JPH0373041U - - Google Patents
Info
- Publication number
- JPH0373041U JPH0373041U JP13256489U JP13256489U JPH0373041U JP H0373041 U JPH0373041 U JP H0373041U JP 13256489 U JP13256489 U JP 13256489U JP 13256489 U JP13256489 U JP 13256489U JP H0373041 U JPH0373041 U JP H0373041U
- Authority
- JP
- Japan
- Prior art keywords
- circuit
- signal
- input
- amplifier
- level
- 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.)
- Granted
Links
- 238000001514 detection method Methods 0.000 claims description 12
- 230000010355 oscillation Effects 0.000 claims description 2
- 230000035945 sensitivity Effects 0.000 claims 1
- 238000010586 diagram Methods 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 1
Landscapes
- Noise Elimination (AREA)
Description
第１図はこの考案に係るＦＭ受信機のＡＧＣ制
御回路の実施例を示す回路ブロツク図である。第
２図は従来例の回路ブロツク図である。
主な符号の説明、１……アンテナ、２……ＲＦ
入力アツテネータ、３……初段ＲＦ同調回路、４
……ＲＦアンプ、５……段階ＲＦ同調回路、６…
…局部発振回路、７……ミキサ回路、８……ＩＦ
同調回路、９……ＡＧＣ検波回路、１０，１２…
…ＩＦアンプ、１１……ＩＦ同調セラミツクフイ
ルタ、１３……信号強度検出回路、１４……レベ
ル比較器、１５……利得制御アンプ、１６……ア
ンテナ入力電界強度検出回路、１７……ＦＭ検波
回路。
FIG. 1 is a circuit block diagram showing an embodiment of an AGC control circuit for an FM receiver according to this invention. FIG. 2 is a circuit block diagram of a conventional example. Explanation of main symbols, 1...Antenna, 2...RF
Input attenuator, 3...First stage RF tuning circuit, 4
...RF amplifier, 5...Step RF tuning circuit, 6...
...Local oscillation circuit, 7...Mixer circuit, 8...IF
Tuning circuit, 9...AGC detection circuit, 10, 12...
...IF amplifier, 11...IF tuning ceramic filter, 13...Signal strength detection circuit, 14...Level comparator, 15...Gain control amplifier, 16...Antenna input field strength detection circuit, 17...FM detection circuit .
Claims (1)
発振回路と、ミキサ回路と、ミキサ回路から出力
するＩＦ信号を同調させるＩＦ同調回路と、この
ＩＦ同調回路の出力信号の一部を検波してＲＦ入
力アツテネータと、ＲＦアンプとを制御するＡＧ
Ｃ制御回路において、 前記ＲＦ入力アツテネータに入力されるアンテ
ナで誘起された信号の強度を検出するアンテナ入
力電界強度検出回路と、ＩＦ同調回路に接続され
たＩＦアンプから出力するＩＦ信号の一部を入力
して同調受信信号の信号強度を検出する信号強度
検出回路と、前記アンテナ入力電界強度検出回路
より出力した検出レベルと信号強度検出回路より
出力した検出レベルとを比較してその差のレベル
を出力するレベル比較器と、このレベル比較より
出力したレベル信号によつてＩＦ同調回路からの
信号を制御する利得制御アンプとを設け、ＲＦ入
力アツテネータ、ＲＦアンプに対するＡＧＣ検波
回路のＡＧＣ検出感度を制御してＲＦ相互変調妨
害比を改善するように構成したことを特徴とする
ＦＭ受信機のＡＧＣ制御回路。[Claims for Utility Model Registration] An RF input attenuator, an RF amplifier, a local oscillation circuit, a mixer circuit, an IF tuning circuit that tunes an IF signal output from the mixer circuit, and one of the output signals of this IF tuning circuit. AG that detects the signal and controls the RF input attenuator and RF amplifier.
The C control circuit includes an antenna input field strength detection circuit that detects the strength of the signal induced by the antenna that is input to the RF input attenuator, and a part of the IF signal output from the IF amplifier connected to the IF tuning circuit. A signal strength detection circuit that detects the signal strength of the input tuned received signal compares the detection level output from the antenna input field strength detection circuit with the detection level output from the signal strength detection circuit and determines the level of the difference. A level comparator that outputs and a gain control amplifier that controls the signal from the IF tuning circuit using the level signal output from the level comparison are provided to control the AGC detection sensitivity of the AGC detection circuit with respect to the RF input attenuator and RF amplifier. An AGC control circuit for an FM receiver, characterized in that the AGC control circuit is configured to improve an RF intermodulation interference ratio.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13256489U JPH0746988Y2 (en) | 1989-11-16 | 1989-11-16 | AGC control circuit of FM receiver |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13256489U JPH0746988Y2 (en) | 1989-11-16 | 1989-11-16 | AGC control circuit of FM receiver |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0373041U true JPH0373041U (en) | 1991-07-23 |
| JPH0746988Y2 JPH0746988Y2 (en) | 1995-10-25 |
Family
ID=31680019
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP13256489U Expired - Lifetime JPH0746988Y2 (en) | 1989-11-16 | 1989-11-16 | AGC control circuit of FM receiver |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0746988Y2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005167860A (en) * | 2003-12-04 | 2005-06-23 | Murata Mfg Co Ltd | Digital television broadcast receiving module |
-
1989
- 1989-11-16 JP JP13256489U patent/JPH0746988Y2/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005167860A (en) * | 2003-12-04 | 2005-06-23 | Murata Mfg Co Ltd | Digital television broadcast receiving module |
| JP4539089B2 (en) * | 2003-12-04 | 2010-09-08 | 株式会社村田製作所 | Digital TV broadcast receiving module |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0746988Y2 (en) | 1995-10-25 |
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