JPH03227137A - Direct conversion receiver - Google Patents
Direct conversion receiverInfo
- Publication number
- JPH03227137A JPH03227137A JP2023556A JP2355690A JPH03227137A JP H03227137 A JPH03227137 A JP H03227137A JP 2023556 A JP2023556 A JP 2023556A JP 2355690 A JP2355690 A JP 2355690A JP H03227137 A JPH03227137 A JP H03227137A
- Authority
- JP
- Japan
- Prior art keywords
- signal
- low frequency
- frequency
- supplied
- signals
- 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
- 238000006243 chemical reaction Methods 0.000 title claims abstract description 23
- 230000010355 oscillation Effects 0.000 claims description 16
- 238000001514 detection method Methods 0.000 claims description 13
- 230000005684 electric field Effects 0.000 abstract description 6
- 230000003321 amplification Effects 0.000 description 6
- 238000003199 nucleic acid amplification method Methods 0.000 description 6
- 238000010586 diagram Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 230000035945 sensitivity Effects 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
Landscapes
- Circuits Of Receivers In General (AREA)
- Mobile Radio Communication Systems (AREA)
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野コ
本発明はポケットベル、移動無線電話機等に採用される
ダイレクトコンバージョン受信機に関し、−層詳細には
、供給される受信信号を低周波信号に変換し、次いで、
高周波数のＦＭ信号に変換して、この後、レベルを示す
検出信号ならびに出力信号を導出し、さらに低周波の復
調信号に変換することにより、比較的簡単な構成におい
て、レベルの検出（受信電界レベル）が行われ、且つ安
定した受信利得が得られるようにしたものである。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a direct conversion receiver employed in pagers, mobile radio telephones, etc. Convert and then
Level detection (received electric field level), and a stable reception gain can be obtained.
［従来の技術］
従来、ボケットベノへ移動無線電話機等の受信部には、
高Ｓ／Ｎ比と高感度が得られ、ミキサから直接的に復調
信号等を得る比較的簡素な構成の受信機、所謂、ダイレ
クトコンバージョン受信機が採用されている。[Prior Art] Conventionally, the receiving section of mobile radio telephones, etc.
A so-called direct conversion receiver, which has a relatively simple configuration that provides a high S/N ratio and high sensitivity and obtains a demodulated signal directly from a mixer, is used.
第２図にダイレクトコンバージョン受信機の−例を示す
。FIG. 2 shows an example of a direct conversion receiver.
この例において、符号２は受信信号Ｓａが入力される高
周波増幅回路であり、ここで分岐した高周波出力信号ｓ
ｂが供給されて低周波の復調信号を送出するＱチャネル
部３、■チャネル部４が設けられている。さらに、高周
波出力信号ｓｂと略同一の発振周波数を生成して送出す
る局部発振器８と、発振周波数を９０°移相する９０°
移相器１０を有している。In this example, reference numeral 2 is a high-frequency amplification circuit into which the received signal Sa is input, and the high-frequency output signal s branched here.
A Q channel section 3 and a (2) channel section 4 are provided to which a low frequency demodulated signal is supplied. Furthermore, a local oscillator 8 that generates and transmits an oscillation frequency that is substantially the same as the high-frequency output signal sb, and a 90° phase shifter that shifts the oscillation frequency by 90°.
It has a phase shifter 10.
Ｑチャネル部３、■チャネル部４はミキサ３ａ、４ａと
、ＬＰＦ３ｂ、４ｂと、低周波増幅回路３Ｃ１４Ｃが夫
々連接されている。The Q channel section 3 and the -channel section 4 are connected with mixers 3a and 4a, LPFs 3b and 4b, and a low frequency amplification circuit 3C14C, respectively.
前記の構成は周知のダイレクトコンバージョンが行われ
るものであり、高周波出力信号ｓｂと略同一の発振周波
数をミキサ３ａ、４ａで混合して、直接に復調信号を導
出し、続いて、ＬＰＦ３ｂ、４ｂで高周波、高次成分信
号等を除去し、さらに、低周波増幅回路３Ｃ１４Ｃで増
幅された復調信号５ＱＳＳｉが導出される。In the above configuration, well-known direct conversion is performed, and the oscillation frequency that is substantially the same as that of the high-frequency output signal sb is mixed by the mixers 3a and 4a to directly derive the demodulated signal, and then the demodulated signal is directly derived by the LPFs 3b and 4b. A demodulated signal 5QSSi is derived by removing high-frequency, high-order component signals, etc., and further amplified by a low-frequency amplification circuit 3C14C.
［発明が解決しようとする課題］
しかしながら、上記の従来例に係るダイレクトコンバー
ジョン受信機においては、極めて高い周波数の受信信号
３ａが供給されることからミキサ３ａ、４ａの前段にリ
ミッタアンプを配設することができない、あるいは低周
波増幅回路３Ｃ１４Ｃからの復調信号Ｓｑ、Ｓｉの導出
後にもリミッタアンプを設けることができない。[Problem to be Solved by the Invention] However, in the direct conversion receiver according to the above-mentioned conventional example, since the reception signal 3a of an extremely high frequency is supplied, a limiter amplifier is disposed before the mixers 3a and 4a. Or, it is not possible to provide a limiter amplifier even after deriving the demodulated signals Sq and Si from the low frequency amplifier circuit 3C14C.
このため、例えば、移動無線電話機においてはゾーンの
切り換え等に供される高周波出力信号ｓｂのレベル（受
信電界）の検出が困難である。For this reason, for example, in mobile radio telephones, it is difficult to detect the level (received electric field) of the high frequency output signal sb used for zone switching and the like.
この場合、比較的複雑な回路構成であるＡＧＣの導入が
必要となる等々の欠点を有している。In this case, there are drawbacks such as the need to introduce AGC, which has a relatively complicated circuit configuration.
本発明は係る点に鑑みてなされたものであって、比較的
簡単な構成において、受信電界レベルの検出が可能とな
り、且つ受信利得の安定化に優れるダイレクトコンバー
ジョン受信機を提供することを目的とする。The present invention has been made in view of the above points, and an object of the present invention is to provide a direct conversion receiver that can detect the received electric field level with a relatively simple configuration and is excellent in stabilizing the receiving gain. do.
［課題を解決するための手段］
前記の課題を解決するた約に、本発明のダイレクトコン
バージョン受信機は、
受信信号と第１の発振器からの発振信号が供給されて低
周波信号を導出する低周波数変換手段と、
前記低周波信号と第２の発振器からの発振信号が供給さ
れて高周波数のＦＭ信号を送出するＦＭ変換手段と、
前記ＦＭ信号が供給されてレベルを示す検出信号と出力
信号を送出するリミッタアンプと、前記出力信号と第３
あるいは前記第２の発振器から前記ＦＭ信号と略同一の
発振周波数信号が供給されて低周波の復調信号を導出す
る復調手段と、
を備えることを特徴とする。[Means for Solving the Problems] In order to solve the above-mentioned problems, the direct conversion receiver of the present invention includes a low-frequency converter that is supplied with a received signal and an oscillation signal from a first oscillator and derives a low-frequency signal. Frequency converting means; FM converting means to which the low frequency signal and the oscillation signal from the second oscillator are supplied to send out a high frequency FM signal; and to which the FM signal is supplied, a detection signal and an output signal indicating the level. a limiter amplifier that sends out the output signal and a third
Alternatively, the present invention is characterized by comprising a demodulating means for deriving a low-frequency demodulated signal by receiving an oscillation frequency signal substantially the same as the FM signal from the second oscillator.
［作用］
上記の構成において、供給される受信信号が低周波信号
に変換される。次いで、高周波数のＦＭ信号に変換され
、この後、例えば、リミッタアンプでレベルを示す検出
信号ならびに出力信号が送出される。そして、低周波に
変換されて、復調信号が導出される。これにより、受信
信号のレベル検出（受信電界レベル）が行われ、且つ受
信利得が安定化する。[Operation] In the above configuration, the supplied received signal is converted into a low frequency signal. Next, it is converted into a high frequency FM signal, and then, for example, a limiter amplifier sends out a detection signal indicating the level and an output signal. Then, it is converted to a low frequency and a demodulated signal is derived. As a result, the level of the received signal (received electric field level) is detected and the reception gain is stabilized.
［実施例］
次に、本発明に係るダイレクトコンバージョン受信機の
実施例を、添付図面を参照して以下詳細に説明する。[Example] Next, an example of the direct conversion receiver according to the present invention will be described in detail below with reference to the accompanying drawings.
第１図は実施例の全体構成を示すブロック図である。FIG. 1 is a block diagram showing the overall configuration of the embodiment.
第１図に示される例は、供給される受信信号Ｓｅを増幅
する高周波増幅回路１１と、ここで導出される増幅受信
信号Ｓｆが供給され、低周波信号Ｓｇａ、Ｓｇｂに変換
して導出する低周波数変換部（低周波数変換手段）１２
と、低周波信号Ｓｇａ、Ｓｇｂを高周波数のＦＭ信号Ｓ
ｉａ、Ｓｉｂに変換するＦＭ変換部（ＦＭ変換手段）２
４と、ＦＭ信号Ｓｉａ、Ｓｉｂが供給されてレベルを示
す検出信号Ｓｊならびに出力信号Ｓｋを送出するリミッ
タアンプ３２と、低周波に変換したｔｉｍ信号Ｓｍａ
（Ｑチャネル）、Ｓｍｂ（Ｉチャネル）を導出する復調
部（復調手段）３４とで概略構成されている。The example shown in FIG. 1 includes a high-frequency amplification circuit 11 that amplifies the supplied received signal Se, and an amplified received signal Sf derived here, which is converted into low-frequency signals Sga, Sgb and derived. Frequency converter (low frequency converter) 12
and the low frequency signals Sga, Sgb are converted into the high frequency FM signal S.
FM conversion unit (FM conversion means) 2 that converts to ia and Sib
4, a limiter amplifier 32 to which the FM signals Sia and Sib are supplied and sends out a detection signal Sj indicating the level and an output signal Sk, and a tim signal Sma converted to a low frequency.
(Q channel) and a demodulation section (demodulation means) 34 that derives Smb (I channel).
低周波数変換部１２は高周波増幅回路１１で分岐された
受信信号Ｓｆが夫々供給されるとともに、Ｑ／Ｉチャネ
ル系に弁別されて構成されており、ミキサ１４ａ、１４
ｂと、ＬＰＦ１６ａ、１６ｂと、局部発振器１８と、９
０°移相器２０とを有し、続いて、ＦＭ変換部２４はミ
キサ２６ａ、２６ｂと、局部発振器２８と、９０°移相
器３０とが設けられている。The low frequency converter 12 is configured to be supplied with the received signal Sf branched by the high frequency amplifier circuit 11 and separated into Q/I channel systems, and mixers 14a, 14
b, LPF16a, 16b, local oscillator 18, 9
The FM converter 24 includes a 0° phase shifter 20, and subsequently, the FM converter 24 is provided with mixers 26a and 26b, a local oscillator 28, and a 90° phase shifter 30.
リミッタアンプ３２には前記のミキサ２６ａ１２６ｂの
出力信号であるＦＭ信号３ｉａ、Ｓｉｂが合成して供給
される。The limiter amplifier 32 is supplied with the combined FM signals 3ia and Sib, which are the output signals of the mixer 26a126b.
さらに、復調部３４はＱ／Ｉチャネル系に弁別されて構
成されており、ミキサ３５ａ、３５ｂと、ＬＰＦ ３５
ａ、３６ｂと、低周波増幅器３８ａ、３８ｂとを有し
ている。Further, the demodulator 34 is configured to be differentiated into Q/I channel systems, and includes mixers 35a, 35b, and an LPF 35.
a, 36b, and low frequency amplifiers 38a, 38b.
次に、上記のように構成される実施例の動作を説明する
。Next, the operation of the embodiment configured as described above will be explained.
先ず、供給される受信信号Ｓｅが高周波増幅回路１１で
増幅される。ここで導出される増幅受信信号Ｓｆが分岐
されて、低周波数変換部１２のミキサ１４ａ、１４ｂに
供給される。ミキサ１４ａ、１４ｂには、夫々局部発振
器１８から増幅受信信号Ｓｆと略同一周波数の局部発振
信号と９０°移相器２０を介した局部発振信号が供給さ
れ、Ｑ／Ｉチャネルの復調された低周波信号が導出され
る。この夫々の低周波信号はＬＰＦ１６ａ、１６ｂで高
次成分等が除去された低周波信号Ｓｇａ、Ｓｇｂが導出
される。First, the supplied received signal Se is amplified by the high frequency amplification circuit 11. The amplified received signal Sf derived here is branched and supplied to mixers 14a and 14b of the low frequency conversion section 12. The mixers 14a and 14b are supplied with a local oscillation signal having substantially the same frequency as the amplified reception signal Sf from the local oscillator 18 and a local oscillation signal passed through the 90° phase shifter 20, respectively, and are supplied with a demodulated low frequency signal of the Q/I channel. A frequency signal is derived. These respective low frequency signals are subjected to LPFs 16a and 16b, from which high-order components and the like are removed, and low frequency signals Sga and Sgb are derived.
続いて、低周波信号Ｓｇａ、ＳｇｂがＦＭ変換部２４の
ミキサ２６ａ、２６ｂに供給される。Subsequently, the low frequency signals Sga and Sgb are supplied to the mixers 26a and 26b of the FM converter 24.
ここで、ミキサ２６ａ、２６ｂには夫々局部発振器２８
から数１０〜数１００ＫＨｚの周波数の局部発振信号と
９０°移相器３０を介した局部発振信号が供給され、Ｑ
／Ｉチャネルの高周波数のＦＭ信号Ｓｉａ、Ｓｉｂが導
出される。Here, the mixers 26a and 26b each have a local oscillator 28.
A local oscillation signal with a frequency of several 10 to several 100 KHz and a local oscillation signal via a 90° phase shifter 30 are supplied from Q.
/I channel high frequency FM signals Sia and Sib are derived.
ＦＭ信号５ｉａＳＳｉｂはリミッタアンプ３２に合成し
て供給される。ここではレベルを示す検出信号Ｓｊなら
びに出力信号Ｓｋが導出される。ここで検出信号ＳＪは
ＦＭ信号３ｉａ。The FM signal 5iaSSib is combined and supplied to the limiter amplifier 32. Here, a detection signal Sj indicating the level and an output signal Sk are derived. Here, the detection signal SJ is the FM signal 3ia.
Ｓ１ｂのレベル、すなわち、受信信号Ｓｅのレベルであ
る。この場合、検出信号Ｓｊは、複数段の増幅器で構成
されるリミッタアンプの場合の後段の増幅器の出力を前
段に帰還する閉ループ制御の制御電圧に相当するもので
ある。This is the level of S1b, that is, the level of the received signal Se. In this case, the detection signal Sj corresponds to a control voltage for closed loop control that feeds back the output of a subsequent stage amplifier to a previous stage in the case of a limiter amplifier composed of multiple stages of amplifiers.
出力信号Ｓｋは復調部３４のミキサ３５ａ１３５ｂに夫
々供給される。ミキサ３５ａ、３５ｂには、前記のＦＭ
変換部２４の局部発振器２８から数１０〜数１００ＫＨ
ｚの周波数の局部発振信号と９０°移相器３０を介した
局部発振信号が同時に供給されており、ここで、Ｑ／Ｉ
チャネルの復調された低周波信号が導出される。The output signal Sk is supplied to mixers 35a and 135b of the demodulator 34, respectively. The mixers 35a and 35b have the above-mentioned FM
Several tens to several hundred KH from the local oscillator 28 of the converter 24
A local oscillation signal with a frequency of
A demodulated low frequency signal of the channel is derived.
この夫々の低周波信号はＬＰＦ３６ａ、３６ｂでミキサ
３５ａ、３５ｂ等で生起した高次成分等を除去した低周
波信号が導出される。この低周波信号は、さらに低周波
増幅器３８ａ、３８ｂで所定の増幅が行われて、復調信
号Ｓｍａ。These low frequency signals are derived by LPFs 36a and 36b from which high-order components generated by mixers 35a and 35b are removed. This low frequency signal is further amplified in a predetermined manner by low frequency amplifiers 38a and 38b to produce a demodulated signal Sma.
Ｓｍｂが導出される。Smb is derived.
このようにして、供給される受信信号Ｓｅ（増幅受信信
号Ｓｆ）が低周波信号Ｓｇａ、Ｓｇｂに変換され、次い
で、高周波数のＦＭ信号５ｉａＳＳｉｂに変換され、こ
の後、レベルを示す検出信号ＳＪならびに出力信号Ｓｋ
が送出される。そして、再び低周波に変換されて、復調
信号ＳｍａＳＳｍｂが導出される。これにより、供給さ
れる受信信号Ｓｅのレベル検出、すなわち検出信号Ｓｊ
導出く受信電界レベル）が行われ、例えば、移動無線電
話機において、ゾーンの切り換えに係る制御が有効に出
来るようになる。さらに復調信号処理における受信利得
が安定する。In this way, the supplied reception signal Se (amplified reception signal Sf) is converted into low frequency signals Sga, Sgb, then converted into a high frequency FM signal 5iaSSib, and then a detection signal SJ indicating the level and Output signal Sk
is sent. Then, it is converted to a low frequency again, and a demodulated signal SmaSSmb is derived. As a result, level detection of the supplied reception signal Se, that is, detection signal Sj
For example, in a mobile radio telephone, zone switching can be effectively controlled. Furthermore, the reception gain in demodulated signal processing is stabilized.
なお、本実施例において、ミキサ１４ａ、１４ｂの以降
における回路構成はデジタル信号処理においても前記同
様の作用効果が得られる。In this embodiment, the circuit configuration after the mixers 14a and 14b provides the same effects as described above in digital signal processing.
この場合、構成回路のＩＣ化が容易であり、装置規模が
低減して小型化され、可搬機器、例えば、ボケットベノ
へ移動無線電話機への適用が容易となる。In this case, the component circuits can be easily integrated into ICs, the scale of the device can be reduced, and the device can be miniaturized, making it easy to apply it to portable equipment, such as mobile radio telephones and mobile radio telephones.
［発明の効果］
以上のように、本発明のダイレクトコンバージョン受信
機によれば、受信信号と第１の発振器からの発振信号が
供給されて低周波信号を導出する低周波数変換手段と、
前記低周波信号と第２の発振器からの発振信号が供給さ
れて高周波数のＦＭ信号を送出するＦＭ変換手段と、前
記ＦＭ信号が供給されてレベルを示す検出信号と出力信
号を送出するリミッタアンプと、前記出力信号と第３あ
るいは前記第２の発振器から前記ＦＭ信号と略同一の発
振周波数信号が供給されて低周波の復調信号を導出する
復調手段とを備えて構成されることを特徴としている。[Effects of the Invention] As described above, the direct conversion receiver of the present invention includes a low frequency conversion means that is supplied with a received signal and an oscillation signal from the first oscillator and derives a low frequency signal;
FM conversion means that is supplied with the low frequency signal and the oscillation signal from the second oscillator and sends out a high frequency FM signal; and a limiter amplifier that is supplied with the FM signal and sends out a detection signal indicating a level and an output signal. and demodulation means for deriving a low-frequency demodulated signal by receiving the output signal and an oscillation frequency signal substantially the same as the FM signal from the third or second oscillator. There is.
これにより、受信電界レベルの検出が可能となり、且つ
受信利得の安定化が向上する効果を奏する。加えて、構
成回路のＩＣ化が容易となり、装置規模が低減して小型
化されて可搬機器、例えば、ポケットベノへ移動無線電
話機への適用が容易になる利点が有る。This makes it possible to detect the reception electric field level, and has the effect of improving the stabilization of the reception gain. In addition, there is an advantage that the component circuits can be easily integrated into ICs, the scale of the device can be reduced, and the device can be miniaturized, making it easy to apply it to portable devices such as pocket benches and mobile radio telephones.
第１図は本発明に係るダイレクトコンバージョン受信機
の一実施例の全体構成を示すブロック図、
第２図は従来の技術に係るダイレクトコンバージョン受
信機の全体構成を示すブロック図である。
１１・・・高周波増幅回路
１２・・・低周波数変換部
１４ａ、１４ｂ−・・ミキサ
１６ ａ、 １６ ｂ・ＬＰＦ
１８・・・局部発振器
２０・・・９０°移相器
２４・・・ＦＭ変換部
２６ａ、２６ｂ・＝ミキサ
２８・・・局部発振器
３０・・・９０°移相器
３２・・・リミッタアンプ
３４・・・復調部
３５ａ、３５ｂ・＝・ミキサ
３６ ａ、 ３６ ｂ・ＬＰＦ
３８ａ、３８ｂ・・・低周波増幅器
Ｓｅ・・・受信信号
Ｓｆ・・・増幅受信信号
ＳｇａＳＳｇｂ・・・低周波信号
Ｓ ｉ ａ、 Ｓ ｉ ｂ・−ＦＭ信号ＳＪ・・・検出
信号
Ｓｋ・・・出力信号
Ｓｍａ、Ｓｍｂ・・・復調信号FIG. 1 is a block diagram showing the overall configuration of an embodiment of a direct conversion receiver according to the present invention, and FIG. 2 is a block diagram showing the overall configuration of a direct conversion receiver according to the prior art. 11... High frequency amplification circuit 12... Low frequency conversion section 14a, 14b... Mixer 16 a, 16 b LPF 18... Local oscillator 20... 90° phase shifter 24... FM conversion Parts 26a, 26b = Mixer 28... Local oscillator 30... 90° phase shifter 32... Limiter amplifier 34... Demodulator part 35a, 35b = Mixer 36 a, 36 b, LPF 38a, 38b...Low frequency amplifier Se...Reception signal Sf...Amplified reception signal SgaSSgb...Low frequency signal Sia, Sib-FM signal SJ...Detection signal Sk...Output signal Sma, Smb... demodulated signal
Claims (1)
れて低周波信号を導出する低周波数変換手段と、 前記低周波信号と第２の発振器からの発振信号が供給さ
れて高周波数のＦＭ信号を送出するＦＭ変換手段と、 前記ＦＭ信号が供給されてレベルを示す検出信号と出力
信号を送出するリミッタアンプと、前記出力信号と第３
あるいは前記第２の発振器から前記ＦＭ信号と略同一の
発振周波数信号が供給されて低周波の復調信号を導出す
る復調手段と、 を備えて構成されるダイレクトコンバージョン受信機。(1) A low frequency conversion means that is supplied with a received signal and an oscillation signal from a first oscillator and derives a low frequency signal; FM converting means for sending out an FM signal; a limiter amplifier to which the FM signal is supplied and sending out a detection signal indicating the level and an output signal;
Alternatively, a direct conversion receiver comprising: demodulation means that is supplied with an oscillation frequency signal substantially the same as the FM signal from the second oscillator and derives a low-frequency demodulated signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2023556A JPH03227137A (en) | 1990-01-31 | 1990-01-31 | Direct conversion receiver |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2023556A JPH03227137A (en) | 1990-01-31 | 1990-01-31 | Direct conversion receiver |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH03227137A true JPH03227137A (en) | 1991-10-08 |
Family
ID=12113781
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2023556A Pending JPH03227137A (en) | 1990-01-31 | 1990-01-31 | Direct conversion receiver |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH03227137A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5867062A (en) * | 1996-11-20 | 1999-02-02 | Nec Corporation | DC-offset canceler circuit and differential amplifier circuit equipped therewith |
-
1990
- 1990-01-31 JP JP2023556A patent/JPH03227137A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5867062A (en) * | 1996-11-20 | 1999-02-02 | Nec Corporation | DC-offset canceler circuit and differential amplifier circuit equipped therewith |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7057426B2 (en) | Frequency converter, orthogonal demodulator and orthogonal modulator | |
| US4648127A (en) | Noise detector | |
| JPH03227137A (en) | Direct conversion receiver | |
| JP3699026B2 (en) | Radio receiver automatic gain control method and apparatus | |
| JP2004297137A (en) | Receiver | |
| JPH03220823A (en) | Direct conversion receiver | |
| KR101132081B1 (en) | Rf signal processing circuit | |
| KR20110051863A (en) | Rf signal processing circuit | |
| JP2001119316A (en) | Direct conversion receiver | |
| JPH08340268A (en) | Receiver | |
| JPH09186618A (en) | Radio receiver | |
| KR920001869A (en) | Radio wave reception circuit using up conversion | |
| JPH06188773A (en) | Radio receiver with adaptive electric current drain | |
| JPS6016732A (en) | Receiver | |
| JPS6041331A (en) | Radio receiver | |
| KR20110067726A (en) | Rf signal processing circuit | |
| JP2545060Y2 (en) | Demodulation circuit | |
| JPH01129535A (en) | Mobile radio telephone equipment | |
| JP2799105B2 (en) | Satellite broadcast receiver | |
| JP2010147975A (en) | High-frequency receiver | |
| JPH0637835A (en) | Direct conversion receiver | |
| JP2001102941A (en) | Radio equipment | |
| JPS54152414A (en) | Squelch system of fm mobile radio equipment | |
| KR20080036723A (en) | Digital tuner | |
| JPS6096930A (en) | Radio receiver |