JPS6223629A - Receiver - Google Patents

Abstract

PURPOSE:To vary electronically the attenuation of an attenuator by using a PINDIODE so as to constitute the attenuator, providing the attenuator to a receiver input section and controlling the bias current by an AGC voltage by the detection of reception input electric field. CONSTITUTION:A reception input electric field inputted to a receiver input terminal (a) is converted into an intermediate frequency by a frequency converter 3 via a variable resistance attenuator 1 and a pre-high frequency low noise amplifier 2. The change in the received input electric field inputted to the receiver inputterminal (a) is kept to a prescribed level within the operating rang of the AGC function of a main intermediate frequency amplifie 6 and an AGC voltage signal (c) in response to the change in the reception input electric field is extracted by an AGC detection circuit 9. A controller 10 uses the level of the AGC voltage signal (c) so as to apply a bias current (d) inputted to the PINDIODE being a component of the variable resistance attenuator 1 thereby controlling the attenuator. That is, the bias current (d) inputted to the PINDIODE of the variable resistance attenuator 1 is controlled automatically by the change in the reception input electric field to give an optional attenuation to the variable resistance attenuator 1.

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明は入力電界が異常に高くなった場合においても正
常に動作する受信入力制御型受信機に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a reception input control type receiver that operates normally even when the input electric field becomes abnormally high.

〔従来の技術〕[Conventional technology]

従来、こ種の受信機の構成は、第３図のブロック図に示
される。図中、２は前置高周波低雑音増幅器、３は周波
数変換器、４は局部発振器、５は前置中間周波増幅器、
６は中間周波帯域ろ波器、７はＡ　Ｇ　Ｃ機能を有した
主中間周波増幅器又はリミッタ機能を有した増幅器、８
は復調器を示し、ａは受信機入力端子、ｂは受信機出力
端子を示す。Conventionally, the configuration of this type of receiver is shown in the block diagram of FIG. In the figure, 2 is a front high frequency low noise amplifier, 3 is a frequency converter, 4 is a local oscillator, 5 is a front intermediate frequency amplifier,
6 is an intermediate frequency band filter; 7 is a main intermediate frequency amplifier having an AGC function or an amplifier having a limiter function; 8
indicates a demodulator, a indicates a receiver input terminal, and b indicates a receiver output terminal.

この種の受信機の入力電界制御は、中間周波帯における
主中間周波増幅器７においてＡＧＣ機能を備えるか、リ
ミッタ機能を備えており、復調器８への入力レベルを一
定にしているだけで主中間周波増幅器７のＡＧＣ範囲又
はリミッタ圧縮範囲に頼っていた。In order to control the input electric field of this type of receiver, the main intermediate frequency amplifier 7 in the intermediate frequency band is equipped with an AGC function or a limiter function. It relied on the AGC range of the frequency amplifier 7 or the limiter compression range.

〔発明が解決しようとする問題点Ｊ 従って、受信機に適切な標準受信入力電界よりら高い受
信入力電界が加わった場合、又はＡＧＣ範囲を越える高
い受信入力電界が加わった場合は、復調器８の入力Ｉノ
ベルが変動したり、前置高周波低雑音増幅器２、前置中
間周波増幅器５及び主中間周波増幅器７の歪が増加し、
受信機の雑音が増加するという欠点があった。[Problem to be Solved by the Invention J] Therefore, when a receiving input electric field higher than the appropriate standard receiving input electric field is applied to the receiver, or when a receiving input electric field exceeding the AGC range is applied, the demodulator 8 The input I-novel changes, the distortion of the pre-high frequency low noise amplifier 2, the pre-intermediate frequency amplifier 5 and the main intermediate frequency amplifier 7 increases,
This had the disadvantage of increasing receiver noise.

本発明の目的は、このような欠点を除き、受信入力電界
が過大に入力しないようにして、受信歪および受信雑音
を少くした受信入力制御型受信機を提供することにある
。SUMMARY OF THE INVENTION An object of the present invention is to provide a reception input control type receiver that eliminates such drawbacks, prevents excessive reception input electric fields from being input, and reduces reception distortion and reception noise.

〔問題点を解決するための手段〕[Means for solving problems]

本発明の受信機の構成は、受信入力段に設けられ制御信
号によって入力１／ベルを電子的に減衰させる可変抵抗
減衰器と、この可変抵抗減衰器と接続される受信回路と
、この受信回路の受信入力電界を検出するレベル検出手
段と、このレベル検出手断により前記受信入力電界が所
定レベルより高くなったことを検出した時その入力電界
に応じて減衰量を大きくしその所定レベルより低くなっ
たことを検出した時減衰量を一定レベルに抑えるよう制
御する前記制御信号をつくる制御手段とを備え、前記受
信回路への受信入力電界を所定レベル以下に抑えたこと
を特徴とする。The configuration of the receiver of the present invention includes: a variable resistance attenuator provided in the reception input stage and electronically attenuating input 1/bell according to a control signal; a reception circuit connected to the variable resistance attenuator; and a reception circuit connected to the variable resistance attenuator. level detection means for detecting a received input electric field; and when it is detected that the received input electric field has become higher than a predetermined level due to the level detection step, the amount of attenuation is increased in accordance with the input electric field to make it lower than the predetermined level. and a control means for generating the control signal for controlling the attenuation amount to be suppressed to a certain level when it is detected that the amount of attenuation has occurred, and the receiving input electric field to the receiving circuit is suppressed to a predetermined level or less.

〔実施例Ｊ 次に図面により本発明の詳細な説明する。[Example J Next, the present invention will be explained in detail with reference to the drawings.

第１図は本発明の一実施例のブロック図である。FIG. 1 is a block diagram of one embodiment of the present invention.

図において、１はピンダイオ−・ド（ＰＩＮ　　ＤＩＯ
ＤＥ）を用いた可変抵抗減衰器、２は前置高周波低雑音
増幅器、３は周波数変換器、４は局部発振器、５は前置
中間周波増幅器、６は中間周波帯域ろ波器、７はＡＧＣ
機能まなはリミッタ機能を有した主中間周波増幅器、８
は復調器、９はＡ　ＧＣ電圧検出回路、１０は可変抵抗
減衰器１を制御する制御器、ａは受信機入力端子、ｂは
受信機出力端子を示す。In the figure, 1 is a pin diode (PIN DIO
DE) variable resistance attenuator, 2 is a pre-high frequency low noise amplifier, 3 is a frequency converter, 4 is a local oscillator, 5 is a pre-intermediate frequency amplifier, 6 is an intermediate frequency band filter, 7 is an AGC
Main intermediate frequency amplifier with limiter function, 8
9 is a demodulator, 9 is an AGC voltage detection circuit, 10 is a controller for controlling the variable resistance attenuator 1, a is a receiver input terminal, and b is a receiver output terminal.

この構成において、受信機入力端子ａに入力された受信
入力電界は、可変抵抗減衰器１、前置高周波低雑音増幅
器２を経て周波数変換器３により中間周波数に変換され
る。この変換された中間周波信号は、前置中間周波増幅
器５により増幅され中間周波帯域ろ波器６により帯域外
雑音を除去されて主中間周波増幅器７に入力される。こ
の主中間周波増幅器７のＡＧＣ機能で一定のレベルにな
った信号は、復調器８で復調されベースバンド信号とな
って受信機出力端子すがら出力される。In this configuration, the received input electric field input to the receiver input terminal a is converted to an intermediate frequency by the frequency converter 3 via the variable resistance attenuator 1 and the pre-high frequency low noise amplifier 2. This converted intermediate frequency signal is amplified by a pre-intermediate frequency amplifier 5, has out-of-band noise removed by an intermediate frequency bandpass filter 6, and is input to a main intermediate frequency amplifier 7. The signal, which has reached a certain level through the AGC function of the main intermediate frequency amplifier 7, is demodulated by the demodulator 8 and output as a baseband signal through the receiver output terminal.

従って、受信機入力端子ａに入力された受信入力電界の
変化は、主中間周波増幅器６のもつＡＧｃＢ能の動作範
囲内で一定レベルに保たれ、ＡＧＣ検出回路９により受
信入力電界の変化に応じたＡＧＣ電圧信号Ｃを取り出す
ことができる。制御器１０は、ＡＧＣ電圧信号Ｃのレベ
ルによって可変抵抗減衰器１を構成しているＰＩＮ　　
ＤＩＯＤＥに入力するバイアス電流ｄを供給して制御す
る機能を持つ。すなわち、受信入力電界の変化によって
、可変抵抗減衰器１のＰＩＮ　　ＤＩＯＤＥに入力さ、
れるバイアス電流ｄが自動的に制御され、可変抵抗減衰
器１が任意の減衰特性を持つことになる。Therefore, changes in the received input electric field input to the receiver input terminal a are kept at a constant level within the operating range of the AGcB function of the main intermediate frequency amplifier 6, and the AGC detection circuit 9 responds to changes in the received input electric field. The AGC voltage signal C can be extracted. The controller 10 controls the PIN that constitutes the variable resistance attenuator 1 depending on the level of the AGC voltage signal C.
It has the function of supplying and controlling the bias current d input to DIODE. That is, due to changes in the received input electric field, the input to the PIN DIODE of the variable resistance attenuator 1,
The bias current d applied is automatically controlled, and the variable resistance attenuator 1 has arbitrary attenuation characteristics.

この可変抵抗減衰器１は、第２図の特性図の如く、受信
入力電界Ｐｒを基準としてこの電界Ｐｒよりも高くなれ
ばそれに応じて減衰量が増加し、この電界Ｐｒよりも低
くなれば減衰量をＯとなるように電界Ｐｒを設定してい
る。従って、受信機の歪が増加を始める入力電界をＰｒ
とすれば、最大可変減衰量まで受信機の特性を劣化する
ことなく、受信機のフェードマージンを増加することが
できる。As shown in the characteristic diagram of FIG. 2, this variable resistance attenuator 1 has a reception input electric field Pr as a reference, and when the electric field Pr becomes higher, the attenuation amount increases accordingly, and when it becomes lower than this electric field Pr, the attenuation amount increases accordingly. The electric field Pr is set so that the amount is O. Therefore, Pr
If so, the fade margin of the receiver can be increased up to the maximum variable attenuation amount without deteriorating the characteristics of the receiver.

〔発明の効果〕〔Effect of the invention〕

以上説明したように、本発明は、ＰＩＮ　　ＤＩＯＤＥ
を用いて減衰器を構成ｌ−て受信機入力部に設置し、そ
のバイアス電流を受信入力電界検出によるＡ　Ｇ　Ｃ′
、を圧によって制御することにより、その減衰器を電子
的に減衰量を可変することができる。そのため受信入力
電界の変化に対し可変抵抗減衰器の減衰特性を、所定入
力電界Ｐｒよりも高いときそれに応じて減衰量が増加し
その電界Ｐｒよりも低いときＸ表置を０となるようにす
れば、最大可変減衰量まで受信機の特性を劣化すること
なく、受信機のフェードマージンを増加することができ
る。また、伝搬距離が非常に短く受信入力電界が上昇す
るような場合にも、自動的に規定の擦準入力電界で受信
機を正常に動作させることができる。As explained above, the present invention provides PIN DIODE
An attenuator is constructed using l- and installed at the receiver input section, and its bias current is converted to A G C' by detecting the received input electric field.
By controlling , by pressure, the amount of attenuation of the attenuator can be electronically varied. Therefore, the attenuation characteristics of the variable resistance attenuator with respect to changes in the receiving input electric field are set such that when the input electric field is higher than a predetermined input electric field Pr, the attenuation amount increases accordingly, and when the electric field is lower than the electric field Pr, the X expression becomes 0. For example, the fade margin of the receiver can be increased up to the maximum variable attenuation amount without deteriorating the receiver characteristics. Further, even when the propagation distance is very short and the received input electric field increases, the receiver can automatically operate normally with a specified standard input electric field.

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

第１図は本発明の一実施例の受信入力電界自動制御受信
機のブロック図、第２図は第１図の可変抵抗減衰器の受
信入力電界増加に対する可変減衰量の特性図、第３図は
従来の受信機の一例のプロ・ツク図を示す。 １・・・可変抵抗減衰器、２・・・前置高周波低雑音増
幅器、３・・・周波数変換器、４・・・局部発振器、５
・・・前置中間周波増幅器、６・・・中間周波帯域ろ波
器、７・・・主中間周波増幅器、８・・・復調器、９・
・・ＡＧＣ電圧検出回路、１０・・・制御回路。 ■ 受信Ｘカ電Ｗ−贈Fig. 1 is a block diagram of a receiving input electric field automatic control receiver according to an embodiment of the present invention, Fig. 2 is a characteristic diagram of the variable attenuation amount with respect to an increase in the receiving input electric field of the variable resistance attenuator shown in Fig. 1, and Fig. 3 is a block diagram of a receiving input electric field automatic control receiver according to an embodiment of the present invention. shows a schematic diagram of an example of a conventional receiver. DESCRIPTION OF SYMBOLS 1... Variable resistance attenuator, 2... Pre-high frequency low noise amplifier, 3... Frequency converter, 4... Local oscillator, 5
... Pre-intermediate frequency amplifier, 6... Intermediate frequency bandpass filter, 7... Main intermediate frequency amplifier, 8... Demodulator, 9.
...AGC voltage detection circuit, 10...control circuit. ■ Receive X-power W-gift

Claims (1)

【特許請求の範囲】[Claims] 受信入力段に設けられ制御信号によつて入力レベルを電
子的に減衰させる可変抵抗減衰器と、この可変減衰器と
接続される受信回路と、この受信回路の受信入力電界を
検出するレベル検出手段と、このレベル検出手段により
前記受信入力電界が所定レベルより高くなったことを検
出した時その入力電界に応じて減衰量を大きくしその所
定レベルより低くなったことを検出した時減衰量を一定
レベルに抑えるよう制御する前記制御信号をつくる制御
手段とを備え、前記受信回路への受信入力電界を所定レ
ベル以下に抑えたことを特徴とする受信機。A variable resistance attenuator provided in the receiving input stage and electronically attenuating the input level in accordance with a control signal, a receiving circuit connected to the variable attenuator, and a level detection means for detecting the receiving input electric field of the receiving circuit. When this level detection means detects that the received input electric field has become higher than a predetermined level, the attenuation amount is increased according to the input electric field, and when it is detected that the received input electric field has become lower than the predetermined level, the attenuation amount is kept constant. a control means for generating the control signal to suppress the received electric field to the receiving circuit to a predetermined level or less.