JPH0865028A - Antenna input circuit - Google Patents
Antenna input circuitInfo
- Publication number
- JPH0865028A JPH0865028A JP21813094A JP21813094A JPH0865028A JP H0865028 A JPH0865028 A JP H0865028A JP 21813094 A JP21813094 A JP 21813094A JP 21813094 A JP21813094 A JP 21813094A JP H0865028 A JPH0865028 A JP H0865028A
- Authority
- JP
- Japan
- Prior art keywords
- coil
- tuning
- input circuit
- wound
- antenna
- 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.)
- Pending
Links
Landscapes
- Details Of Aerials (AREA)
- Input Circuits Of Receivers And Coupling Of Receivers And Audio Equipment (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、アンテナと高周波同調
回路の間に接続されるＡＭラジオ用のアンテナ入力回路
に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna input circuit for an AM radio connected between an antenna and a high frequency tuning circuit.
【０００２】[0002]
【従来の技術】図４は、従来のアンテナ入力回路の回路
図である。従来のアンテナ入力回路は、アンテナが接続
される１対の入力端子４１、４２間に、第１のコイルＬ
４が接続される。第１のコイルＬ４は、同調コイルＬ５
が電磁気的に結合している。同調コイルＬ５は、同調コ
イルＬ５と並列に可変コンデンサＣ２が接続される。そ
して、同調コイルＬ５のインダクタンスと可変コンデン
サＣ２の静電容量で、受信周波数に同調させている。同
調コイルＬ５には、第２のコイルＬ６が電磁気的に結合
している。第２のコイルＬ６は、１対の出力端子４３、
４４に接続され、高周波同調回路に接続される。2. Description of the Related Art FIG. 4 is a circuit diagram of a conventional antenna input circuit. In the conventional antenna input circuit, the first coil L is provided between the pair of input terminals 41 and 42 to which the antenna is connected.
4 is connected. The first coil L4 is a tuning coil L5.
Are electromagnetically coupled. The tuning coil L5 is connected with the variable capacitor C2 in parallel with the tuning coil L5. The inductance of the tuning coil L5 and the electrostatic capacity of the variable capacitor C2 are tuned to the reception frequency. A second coil L6 is electromagnetically coupled to the tuning coil L5. The second coil L6 has a pair of output terminals 43,
44 to the high frequency tuning circuit.
【０００３】このアンテナ入力回路は、図５の様な２枚
の鍔５２、５３によって挟まれた巻溝５４を有するドラ
ム状コア５１の巻溝５４に、第１のコイルＬ４と同調コ
イルＬ５と第２のコイルＬ６を重ねて巻いて形成され
る。この例の場合は、ドラム状コア５１の巻溝５４に巻
く順番は、第１のコイルＬ４、同調コイルＬ５、第２の
コイルＬ６の順に巻いてある。In this antenna input circuit, a first coil L4 and a tuning coil L5 are provided in a winding groove 54 of a drum-shaped core 51 having a winding groove 54 sandwiched by two flanges 52 and 53 as shown in FIG. The second coil L6 is formed by overlapping and winding. In the case of this example, the winding order of the winding groove 54 of the drum-shaped core 51 is the first coil L4, the tuning coil L5, and the second coil L6.
【０００４】この様なアンテナ入力回路は、第１のコイ
ルＬ４と同調コイルＬ５の結合係数及び、同調コイルＬ
５と第２のコイルＬ６の結合係数を、１にすることが困
難である。従って、中波帯（５３０〜１６００ＫＨｚ）
のラジオ局を受信するラジオにこのアンテナ入力回路を
用いた場合、２６ＭＨｚ〜３０ＭＨｚの間にスプリアス
が発生するという問題を有していた。このスプリアスを
除去するためには、出力端子４３と高周波同調回路の間
に、別のＴ形やπ形のフィルタを接続する必要があっ
た。これは、部品の数が増加し、高価になるという問題
を有している。In such an antenna input circuit, the coupling coefficient of the first coil L4 and the tuning coil L5 and the tuning coil L5 are used.
It is difficult to set the coupling coefficient between 5 and the second coil L6 to 1. Therefore, the medium wave band (530 to 1600 KHz)
When this antenna input circuit is used for a radio that receives the radio station, there is a problem that spurious signals are generated between 26 MHz and 30 MHz. In order to remove this spurious, it is necessary to connect another T-type or π-type filter between the output terminal 43 and the high frequency tuning circuit. This has the problem that the number of parts increases and it becomes expensive.
【０００５】[0005]
【発明が解決しようとする課題】本発明は、２６ＭＨｚ
〜３０ＭＨｚの間にスプリアスが発生しないアンテナ入
力回路を提供することを目的とする。また、別の目的
は、従来の様にスプリアスを除去するための別のフィル
タ等を用いることなく、１個のコアで２６ＭＨｚ〜３０
ＭＨｚの間に発生するスプリアスを防止するものであ
る。DISCLOSURE OF THE INVENTION The present invention is based on 26 MHz.
It is an object of the present invention to provide an antenna input circuit in which spurious is not generated in the range of -30 MHz. Further, another object is to achieve 26 MHz to 30 with one core without using another filter for removing spurious as in the conventional case.
It is intended to prevent spurious that occurs during MHz.
【０００６】[0006]
【課題を解決するための手段】本発明のアンテナ入力回
路は、アンテナが接続される第１のコイル、該第１のコ
イルに結合し、可変容量素子が並列に接続される同調コ
イル、該同調コイルに結合し、高周波同調回路に接続さ
れる第２のコイルからなり、第１のコイルと同調コイル
と第２のコイルが、鍔で分割された複数の巻溝を有する
ドラム状コアの巻溝に巻かれ、かつ同調コイルと第２の
コイルが、それぞれ別の巻溝に巻いたり、同じ巻溝に部
分的に重ねて巻いたりして結合係数を調節したものであ
る。また、本発明のアンテナ入力回路は、３つの鍔で分
割された２つの巻溝を有するドラム状コアのそれぞれの
巻溝に、同調コイルと第２のコイルを巻いたり、同じ巻
溝に、同調コイルの１部分と第２のコイル又は、第２の
コイルの１部分と同調コイルを巻いたりして結合係数を
調節したものである。An antenna input circuit according to the present invention comprises a first coil to which an antenna is connected, a tuning coil coupled to the first coil and having a variable capacitance element connected in parallel, and the tuning coil. A winding groove of a drum-shaped core, which is composed of a second coil coupled to the coil and connected to a high frequency tuning circuit, wherein the first coil, the tuning coil and the second coil have a plurality of winding grooves divided by a collar. The tuning coil and the second coil are wound in different winding grooves or partially overlapped in the same winding groove to adjust the coupling coefficient. Further, the antenna input circuit of the present invention is such that a tuning coil and a second coil are wound around each winding groove of a drum-shaped core having two winding grooves divided by three flanges, or the same winding groove is tuned. The coupling coefficient is adjusted by winding a part of the coil and the second coil or a part of the second coil and the tuning coil.
【０００７】[0007]
【実施例】以下、本発明のアンテナ入力回路の実施例を
図１、図２を参照しながら説明する。図１は本発明のア
ンテナ入力回路の実施例の回路図である。１対の入力端
子１１、１２の間に、第１のコイルＬ１が接続される。
第１のコイルＬ１は、同調コイルＬ２に電磁気的に結合
している。同調コイルＬ２には、可変コンデンサＣ１が
同調コイルＬ２と並列に接続されている。また、同調コ
イルＬ２は、１対の出力端子１３、１４の間に接続され
た第２のコイルＬ３に、電磁気的に結合している。そし
て、入力端子１１、１２には、アンテナが接続される。
また、出力端子１３、１４には、高周波同調回路が接続
される。このアンテナ入力回路は、同調コイルＬ２のイ
ンダクタンスと可変コンデンサＣ１の静電容量で受信周
波数に受信し、可変コンデンサＣ１の静電容量を変える
ことにより受信周波数を変えている。また、第２のコイ
ルＬ３と高周波同調回路の回路容量による共振周波数
は、受信周波数と２６ＭＨｚの間に設定してある。Embodiments of the antenna input circuit of the present invention will be described below with reference to FIGS. FIG. 1 is a circuit diagram of an embodiment of an antenna input circuit of the present invention. The first coil L1 is connected between the pair of input terminals 11 and 12.
The first coil L1 is electromagnetically coupled to the tuning coil L2. A variable capacitor C1 is connected to the tuning coil L2 in parallel with the tuning coil L2. The tuning coil L2 is electromagnetically coupled to the second coil L3 connected between the pair of output terminals 13 and 14. An antenna is connected to the input terminals 11 and 12.
A high frequency tuning circuit is connected to the output terminals 13 and 14. This antenna input circuit receives the reception frequency with the inductance of the tuning coil L2 and the electrostatic capacitance of the variable capacitor C1, and changes the reception frequency by changing the electrostatic capacitance of the variable capacitor C1. Further, the resonance frequency due to the circuit capacity of the second coil L3 and the high frequency tuning circuit is set between the reception frequency and 26 MHz.
【０００８】図２は、本発明のアンテナ入力回路の実施
例の断面図である。第１のコイルＬ１、同調コイルＬ
２、第２のコイルＬ３は、ドラム状コア２１に巻かれて
いる。ドラム状コア２１は、３枚の鍔２２、２３、２４
と、鍔２２、２３、２４によって分割された２つの巻溝
２５、２６を有している。そして、ドラム状コア２１の
巻溝２５に、第１のコイルＬ１と同調コイルＬ２を重ね
て巻いている。また、ドラム状コア２１の巻溝２６に、
第２のコイルＬ３を巻いている。この様にして、同調コ
イルＬ２と第２のコイルＬ３の結合係数を小さくしてい
る。FIG. 2 is a sectional view of an embodiment of the antenna input circuit of the present invention. First coil L1, tuning coil L
The second and second coils L3 are wound around the drum-shaped core 21. The drum-shaped core 21 includes three collars 22, 23, 24.
And two winding grooves 25, 26 divided by the collars 22, 23, 24. Then, in the winding groove 25 of the drum-shaped core 21, the first coil L1 and the tuning coil L2 are overlapped and wound. In addition, in the winding groove 26 of the drum-shaped core 21,
The second coil L3 is wound. In this way, the coupling coefficient between the tuning coil L2 and the second coil L3 is reduced.
【０００９】図３は、アンテナ入力回路の特性図であ
り、特性３２は、従来のアンテナ入力回路のものであ
る。なお、図３において、横軸は周波数、縦軸は減衰
量、ＦO は受信周波数、ＦS はスプリアスの周波数であ
る。このアンテナ入力回路の受信周波数を、特性３２の
受信周波数ＦO と同じにすると特性は、３１の様にな
る。特性３１のスプリアスの周波数ＦS は、点線で示し
てある部分の様に２６ＭＨｚよりも低い周波数である。
この特性３１のスプリアスの周波数ＦS は、同調コイル
Ｌ２と第２のコイルＬ3 の結合係数を調節することによ
り、スプリアスの周波数の位置を調節できる。従って、
２６ＭＨｚ〜３０ＭＨｚの間にスプリアスが発生するの
を防ぐことができる。さらに、スプリアスを利用するこ
とにより、複同調のアンテナ入力回路と同じ効果が得ら
れ、選択度が向上する。FIG. 3 is a characteristic diagram of the antenna input circuit, and the characteristic 32 is that of the conventional antenna input circuit. In FIG. 3, the horizontal axis represents frequency, the vertical axis represents attenuation, F O is the reception frequency, and F S is the spurious frequency. When the reception frequency of this antenna input circuit is made the same as the reception frequency F O of the characteristic 32, the characteristic becomes like 31. The spurious frequency F S of the characteristic 31 is a frequency lower than 26 MHz as shown by the dotted line.
With respect to the spurious frequency F S of the characteristic 31, the position of the spurious frequency can be adjusted by adjusting the coupling coefficient between the tuning coil L2 and the second coil L3. Therefore,
It is possible to prevent spurious emission between 26 MHz and 30 MHz. Further, by using spurious, the same effect as that of the double-tuned antenna input circuit can be obtained, and the selectivity is improved.
【００１０】以上、本発明のアンテナ入力回路の実施例
を述べたが、本実施例に限られるものではない。例え
ば、ドラム状コア２１の巻溝２５に、第１のコイルＬ１
と同調コイルＬ２を重ねて巻いて、ドラム状コア２１の
巻溝２６に、第２のコイルＬ３と同調コイルＬ２の１部
分を重ねて巻いてもよい。また、ドラム状コア２１の巻
溝２５に、第２のコイルＬ３を巻いて、ドラム状コア２
１の巻溝２６に、第１のコイルＬ１と同調コイルＬ２と
第２のコイルＬ３の一部分を重ねて巻いてもよい。さら
に、第１のコイルＬ１と第２のコイルＬ３は、同調コイ
ルＬ２にタップを設けることにより形成してもよい。こ
れらの場合、いずれの場合でもスプリアスが発生する周
波数を、２６〜３０ＭＨｚよりも低い周波数に動かし、
中波帯のラジオ局を受信するのに支障のない位置に調整
できる。Although the embodiment of the antenna input circuit of the present invention has been described above, the present invention is not limited to this embodiment. For example, in the winding groove 25 of the drum-shaped core 21, the first coil L1
The tuning coil L2 and the tuning coil L2 may be overlapped and wound, and a part of the second coil L3 and the tuning coil L2 may be overlapped and wound in the winding groove 26 of the drum-shaped core 21. Further, the second coil L3 is wound around the winding groove 25 of the drum-shaped core 21 to form the drum-shaped core 2
A part of the first coil L1, the tuning coil L2, and the second coil L3 may be overlapped and wound in one winding groove 26. Further, the first coil L1 and the second coil L3 may be formed by providing the tuning coil L2 with taps. In these cases, in any case, the frequency at which spurious is generated is moved to a frequency lower than 26 to 30 MHz,
It can be adjusted to a position that does not interfere with reception of mid-range radio stations.
【００１１】[0011]
【発明の効果】以上述べた様に、本発明のアンテナ入力
回路は、同調コイルＬ２と第２のコイルＬ3 の結合係数
を調節できるので２６ＭＨｚ〜３０ＭＨｚの間にスプリ
アスが発生するのを防ぐことができる。また、従来例の
様に２６〜３０ＭＨｚのスプリアスを除去するための部
品を必要とせず、３枚鍔を有する１つのコアに巻くコイ
ルの結合係数の調整によって２６〜３０ＭＨｚのスプリ
アスを除去できるので経済的である。As described above, since the antenna input circuit of the present invention can adjust the coupling coefficient of the tuning coil L2 and the second coil L3, it prevents spurious emission from occurring at 26 MHz to 30 MHz. it can. Further, unlike the conventional example, a component for removing spurious of 26 to 30 MHz is not required, and spurious of 26 to 30 MHz can be removed by adjusting the coupling coefficient of the coil wound around one core having three flanges, which is economical. Target.
【図１】 本発明のアンテナ入力回路の実施例の回路図
である。FIG. 1 is a circuit diagram of an embodiment of an antenna input circuit of the present invention.
【図２】 本発明のアンテナ入力回路の実施例の断面図
である。FIG. 2 is a sectional view of an embodiment of an antenna input circuit of the present invention.
【図３】 アンテナ入力回路の特性図である。FIG. 3 is a characteristic diagram of an antenna input circuit.
【図４】 従来のアンテナ入力回路の回路図である。FIG. 4 is a circuit diagram of a conventional antenna input circuit.
【図５】 従来のアンテナ入力回路の断面図である。FIG. 5 is a cross-sectional view of a conventional antenna input circuit.
１１ 入力端子 １２ 入力端子 １３ 出力端子 １４ 出力端子 Ｌ１ 第１のコイル Ｌ２ 同調コイル Ｌ３ 第２のコイル Ｃ１ 可変コンデンサ 11 Input Terminal 12 Input Terminal 13 Output Terminal 14 Output Terminal L1 First Coil L2 Tuning Coil L3 Second Coil C1 Variable Capacitor
Claims (7)
第１のコイルに結合し、可変容量素子が並列に接続され
る同調コイル、該同調コイルに結合し、高周波同調回路
に接続される第２のコイルからなるアンテナ入力回路に
おいて、該第１のコイルと該同調コイルと該第２のコイ
ルが、鍔で分割された複数の巻溝を有するドラム状コア
の巻溝に巻かれ、かつ該同調コイルと該第２のコイル
が、それぞれ別の巻溝に巻かれることを特徴とするＡＭ
ラジオ用アンテナ入力回路。1. A first coil to which an antenna is connected, a tuning coil coupled to the first coil and a variable capacitance element connected in parallel, coupled to the tuning coil and connected to a high frequency tuning circuit. In an antenna input circuit including a second coil, the first coil, the tuning coil, and the second coil are wound in a winding groove of a drum-shaped core having a plurality of winding grooves divided by a collar, and AM in which the tuning coil and the second coil are respectively wound in different winding grooves.
Radio antenna input circuit.
第１のコイルに結合し、可変容量素子が並列に接続され
る同調コイル、該同調コイルに結合し、高周波同調回路
に接続される第２のコイルからなるアンテナ入力回路に
おいて、該同調コイルが、鍔で分割された２つの巻溝を
有するドラム状コアのいずれか一方の巻溝に巻かれ、該
第２のコイルが該ドラム状コアの他方の巻溝に巻かれる
ことを特徴とするＡＭラジオ用アンテナ入力回路。2. A first coil to which an antenna is connected, a tuning coil coupled to the first coil and a variable capacitance element connected in parallel, coupled to the tuning coil and connected to a high frequency tuning circuit. In an antenna input circuit including a second coil, the tuning coil is wound in one winding groove of a drum-shaped core having two winding grooves divided by a collar, and the second coil is formed in the drum-shaped winding. An antenna input circuit for an AM radio, which is wound in the other winding groove of the core.
第１のコイルに結合し、可変容量素子が並列に接続され
る同調コイル、該同調コイルに結合し、高周波同調回路
に接続される第２のコイルからなるアンテナ入力回路に
おいて、該第１のコイルと該同調コイルと該第２のコイ
ルが、鍔で分割された複数の巻溝を有するドラム状コア
の巻溝に巻かれ、かつ該同調コイルと該第２のコイル
が、部分的に重ねて巻かれることを特徴とするＡＭラジ
オ用アンテナ入力回路。3. A first coil to which an antenna is connected, a tuning coil coupled to the first coil and a variable capacitance element connected in parallel, coupled to the tuning coil and connected to a high frequency tuning circuit. In an antenna input circuit including a second coil, the first coil, the tuning coil, and the second coil are wound in a winding groove of a drum-shaped core having a plurality of winding grooves divided by a collar, and An antenna input circuit for an AM radio, wherein the tuning coil and the second coil are partially overlapped and wound.
第１のコイルに結合し、可変容量素子が並列に接続され
る同調コイル、該同調コイルに結合し、高周波同調回路
に接続される第２のコイルからなるアンテナ入力回路に
おいて、該同調コイルが、鍔で分割された２つの巻溝を
有するドラム状コアのいずれか一方の巻溝に巻かれ、該
第２のコイルが該ドラム状コアの他方の巻溝に巻かれ、
かつ該第２のコイルの１部分を、該同調コイルが巻かれ
る巻溝にも巻かれることを特徴とするＡＭラジオ用アン
テナ入力回路。4. A first coil to which an antenna is connected, a tuning coil coupled to the first coil and a variable capacitance element connected in parallel, coupled to the tuning coil and connected to a high frequency tuning circuit. In an antenna input circuit including a second coil, the tuning coil is wound in one of the winding grooves of a drum-shaped core having two winding grooves divided by a collar, and the second coil is formed in the drum-shaped core. It is wound in the other winding groove of the core,
An antenna radio input circuit for an AM radio, characterized in that a part of the second coil is also wound in a winding groove around which the tuning coil is wound.
第１のコイルに結合し、可変容量素子が並列に接続され
る同調コイル、該同調コイルに結合し、高周波同調回路
に接続される第２のコイルからなるアンテナ入力回路に
おいて、該第２のコイルが、鍔で分割された２つの巻溝
を有するドラム状コアのいずれか一方の巻溝に巻かれ、
該同調コイルが該ドラム状コアの他方の巻溝に巻かれ、
かつ該同調コイルの１部分を、該第２のコイルが巻かれ
る巻溝にも巻かれることを特徴とするＡＭラジオ用アン
テナ入力回路。5. A first coil to which an antenna is connected, a tuning coil coupled to the first coil and a variable capacitance element connected in parallel, coupled to the tuning coil and connected to a high frequency tuning circuit. In an antenna input circuit including a second coil, the second coil is wound around either one of the winding grooves of a drum-shaped core having two winding grooves divided by a collar,
The tuning coil is wound in the other winding groove of the drum-shaped core,
An antenna radio input circuit for an AM radio, characterized in that a part of the tuning coil is also wound in a winding groove around which the second coil is wound.
より第２のコイルを形成した請求項１、２、３記載のＡ
Ｍラジオ用アンテナ入力回路。6. The A according to claim 1, wherein the second coil is formed by providing a tap on the tuning coil.
Antenna input circuit for M radio.
の同調コイルが巻かれる巻溝に巻かれる請求項１、２、
３、４、５、６記載のＡＭラジオ用アンテナ入力回路。7. The first coil is wound in a winding groove around which the tuning coil of the drum-shaped core is wound.
Antenna input circuit for AM radio according to 3, 4, 5, and 6.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21813094A JPH0865028A (en) | 1994-08-19 | 1994-08-19 | Antenna input circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21813094A JPH0865028A (en) | 1994-08-19 | 1994-08-19 | Antenna input circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0865028A true JPH0865028A (en) | 1996-03-08 |
Family
ID=16715113
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP21813094A Pending JPH0865028A (en) | 1994-08-19 | 1994-08-19 | Antenna input circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0865028A (en) |
-
1994
- 1994-08-19 JP JP21813094A patent/JPH0865028A/en active Pending
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