JPH0552093B2 - - Google Patents
Info
- Publication number
- JPH0552093B2 JPH0552093B2 JP62170083A JP17008387A JPH0552093B2 JP H0552093 B2 JPH0552093 B2 JP H0552093B2 JP 62170083 A JP62170083 A JP 62170083A JP 17008387 A JP17008387 A JP 17008387A JP H0552093 B2 JPH0552093 B2 JP H0552093B2
- Authority
- JP
- Japan
- Prior art keywords
- circuit
- frequency
- tuning
- amplifier
- tuning voltage
- 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 - Lifetime
Links
- 230000010355 oscillation Effects 0.000 claims description 3
- 238000010586 diagram Methods 0.000 description 9
- 239000003990 capacitor Substances 0.000 description 8
- 238000001514 detection method Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 230000002452 interceptive effect Effects 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
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- Superheterodyne Receivers (AREA)
- Noise Elimination (AREA)
- Input Circuits Of Receivers And Coupling Of Receivers And Audio Equipment (AREA)
Description
【発明の詳細な説明】
［産業上の利用分野］
本発明は、電子チユーナに係り、特に妨害電波
の影響を低減する電子チユーナに関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electronic tuner, and particularly to an electronic tuner that reduces the influence of jamming waves.
［従来の技術］
従来より、アンテナにて受信された受信信号か
ら希望周波数の受信信号を選択する同調回路をそ
の内部に備えていないRF増幅器（高周波増幅器）
を具備した電子チユーナがある。係る電子チユー
ナは例えば１個のICとして構成されている。第
７図は従来のアツプコンバータ方式のAM電子チ
ユーナの一例の構成を示すブロツク図である。こ
こで、アンテナ１により受信された受信信号は非
同調のRF増幅器２に供給される。このRF増幅器
２は内部に同調回路を備えておらず、希望周波数
1の受信信号を含む種々の周波数を増幅して低減
フイルタ（LPF）３を介して混合器４に供給す
る。[Prior Art] Conventionally, RF amplifiers (high-frequency amplifiers) do not have internal tuning circuits that select a received signal of a desired frequency from the received signals received by an antenna.
There is an electronic tuner equipped with Such an electronic tuner is configured as a single IC, for example. FIG. 7 is a block diagram showing the configuration of an example of a conventional up-converter type AM electronic tuner. Here, the received signal received by the antenna 1 is supplied to an untuned RF amplifier 2. This RF amplifier 2 is not equipped with an internal tuning circuit, and the desired frequency
Various frequencies including the received signal of 1 are amplified and supplied to a mixer 4 via a reduction filter (LPF) 3.
混合器４は、LPF３を介して供給される周波
数1の受信信号に局部発信器５から供給される周
波数2（希望信号周波数＋10.7MHz）の周波数信
号を混合して周波数変換を行う。一方、PLL（フ
エーズ・ロツクト・ループ）６は局部発信器５の
発信周波数2に応じた同調電圧VTを発生して局
部発信器５に供給する。これにより、受信周波数
1が発信周波数2に対応して設定される。 The mixer 4 performs frequency conversion by mixing the received signal of frequency 1 supplied via the LPF 3 with the frequency signal of frequency 2 (desired signal frequency + 10.7 MHz) supplied from the local oscillator 5. On the other hand, a PLL (phase locked loop) 6 generates a tuning voltage V T corresponding to the oscillation frequency 2 of the local oscillator 5 and supplies it to the local oscillator 5. This allows the receiving frequency to
1 is set corresponding to transmission frequency 2 .
混合器４の出力信号は、その通過帯域の中心周
波数が3（例えば、10.7MHz）である帯域フイル
タ（BPF）７を介して混合器８に供給され、こ
こで、局部発信器９よりの周波数4（例えば
10.25MHz）の周波数信号と混合されて第二中間
周波信号に変換される。この第二中間周波信号
は、その通過帯域の中心周波数が5（例えば450k
Hz）である帯域フイルタ（BPF）１０を介して
IF増幅器（中間周波増幅器）１１に供給され、
ここで、増幅された後検波器１２に供給される。
検波器１２は入来する第二中間周波信号をAM検
波して得た検波信号を出力端子１３を介して当該
AM電子チユーナ内の他の回路に供給する。 The output signal of the mixer 4 is fed to a mixer 8 via a bandpass filter (BPF) 7 whose passband has a center frequency of 3 (for example, 10.7MHz), where the frequency from the local oscillator 9 is 4 (for example
10.25MHz) frequency signal and converted into a second intermediate frequency signal. This second intermediate frequency signal has a passband center frequency of 5 (e.g. 450k
Hz) through a bandpass filter (BPF) 10
is supplied to an IF amplifier (intermediate frequency amplifier) 11,
Here, the signal is amplified and then supplied to the detector 12.
The detector 12 performs AM detection on the incoming second intermediate frequency signal and outputs the detected signal through the output terminal 13.
Supplies other circuits in the AM electronic tuner.
［発明が解決しようとする問題点］
以上説明した様に、従来のアツプコンバーター
方式のAM電子チユーナではRF増幅器内に同調
回路が具備されておらず、妨害電波に弱いという
問題点があつた。また、同調電圧VTの範囲も狭
いため、容易に同調回路を追加することもできな
かつた。[Problems to be Solved by the Invention] As explained above, the conventional up-converter type AM electronic tuner does not have a tuning circuit in the RF amplifier, and has the problem of being susceptible to radio interference. Furthermore, since the range of the tuning voltage V T is narrow, it is not possible to easily add a tuning circuit.
本発明は、上述した事情に鑑みてなされたもの
で、同調電圧の範囲を拡大し、RF増幅器の前又
は後に同調回路を具備することにより、妨害電波
の影響を低減した電子チユーナを提供することを
目的とする。 The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide an electronic tuner in which the influence of radio interference is reduced by expanding the tuning voltage range and providing a tuning circuit before or after the RF amplifier. With the goal.
［問題点を解決するための手段］
本発明は、所望の局部発信周波数に対応する同
調電圧の範囲を拡大する拡大回路と、RF増幅器
の近傍に接続配置され、同調電圧に基づいて受信
信号中の妨害電波成分を低減する同調回路とを具
備している。[Means for Solving the Problems] The present invention includes an expansion circuit that expands the range of tuning voltage corresponding to a desired local oscillation frequency, and an expansion circuit that is connected near an RF amplifier and that adjusts the range of received signals based on the tuning voltage. and a tuning circuit that reduces interference radio wave components.
［作用］
同調電圧の範囲を拡大してRF増幅器の近傍に
具備された同調回路に供給しているので、この同
調回路により受信信号中の妨害電波成分を低減さ
せることができる。[Function] Since the range of the tuning voltage is expanded and supplied to the tuning circuit provided near the RF amplifier, this tuning circuit can reduce the interference radio wave component in the received signal.
［実施例］
第１図は、本発明の一実施例を示すブロツク系
統図である。同図中、第７図と同一構成部分には
同一符号を付し、その説明を適宜省略する。ここ
で、前記アンテナ１により受信された受信信号は
バツフア２１を介して同調回路２２に供給され
る。一方、前記PLL６の出力同調電圧VTは拡大
回路２３に供給され、ここで、その範囲が拡大さ
れた同調電圧VTLとされて同調回路２２に供給さ
れる。同調回路２２は入来する同調電圧VTLに基
づいて受信信号中の妨害電波成分を低減して前記
RF増幅器２に供給する。RF増幅器２から出力さ
れる前記希望周波数の受信信号は、前記の如く、
LPF３、混合器４及び端子２４を介して前記
BPF７に供給される。尚、第１図では前記BPF
７以降の回路の図示は省略してある。[Embodiment] FIG. 1 is a block system diagram showing an embodiment of the present invention. In the figure, the same components as those in FIG. 7 are denoted by the same reference numerals, and the explanation thereof will be omitted as appropriate. Here, the received signal received by the antenna 1 is supplied to a tuning circuit 22 via a buffer 21. On the other hand, the output tuning voltage V T of the PLL 6 is supplied to an expansion circuit 23 , where it is converted into a tuning voltage V TL whose range has been expanded and supplied to the tuning circuit 22 . The tuning circuit 22 reduces the interference radio wave component in the received signal based on the incoming tuning voltage V TL and
RF amplifier 2 is supplied. The received signal of the desired frequency output from the RF amplifier 2 is as described above.
The above through LPF 3, mixer 4 and terminal 24
Supplied to BPF7. In addition, in Figure 1, the BPF
The illustration of the circuit after 7 is omitted.
第２図は、第１図に示す実施例の要部の詳細な
回路系統図である。同図中、同調回路２２はコイ
ルＬ、コンデンサＣ、可変コンデンサCU及び可
変容量ダイオードDUよりなる周知の構成である。
また、拡大回路２３はオペアンプ３１、定電圧回
路３２、ダイオードD1〜D7、コンデンサC1〜C5
及び抵抗R1〜R6より構成される。 FIG. 2 is a detailed circuit diagram of the main parts of the embodiment shown in FIG. 1. In the figure, a tuning circuit 22 has a well-known configuration consisting of a coil L, a capacitor C, a variable capacitor C U , and a variable capacitance diode D U.
Further, the expansion circuit 23 includes an operational amplifier 31, a constant voltage circuit 32, diodes D1 to D7 , and capacitors C1 to C5.
and resistors R1 to R6 .
拡大回路２３において、前記PLL６より同調
電圧VTが供給される入力端子３３は、ダイオー
ドD1〜D4を直列に介してオペアンプ３１の非反
転入力端子に接続される。ダイオードD4のカソ
ードとオペアンプ３１の非反転入力端子との接続
点は、コンデンサC1及び抵抗R1を並列に介して
接地される。オペアンプ３１の反転入力端子は抵
抗R2を介してその出力端子に接続されると共に、
抵抗R3、ダイオードD5及びD6を直列に介して接
地される。一方、電源電圧VPの電源端子はコン
デンサC2を介して接地されると共に、定電圧回
路３２に接続される。定電圧回路３２は、いわゆ
る３端子レギユレータより構成されており、コン
デンサC3を介して接地されると共に、オペアン
プ３１に接続される。オペアンプ３１の出力端子
及び抵抗R2の接続点は抵抗R4及びダイオードD7
を直列に介して出力端子３４に接続される。抵抗
R4及びダイオードD7のアノードとの接続点はコ
ンデンサC4を介して接地されると共に抵抗R5を
介してテスト端子３５に接続される。このテスト
端子３５は拡大された同調電圧VTLを測定するた
めの端子であるため、拡大回路２３の動作とは関
係ない。ダイオードD7のカソード及び出力端子
３４の接続点は抵抗R6及びコンデンサC5を並列
に介して接地される。 In the expansion circuit 23, an input terminal 33 to which the tuning voltage V T is supplied from the PLL 6 is connected to a non-inverting input terminal of an operational amplifier 31 via diodes D 1 to D 4 in series. A connection point between the cathode of the diode D 4 and the non-inverting input terminal of the operational amplifier 31 is grounded via a capacitor C 1 and a resistor R 1 in parallel. The inverting input terminal of the operational amplifier 31 is connected to its output terminal via a resistor R2 , and
It is grounded through a resistor R 3 and diodes D 5 and D 6 in series. On the other hand, the power supply terminal of the power supply voltage V P is grounded via the capacitor C 2 and is also connected to the constant voltage circuit 32 . The constant voltage circuit 32 is composed of a so-called three-terminal regulator, and is grounded via a capacitor C 3 and also connected to the operational amplifier 31 . The connection point between the output terminal of the operational amplifier 31 and the resistor R2 is the resistor R4 and the diode D7.
are connected to the output terminal 34 through the terminals in series. resistance
The connection point between R 4 and the anode of diode D 7 is grounded via capacitor C 4 and connected to test terminal 35 via resistor R 5 . Since this test terminal 35 is a terminal for measuring the enlarged tuning voltage VTL , it is not related to the operation of the enlargement circuit 23. The connection point between the cathode of the diode D7 and the output terminal 34 is grounded through a resistor R6 and a capacitor C5 in parallel.
上記構成において、周波数522kHz及び1620kHz
における同調電圧VTは各々3.3V及び5.8Vである
ため、その範囲は2.5Vとなつている。また、拡
大回路２３のテスト端子３５における拡大された
同調電圧VTLは各々1.6V及び7.6Vとなるため、そ
の範囲は6Vに拡大されることになる。このよう
にして拡大された同調電圧VTLは抵抗R7を介して
同調回路２２に供給される。 In the above configuration, frequency 522kHz and 1620kHz
Since the tuning voltages V T are 3.3V and 5.8V, respectively, the range is 2.5V. Further, the expanded tuning voltage V TL at the test terminal 35 of the expansion circuit 23 becomes 1.6V and 7.6V, respectively, so that the range is expanded to 6V. The thus expanded tuning voltage V TL is supplied to the tuning circuit 22 via the resistor R 7 .
上記同調回路２２は第１図に示す如くRF増幅
器２の前段に接続されるものとは限らず、第３図
に示す如くRF増幅器２の後段に接続しても良い。 The tuning circuit 22 is not necessarily connected to the front stage of the RF amplifier 2 as shown in FIG. 1, but may be connected to the rear stage of the RF amplifier 2 as shown in FIG.
第４図〜第６図は、受信周波数を999kHzとし、
これに所定周波数の妨害電波を混在して従来回路
及び本発明回路に各々供給した場合の両者の出力
検波レベルの比較結果を示した図である。ここ
で、従来回路の特性は破線で、本発明回路の特性
は実線で示すものとする。 In Figures 4 to 6, the reception frequency is 999kHz,
FIG. 7 is a diagram showing a comparison result of the output detection level of the conventional circuit and the circuit of the present invention when the interfering radio waves of a predetermined frequency are mixed and supplied to the conventional circuit and the circuit of the present invention, respectively. Here, the characteristics of the conventional circuit are shown by broken lines, and the characteristics of the circuit of the present invention are shown by solid lines.
第４図は妨害電波周波数を799kHzとし、第５
図は妨害電波周波数を599kHzとした場合の混変
調特性を各々示す。両図に示す如く、本発明によ
れば、妨害波出力レベルが3dB増加する妨害波の
入力レベルが著しく改善される。すなわち、妨害
電波周波数799kHzでは約3.5dB改善され、妨害電
波周波数599kHzでは約13dB改善される。 In Figure 4, the jamming frequency is 799kHz, and the 5th
The figures show the cross-modulation characteristics when the jamming frequency is 599kHz. As shown in both figures, according to the present invention, the input level of the interference wave is significantly improved, which increases the output level of the interference wave by 3 dB. That is, at a jamming frequency of 799kHz, the improvement is about 3.5dB, and at a jamming frequency of 599kHz, it is improved by about 13dB.
第６図は、受信周波数999kHzを中心として妨
害電波周波数を変化させた場合の特性を示してお
り、希望信号40dBμ時の検波出力レベルが3dB抑
圧される妨害波の入力レベルを測定した結果、こ
こでも、本発明により妨害電波成分が著しく低減
されることが解る。 Figure 6 shows the characteristics when the interfering frequency is changed around the receiving frequency of 999 kHz.As a result of measuring the input level of the interfering wave at which the detection output level is suppressed by 3 dB when the desired signal is 40 dBμ, However, it can be seen that the interference radio wave components are significantly reduced by the present invention.
尚、本発明の具体的回路構成は第２図に示した
ものに限定されず、他の回路構成としても良いこ
とは勿論である。 Note that the specific circuit configuration of the present invention is not limited to that shown in FIG. 2, and it goes without saying that other circuit configurations may be used.
［発明の効果］
以上説明したように、本発明によれば、同調電
圧の範囲を拡大する拡大回路と、RF増幅器の近
傍に接続配置され、同調電圧に基づいて受信信号
中の妨害電波成分を低減する同調回路とを具備し
たので、従来回路（例えばIC）のAMフロントエ
ンド側に容易に同調回路を追加接続することがで
き、受信電波中に混在する妨害電波成分を低減し
て良好な受信音声を得ることができる等の効果が
得られる。[Effects of the Invention] As explained above, according to the present invention, an expansion circuit that expands the range of the tuning voltage is connected to the RF amplifier, and the interference radio wave component in the received signal is removed based on the tuning voltage. Since it is equipped with a tuning circuit that reduces interference, it is possible to easily add a tuning circuit to the AM front end side of a conventional circuit (for example, an IC), reducing interference components mixed in received radio waves and improving reception. Effects such as being able to obtain audio can be obtained.
第１図は本発明になる電子チユーナの一実施例
を示すブロツク系統図、第２図は第１図に示す実
施例の要部の詳細な構成を示す回路系統図、第３
図は本発明の他の変形例を示すブロツク系統図、
第４図〜第６図は本発明による妨害電波成分低減
効果を示す周波数特性図、第７図は従来のAM電
子チユーナの一例の構成を示すブロツク系統図で
ある。
１……アンテナ、２……RF増幅器、４……混
合器、５……局部発信器、６……PLL、２２…
…同調回路、２３……拡大回路、３１……オペア
ンプ、３２……定電圧回路。
FIG. 1 is a block system diagram showing one embodiment of an electronic tuner according to the present invention, FIG. 2 is a circuit system diagram showing the detailed configuration of the main part of the embodiment shown in FIG. 1, and FIG.
The figure is a block system diagram showing another modification of the present invention.
4 to 6 are frequency characteristic diagrams showing the effect of reducing interference radio wave components according to the present invention, and FIG. 7 is a block system diagram showing the configuration of an example of a conventional AM electronic tuner. 1...Antenna, 2...RF amplifier, 4...Mixer, 5...Local oscillator, 6...PLL, 22...
... Tuning circuit, 23 ... Expansion circuit, 31 ... Operational amplifier, 32 ... Constant voltage circuit.
Claims (1)
て、 所望の局部発信周波数に対応する同調電圧の範
囲を拡大する拡大回路と、 RF増幅器の近傍に接続配置され、前記同調電
圧に基づいて前記受信信号中の妨害電波成分を低
減する同調回路と を具備したことを特徴とする電子チユーナ。[Scope of Claims] 1. An up-converter type electronic tuner, comprising: an expansion circuit for expanding the range of tuning voltage corresponding to a desired local oscillation frequency; and an expansion circuit connected near an RF amplifier to increase the range of the tuning voltage based on the tuning voltage. An electronic tuner comprising a tuning circuit that reduces interference radio wave components in a received signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17008387A JPS6413822A (en) | 1987-07-08 | 1987-07-08 | Electronic tuner |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17008387A JPS6413822A (en) | 1987-07-08 | 1987-07-08 | Electronic tuner |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6413822A JPS6413822A (en) | 1989-01-18 |
| JPH0552093B2 true JPH0552093B2 (en) | 1993-08-04 |
Family
ID=15898327
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP17008387A Granted JPS6413822A (en) | 1987-07-08 | 1987-07-08 | Electronic tuner |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6413822A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5669232A (en) * | 1994-11-22 | 1997-09-23 | Sanyo Electric Co., Ltd. | Refrigerating unit |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5916914B2 (en) * | 1976-06-14 | 1984-04-18 | エヌ・テ−・エヌ東洋ベアリング株式会社 | Workpiece attachment/detachment device |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5916914U (en) * | 1982-07-21 | 1984-02-01 | 株式会社日立製作所 | Base structure of integrated air conditioner |
-
1987
- 1987-07-08 JP JP17008387A patent/JPS6413822A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5916914B2 (en) * | 1976-06-14 | 1984-04-18 | エヌ・テ−・エヌ東洋ベアリング株式会社 | Workpiece attachment/detachment device |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6413822A (en) | 1989-01-18 |
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