JPS6243374B2 - - Google Patents

Info

Publication number
JPS6243374B2
JPS6243374B2 JP16777081A JP16777081A JPS6243374B2 JP S6243374 B2 JPS6243374 B2 JP S6243374B2 JP 16777081 A JP16777081 A JP 16777081A JP 16777081 A JP16777081 A JP 16777081A JP S6243374 B2 JPS6243374 B2 JP S6243374B2
Authority
JP
Japan
Prior art keywords
signal
antenna
field strength
electric field
filter
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
Application number
JP16777081A
Other languages
Japanese (ja)
Other versions
JPS5868323A (en
Inventor
Fujihiro Iwaki
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Matsuda KK
Original Assignee
Matsuda KK
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Matsuda KK filed Critical Matsuda KK
Priority to JP16777081A priority Critical patent/JPS5868323A/en
Publication of JPS5868323A publication Critical patent/JPS5868323A/en
Publication of JPS6243374B2 publication Critical patent/JPS6243374B2/ja
Granted legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H03ELECTRONIC CIRCUITRY
    • H03GCONTROL OF AMPLIFICATION
    • H03G3/00Gain control in amplifiers or frequency changers
    • H03G3/20Automatic control
    • H03G3/30Automatic control in amplifiers having semiconductor devices
    • H03G3/3052Automatic control in amplifiers having semiconductor devices in bandpass amplifiers (H.F. or I.F.) or in frequency-changers used in a (super)heterodyne receiver

Landscapes

  • Circuits Of Receivers In General (AREA)
  • Input Circuits Of Receivers And Coupling Of Receivers And Audio Equipment (AREA)
  • Details Of Aerials (AREA)
  • Noise Elimination (AREA)

Description

【発明の詳細な説明】 この発明は、自動車用受信機のアンテナアンプ
に関するものである。
DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an antenna amplifier for an automobile receiver.

従来、自動車用受信機のアンテナには、リヤウ
インドガラスのくもりを除去するために設けた熱
線を利用してラジオ放送電波を受信するようにし
たものがあるが(特公昭56―244号公報参照)、こ
のようなアンテナを用いる場合、通常、車載のラ
ジオ受信機は車室前部のインストルメントパネル
に設けられてアンテナから離れており、しかも熱
線を兼用したアンテナはそれほど受信感度がよく
ないことから、アンテナからの信号を一旦アンテ
ナアンプで増幅して受信機に送ることが行なわれ
ている。
Conventionally, some car receiver antennas receive radio broadcast waves by using hot wires installed to remove fog from the rear window glass (see Japanese Patent Publication No. 1983-244). ), when using such an antenna, the in-vehicle radio receiver is usually installed in the instrument panel at the front of the vehicle and is away from the antenna, and antennas that also serve as hot wires do not have very good reception sensitivity. Since then, the signal from the antenna is first amplified by an antenna amplifier and then sent to the receiver.

しかしながら従来のアンテナアンプでは、アン
テナの受信帯全域を増幅するようにしていたの
で、選局した放送局の電波の電界強度がアンテナ
の受信帯全域の電界強度、特に隣接する周波数の
電界強度より小さい場合には、選局した周波数と
隣接する周波数間の電界強度の差がより一層増大
し、そのため混信を生じて聞きとりにくくなると
いう問題がある。
However, with conventional antenna amplifiers, the entire receiving band of the antenna is amplified, so the electric field strength of the radio waves of the selected broadcasting station is smaller than the electric field strength of the entire receiving band of the antenna, especially the field strength of adjacent frequencies. In this case, there is a problem in that the difference in electric field strength between the selected frequency and the adjacent frequency increases further, causing interference and making it difficult to hear.

そこでこのような問題を解消するためには、ア
ンテナからの信号を狭帯域フイルタを通過させた
後増幅器に入力し、選局した周波数の受信信号の
みを増幅することが考えられるが、上記とは逆に
選局した周波数の電界強度が隣接する周波数のそ
れより大きい場合には狭帯域フイルタはそれほど
必要とされず、そのため上記フイルタを常時作動
させるようにしたのでは出力ロスや無駄な電力消
費を生ずることとなり、好まくない。
In order to solve this problem, it is conceivable to pass the signal from the antenna through a narrowband filter and then input it to an amplifier to amplify only the received signal of the selected frequency, but this is different from the above. On the other hand, if the electric field strength of the selected frequency is greater than that of the adjacent frequency, the narrow band filter is not so necessary, so if the filter is always activated, it will cause output loss and wasteful power consumption. This is not desirable.

この発明は以上のような問題点に鑑みてなされ
たもので、同調周波数の受信信号の電界強度が受
信アンテナの受信帯域の電界強度より小さいか否
かを判別回路で判別し、小さいときはフイルタの
通過帯域を狭帯域として同調周波数の受信信号の
みを増幅し、そうでないときは上記フイルタの通
過帯域を受信帯全域として受信信号をすべてその
まま受信機に送ることにより、受信感度を向上す
るとともに、無駄な電力消費をなくするようにし
た自動車用受信機のアンテナアンプを提供するこ
とを目的としている。
This invention was made in view of the above-mentioned problems, and uses a discriminating circuit to determine whether or not the electric field strength of the received signal at the tuned frequency is smaller than the electric field strength of the receiving band of the receiving antenna. By setting the passband of the filter as a narrow band to amplify only the received signal at the tuned frequency, and otherwise setting the passband of the filter to be the entire receiving band and sending all the received signals as they are to the receiver, the receiving sensitivity is improved. The purpose of the present invention is to provide an antenna amplifier for an automobile receiver that eliminates wasteful power consumption.

以下本発明の一実施例を図について説明する。 An embodiment of the present invention will be described below with reference to the drawings.

第1図は本発明の一実施例による自動車用受信
機のアンテナアンプを示す。図において、1は自
動車のリヤウインドガラス、2はリヤウインドガ
ラス1に相互に平行に固着され、該ガラス1のく
もりを除去するための複数の熱線、3は熱線2の
電極、4は上記複数の熱線2と電極3とにより構
成されたAM放送受信用のアンテナ、5は上記ア
ンテナ4の受信信号がアースに逃げるのを防止す
るためのチヨークコイル、6はリヤウインドガラ
ス1のアンテナ4の上方に固着されたFM放送受
信用のアンテナ、7はアンテナ6の受信信号がア
ンテナ4を介してアースに逃げるのを防止するた
めのスタブ、8は上記両アンテナ4,6からなる
受信アンテナ、9は受信アンテナ8の信号引き出
し用の端子、10aはコンデンサ、10bはバツ
テリ、10cは熱線2に通電を行なうためのスイ
ツチである。
FIG. 1 shows an antenna amplifier for an automobile receiver according to an embodiment of the present invention. In the figure, 1 is a rear window glass of an automobile, 2 is a plurality of hot wires fixed to the rear window glass 1 in parallel with each other and used to remove fog from the glass 1, 3 is an electrode of the hot wire 2, and 4 is a plurality of the above-mentioned hot wires. An antenna for receiving AM broadcasting consisting of a hot wire 2 and an electrode 3; 5 is a choke coil for preventing the received signal of the antenna 4 from escaping to the ground; 6 is an antenna above the antenna 4 of the rear window glass 1; A fixed antenna for receiving FM broadcasting, 7 is a stub for preventing the received signal of antenna 6 from escaping to the ground via antenna 4, 8 is a receiving antenna consisting of both antennas 4 and 6, and 9 is a receiving antenna. 10a is a capacitor, 10b is a battery, and 10c is a switch for energizing the hot wire 2.

また12は車室前部のインストルメントパネル
(図示せず)に取付けられたラジオ受信機、13
はそのスピーカ、14は上記受信アンテナ8の端
子9に接続されたフイルタであり、該フイルタ1
4の通過帯域は上記ラジオ受信機12からの同調
信号の入力時にラジオ受信機12の同調周波数を
中心周波数とする狭帯域となり、同調信号の非入
力時には受信アンテナ8の受信帯全域となる。1
5は後述する利得制御信号bの入力時に上記フイ
ルタ14の信号を増幅してラジオ受信機12に出
力し、利得制御信号bの非入力時に上記フイルタ
14の信号をそのまま出力する増幅器である。
12 is a radio receiver mounted on the instrument panel (not shown) at the front of the vehicle; 13
is the speaker, 14 is a filter connected to the terminal 9 of the receiving antenna 8, and the filter 1
The pass band 4 becomes a narrow band centered on the tuning frequency of the radio receiver 12 when a tuning signal from the radio receiver 12 is input, and becomes the entire receiving band of the receiving antenna 8 when no tuning signal is input. 1
Reference numeral 5 denotes an amplifier that amplifies the signal of the filter 14 and outputs it to the radio receiver 12 when a gain control signal b (described later) is input, and outputs the signal of the filter 14 as is when the gain control signal b is not input.

さらに16は上記受信アンテナ8の端子9に接
続され、通過帯域の中心周波数がジオ受信機12
の同調周波数となる狭帯域通過フイルタ、17は
同調周波数の受信信号の電界強度、即ち狭帯域通
過フイルタ16の出力の大きさを検出する第1の
電界強度検出回路、18は受信アンテナ8の受信
帯全域の電界強度を検出する第2の電界強度検出
回路、19は上記両電界強度検出回路17,18
の出力を比較する第1の比較器、20は上記16
〜19によつて構成され、上記同調周波数の受信
信号の電界強度が上記受信帯全域の電界強度より
小さいか否かを判別する判別回路、21は判別回
路20の出力に応じて上記フイルタ14に対する
同調信号入力に接断するアナログスイツチ(特性
切換回路)、22は上記第1の電界強度検出回路
17の出力と基準電圧23とを比較して上記利得
制御信号bを出力する第2の比較器であり、以上
の14〜23によつてアンテナアンプ24が構成
されている。
Further, 16 is connected to the terminal 9 of the receiving antenna 8, and the center frequency of the passband is set to the geo receiver 12.
17 is a first electric field strength detection circuit that detects the electric field strength of the received signal at the tuned frequency, that is, the magnitude of the output of the narrow band pass filter 16; 18 is the reception signal of the receiving antenna 8; A second electric field strength detection circuit 19 detects the electric field strength over the entire band;
A first comparator 20 compares the outputs of the above 16
- 19, a discriminating circuit for discriminating whether the electric field strength of the received signal of the tuned frequency is smaller than the electric field strength of the entire receiving band; An analog switch (characteristic switching circuit) that connects and disconnects the tuning signal input, and 22 a second comparator that compares the output of the first field strength detection circuit 17 with a reference voltage 23 and outputs the gain control signal b. The above 14 to 23 constitute the antenna amplifier 24.

次に第2図ないし第4図を用いて動作について
説明する。
Next, the operation will be explained using FIGS. 2 to 4.

第2図aはラジオ受信機12の同調周波数
の受信信号の電界強度が隣接する周波数
のの電界強度より小さく、かつそれが設定レベ
ルである100dB以下である場合を示す。この場
合、まずラジオ受信機12で周波数を選局す
ると、この受信機12は同調信号aを発生する。
するとこの同調信号aは狭帯域通過フイルタ16
に入力され、このフイルタ16の中心周波数は同
調周波数となり、フイルタ16は受信アンテ
ナ8からの受信信号のうち周波数のみを通過
させ、第1の電界強度検出回路17は周波数
の信号の電界強度を検出する。一方第2の電界強
度検出回路18は受信アンテナ8の受信帯全域の
電界強度、従つてこの場合周波数
のうち一番強い周波数の電界強度を検出
し、今、同調周波数の信号の電界強度は周波
の信号のそれより小さいので、第1の比較
器19の出力は“ハイ”となり、アナログスイツ
チ21はフイルタ14に上記同調信号aを印加
し、フイルタ14の通過帯域は中心周波数が同調
周波数である狭帯域となる。また同調周波数
の信号の電界強度が設定レベルである100dB
以下であることから第2の比較器22の出力は
“ハイ”となつて利得制御信号bが出力され、増
幅器15はフイルタ14の出力信号を増幅するた
め、アンテナアンプ24は第2図bに示すように
同調周波数の信号のみを増幅してラジオ受信
機12に出力する。
FIG. 2a shows the tuning frequency of the radio receiver 12 at 0.
The electric field strength of the received signal is adjacent to the frequency 1 ,
This shows the case where the electric field strength is smaller than the electric field strength of 2 and below the set level of 100 dB. In this case, when the radio receiver 12 first tunes to frequency 0 , the receiver 12 generates a tuning signal a.
Then, this tuning signal a is passed through the narrow band pass filter 16.
The center frequency of this filter 16 becomes the tuning frequency 0 , the filter 16 passes only the frequency 0 of the received signal from the receiving antenna 8, and the first electric field strength detection circuit 17 uses the tuned frequency 0 .
Detect the electric field strength of the signal. On the other hand, the second electric field strength detection circuit 18 detects the electric field strength of the entire receiving band of the receiving antenna 8, so in this case, the frequencies 0 , 1 ,
2 , the electric field strength of the signal with the tuning frequency 0 is now smaller than that of the signal with the frequency 1 , so the output of the first comparator 19 becomes "high", The analog switch 21 applies the tuning signal a to the filter 14, and the passband of the filter 14 becomes a narrow band whose center frequency is the tuning frequency 0 . Also the tuning frequency
0 signal electric field strength is set level 100dB
Since the output of the second comparator 22 becomes "high" and the gain control signal b is outputted, and the amplifier 15 amplifies the output signal of the filter 14, the antenna amplifier 24 becomes as shown in FIG. 2b. As shown, only the signal with tuning frequency 0 is amplified and output to the radio receiver 12.

また第3図aは同調周波数の信号の電界強
度が隣接周波数の信号の電界強度より
大きく、かつそれが100dB以下である場合を示
す。この場合は、受信アンテナ8の受信帯全域の
信号を増幅してラジオ受信機12に送るようにし
ても混信を生ずることはないので、このアンテナ
アンプ24においては、第1の比較器19の出力
は“ロウ”となり、アナログスイツチ21はフイ
ルタ14への同調信号aの入力を遮断し、フイル
タ14の通過帯域は受信帯全域となり、アンテナ
アンプ24は第3図bに示すように周波数
のすべての信号を増幅して出力する。
Further, FIG. 3a shows a case where the electric field strength of the signal of tuning frequency 0 is larger than the electric field strength of the signals of adjacent frequencies 1 and 2 , and is 100 dB or less. In this case, even if the signals in the entire receiving band of the receiving antenna 8 are amplified and sent to the radio receiver 12, no interference will occur, so in the antenna amplifier 24, the output of the first comparator 19 becomes "low", the analog switch 21 cuts off the input of the tuning signal a to the filter 14, the pass band of the filter 14 becomes the entire reception band, and the antenna amplifier 24 changes to the frequency 0 , as shown in FIG. 3b.
Amplify and output all signals 1 and 2 .

また第4図aは同調周波数の信号の電界強
度が隣接周波数の信号の電界強度より
大きく、かつそれが100dB以上である場合を示
す。この場合は受信アンテナ8の受信帯全域の信
号をそのままラジオ受信機12に送るようにして
もよいので、フイルタ14の通過帯域は上記と同
様に受信帯全域となり、又第2の比較器22の出
力は“ロウ”となり、増幅器15はフイルタ14
の信号を増幅せずにそのまま出力するため、アン
テナアンプ24は第4図bに示すように受信アン
テナ8の受信帯全域の信号をそのまま出力する。
Further, FIG. 4a shows a case where the electric field strength of the signal with the tuning frequency 0 is larger than the electric field strength of the signals with the adjacent frequencies 1 and 2 , and is 100 dB or more. In this case, the signal of the entire receiving band of the receiving antenna 8 may be sent as it is to the radio receiver 12, so the pass band of the filter 14 is the entire receiving band as described above, and the signal of the second comparator 22 is The output becomes “low” and the amplifier 15 is connected to the filter 14.
Since the antenna amplifier 24 outputs the signal as it is without amplifying it, the antenna amplifier 24 outputs the signal of the entire receiving band of the receiving antenna 8 as it is, as shown in FIG. 4b.

以上のような本実施例のアンテナアンプでは、
ラジオ受信機の同調周波数の受信信号の電界強度
に応じてフイルタの通過帯域を切換えるようにし
ているので、ラジオ受信機の混信の発生を防止で
きるとともに、フイルタ14による出力ロスや無
駄な電力消費を防止できる。また上記同調周波数
の受信信号の電界強度に応じて増幅器の利得を切
換えるようにしているので、増幅器の特性に歪が
発生することはなく、これによつてもラジオ受信
機の受信感度を向上できる。
In the antenna amplifier of this embodiment as described above,
Since the passband of the filter is switched according to the electric field strength of the received signal at the tuning frequency of the radio receiver, it is possible to prevent interference in the radio receiver, and also to reduce output loss and wasteful power consumption due to the filter 14. It can be prevented. In addition, since the gain of the amplifier is switched according to the electric field strength of the received signal at the above-mentioned tuning frequency, distortion does not occur in the characteristics of the amplifier, and this also improves the reception sensitivity of the radio receiver. .

なお上記実施例では同調周波数の受信信号の電
界強度に応じて増幅器の利得を変えるようにして
いるが、この増幅器の利得は一定としてもよい。
また上記実施例では受信アンテナとしてリヤウイ
ンドガラスの熱線を利用したものについて説明し
たが、この受信アンテナは電波の受信専用のもの
であつてもよく、又フロント側に設けたものであ
つてもよい。
In the above embodiment, the gain of the amplifier is changed depending on the electric field strength of the received signal at the tuning frequency, but the gain of the amplifier may be constant.
Furthermore, in the above embodiment, an example was explained in which the hot wire of the rear window glass was used as the receiving antenna, but this receiving antenna may be used only for receiving radio waves, or may be provided on the front side. .

以上のように本発明に係る自動車用受信機のア
ンテナアンプによれば、受信機の同調周波数の受
信信号の電界強度が受信アンテナの受信帯全域の
電界強度より小さいときにそれを判別してフイル
タの通過帯域を狭帯域とし、同調周波数信号のみ
を増幅して受信機に送るようにしたので、受信機
の混信を防止して受信感度を向上でき、しかも上
記フイルタによる出力ロスや無駄な電力消費を防
止できる効果がある。
As described above, according to the antenna amplifier for an automobile receiver according to the present invention, when the electric field strength of the received signal at the tuned frequency of the receiver is smaller than the electric field strength of the entire receiving band of the receiving antenna, it is determined and the filter is activated. The passband is narrow band, and only the tuned frequency signal is amplified and sent to the receiver, which prevents interference at the receiver and improves reception sensitivity, while also reducing output loss and wasteful power consumption due to the filter mentioned above. It has the effect of preventing

【図面の簡単な説明】[Brief explanation of the drawing]

第1図は本発明の一実施例による自動車用受信
機のアンテナアンプの電気回路図、第2図ないし
第4図は各ケースの受信帯の電界強度及びそのと
きのアンテナアンプの出力を示す図である。 8…受信アンテナ、12…ラジオ受信機(車載
受信機)、14…フイルタ、15…増幅器、20
…判別回路、21…アナログスイツチ(特性切換
回路)。
FIG. 1 is an electric circuit diagram of an antenna amplifier for an automobile receiver according to an embodiment of the present invention, and FIGS. 2 to 4 are diagrams showing the electric field strength of the receiving band in each case and the output of the antenna amplifier at that time. It is. 8...Reception antenna, 12...Radio receiver (vehicle receiver), 14...Filter, 15...Amplifier, 20
...Discrimination circuit, 21...Analog switch (characteristic switching circuit).

Claims (1)

【特許請求の範囲】[Claims] 1 自動車に取付けた受信アンテナアンプであつ
て、車載受信機からの同調信号の入力時その通過
帯域が上記車載受信機の同調周波数を中心周波数
とする狭帯域となり上記同調信号の非入力時上記
通過帯域が上記受信アンテナの受信帯全域となる
フイルタと、該フイルタからの信号を増幅して上
記車載受信機に出力する増幅器と、上記受信アン
テナからの受信信号が入力され上記車載受信機の
同調周波数の受信信号の電界強度が上記受信アン
テナの受信帯全域の電界強度より小さいか否かを
判別する判別回路と、該判別回路の出力に応じて
上記フイルタに対する上記同調信号入力を接断す
る特性切換回路とを備えたことを特徴とする自動
車用受信機のアンテナアンプ。
1. A receiving antenna amplifier installed in a car, when a tuning signal from an on-vehicle receiver is input, its passband becomes a narrow band centered on the tuning frequency of the on-vehicle receiver, and when the tuning signal is not input, the passband becomes narrow. a filter whose band covers the entire receiving band of the receiving antenna; an amplifier that amplifies the signal from the filter and outputs it to the vehicle-mounted receiver; and a tuning frequency of the vehicle-mounted receiver to which the reception signal from the reception antenna is input. a determination circuit that determines whether the electric field strength of the received signal is smaller than the electric field strength of the entire reception band of the receiving antenna; and a characteristic switch that connects or disconnects the tuning signal input to the filter in accordance with the output of the determination circuit. An antenna amplifier for an automobile receiver, characterized by comprising a circuit.
JP16777081A 1981-10-19 1981-10-19 Antenna amplifier of receiver for motorcar Granted JPS5868323A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP16777081A JPS5868323A (en) 1981-10-19 1981-10-19 Antenna amplifier of receiver for motorcar

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP16777081A JPS5868323A (en) 1981-10-19 1981-10-19 Antenna amplifier of receiver for motorcar

Publications (2)

Publication Number Publication Date
JPS5868323A JPS5868323A (en) 1983-04-23
JPS6243374B2 true JPS6243374B2 (en) 1987-09-14

Family

ID=15855771

Family Applications (1)

Application Number Title Priority Date Filing Date
JP16777081A Granted JPS5868323A (en) 1981-10-19 1981-10-19 Antenna amplifier of receiver for motorcar

Country Status (1)

Country Link
JP (1) JPS5868323A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS647792U (en) * 1987-07-01 1989-01-17

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3475037B2 (en) 1997-03-14 2003-12-08 株式会社東芝 transceiver

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS647792U (en) * 1987-07-01 1989-01-17

Also Published As

Publication number Publication date
JPS5868323A (en) 1983-04-23

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