JPS6259496B2 - - Google Patents
Info
- Publication number
- JPS6259496B2 JPS6259496B2 JP59056646A JP5664684A JPS6259496B2 JP S6259496 B2 JPS6259496 B2 JP S6259496B2 JP 59056646 A JP59056646 A JP 59056646A JP 5664684 A JP5664684 A JP 5664684A JP S6259496 B2 JPS6259496 B2 JP S6259496B2
- Authority
- JP
- Japan
- Prior art keywords
- transistor
- emitter
- agc
- circuit
- pnp transistor
- 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
Links
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03G—CONTROL OF AMPLIFICATION
- H03G3/00—Gain control in amplifiers or frequency changers
- H03G3/20—Automatic control
- H03G3/30—Automatic control in amplifiers having semiconductor devices
- H03G3/3052—Automatic control in amplifiers having semiconductor devices in bandpass amplifiers (H.F. or I.F.) or in frequency-changers used in a (super)heterodyne receiver
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03G—CONTROL OF AMPLIFICATION
- H03G1/00—Details of arrangements for controlling amplification
- H03G1/0005—Circuits characterised by the type of controlling devices operated by a controlling current or voltage signal
- H03G1/0035—Circuits characterised by the type of controlling devices operated by a controlling current or voltage signal using continuously variable impedance elements
- H03G1/0082—Circuits characterised by the type of controlling devices operated by a controlling current or voltage signal using continuously variable impedance elements using bipolar transistor-type devices
Landscapes
- Control Of Amplification And Gain Control (AREA)
- Noise Elimination (AREA)
- Circuits Of Receivers In General (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、車載用の電子式AM受信機（以下受
信機と云う）等のラジオ受信機に関するものであ
る。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a radio receiver such as a vehicle-mounted electronic AM receiver (hereinafter referred to as a receiver).
従来例の構成とその問題点
従来この種のラジオ受信機のフロントエンド部
は第１図に示す様な回路構成を採用している。す
なわち１は車のロツドアンテナであり、２は高周
波増幅段、３は局部発振回路、４は混合回路であ
り、混合回路４の出力端子５から中間信号が取り
出される。６は中間増幅回路からの自動利得制御
（以下AGCと云う。）信号であり、高周波増幅段
２の入力側と接地間にコンデンサ８を介してコレ
クタ，エミツタが接続されたAGC用トランジス
タを駆動するようになつている。Conventional configuration and its problems Conventionally, the front end section of this type of radio receiver has adopted a circuit configuration as shown in FIG. That is, 1 is a rod antenna of a car, 2 is a high frequency amplification stage, 3 is a local oscillation circuit, and 4 is a mixing circuit. An intermediate signal is taken out from an output terminal 5 of the mixing circuit 4. 6 is an automatic gain control (hereinafter referred to as AGC) signal from the intermediate amplifier circuit, which drives an AGC transistor whose collector and emitter are connected via a capacitor 8 between the input side of the high-frequency amplifier stage 2 and ground. It's becoming like that.
このような従来の構成において、ロツドアンテ
ナ１に入つてくる到来電波のレベルに応じて中間
増幅回路からAGC信号がトランジスタ７に印加
され、そのトランジスタ７のコレクタ，エミツタ
間のインピーダンスを制御し、出力端子５の出力
を一定に保つように動作するものである。しかし
ながらここで問題となるのは、トランジスタ７が
動作しはじめるときである。即ちトランジスタが
動作しはじめるとき第２図に示すようにＶBE−Ｉ
E特性の非直線部によつて高周波が発生し、これ
がスプリアス特性を悪化させる要因の一つとなつ
ていることである。 In such a conventional configuration, an AGC signal is applied from the intermediate amplifier circuit to the transistor 7 according to the level of the incoming radio wave entering the rod antenna 1, and the impedance between the collector and emitter of the transistor 7 is controlled, and the output terminal It operates to keep the output of 5 constant. However, the problem here is when the transistor 7 starts operating. That is, when the transistor starts operating, V BE -I as shown in Figure 2.
High frequencies are generated by the nonlinear portion of the E characteristic, and this is one of the factors that worsens spurious characteristics.
発明の目的
本発明は上記従来の欠点を解消するもので、大
入力時のスプリアス特性を改善することを目的と
する。OBJECTS OF THE INVENTION The present invention solves the above-mentioned conventional drawbacks, and aims to improve spurious characteristics at the time of large input.
発明の構成
本発明はアンテナの入力レベルを自動利得制御
用トランジスタで制御するようにしたラジオ受信
機であつて、前記トランジスタをNPN型トラン
ジスタとPNP型トランジスタにより相互に動作開
始時の非直線動作を相殺するように構成したもの
である。Composition of the Invention The present invention is a radio receiver in which the input level of an antenna is controlled by an automatic gain control transistor, in which the transistors are mutually controlled by an NPN type transistor and a PNP type transistor to control non-linear operation at the start of operation. It is constructed so that they cancel each other out.
実施例の説明
本発明の一実施例を第３図，第４図に示して説
明する。まず、第３図において上記第１図の従来
の構成と同一部分には同一番号が附してあり、本
発明はAGC用トランジスタ７としてNPN型トラ
ンジスタ７ａとPNP型トランジスタ７ｂを用い、
高周波増幅段２の入力側と接地間にコンデンサ８
とトランジスタ７ａのコレクタ，エミツタ，トラ
ンジスタ７ｂのエミツタ，コレクタの直列回路を
接続し、そしてトランジスタ７ｂのベースAGC
信号が印加されるようにするとともにトランジス
タ７ａのベースを接地したものである。DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. 3 and 4. First, in FIG. 3, the same parts as in the conventional configuration shown in FIG.
Capacitor 8 between the input side of high frequency amplification stage 2 and ground
A series circuit of the collector and emitter of transistor 7a and the emitter and collector of transistor 7b is connected to the base AGC of transistor 7b.
A signal is applied thereto, and the base of the transistor 7a is grounded.
このように構成することにより、トランジスタ
７が動作しはじめる時のエミツタ電流は第４図の
ＶBE−ＩE特性から明らかなようにそれぞれのト
ランジスタ７ａ，７ｂのＶBE−ＩE特性の非直線
部を相殺するように流れるため、高調波歪が著し
く少なくなり、したがつてスプリアス特性が良好
となるものである。 With this configuration, the emitter current when the transistor 7 starts operating is determined by the non-linearity of the V BE -I E characteristics of each transistor 7a and 7b, as is clear from the V BE -I E characteristics in FIG. Since the current flows so as to cancel out the harmonic distortion, harmonic distortion is significantly reduced and spurious characteristics are improved.
発明の効果
本発明は上述のような簡単な構成により大入力
時のAGC回路に起因するスプリアス特性を改善
することができるもので、その効果は大なるもの
である。しかもAGC信号は一極性のものでよ
く、中間増幅回路からのAGC信号をそのまま利
用でき、他に回路付加の必要がなく構成も簡素化
できるものである。Effects of the Invention The present invention can improve the spurious characteristics caused by the AGC circuit at the time of large input with the above-mentioned simple configuration, and its effects are significant. Moreover, the AGC signal may be unipolar, and the AGC signal from the intermediate amplifier circuit can be used as is, and there is no need to add any other circuits, and the configuration can be simplified.
第１図は従来例を示すブロツク回路図、第２図
は同トランジスタのＶBE−ＩE特性図、第３図は
本発明の一実施例を示すブロツク回路図、第４図
は同トランジスタのＶBE−ＩE特性図である。
１……ロツドアンテナ、２……高周波増幅段、
６……利得制御信号、７……トランジスタ、７ａ
……NPN型トランジスタ、７ｂ……PNP型トラ
ンジスタ。
Fig. 1 is a block circuit diagram showing a conventional example, Fig. 2 is a V BE -I E characteristic diagram of the same transistor, Fig. 3 is a block circuit diagram showing an embodiment of the present invention, and Fig. 4 is a block circuit diagram of the same transistor. It is a VBE - IE characteristic diagram. 1... Rod antenna, 2... High frequency amplification stage,
6...gain control signal, 7...transistor, 7a
...NPN type transistor, 7b...PNP type transistor.
Claims (1)
御するようにしたラジオ受信機であつて、前記自
動利得制御器はNPN型トランジスタのエミツタ
とPNP型トランジスタのエミツタを接続するとと
もにそのNPN型トランジスタのベースとPNP型
トランジスタのコレクタをそれぞれ接地し、かつ
前記PNP型トランジスタのベースに中間増幅回路
からの一極性の利得制御信号を印加するように構
成したラジオ受信機。1. A radio receiver in which the input level of an antenna is controlled by an automatic gain controller, wherein the automatic gain controller connects the emitter of an NPN transistor and the emitter of a PNP transistor, and connects the base of the NPN transistor. and a PNP transistor whose collectors are grounded, and a unipolar gain control signal from an intermediate amplifier circuit is applied to the base of the PNP transistor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59056646A JPS59188236A (en) | 1984-03-23 | 1984-03-23 | Radio receiver |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59056646A JPS59188236A (en) | 1984-03-23 | 1984-03-23 | Radio receiver |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS59188236A JPS59188236A (en) | 1984-10-25 |
| JPS6259496B2 true JPS6259496B2 (en) | 1987-12-11 |
Family
ID=13033106
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59056646A Granted JPS59188236A (en) | 1984-03-23 | 1984-03-23 | Radio receiver |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS59188236A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63175999U (en) * | 1987-05-01 | 1988-11-15 |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5227021B2 (en) * | 1974-05-13 | 1977-07-18 | ||
| JPS50146446U (en) * | 1974-05-21 | 1975-12-04 |
-
1984
- 1984-03-23 JP JP59056646A patent/JPS59188236A/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63175999U (en) * | 1987-05-01 | 1988-11-15 |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS59188236A (en) | 1984-10-25 |
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