回路により受信電界強度検出回路の出力と反
転回路の出力がそれぞれ高レベルのときに高周波切換ス
イッチを高周波増幅器をバイパスする側に切り換え制御
する構成としているので、マイクロコンピュータ等の複
雑な回路構成の回路要素を用いなくとも、高周波スイッ
チを切り換え制御するための回路構成が簡易化でき、セ
ルラー受信機の構成を簡易化することも可能となる。Further, in the present invention, the reception electric field intensity detection circuit outputs a high level when the reception input electric field intensity is equal to or higher than a predetermined level, and the SAT detection detection circuit outputs a high level when the SAT signal is detected. Since the output of the circuit is inverted by the inverting circuit, and the logic circuit controls the high-frequency switch to bypass the high-frequency amplifier when the output of the receiving electric field strength detection circuit and the output of the inverting circuit are each at a high level. Even without using a circuit element having a complicated circuit configuration such as a microcomputer, the circuit configuration for switching and controlling the high-frequency switch can be simplified, and the configuration of the cellular receiver can also be simplified.
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、６…
…第１局発回路、７……IFフィルタ、８……第２ミキサ
ー、９……第２局発回路、10……IF増幅器、11……復調
回路、12……受信電界強度検出回路、13……低周波増幅
器、14……SAT信号検出回路、15……スピーカ、16……
高周波切換スイッチ、17……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. DESCRIPTION OF SYMBOLS 1 ... Antenna, 2 ... Transmission / reception splitter, 3 ... High frequency amplifier, 4 ... High frequency filter, 5 ... 1st mixer, 6 ...
... First local oscillator circuit, 7 IF filter, 8 second mixer, 9 second local oscillator circuit, 10 IF amplifier, 11 demodulator circuit, 12 received electric field strength detection circuit, 13 ... Low frequency amplifier, 14 ... SAT signal detection circuit, 15 ... Speaker, 16 ...
High frequency changeover switch, 17… Nand circuit, 18… Knot circuit.
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 昭61−219232（ＪＰ，Ａ) 特開 昭60−152133（ＪＰ，Ａ) 実開 昭64−54432（ＪＰ，Ｕ) 実開 昭56−50138（ＪＰ，Ｕ) (58)調査した分野(Int.Cl.7，ＤＢ名) H04B 1/10 H04B 7/24 - 7/26 H04Q 7/00 - 7/38 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-219232 (JP, A) JP-A-60-152133 (JP, A) Fully open Showa 64-54432 (JP, U) Really open Showa 56- 50138 (JP, U) (58) Fields investigated (Int. Cl. 7 , DB name) H04B 1/10 H04B 7/ 24-7/26 H04Q 7 /00-7/38
Claims (1)
前記受信入力波から受信入力電界の強度を検出し、検出
した受信入力電界が所定レベル以上のときに高レベルを
出力する受信電界強度検出回路と、前記受信入力波から
SAT信号を検出し、SAT信号を検出したときに高レベルを
出力するSAT信号検出回路と、前記受信入力波を前記高
周波増幅器に入力させる状態と当該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
波切換スイッチと、前記SAT信号検出回路の出力を反転
する反転回路と、前記受信電界強度検出回路の出力と前
記反転回路の出力がそれぞれ高レベルのときに前記高周
波切換スイッチを前記高周波増幅器をバイパスする側に
切り換え制御する論理回路とを備えることを特徴とする
セルラー受信機。A high-frequency amplifier capable of amplifying a received input wave;
A reception field strength detection circuit that detects the strength of the reception input electric field from the reception input wave, and outputs a high level when the detected reception input electric field is equal to or higher than a predetermined level,
A SAT signal detection circuit that detects a SAT signal and outputs a high level when the SAT signal is detected; a state where the received input wave is input to the high frequency amplifier; and a state where the high frequency amplifier is bypassed and input to the next stage. A high-frequency changeover switch that can be switched between, an inversion circuit that inverts the output of the SAT signal detection circuit, and the high-frequency changeover switch when the output of the reception field strength detection circuit and the output of the inversion circuit are each at a high level. And a logic circuit for switching and controlling the high-frequency amplifier to bypass the high-frequency amplifier.
Priority Applications (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2158257A JP3068159B2 (en) | 1990-06-16 | 1990-06-16 | Cellular receiver |
| AU78467/91A AU646672B2 (en) | 1990-06-16 | 1991-06-17 | Receiver for a cellular mobile radio communication system |
| EP91305467A EP0462782B1 (en) | 1990-06-16 | 1991-06-17 | Receiver for a cellular mobile radio communication system |
| 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. |
| 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 JPH0448825A (en) | 1992-02-18 |
| JP3068159B2 true 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) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3067308B2 (en) * | 1991-08-28 | 2000-07-17 | 日本電気株式会社 | Cellular receiver |
| JPH07183822A (en) * | 1993-12-24 | 1995-07-21 | Nec Corp | Reception circuit provided with function for preventing malfunction due to high level disturbing wave of adjacent channel |
-
1990
- 1990-06-16 JP JP2158257A patent/JP3068159B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0448825A (en) | 1992-02-18 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |