JPS6119238A - Am receiver - Google Patents

Abstract

PURPOSE:To receive stably an AM signal by providing the 1st frequency converter using a PLL synthesizer oscillator and the 2nd frequency converter using the 2nd local oscillator to use a ceramic resonator without using an expensive crystal oscillator. CONSTITUTION:A radio wave from an antenna is fed to the 1st frequency converter 10, mixed with the 1st local oscillation signal from the 1st local oscillator B to form the 1st IF signal. The IF signal is amplified by the 1st IF signal amplifier 17, fed to the 2nd frequency converter 18, converted to the 2nd IF signal by the 2nd local oscillating frequency from the 2nd local oscillator 19 and inputted to the 2nd IF amplifier 21. The local oscillator B is formed as PLL synthesizer constitution and a ceramic resonator 16 is used for a reference signal generator 15. Further, the ceramic resonator 20 is used for the oscillator 19. The frequency drift of the oscillators 19 and the generator 15 is cancelled by using the characteristic of resonators 16, 20 and an AM signal is received stably without using an expensive crystal oscillator.

Description

【発明の詳細な説明】 産業上の利用分野 本光１１１１は、Ａ−ルバンドのＡＭ受信機に関するも
ので５ある。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This light 1111 relates to an AM receiver in the A-band.

（，１来例の構成どイの問題点 第１図１１従来のＡ−ルバンドスーパーヘテ１コグイン
方式のＡＭ受信機の回路ブロック図で、１は周波数変換
器、２は電圧制御発振器〈以１”ｒＶＯＣ」と記す）、
３は低域フィルタ、４は位相比較器、５はプログラマブ
ルディバイダ、６は基準信号発生器、７は水晶振動子、
８は中間周波増幅器、９は検波器である。Ａは、ＶＣＯ
２の出力をプログラマブルディバイダ５でＮ分周（Ｎは
任意の正の整数）を行なった出力と基準信号発生器６の
出力とを位相比較する位相比較器４の出力を低域フィル
タ３を通しＵＶＣＯ２に供給する構成とした、基準信号
の位相に追随するＰＬＬ回路（位相同期回路）を使用し
た局部発振回路である。アンテナに到来した電波を周波
数変換器１に供給し、局部発振回路Ａの出力である局部
発振信号と混合して中間周波信号を作り出し、中間周波
増幅器８で増幅した後、検波器９によって復調している
。(, 1 Problems with the conventional configuration) Fig. 11 is a circuit block diagram of a conventional A-band superhet 1 cog-in type AM receiver, where 1 is a frequency converter and 2 is a voltage controlled oscillator. 1"rVOC"),
3 is a low-pass filter, 4 is a phase comparator, 5 is a programmable divider, 6 is a reference signal generator, 7 is a crystal resonator,
8 is an intermediate frequency amplifier, and 9 is a wave detector. A is VCO
The output of the phase comparator 4 is passed through the low-pass filter 3 and the output of the reference signal generator 6 is phase-compared with the output of the reference signal generator 6 which is divided by N (N is any positive integer) using the programmable divider 5. This is a local oscillation circuit using a PLL circuit (phase locked circuit) that follows the phase of a reference signal and is configured to supply UVCO2. The radio waves arriving at the antenna are supplied to the frequency converter 1, mixed with the local oscillation signal output from the local oscillation circuit A to create an intermediate frequency signal, amplified by the intermediate frequency amplifier 8, and then demodulated by the detector 9. ing.

しかしながらこのような従来の構成では、基準信号の発
生に高価な水晶振動子７が必要であった。However, such a conventional configuration requires an expensive crystal oscillator 7 to generate the reference signal.

発明の目的 本発明は上記従来の欠点を解消りるもので、高価な水晶
振動子を用いることなく、しかも高性能なＡＭ受信機を
提供することを［１的とする。OBJECTS OF THE INVENTION The present invention solves the above-mentioned conventional drawbacks, and has an object of the present invention to provide a high-performance AM receiver without using an expensive crystal resonator.

発明の構成 十ｉｉ目的を達成Ｊるため、水弁１！ＩＪのＡＭ受（８
機は、第１のセラミック共振子を用いたＰｔＬシンレリ
イ１Ｆ発振器からなる第１局部発振器と、この第１局部
発振器からの第１局部発振信号と受信信５づどから第１
中間周波信号を作用する第１周波数変換器と、第２のセ
ラミック共振子を用いた第２局部発振器と、この第２局
部発振器からの第２局部発振信号と前記第１中間周波信
号を選択増幅した信号とから第２中間周波信号を作用Ｊ
°る第２周波数変換器とを備えた構成としたものである
。Structure of the Invention In order to achieve the 10th objective, a water valve 1! IJ AM reception (8
The machine includes a first local oscillator consisting of a PtL thin relay 1F oscillator using a first ceramic resonator, and a first local oscillation signal from the first local oscillator and a first signal from the received signal 5.
a first frequency converter that applies an intermediate frequency signal; a second local oscillator using a second ceramic resonator; and selective amplification of the second local oscillation signal from the second local oscillator and the first intermediate frequency signal. A second intermediate frequency signal is applied from the signal
This configuration includes a second frequency converter that converts the frequency.

実施例の説明 以下、本発明の一実施例について、図面に基づいて説明
する。DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

第２図は本発明の一実施例におけるＡＭ受信機の回路１
０７９図で、１０ば第１周波数変換器、１１はＶＣｏ、
１２は低域フィルタ、１３は位相比較器、１４はプログ
ラマブルディバイダ、１５は基準信号発生器、１６はセ
ラミック共振子、１７は第１中間周波増幅器、１８は第
２周波数変換器、１９は固定の第２局部発振器、２０は
セラミック共振子、２０は第２中間周波増幅器、２２は
検波器である。Ｂは、ＶＣｏｌｌの出力をプログラマブ
ルディバイダ１４でＮ分周（Ｎは任意の正の整数）を行
なった出力と基準信号発生器１５の出力とを位相比較す
る位相比較器１３の出力を低域フィルタ１２を通してＶ
ＣＯｌｌに供給する構成とした、基準信号の位相に追随
するＰ［１回路を使用した第１局部発振器である。FIG. 2 shows a circuit 1 of an AM receiver in an embodiment of the present invention.
079, 10 is the first frequency converter, 11 is VCo,
12 is a low-pass filter, 13 is a phase comparator, 14 is a programmable divider, 15 is a reference signal generator, 16 is a ceramic resonator, 17 is a first intermediate frequency amplifier, 18 is a second frequency converter, and 19 is a fixed frequency converter. A second local oscillator, 20 a ceramic resonator, 20 a second intermediate frequency amplifier, and 22 a wave detector. B is a low-pass filter for the output of the phase comparator 13 which compares the phase of the output of the VColl which is divided by N (N is any positive integer) with the programmable divider 14 and the output of the reference signal generator 15. V through 12
This is a first local oscillator using a P[1 circuit that tracks the phase of a reference signal and is configured to supply the signal to COll.

アンテナに到来した電波は、第１周波数変換器１０に供
給され、第２局部発振器Ｂの出力である第１局部発振信
号と混合されて第１中間周波信号が作用され、この第１
中間周波信号は第１中間周波増幅器１７で増された後、
第２周波数変換器１８に供給される。第２周波数変換器
１８には、第２局部発振器１９の出力も供給され、第２
中間周波信号が作用される。この第２中間周波信号は第
２中間周波増幅器２１で増幅され、検波器２２で検波さ
れ、復調信号が得られる。The radio waves arriving at the antenna are supplied to the first frequency converter 10, mixed with the first local oscillation signal which is the output of the second local oscillator B, and acted on by the first intermediate frequency signal.
After the intermediate frequency signal is amplified by a first intermediate frequency amplifier 17,
A second frequency converter 18 is supplied. The second frequency converter 18 is also supplied with the output of the second local oscillator 19, and the second
An intermediate frequency signal is applied. This second intermediate frequency signal is amplified by a second intermediate frequency amplifier 21 and detected by a wave detector 22 to obtain a demodulated signal.

一般にセラミック共振子は、マイクロコンピュータの基
準信号として使用されたりしているが、周波数精度と安
定な温度特性とを必要とづるシンセサイザ発振器の基準
信号発生用としては使用されず、高価な水晶発撮子が使
用されている。ところが本実施例の様なダブルス−パー
構成に於いてセラミック共振子１６．２０を使用すると
、周波数精度に関しては、第２中間周波増幅器２１の同
調特性を調整することによって表示周波数と一致させる
ことが可能となる。また基準信号発生器１５と第２局部
発振器１９との双方にセラミック共振子１６．２０を用
いたので、基準信号と第２局部発振信号との温度トリッ
ト特性が打ち消し合う周波数関係になる様に、第１８部
発振器５Ｂと第２局部発振器１９との周波数関係を設定
することが出来る。Ceramic resonators are generally used as reference signals for microcomputers, but they are not used for generating reference signals for synthesizer oscillators, which require frequency accuracy and stable temperature characteristics, and are expensive crystal resonators. child is used. However, when the ceramic resonators 16 and 20 are used in the double super configuration as in this embodiment, it is possible to match the display frequency with respect to frequency accuracy by adjusting the tuning characteristics of the second intermediate frequency amplifier 21. It becomes possible. Furthermore, since the ceramic resonators 16 and 20 are used for both the reference signal generator 15 and the second local oscillator 19, the frequency relationship is such that the temperature trit characteristics of the reference signal and the second local oscillation signal cancel each other out. The frequency relationship between the 18th section oscillator 5B and the second local oscillator 19 can be set.

発明の詳細 な説明したように本発明によれば、水晶振動子に比して
安価ではあるが、周波数精度と温度ドリフト特性とが劣
っているセラミック共振子を使用したものでありながら
温度変化に対して安定でかつ必要な受信精度を有するＰ
　Ｌ　ＬシンセザイザＡＭ受信機を安価に提供できる。DETAILED DESCRIPTION OF THE INVENTION According to the present invention, although a ceramic resonator is used which is cheaper than a crystal resonator but has inferior frequency accuracy and temperature drift characteristics, it is resistant to temperature changes. P that is stable and has the necessary reception accuracy for
LL synthesizer AM receiver can be provided at low cost.

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

第１図は従来のＰＬＬシンセサイザ受信機の回路ブロッ
ク図、第２図は本発明の一実施例におけるＡＭ受信機の
回路ブロック図である。 １０・・・第１周波数変換器、１１・・・ＶＣＯ１１２
・・・低域フィルタ、１３・・・位相比較器、１４・・
・プログラマブルディバイダ、１５・・・基準信号発生
器、１６・・・セラミック共振子、１７・・・第１中間
周波増幅器、１８・・・第２周波数変換器、１９・・・
第２局部発振器、２０・・・セラミック共振子、２１・
・・第２中間周波増幅器、２２・・・検波器、Ｂ・・・
第１局部発振器FIG. 1 is a circuit block diagram of a conventional PLL synthesizer receiver, and FIG. 2 is a circuit block diagram of an AM receiver according to an embodiment of the present invention. 10...First frequency converter, 11...VCO112
...Low pass filter, 13...Phase comparator, 14...
- Programmable divider, 15... Reference signal generator, 16... Ceramic resonator, 17... First intermediate frequency amplifier, 18... Second frequency converter, 19...
Second local oscillator, 20... Ceramic resonator, 21...
...Second intermediate frequency amplifier, 22...Detector, B...
First local oscillator

Claims (1)

【特許請求の範囲】[Claims] １、第１のセラミック共振子を用いたＰＬＬシンセサイ
ザ発振器からなる第１局部発振器と、この第１局部発振
器からの第１局部発振信号と受信信号とから第１中間周
波信号を作用する第１周波数変換器と、第２のセラミッ
ク共振子を用いた第２局部発振器と、この第２局部発振
器からの第２局部発振信号と前記第１中間周波信号を選
択増幅した信号とから第２中間周波信号を作用する第２
周波数変換器とを備えたＡＭ受信機。1. A first local oscillator consisting of a PLL synthesizer oscillator using a first ceramic resonator, and a first frequency that applies a first intermediate frequency signal from the first local oscillation signal from the first local oscillator and the received signal. a converter, a second local oscillator using a second ceramic resonator, and a second intermediate frequency signal from a second local oscillation signal from the second local oscillator and a signal obtained by selectively amplifying the first intermediate frequency signal. The second
AM receiver equipped with a frequency converter.