JPH07254865A - Double supertuner - Google Patents
Double supertunerInfo
- Publication number
- JPH07254865A JPH07254865A JP4294394A JP4294394A JPH07254865A JP H07254865 A JPH07254865 A JP H07254865A JP 4294394 A JP4294394 A JP 4294394A JP 4294394 A JP4294394 A JP 4294394A JP H07254865 A JPH07254865 A JP H07254865A
- Authority
- JP
- Japan
- Prior art keywords
- frequency
- signal
- local oscillation
- mutual interference
- mhz
- 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
Landscapes
- Superheterodyne Receivers (AREA)
- Noise Elimination (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】この発明は、例えばＣＡＴＶ（ケ
ーブルテレビジョン）放送等のように多チャンネルの放
送電波を受信するダブルスーパーチューナの改良に関す
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a double super tuner for receiving broadcast radio waves of multiple channels such as CATV (cable television) broadcasting.
【０００２】[0002]
【従来の技術】周知のように、首記の如きダブルスーパ
ーチューナは、一般に図４に示すように構成されてい
る。すなわち、入力端子１１に供給されたＲＦ信号は、
ＲＦ回路１２を介して第１の混合回路１３に供給され、
可変局部発振回路１４から出力される第１局部発振信号
と混合されることにより、第１中間周波数信号に変換さ
れる。2. Description of the Related Art As is well known, a double super tuner as mentioned above is generally constructed as shown in FIG. That is, the RF signal supplied to the input terminal 11 is
Is supplied to the first mixing circuit 13 via the RF circuit 12,
It is converted into a first intermediate frequency signal by being mixed with the first local oscillation signal output from the variable local oscillation circuit 14.
【０００３】第１の混合回路１３から出力された第１中
間周波数信号は、第１中間周波数回路１５により帯域制
限及び増幅された後、第２の混合回路１６に供給され、
固定局部発振回路１７から出力される第２局部発振信号
と混合されることで、第２中間周波数信号に変換され
る。第２の混合回路１６から出力された第２中間周波数
信号は、第２中間周波数回路１８により帯域制限及び増
幅された後、出力端子１９から取り出される。The first intermediate frequency signal output from the first mixing circuit 13 is band-limited and amplified by the first intermediate frequency circuit 15, and then supplied to the second mixing circuit 16.
It is converted into a second intermediate frequency signal by being mixed with the second local oscillation signal output from the fixed local oscillation circuit 17. The second intermediate frequency signal output from the second mixing circuit 16 is band-limited and amplified by the second intermediate frequency circuit 18, and then output from the output terminal 19.
【０００４】図５は、入力端子１１に供給されるＲＦ信
号の周波数スペクトラムを示している。ＲＦ信号は、５
０〜５５０ＭＨｚまたはそれ以上の広帯域に渡ってほぼ
一定のチャンネル間隔ａで周波数分割されて伝送されて
いる。可変局部発振回路１４から出力される第１局部発
振信号の周波数は、ＲＦ信号の周波数よりも第１中間周
波数だけ高い側に設定されるように、受信チャンネルに
対応して可変され、これにより、固定周波数の第１中間
周波数信号が得られる。つまり、可変局部発振回路１４
から出力される第１局部発振信号の周波数は、ＲＦ信号
のチャンネル間隔ａと同じ間隔で可変されることにな
る。FIG. 5 shows the frequency spectrum of the RF signal supplied to the input terminal 11. RF signal is 5
It is frequency-divided and transmitted at a substantially constant channel interval a over a wide band of 0 to 550 MHz or higher. The frequency of the first local oscillation signal output from the variable local oscillation circuit 14 is changed corresponding to the reception channel so that the frequency is set higher than the frequency of the RF signal by the first intermediate frequency. A first intermediate frequency signal of fixed frequency is obtained. That is, the variable local oscillation circuit 14
The frequency of the first locally oscillated signal output from the device is varied at the same interval as the channel interval a of the RF signal.
【０００５】以上に述べた構成のダブルスーパーチュー
ナにおいて、最も一般的な周波数関係の一例は、以下の
通りである。ＲＦ信号の周波数ｆRFは５５．２５ＭＨ
ｚ，６１．２５ＭＨｚ，６７．２５ＭＨｚ，……（以下
省略）であり、第１中間周波数ｆIF1 は６１２．７５Ｍ
Ｈｚ（固定）であり、第２中間周波数ｆIF2 は６１．２
５ＭＨｚ（固定）であり、第１局部発振信号の周波数ｆ
LO1 は６６８ＭＨｚ，６７４ＭＨｚ，６８０ＭＨｚ，…
…（以下省略）であり、第２局部発振信号の周波数ｆ
LO2 は６７４ＭＨｚ（固定）であり、ＲＦ信号のチャン
ネル間隔ａつまり第１局部発振信号の周波数間隔は６Ｍ
Ｈｚである。An example of the most general frequency relationship in the double super tuner having the above-mentioned configuration is as follows. The frequency f RF of the RF signal is 55.25 MHz
z, 61.25 MHz, 67.25 MHz, ... (Hereafter omitted), and the first intermediate frequency f IF1 is 612.75 M.
Hz (fixed), and the second intermediate frequency f IF2 is 61.2.
5 MHz (fixed), the frequency f of the first local oscillation signal
LO1 is 668MHz, 674MHz, 680MHz, ...
... (hereinafter omitted), and the frequency f of the second local oscillation signal
LO2 is 674 MHz (fixed), and the channel interval a of the RF signal, that is, the frequency interval of the first local oscillation signal is 6M.
Hz.
【０００６】ところで、ダブルスーパーチューナは、２
つの局部発振回路１４，１７のそれぞれの基本波及び高
調波による相互干渉妨害が発生することがある。上記し
た周波数関係において、例えばＲＦ信号の周波数ｆRFが
３６７．２５ＭＨｚのとき、第１局部発振信号の周波数
ｆLO1 は９８０ＭＨｚとなり、このときの相互干渉妨害
周波数ｆSPは、ｆSP＝３×ｆLO1 −２×ｆLO2 ＝３×９
８０−２×６７４＝６２ＭＨｚとなる。この例の場合、
相互干渉妨害周波数ｆSP＝６２ＭＨｚは、第２中間周波
数ｆIF2 ＝６１．２５ＭＨｚからわずか０．７５ＭＨｚ
しか離れていないため、妨害レベルを十分に抑圧するこ
とができない場合には、復調後の映像信号に悪影響が及
ぼされるという問題が生じることになる。By the way, the double super tuner is 2
Mutual interference may occur due to the fundamental wave and harmonics of each of the local oscillator circuits 14 and 17. In the frequency relationship described above, for example, when the frequency f RF of the RF signal is 367.25 MHz, the frequency f LO1 of the first local oscillation signal is 980 MHz, and the mutual interference frequency f SP at this time is f SP = 3 × f LO1 -2 x f LO2 = 3 x 9
80−2 × 674 = 62 MHz. In this example,
The mutual interference jamming frequency f SP = 62 MHz is only 0.75 MHz from the second intermediate frequency f IF2 = 61.25 MHz.
Since they are only apart from each other, if the interference level cannot be sufficiently suppressed, there arises a problem that the demodulated video signal is adversely affected.
【０００７】[0007]
【発明が解決しようとする課題】以上のように、従来の
ダブルスーパーチューナでは、各局部発振回路のそれぞ
れの基本波及び高調波による相互干渉妨害によって復調
される信号に悪影響が及ぼされるという問題を有してい
る。As described above, in the conventional double super tuner, the problem that the demodulated signal is adversely affected by the mutual interference interference due to the fundamental wave and the harmonic wave of each local oscillation circuit has a problem. Have
【０００８】そこで、この発明は上記事情を考慮してな
されたもので、相互干渉妨害によって受信信号に悪影響
が及ぼされることを防止し得る極めて良好なダブルスー
パーチューナを提供することを目的とする。Therefore, the present invention has been made in view of the above circumstances, and an object thereof is to provide an extremely good double super tuner capable of preventing a received signal from being adversely affected by mutual interference.
【０００９】[0009]
【課題を解決するための手段】この発明に係るダブルス
ーパーチューナは、略一定のチャンネル間隔で周波数分
割された複数の入力信号と、この複数の入力信号のうち
所望の周波数の入力信号に対応させて周波数が可変され
る第１局部発振信号とを混合して、固定周波数の第１中
間周波数信号を得る第１の周波数変換手段と、この第１
の周波数変換手段から出力される第１中間周波数信号
と、固定周波数の第２局部発振信号とを混合して第２中
間周波数信号を得る第２の周波数変換手段とを有するも
のを対象としている。そして、第１局部発振信号及び第
２局部発振信号の周波数を、複数の入力信号のチャンネ
ル間隔の整数倍に設定するように構成したものである。SUMMARY OF THE INVENTION A double super tuner according to the present invention makes a plurality of input signals frequency-divided at substantially constant channel intervals correspond to an input signal of a desired frequency among the plurality of input signals. First frequency conversion means for obtaining a first intermediate frequency signal of a fixed frequency by mixing with a first local oscillation signal whose frequency is variable, and the first frequency conversion means.
The second frequency conversion means for obtaining the second intermediate frequency signal by mixing the first intermediate frequency signal output from the frequency conversion means and the second local oscillation signal having a fixed frequency is targeted. Then, the frequencies of the first local oscillation signal and the second local oscillation signal are set to be an integral multiple of the channel interval of the plurality of input signals.
【００１０】[0010]
【作用】上記のような構成によれば、第１局部発振信号
及び第２局部発振信号の周波数を、複数の入力信号のチ
ャンネル間隔の整数倍に設定するようにしたので、相互
干渉妨害周波数の間隔も入力信号のチャンネル間隔と同
様になる。すると、１つのチャンネルの受信帯域幅は、
入力信号のチャンネル間隔未満であるため、相互干渉妨
害周波数を受信帯域外に設定することができ、相互干渉
妨害によって受信信号に悪影響が及ぼされることを防止
することができるようになる。According to the above construction, the frequencies of the first local oscillation signal and the second local oscillation signal are set to integer multiples of the channel intervals of the plurality of input signals. The interval also becomes similar to the channel interval of the input signal. Then, the reception bandwidth of one channel is
Since it is less than the channel interval of the input signal, the mutual interference frequency can be set outside the reception band, and the reception signal can be prevented from being adversely affected by the mutual interference.
【００１１】[0011]
【実施例】以下、この発明の一実施例について図面を参
照して詳細に説明する。すなわち、前記可変局部発振回
路１４から出力される第１局部発振信号の周波数ｆLO1
と、固定局部発振回路１７から出力される第２局部発振
信号の周波数ｆLO2 とを、ＲＦ信号のチャンネル間隔ａ
の整数倍になるように設定したことが、従来と異なる部
分である。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. That is, the frequency f LO1 of the first local oscillation signal output from the variable local oscillation circuit 14
And the frequency f LO2 of the second local oscillation signal output from the fixed local oscillation circuit 17,
The difference from the conventional method is that it is set to be an integral multiple of.
【００１２】このように設定することにより、２つの局
部発振回路１４，１７のそれぞれの基本波及び高調波に
よる相互干渉妨害周波数ｆSPは、 ｆSP＝｜ｍ×ｆLO1 −ｎ×ｆLO2 ｜ ＝｜ｍ×ａ×ｘ−ｎ×ａ×ｙ｜ ＝ａ×｜ｍｘ−ｎｙ｜ （ｍ，ｎ，ｘ，ｙは自
然数） となる。換言すれば、相互干渉妨害周波数ｆSPの間隔
は、入力ＲＦ信号のチャンネル間隔と同様にａとなる。With this setting, the mutual interference frequency f SP due to the fundamental wave and the harmonic of each of the two local oscillator circuits 14 and 17 is f SP = | m × f LO1 −n × f LO2 | = | M * a * x-n * a * y | = a * | mx-ny | (m, n, x, y are natural numbers). In other words, the interval of the mutual interference jamming frequency f SP becomes a, like the channel interval of the input RF signal.
【００１３】すると、１つのチャンネルの受信帯域幅
は、入力ＲＦ信号のチャンネル間隔ａ未満であるため、
相互干渉妨害周波数ｆSPを受信帯域外に設定することが
でき、相互干渉妨害によって受信信号に悪影響が及ぼさ
れることを防止することができるようになる。なお、入
力ＲＦ信号のチャンネル間隔が一定でない場合には、受
信帯域内に最も多く存在するチャンネル間隔をａとし
て、第１及び第２局部発振信号の周波数ｆLO1 ，ｆLO2
を、その整数倍に設定すればよい。Then, since the reception bandwidth of one channel is less than the channel interval a of the input RF signal,
The mutual interference jamming frequency f SP can be set outside the reception band, and it becomes possible to prevent the received signal from being adversely affected by the mutual interference jamming. When the channel spacing of the input RF signal is not constant, the channel spacing most present in the reception band is set to a, and the frequencies f LO1 and f LO2 of the first and second local oscillation signals are set.
Should be set to an integer multiple of that.
【００１４】具体的に言えば、ＲＦ信号の周波数ｆRFは
５５．２５ＭＨｚ，６１．２５ＭＨｚ，６７．２５ＭＨ
ｚ，……（以下省略）であり、第２中間周波数ｆIF2 は
６１．２５ＭＨｚ（固定）であり、ＲＦ信号のチャンネ
ル間隔ａつまり第１局部発振信号の周波数間隔は６ＭＨ
ｚのままであるが、第１中間周波数ｆIF1 を６１０．７
５ＭＨｚ（固定）とし、第１局部発振信号の周波数ｆ
LO1 を６６６ＭＨｚ，６７２ＭＨｚ，６７８ＭＨｚ，…
…（以下省略）とし、第２局部発振信号の周波数ｆLO2
を６７２ＭＨｚ（固定）としている。Specifically, the frequency f RF of the RF signal is 55.25 MHz, 61.25 MHz, 67.25 MH.
z, ... (Omitted below), the second intermediate frequency f IF2 is 61.25 MHz (fixed), and the channel interval a of the RF signal, that is, the frequency interval of the first local oscillation signal is 6 MH.
z remains, but the first intermediate frequency f IF1 is 610.7
5 MHz (fixed) and the frequency f of the first local oscillation signal
LO1 is set to 666MHz, 672MHz, 678MHz, ...
... (hereinafter omitted), and the frequency f LO2 of the second local oscillation signal
Is 672 MHz (fixed).
【００１５】このようにすれば、第１局部発振信号の周
波数ｆLO1 及び第２局部発振信号の周波数ｆLO2 は、共
にＲＦ信号のチャンネル間隔ａ（６ＭＨｚ）の整数倍に
なっているため、前述したように、２つの局部発振回路
１４，１７のそれぞれの基本波及び高調波による相互干
渉妨害周波数ｆSPも６ＭＨｚの整数倍になっている。こ
のとき、第２中間周波数ｆIF2 （６１．２５ＭＨｚ）に
最も近い相互干渉妨害周波数ｆSP1 は６０ＭＨｚであ
り、次に近い相互干渉妨害周波数ｆSP2 は６６ＭＨｚで
ある。With this configuration, the frequency f LO1 of the first local oscillation signal and the frequency f LO2 of the second local oscillation signal are both integral multiples of the channel interval a (6 MHz) of the RF signal, and thus As described above, the mutual interference jamming frequency f SP due to the fundamental wave and the harmonic of each of the two local oscillation circuits 14 and 17 is also an integral multiple of 6 MHz. At this time, the mutual interference jamming frequency f SP1 closest to the second intermediate frequency f IF2 (61.25 MHz) is 60 MHz, and the next mutual interference jamming frequency f SP2 is 66 MHz.
【００１６】図１は、第２中間周波数ｆIF2 の受信帯域
と相互干渉妨害周波数ｆSP1 ，ｆSP2 との関係を示して
いる。第２中間周波数ｆIF2 の受信帯域は、映像キャリ
ア周波数ｆP ＝６１．２５ＭＨｚ及び音声キャリア周波
数ｆS ＝６５．７５ＭＨｚであるから、残留側波帯まで
含んでも、 ６０ＭＨｚ＜第２中間周波数ｆIF2 の受信帯域＜６６Ｍ
Ｈｚ となる。つまり、相互干渉妨害周波数ｆSP1 ＝６０ＭＨ
ｚとｆSP2 ＝６６ＭＨｚとは、完全に第２中間周波数ｆ
IF2 の受信帯域外となり、相互干渉妨害によって映像や
音声信号に悪影響が及ぼされることを防止することがで
きる。FIG. 1 shows the relationship between the reception band of the second intermediate frequency f IF2 and the mutual interference and interference frequencies f SP1 and f SP2 . Since the reception band of the second intermediate frequency f IF2 is the video carrier frequency f P = 61.25 MHz and the audio carrier frequency f S = 65.75 MHz, 60 MHz <the second intermediate frequency f IF2 even including the vestigial sideband. Reception band <66M
It becomes Hz. That is, the mutual interference jamming frequency f SP1 = 60 MH
z and f SP2 = 66 MHz are completely equal to the second intermediate frequency f
It is possible to prevent the video and audio signals from being adversely affected by the mutual interference and interference because they are out of the reception band of IF2 .
【００１７】以上の例は、第２中間周波数ｆIF2 が入力
ＲＦ信号の周波数ｆRFの１つ（６１．２５ＭＨｚ）と一
致している場合を示したが、第２中間周波数ｆIF2 が入
力ＲＦ信号の最低周波数ｆRFmin.（５５．２５ＭＨｚ）
よりも低く、かつ、第２中間周波数帯域内において映像
キャリア周波数ｆP が音声キャリア周波数ｆS よりも高
い場合についても、上記の例と同様のことが考えられ
る。具体的に言えば、ＲＦ信号の周波数ｆRF，第１中間
周波数ｆIF1 ，第１局部発振信号の周波数ｆLO1及びチ
ャンネル間隔ａは上記の例と同じで、第２中間周波数ｆ
IF2 が４６．７５ＭＨｚであり、第２局部発振信号の周
波数ｆLO2 が５６４ＭＨｚである場合が考えられる。Although the above example shows the case where the second intermediate frequency f IF2 matches one of the frequencies f RF (61.25 MHz) of the input RF signal, the second intermediate frequency f IF2 is the input RF signal. Minimum frequency f RFmin. Of signal ( 55.25MHz )
Even when the video carrier frequency f P is lower than the audio carrier frequency f S in the second intermediate frequency band, the same thing as the above example can be considered. Specifically, the frequency f RF of the RF signal, the first intermediate frequency f IF1 , the frequency f LO1 of the first local oscillation signal, and the channel interval a are the same as in the above example, and the second intermediate frequency f
It is conceivable that IF2 is 46.75 MHz and the frequency f LO2 of the second local oscillation signal is 564 MHz.
【００１８】この場合も、第１局部発振信号の周波数ｆ
LO1 及び第２局部発振信号の周波数ｆLO2 は、共にＲＦ
信号のチャンネル間隔ａ（６ＭＨｚ）の整数倍になって
いるため、前述したように、２つの局部発振回路１４，
１７のそれぞれの基本波及び高調波による相互干渉妨害
周波数ｆSPも６ＭＨｚの整数倍になっている。このと
き、第２中間周波数ｆIF2 （４６．７５ＭＨｚ）に最も
近い相互干渉妨害周波数ｆSP2 は４８ＭＨｚであり、次
に近い相互干渉妨害周波数ｆSP1 は４２ＭＨｚである。Also in this case, the frequency f of the first local oscillation signal
LO1 and the frequency f LO2 of the second local oscillation signal are both RF
Since it is an integral multiple of the signal channel interval a (6 MHz), as described above, the two local oscillation circuits 14,
The mutual interference jamming frequency f SP due to each of the fundamental wave and the harmonic wave of 17 is also an integral multiple of 6 MHz. At this time, the mutual interference disturbance frequency f SP2 closest to the second intermediate frequency f IF2 (46.75 MHz) is 48 MHz, and the next mutual interference disturbance frequency f SP1 is 42 MHz.
【００１９】図２は、第２中間周波数ｆIF2 の受信帯域
と相互干渉妨害周波数ｆSP1 ，ｆSP2 との関係を示して
いる。第２中間周波数ｆIF2 の受信帯域は、映像キャリ
ア周波数ｆP ＝４６．７５ＭＨｚ及び音声キャリア周波
数ｆS ＝４２．２５ＭＨｚであるから、残留側波帯まで
含んでも、 ４２ＭＨｚ＜第２中間周波数ｆIF2 の受信帯域＜４８Ｍ
Ｈｚ となる。つまり、相互干渉妨害周波数ｆSP1 ＝４２ＭＨ
ｚとｆSP2 ＝４８ＭＨｚとは、完全に第２中間周波数ｆ
IF2 の受信帯域外となり、相互干渉妨害によって映像や
音声信号に悪影響が及ぼされることを防止することがで
きる。FIG. 2 shows the relationship between the reception band of the second intermediate frequency f IF2 and the mutual interference and interference frequencies f SP1 and f SP2 . Since the reception band of the second intermediate frequency f IF2 is the video carrier frequency f P = 46.75 MHz and the audio carrier frequency f S = 42.25 MHz, 42 MHz <the second intermediate frequency f IF2 even if the vestigial sideband is included. Reception band <48M
It becomes Hz. That is, the mutual interference jamming frequency f SP1 = 42 MH
z and f SP2 = 48 MHz are completely equal to the second intermediate frequency f
It is possible to prevent the video and audio signals from being adversely affected by the mutual interference and interference because they are out of the reception band of IF2 .
【００２０】なお、上述した実施例では、第２中間周波
数ｆIF2 の受信帯域と相互干渉妨害周波数ｆSP1 ，ｆ
SP2 との関係で説明したが、これは、第１中間周波数ｆ
IF1 の受信帯域と相互干渉妨害周波数との関係で考えて
も、周波数の絶対値が異なるのみで同様の相対関係が成
立することはもちろんである。In the embodiment described above, the reception band of the second intermediate frequency f IF2 and the mutual interference jamming frequencies f SP1 , f
As described in relation to SP2 , this is the first intermediate frequency f
Considering the relationship between the reception band of IF1 and the mutual interference frequency, it goes without saying that the same relative relationship is established only when the absolute values of the frequencies are different.
【００２１】次に、図３は、２つのダブルスーパーチュ
ーナＡ，Ｂが並設されている場合を示している。ダブル
スーパーチューナＡは、図４と同一部分に同一番号を付
し添字ａを付している。ダブルスーパーチューナＢは、
図４と同一部分に同一番号を付し添字ｂを付している。
この場合、合計４つの局部発振回路１４ａ，１７ａ，１
４ｂ，１７ｂの基本波及び高調波による相互干渉妨害が
発生することになるが、この発明によれば、相互干渉妨
害周波数を受信帯域外に設定することができるようにな
る。なお、この発明は上記各実施例に限定されるもので
はなく、この外その要旨を逸脱しない範囲で種々変形し
て実施することができる。Next, FIG. 3 shows a case where two double super tuners A and B are arranged in parallel. The double super tuner A has the same numbers as those in FIG. Double Super Tuner B is
The same parts as those in FIG. 4 are denoted by the same reference numerals and the subscript b is added.
In this case, a total of four local oscillator circuits 14a, 17a, 1
Mutual interference due to the fundamental waves and harmonics of 4b and 17b occurs, but according to the present invention, the mutual interference frequency can be set outside the reception band. The present invention is not limited to the above-described embodiments, but can be variously modified and implemented without departing from the scope of the invention.
【００２２】[0022]
【発明の効果】以上詳述したようにこの発明によれば、
相互干渉妨害によって受信信号に悪影響が及ぼされるこ
とを防止し得る極めて良好なダブルスーパーチューナを
提供することができる。As described above in detail, according to the present invention,
It is possible to provide a very good double super tuner capable of preventing the received signal from being adversely affected by mutual interference.
【図１】この発明に係るダブルスーパーチューナの一実
施例を示すもので、第２中間周波数の受信帯域と相互干
渉妨害周波数との関係を示す図。FIG. 1 is a diagram showing an embodiment of a double super tuner according to the present invention and is a diagram showing a relationship between a reception band of a second intermediate frequency and a mutual interference frequency.
【図２】同実施例の変形例を示すもので、第２中間周波
数の受信帯域と相互干渉妨害周波数との関係を示す図。FIG. 2 is a diagram showing a modification of the embodiment, showing a relationship between a reception band of a second intermediate frequency and a mutual interference jamming frequency.
【図３】この発明の他の実施例を示すブロック構成図。FIG. 3 is a block diagram showing another embodiment of the present invention.
【図４】一般的なダブルスーパーチューナを示すブロッ
ク構成図。FIG. 4 is a block diagram showing a general double super tuner.
【図５】同チューナに対する入力ＲＦ信号のチャンネル
間隔を説明するための図。FIG. 5 is a diagram for explaining a channel interval of an input RF signal with respect to the tuner.
１１…入力端子、１２…ＲＦ回路、１３…第１の混合回
路、１４…可変局部発振回路、１５…第１中間周波数回
路、１６…第２の混合回路、１７…固定局部発振回路、
１８…第２中間周波数回路、１９…出力端子。11 ... Input terminal, 12 ... RF circuit, 13 ... First mixing circuit, 14 ... Variable local oscillation circuit, 15 ... First intermediate frequency circuit, 16 ... Second mixing circuit, 17 ... Fixed local oscillation circuit,
18 ... 2nd intermediate frequency circuit, 19 ... Output terminal.
Claims (1)
れた複数の入力信号と、この複数の入力信号のうち所望
の周波数の入力信号に対応させて周波数が可変される第
１局部発振信号とを混合して、固定周波数の第１中間周
波数信号を得る第１の周波数変換手段と、 この第１の周波数変換手段から出力される第１中間周波
数信号と、固定周波数の第２局部発振信号とを混合して
第２中間周波数信号を得る第２の周波数変換手段とを有
するダブルスーパーチューナにおいて、 前記第１局部発振信号及び第２局部発振信号の周波数
を、前記複数の入力信号のチャンネル間隔の整数倍に設
定するように構成してなることを特徴とするダブルスー
パーチューナ。1. A plurality of input signals frequency-divided at substantially constant channel intervals, and a first local oscillation signal whose frequency is variable corresponding to an input signal of a desired frequency among the plurality of input signals. First frequency conversion means for mixing to obtain a first intermediate frequency signal having a fixed frequency, a first intermediate frequency signal output from the first frequency conversion means, and a second local oscillation signal having a fixed frequency. In a double super tuner having a second frequency conversion means for mixing to obtain a second intermediate frequency signal, the frequencies of the first local oscillation signal and the second local oscillation signal are integers of the channel intervals of the plurality of input signals. A double super tuner characterized by being configured to be set to double.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP04294394A JP3490493B2 (en) | 1994-03-15 | 1994-03-15 | Double superheterodyne tuner |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP04294394A JP3490493B2 (en) | 1994-03-15 | 1994-03-15 | Double superheterodyne tuner |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH07254865A true JPH07254865A (en) | 1995-10-03 |
| JP3490493B2 JP3490493B2 (en) | 2004-01-26 |
Family
ID=12650102
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP04294394A Expired - Fee Related JP3490493B2 (en) | 1994-03-15 | 1994-03-15 | Double superheterodyne tuner |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3490493B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6094236A (en) * | 1996-04-26 | 2000-07-25 | Kabushiki Kaisha Toshiba | Tuner circuit |
| JP2006261858A (en) * | 2005-03-15 | 2006-09-28 | Fujitsu Ltd | Receiving device and method of processing received signal |
| JP2011055202A (en) * | 2009-09-01 | 2011-03-17 | Sharp Corp | Front-end circuit, tuner, and television broadcasting receiver |
| US8954020B2 (en) | 1997-02-20 | 2015-02-10 | Telefonaktiebolaget L M Ericsson (Publ) | Radio transceiver on a chip |
-
1994
- 1994-03-15 JP JP04294394A patent/JP3490493B2/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6094236A (en) * | 1996-04-26 | 2000-07-25 | Kabushiki Kaisha Toshiba | Tuner circuit |
| US8954020B2 (en) | 1997-02-20 | 2015-02-10 | Telefonaktiebolaget L M Ericsson (Publ) | Radio transceiver on a chip |
| JP2006261858A (en) * | 2005-03-15 | 2006-09-28 | Fujitsu Ltd | Receiving device and method of processing received signal |
| JP4674103B2 (en) * | 2005-03-15 | 2011-04-20 | 富士通セミコンダクター株式会社 | Reception apparatus and received signal processing method |
| JP2011055202A (en) * | 2009-09-01 | 2011-03-17 | Sharp Corp | Front-end circuit, tuner, and television broadcasting receiver |
| US8319899B2 (en) | 2009-09-01 | 2012-11-27 | Sharp Kabushiki Kaisha | Front-end circuit, tuner, and television broadcasting receiver |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3490493B2 (en) | 2004-01-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1224529A (en) | Shf receiver | |
| JPH0678227A (en) | Method and apparatus for reception of broadcasting signal | |
| JP2000513896A (en) | Multi-tuner receiver | |
| US7002639B2 (en) | Dual digital television tuner | |
| JP3725402B2 (en) | Television tuner | |
| JPH07254865A (en) | Double supertuner | |
| US6272312B1 (en) | Satellite broadcasting receiving tuner which inhibits interference caused by satellite broadcast signals having one octave higher frequency band | |
| US7343142B2 (en) | Tuner | |
| JP3592159B2 (en) | Television signal transmitter | |
| JP2002101032A (en) | Gap filler for ground-wave digital broadcasting | |
| KR900010965Y1 (en) | Catv converter | |
| JPH10304262A (en) | Digital television broadcast receiver | |
| JP3038280B2 (en) | Receiver | |
| JPH09182047A (en) | Tuner for catv broadcast reception | |
| JP3495661B2 (en) | Receiver | |
| KR200144593Y1 (en) | Cable TV Tuning Equipment | |
| JPS6337533B2 (en) | ||
| KR900006436B1 (en) | Multi-tuner system | |
| JP3495656B2 (en) | Receiver | |
| JP3617513B2 (en) | Receiver | |
| JP3596760B2 (en) | Receiver | |
| JP3495657B2 (en) | Receiver | |
| JPH0779473B2 (en) | Receiver | |
| JPH1056598A (en) | Trap circuit for tuner | |
| JP2003249866A (en) | Receiving apparatus |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Year of fee payment: 4 Free format text: PAYMENT UNTIL: 20071107 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20081107 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Year of fee payment: 6 Free format text: PAYMENT UNTIL: 20091107 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Year of fee payment: 7 Free format text: PAYMENT UNTIL: 20101107 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20101107 Year of fee payment: 7 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20111107 Year of fee payment: 8 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20121107 Year of fee payment: 9 |
|
| LAPS | Cancellation because of no payment of annual fees |