JPH0219028A - Fm receiver - Google Patents
Fm receiverInfo
- Publication number
- JPH0219028A JPH0219028A JP17030188A JP17030188A JPH0219028A JP H0219028 A JPH0219028 A JP H0219028A JP 17030188 A JP17030188 A JP 17030188A JP 17030188 A JP17030188 A JP 17030188A JP H0219028 A JPH0219028 A JP H0219028A
- Authority
- JP
- Japan
- Prior art keywords
- frequency
- circuit
- signal
- trap
- 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
- 230000002238 attenuated effect Effects 0.000 claims abstract description 5
- 230000003321 amplification Effects 0.000 claims description 7
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 7
- 238000001514 detection method Methods 0.000 abstract description 6
- 230000010355 oscillation Effects 0.000 abstract description 5
- 230000035945 sensitivity Effects 0.000 abstract description 4
- 238000010586 diagram Methods 0.000 description 8
- 230000002452 interceptive effect Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 2
- 230000007423 decrease Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 230000005236 sound signal Effects 0.000 description 1
Landscapes
- Circuits Of Receivers In General (AREA)
- Input Circuits Of Receivers And Coupling Of Receivers And Audio Equipment (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、ＦＭ受信機に関し特に電子同調用ＦＭ受信機
に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an FM receiver, and more particularly to an FM receiver for electronic tuning.
従来この種のＦＭ受信機としては、第６図に示すブロッ
ク図のようなものがあった。このＦＭ受信機はアンテナ
広帯域減衰器（Ｗ−ＡＴＴ）１４、高周波増幅器（ＲＦ
）３、混合回路（ＭＩＸ）４、局部発振回路（Ｏ２０）
５、広帯域検出回路（Ｗ−ＡＧＣ）１５、中間周波増幅
回路（ＩＦ）６、検波回路（ＤＥＴ）７、電子同調用コ
ントローラ回路（ＤＴＳ）１６で構成されている。A conventional FM receiver of this type has one as shown in the block diagram shown in FIG. This FM receiver includes an antenna wideband attenuator (W-ATT) 14, a high frequency amplifier (RF
) 3, Mixing circuit (MIX) 4, Local oscillation circuit (O20)
5, a wideband detection circuit (W-AGC) 15, an intermediate frequency amplifier circuit (IF) 6, a detection circuit (DET) 7, and an electronic tuning controller circuit (DTS) 16.
アンテナ１より入力されたＦＭ信号はＷＡＴＴ１４を通
りＲＦ３で増幅およびある帯域を持って同調されＭＩＸ
４に入力される。０８Ｃ５では“受信希望周波数上中間
周波数”で発振が行われＭＩＸ４ではこの０８Ｃ５の周
波数とＲＦ３を通過した信号が混合され中間周波数に変
更される。The FM signal input from antenna 1 passes through WATT 14, is amplified by RF 3, is tuned in a certain band, and is MIXed.
4 is input. In 08C5, oscillation is performed at an "intermediate frequency above the desired reception frequency", and in MIX4, the frequency of 08C5 and the signal passed through RF3 are mixed and changed to the intermediate frequency.
中間周波数に変更された信号は、ＩＦ６で増幅および狭
帯域フィルタを通ってＤＥＴ７に入力されＤＥＴ７回路
で検波され音声信号となる。一方ＭＩＸ４にて変換され
た信号はＷ−ＡＧＣｌ５の入力となりＷ−ＡＧＣｌ ５
では信号強度を検出し信号があるレベルより大きい場合
、Ｗ−ＡＴＴ１４を動作させる。このためＲＦ３に入力
される信号は弱められる。The signal changed to the intermediate frequency is amplified by the IF 6, passes through a narrow band filter, is input to the DET 7, is detected by the DET 7 circuit, and becomes an audio signal. On the other hand, the signal converted by MIX4 becomes the input to W-AGCl5.
Then, the signal strength is detected, and if the signal is greater than a certain level, the W-ATT 14 is activated. Therefore, the signal input to RF3 is weakened.
上述した従来のＦＭ受信機に希望周波数と他の周波数の
信号（妨害信号）が入力され妨害信号がＷ−ＡＧＣ６を
動作させた場合希望周波数の信号がＷ−ＡＴＴ２にて減
衰され、受信感度が低下するという欠点がある。When signals of the desired frequency and other frequencies (interfering signals) are input to the above-mentioned conventional FM receiver and the interfering signals operate the W-AGC 6, the signal of the desired frequency is attenuated by the W-ATT 2, and the reception sensitivity is reduced. The disadvantage is that it decreases.
本発明のＦＭ受信機は、アンテナと高周波増幅回路の間
に減衰させる周波数を可変することのできるトラップ回
路を有している。The FM receiver of the present invention has a trap circuit between the antenna and the high frequency amplification circuit that can vary the frequency to be attenuated.
次に、本発明について図面を参照して説明する。 Next, the present invention will be explained with reference to the drawings.
第１図は本発明の一実施例のＦＭ受信機である。FIG. 1 shows an FM receiver according to an embodiment of the present invention.
アンテナ１により入力された信号は電圧により周波数を
可変できるトラップ回路（ＴＣ）２を通り高周波増幅回
路（ＲＦ）３により同調・増幅され混合回路（ＭＩＸ）
４に入力される。局部発振回路（Ｏ２０）５では“希望
周波数十中間周波数”で発振されＭＩＸ４に加えられ前
述の信号と混合されて中間周波数を得る。中間周波数と
なった信号は狭帯域のフィルタを持つ中間周波増幅回路
（ＩＦ）６で増幅、リミッタがかけられ検波回路（ＤＥ
Ｔ）７に送られる。またＩＦ６はＭＩＸ４出力の信号の
強度に応じて出力を出すシグナルメータ回路（ＳＭ）８
にも接続される。The signal inputted by the antenna 1 passes through a trap circuit (TC) 2 whose frequency can be varied by voltage, and is tuned and amplified by a radio frequency amplifier circuit (RF) 3 to a mixing circuit (MIX).
4 is input. In the local oscillation circuit (O20) 5, the signal is oscillated at "the desired frequency and the intermediate frequency" and is added to the MIX 4 where it is mixed with the above-mentioned signal to obtain an intermediate frequency. The intermediate frequency signal is amplified and limited by an intermediate frequency amplification circuit (IF) 6 having a narrow band filter, and then sent to a detection circuit (DE).
T) Sent to 7. In addition, IF6 is a signal meter circuit (SM) 8 that outputs an output according to the strength of the MIX4 output signal.
is also connected to.
また０８Ｃ５には“希望周波数十中間周波数”を発振さ
せるためのＰＬＬ回路を持つコントローラ９と接続され
る。またこのＰＬＬ回路のローパスフィルタ（ＬＰＦ）
１７の出力は’ＲＦアンプの同調回路のバラクタ電圧と
もなる。シグナルメータの出力はこのコントローラに入
力されトラップ周波数を可変するための電圧端子はこの
コントローラにより出力される。Further, 08C5 is connected to a controller 9 having a PLL circuit for oscillating "desired frequency and intermediate frequency". Also, the low pass filter (LPF) of this PLL circuit
The output of 17 also becomes the varactor voltage of the tuning circuit of the RF amplifier. The output of the signal meter is input to this controller, and a voltage terminal for varying the trap frequency is output from this controller.
ＴＯ２回路の具体的回路例を第２図にその特性図を第２
図および第３図、第４図に示す。前述コントローラの動
作を以下に説明する。コントローラは人為的に希望周波
数が入力される前もしくはその前後にＰＬＬ回路を動作
させ全放送周波数帯域に対して信号強度を持つ周波数と
その強度をメモリ領域にメモリする。A specific circuit example of the TO2 circuit is shown in Figure 2, and its characteristic diagram is shown in Figure 2.
3 and 4. The operation of the aforementioned controller will be explained below. The controller operates the PLL circuit before or before or after the desired frequency is artificially input, and stores in the memory area the frequencies having signal strengths for the entire broadcast frequency band and their strengths.
希望周波数が人為的に決められた後メモリ領域より希望
周波数の妨害となる周波数を選びたす。After the desired frequency is artificially determined, a frequency that interferes with the desired frequency is selected from the memory area.
選びだされた妨害周波数となるようにＴＲ２の制御電圧
を動かしその周波数のみを減衰させる。なお全放送周波
数帯域の強度をメモリする時はＴＲ２の周波数は放送帯
域外に動かす。またこのコントローラの入力、出力には
一般的にＡ／Ｄ、Ｄ／Ａコンバータが接続される。また
トラップ回路の個数は前述では２個使用したが多数使用
されてもかまわない。The control voltage of TR2 is moved so that the selected interfering frequency is achieved, and only that frequency is attenuated. Note that when storing the intensity of the entire broadcast frequency band, the frequency of TR2 is moved outside the broadcast band. Further, an A/D and D/A converter is generally connected to the input and output of this controller. Further, although two trap circuits are used in the above example, a large number of trap circuits may be used.
第５図は本発明の他の実施例２の構成である。FIG. 5 shows the configuration of another embodiment 2 of the present invention.
第１図の実施例との相違はトラップ回路とＲＦ増幅の間
に減衰器（ＡＴＴ）１３がありまたこのＡＴＴ１３を動
作させるためコントローラに接続されている。The difference from the embodiment shown in FIG. 1 is that an attenuator (ATT) 13 is provided between the trap circuit and the RF amplification, and the ATT 13 is connected to a controller for operation.
この実施例では希望周波数の信号が強い場合ＲＦおよび
ＭＩＸに入力される信号を弱めることができ希望周波数
の強入力によるひずみの悪化を減少させる利点がある。This embodiment has the advantage that when the signal of the desired frequency is strong, the signal input to the RF and MIX can be weakened, thereby reducing the deterioration of distortion due to the strong input of the desired frequency.
以上説明したように本発明は、アンテナと高周波増幅回
路の間に周波数を可変することのできるトラップ回路を
用いることにより、妨害周波数により希望する周波数の
信号を減衰させることがなく受信感度が低下することが
ないという効果がある。As explained above, the present invention uses a trap circuit that can vary the frequency between the antenna and the high-frequency amplification circuit, thereby reducing reception sensitivity without attenuating the signal of the desired frequency due to the interfering frequency. It has the effect of never happening.
第１図は本発明の一実施例のブロック図、第２図はトラ
ップ回路の具体例、第３図、第４図はトラップ回路の特
性図、第５図は本発明の他の実施例のブロック図、第６
図は従来のＦＭ受信機のブロック図である。
■・・・・・・アンテナ、２・・・・・・周波数を可変
できるトラップ回路、３・・・・・・高周波増幅回路、
４・・・・・・混合回路、５・・・・・・局部発振回路
、６・・・・・・中間周波増幅回路、７・・・・・・検
波回路、８・・・・・・シグナルメータ回路、９・・・
・・・コントローラ、１０・・・・・・バラクタダイオ
ード、１１・・・・・・コイル、１２・・・・・・抵抗
、１３・・・・・・減衰器、１４・・・・・・広帯域減
衰器、１５・・・・・・広帯域検波回路、１６・・・・
・・電子同調用コントローラ回路、１７・・・・・・ロ
ーパスフィルタ代理人 弁理士 内 原 音
コ＞１−Ｕ−ラベ
万５図Fig. 1 is a block diagram of one embodiment of the present invention, Fig. 2 is a specific example of a trap circuit, Figs. 3 and 4 are characteristic diagrams of the trap circuit, and Fig. 5 is a diagram of another embodiment of the present invention. Block diagram, 6th
The figure is a block diagram of a conventional FM receiver. ■... Antenna, 2... Trap circuit that can vary the frequency, 3... High frequency amplification circuit,
4...Mixing circuit, 5...Local oscillation circuit, 6...Intermediate frequency amplification circuit, 7...Detection circuit, 8...... Signal meter circuit, 9...
... Controller, 10 ... Varactor diode, 11 ... Coil, 12 ... Resistor, 13 ... Attenuator, 14 ... Broadband attenuator, 15...Broadband detection circuit, 16...
...Electronic tuning controller circuit, 17...Low-pass filter agent Patent attorney Uchihara Otoko>1-U-Labe Man5 Diagram
Claims (1)
変することのできるトラップ回路を有していることを特
徴とするＦＭ受信機。An FM receiver comprising a trap circuit that can vary the frequency attenuated between an antenna and a high frequency amplification circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17030188A JPH0219028A (en) | 1988-07-07 | 1988-07-07 | Fm receiver |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17030188A JPH0219028A (en) | 1988-07-07 | 1988-07-07 | Fm receiver |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0219028A true JPH0219028A (en) | 1990-01-23 |
Family
ID=15902430
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP17030188A Pending JPH0219028A (en) | 1988-07-07 | 1988-07-07 | Fm receiver |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0219028A (en) |
-
1988
- 1988-07-07 JP JP17030188A patent/JPH0219028A/en active Pending
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