JPS6359108A - Bias circuit - Google Patents

Bias circuit

Info

Publication number
JPS6359108A
JPS6359108A JP61204204A JP20420486A JPS6359108A JP S6359108 A JPS6359108 A JP S6359108A JP 61204204 A JP61204204 A JP 61204204A JP 20420486 A JP20420486 A JP 20420486A JP S6359108 A JPS6359108 A JP S6359108A
Authority
JP
Japan
Prior art keywords
bias circuit
impedance
resistor
distributed constant
frequency
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
Application number
JP61204204A
Other languages
Japanese (ja)
Other versions
JPH0577211B2 (en
Inventor
Kiyoharu Kiyono
清春 清野
Sunao Takagi
直 高木
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Electric Corp
Original Assignee
Mitsubishi Electric Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Mitsubishi Electric Corp filed Critical Mitsubishi Electric Corp
Priority to JP61204204A priority Critical patent/JPS6359108A/en
Publication of JPS6359108A publication Critical patent/JPS6359108A/en
Publication of JPH0577211B2 publication Critical patent/JPH0577211B2/ja
Granted legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H03ELECTRONIC CIRCUITRY
    • H03FAMPLIFIERS
    • H03F3/00Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
    • H03F3/60Amplifiers in which coupling networks have distributed constants, e.g. with waveguide resonators
    • H03F3/605Distributed amplifiers
    • H03F3/607Distributed amplifiers using FET's

Abstract

PURPOSE:To obtain a high impedance characteristic over a broad band by forming a low pass filter by plural distributed constant lines having a high characteristic impedance and plural capacitors and connecting a resistor in series with at least one of the capacitors. CONSTITUTION:Distributed constant lines 8, 17 and capacitors 9, 16 form a low pass filter in a bias circuit 10 and a resistor 15 is connected in series with the capacitor 16. The length of the distributed constant lines 8, 17 is selected to be 1/8 wavelength with respect to the frequency (f) and the characteristic impedance is selected to be Z, then the impedance ZA viewing the bias circuit 10 from a point A is nearly infinity OMEGA with respect to the frequency (f). Moreover, the impedance ZA is expressed as ZA=Z<2>/R ohms with respect to a frequency 2f, where R is a resistance of the resistor 15. In selecting the characteristic impedance of the distributed constant line 17 higher, the impedance ZA is a larger value also with respect to the frequency 2f.

Description

【発明の詳細な説明】 〔産業上の利用分野〕 この発明は通信、レーダ等に用いられる超広帯域増幅器
、とくに分布型増幅器に用いられるバイアス回路に関す
るものである。
DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to ultra-wideband amplifiers used in communications, radar, etc., and particularly to bias circuits used in distributed amplifiers.

〔従来の技術〕[Conventional technology]

第4図はIEEE Transaction on M
ierow’ave The。
Figure 4 shows IEEE Transaction on M
yellow'ave The.

−ry and Techniques、 Vol、 
MTT−32,No、 12. December19
84、 p1705に示された従来のバイアス回路を用
いた分布型増幅器の構成図である。上記文献中では6個
の単位FETを用いた場合;こつぃて示しているが、こ
こでは説明を簡単にするために3個の単位FETの場合
について示している。
-ry and Techniques, Vol.
MTT-32, No, 12. December19
84, p1705 is a configuration diagram of a distributed amplifier using a conventional bias circuit. In the above-mentioned document, a case is shown in which six unit FETs are used; however, in order to simplify the explanation, a case in which three unit FETs are used is shown here.

この図において(1)は単位FET、(2+はこの単位
F E T (]、)のゲート間を接続する伝送線路、
(3)は同じく単位F E T (11のドレイン間を
接続する伝送線路、(4)は終端抵抗、(5)は単位F
 E T (1)のゲートに直流バイアスを印加するた
めのゲートバイアス抵抗、(6)は直流阻止コンデンサ
、(7)は所望のインピーダンスを得るためのコンデン
サ、(8)は分布定数線路、(9)はコンデンサ、00
)はこの分布定数線路(8)とコンデンサ(9)からな
るバイアス回路、 (11)は入力端子、 (12)は
出力端子、 (13)はゲートバイアス端子、 (14
)はドレインパノアス端子である。
In this figure, (1) is a unit FET, (2+ is a transmission line connecting the gates of this unit FET (],),
(3) is the same unit F
E T (1) A gate bias resistor for applying a DC bias to the gate, (6) a DC blocking capacitor, (7) a capacitor for obtaining a desired impedance, (8) a distributed constant line, (9) ) is a capacitor, 00
) is a bias circuit consisting of this distributed constant line (8) and a capacitor (9), (11) is an input terminal, (12) is an output terminal, (13) is a gate bias terminal, (14)
) is the drain panoass terminal.

直流阻止コンデンサ(6)の容量はマイクロ波帯で十分
小さなリアクタンスになるように選ばれており、ゲート
バイアス抵抗(5)は増幅器特性への影響が小さくなる
ように高抵抗に選ばれている。また。
The capacitance of the DC blocking capacitor (6) is selected so as to have a sufficiently small reactance in the microwave band, and the gate bias resistor (5) is selected to have a high resistance so as to have a small influence on the amplifier characteristics. Also.

終端抵抗(4)は広帯域にわたって入力、:、、IA1
子(11)および出力端子(12)のVSWRの改善を
図るために用いられており、はぼ50Ωに選ばれている
The terminating resistor (4) inputs over a wide band: , IA1
It is used to improve the VSWR of the terminal (11) and the output terminal (12), and is selected to be approximately 50Ω.

以上のように構成された分布型増幅器において。In the distributed amplifier configured as above.

ゲートバイアス端子(13)とドレインバイアス端子(
14)とからそれぞれ直流バイアスを印加することによ
り、各単位F E T (11が動作状態となる。この
ような状態において、入力端子(11)からマイクロ波
が入射した場合、マイクロ波は各単位F E T (1
)にほぼ等しく分配される。分配されたマイクロ波は各
単位F E T (11で増幅され、出力端子(12)
に到達する。
Gate bias terminal (13) and drain bias terminal (
By applying a DC bias from 14) to each unit, each unit FET (11) becomes operational.In such a state, when microwaves are incident from the input terminal (11), the microwaves FET (1
) is distributed approximately equally. The distributed microwaves are amplified by each unit FET (11) and sent to the output terminal (12).
reach.

−fflにこの種の増幅器は1オクタ一ブ以上の広帯域
増幅器に適した構造である。これに用いるバイアス回路
α0)は広帯域にわたって増幅器特性に影響を与えない
ように高インピーダンス特性を有するものが必要となる
-ffl This type of amplifier has a structure suitable for a wideband amplifier of one octave or more. The bias circuit α0) used for this needs to have high impedance characteristics so as not to affect the amplifier characteristics over a wide band.

この図に示すバイアス回路001において分布定数線路
(8)の特性インピーダンスをZ、長さを1とし。
In the bias circuit 001 shown in this figure, the characteristic impedance of the distributed constant line (8) is Z and the length is 1.

コンデンサ(9)の容量を十分大きく選べば、第4図の
A点からバイアス回路αω側を見たインピーダンスZ^
は第(1)式で与えられる。
If the capacitance of the capacitor (9) is selected to be sufficiently large, the impedance Z^ when looking at the bias circuit αω side from point A in Figure 4
is given by equation (1).

Z  = Z tan−”−’−’−(11八    
     λ ここでλは波長である。
Z = Z tan-”-'-'-(118
λ where λ is the wavelength.

分布定数線路(8)の長さIをある周波数fに対して一
波長に選んだ場合t lAはOO(Ω)となる。しかし
、2fに対してはzAは0(Ω)となってしまう。
When the length I of the distributed constant line (8) is selected to be one wavelength for a certain frequency f, tlA becomes OO(Ω). However, for 2f, zA becomes 0 (Ω).

〔発明が解決しようとする問題点〕[Problem that the invention seeks to solve]

従来の広帯域型増幅器、とくに分布型増幅器に用いられ
るバイアス回路α0)は以上のように構成されているの
で、ある周波数に対しては高インピーダンス特性を有す
るが、2倍の周波数に対しては低インピーダンス特性と
なる。従って、2倍の周波数に対しては第4図のA点で
マイクス波的に短絡されるため、出力端子(12)にお
けるVSWRは非常に劣化してしまうとともに平担な利
得特性が得られない問題点があった。
The bias circuit α0) used in conventional broadband amplifiers, especially distributed amplifiers, is configured as described above, so it has a high impedance characteristic at a certain frequency, but a low impedance characteristic at twice the frequency. It becomes an impedance characteristic. Therefore, for twice the frequency, the microphone wave is short-circuited at point A in Fig. 4, so the VSWR at the output terminal (12) deteriorates significantly and a flat gain characteristic cannot be obtained. There was a problem.

この発明は上記のような問題点を解消するためになされ
たもので、広帯域増幅器の増幅特性に影響を与丸る乙と
なく、各単位F E T (11に所望の直流バイアス
を印加するためのバイアス回路を得ることを目的とする
This invention was made in order to solve the above-mentioned problems, and it is possible to apply a desired DC bias to each unit FET (11) without affecting the amplification characteristics of the wideband amplifier. The purpose is to obtain a bias circuit for

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

この発明に係わるバイアス回路は高特性インピーダンス
を有する複数個の分布定数線路と複数個のコンデンサと
で低域通過フィルタを形成し、かつ、上記コンデンサの
少なくとも1個に直列に抵抗を接続しtこ構成にしたも
のである。
The bias circuit according to the present invention includes a low-pass filter formed by a plurality of distributed constant lines having high characteristic impedance and a plurality of capacitors, and a resistor connected in series with at least one of the capacitors. It is structured as follows.

〔作用〕[Effect]

この発明におけるバイアス回路は広帯域にわtこって高
インピーダンス特性を得ることにより、バイアス回路の
増幅器特性への影響を小さくする。
The bias circuit according to the present invention has high impedance characteristics over a wide band, thereby reducing the influence of the bias circuit on amplifier characteristics.

〔発明の実施例〕[Embodiments of the invention]

以下、この発明の一実施例を図について説明する。第1
図はこの発明の一実施例を用いた分布型増幅器の構成図
であり、この図において(10)はこの発明要点をなす
バイアス回路でこのバイアス回路aO+は分布定数線路
+81. (17)とコンデンサ(91,(16)とで
低域通過フィルタを形成し、しかもコンデンサ(16)
には直列に抵抗(15)が直列に接続された構成である
。なおこのバイアス回路以外の構成は第4図に示す従来
の回路と同様なものである。
An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure is a block diagram of a distributed amplifier using an embodiment of the present invention. In this figure, (10) is a bias circuit which is the essential point of this invention, and this bias circuit aO+ is a distributed constant line +81. (17) and the capacitor (91, (16)) form a low-pass filter, and the capacitor (16)
A resistor (15) is connected in series with the resistor (15). Note that the configuration other than this bias circuit is similar to the conventional circuit shown in FIG.

上記コンデンサ(16)の容量は周波数fに対して比較
的大きなりアクタンスを示し、2fに対しては小さなリ
アクタンスを示すように適当な値に選ばれている。また
、コンデンサ(9)はfに対して十分小さなリアクタン
スを示すような容量に選ばれている。
The capacitance of the capacitor (16) is selected to be an appropriate value so that it exhibits a relatively large actance with respect to the frequency f and a small reactance with respect to 2f. Further, the capacitor (9) is selected to have a capacitance that exhibits a sufficiently small reactance with respect to f.

分布定数線路(81,(17)の長さをfに対して4波
長に選び、特性インピーダンスをZに選んだ場合。
When the length of the distributed constant line (81, (17) is selected to be 4 wavelengths for f, and the characteristic impedance is selected to be Z.

図のA点からバイアス回路頭側を見たインピーダンス2
^はfに対してほぼoO(Ω)となる。また、2fに対
してはZA= Z2/ I’t (Ω)となる。たf!
シ、Rは抵抗(15)の抵抗値である。
Impedance 2 when looking at the head side of the bias circuit from point A in the diagram
^ becomes approximately oO (Ω) with respect to f. Further, for 2f, ZA=Z2/I't (Ω). Ta f!
C and R are the resistance values of the resistor (15).

ここで分布定数線路(17)の特性インピーダンスを高
く選ぶことにより、2fに対してもZAは大きな値とな
る。
By selecting a high characteristic impedance of the distributed constant line (17), ZA becomes a large value even for 2f.

従って、f〜2fにわたってA点からバイアス回路頭側
を見たインピーダンスZdj高インピーダンス特性とな
る。
Therefore, the impedance Zdj seen from point A toward the head of the bias circuit has a high impedance characteristic over f to 2f.

このバイアス回路α0)はマイクロ波集積回路技術を用
いることにより、容易に実現できる回路構成である。ま
た、モノリシック集積回路技術を用いればバイアス回路
aolを含む分布型増幅器全体を1個の半導体基板上に
実現することが可能である。
This bias circuit α0) has a circuit configuration that can be easily realized by using microwave integrated circuit technology. Further, by using monolithic integrated circuit technology, it is possible to realize the entire distributed amplifier including the bias circuit aol on one semiconductor substrate.

なお、上記実施例では分布定数を2路(8)と(16)
の特性インピーダンスおよび長さが同一の場合について
示したが、異なっていても良い。また、第2図に示すよ
うにバイアス回路−の構成素子数を増やしたものであっ
ても良い。さらに、第3図に示すようにこのバイアス回
路α切は各単位F E T [1)のソースに抵抗(1
5)とコンデンサ(16)とを装荷して単一電源で動作
する分布型増幅器に使用しても良い。
In addition, in the above example, the distribution constant is divided into two paths (8) and (16).
Although the case where the characteristic impedance and length of are the same is shown, they may be different. Further, as shown in FIG. 2, the number of constituent elements of the bias circuit may be increased. Furthermore, as shown in FIG.
5) and a capacitor (16) may be used in a distributed amplifier that operates from a single power supply.

以上は分布型増幅器にバイアス回路001を用いた場合
について説明したが帰還型増幅器等、広帯域増幅器であ
れば全てに適用できるものである。
Although the case where the bias circuit 001 is used in a distributed amplifier has been described above, it can be applied to any wideband amplifier such as a feedback amplifier.

〔発明の効果〕〔Effect of the invention〕

以上のように、この発明のバイアス回路は高特性インピ
ーダンスを有する複数個の分布定数線路と複数個のコン
デンサとで低域通過フィルタを形成し、かつ、コンデン
サの少なくとも1個に直列に抵抗を接続した構成となっ
ているtこめ、広帯域にわたって高インピーダンス特性
が得られろ。従って、このようなバイアス回路を分布型
増幅器に用いた場合、広帯域にわたってバイアス回路の
増幅器特性への影響が小さくなるため、低vswrt。
As described above, the bias circuit of the present invention forms a low-pass filter with a plurality of distributed constant lines having high characteristic impedance and a plurality of capacitors, and a resistor is connected in series with at least one of the capacitors. Because of this configuration, high impedance characteristics can be obtained over a wide band. Therefore, when such a bias circuit is used in a distributed amplifier, the influence of the bias circuit on the amplifier characteristics over a wide band is reduced, resulting in a low vswrt.

平担な利得特性等を有する広帯域増幅器を実現できる。A wideband amplifier having flat gain characteristics etc. can be realized.

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

第1図はこの発明の一実施例によるバイアス回路を用い
た分布型増幅器の構成図、第2図はこの発明の他の実施
例のバイアス回路の構成図、第3図はこのバイアス回路
を単一電源で動作する分布型増幅器に適用した場合の構
成図、第4図は従来のバイアス回路を用いた分布型増幅
器の構成図である。 これらの図において+11は単位F E T 、 (2
+、 (31は伝送線路、(4)は終端抵抗、(5)は
ゲーI・バイアス抵抗、(6)は直流阻止コンデンサ、
 (71,(91,(16)はコンデンサ、 +81.
 (17)は分布定数線路、aO)はバイアス回路、 
(11)は入力端子、 (12)は出力端子、 (13
)ハ’y’  I・/<イアス端子、 (14)はドレ
インバイアス端子、 (15)は抵抗である。 なお2図中、同一符号は同一、又は相当部分を示す。
FIG. 1 is a block diagram of a distributed amplifier using a bias circuit according to one embodiment of the present invention, FIG. 2 is a block diagram of a bias circuit according to another embodiment of the present invention, and FIG. 3 is a simplified diagram of this bias circuit. FIG. 4 is a block diagram of a distributed amplifier using a conventional bias circuit. In these figures, +11 is the unit F ET , (2
+, (31 is a transmission line, (4) is a terminating resistor, (5) is a gate I/bias resistor, (6) is a DC blocking capacitor,
(71, (91, (16) are capacitors, +81.
(17) is a distributed constant line, aO) is a bias circuit,
(11) is the input terminal, (12) is the output terminal, (13
) H'y'I/<Ias terminal, (14) is a drain bias terminal, and (15) is a resistor. Note that in the two figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

【特許請求の範囲】[Claims] 広帯域増幅器に用いられるバイアス回路において、複数
個の高特性インピーダンスを有する分布定数線路と複数
個のコンデンサとで低域通過フィルタを形成し、かつ、
上記コンデンサのうち少なくとも1個のコンデンサに直
列に抵抗を接続したことを特徴とするバイアス回路。
In a bias circuit used in a wideband amplifier, a low-pass filter is formed by a plurality of distributed constant lines having high characteristic impedance and a plurality of capacitors, and
A bias circuit characterized in that a resistor is connected in series to at least one of the capacitors.
JP61204204A 1986-08-28 1986-08-28 Bias circuit Granted JPS6359108A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP61204204A JPS6359108A (en) 1986-08-28 1986-08-28 Bias circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP61204204A JPS6359108A (en) 1986-08-28 1986-08-28 Bias circuit

Publications (2)

Publication Number Publication Date
JPS6359108A true JPS6359108A (en) 1988-03-15
JPH0577211B2 JPH0577211B2 (en) 1993-10-26

Family

ID=16486556

Family Applications (1)

Application Number Title Priority Date Filing Date
JP61204204A Granted JPS6359108A (en) 1986-08-28 1986-08-28 Bias circuit

Country Status (1)

Country Link
JP (1) JPS6359108A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02104115A (en) * 1988-10-13 1990-04-17 Mitsubishi Electric Corp Bias circuit

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60233912A (en) * 1984-04-16 1985-11-20 レイセオン カンパニ− Distributed amplifier

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60233912A (en) * 1984-04-16 1985-11-20 レイセオン カンパニ− Distributed amplifier

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02104115A (en) * 1988-10-13 1990-04-17 Mitsubishi Electric Corp Bias circuit

Also Published As

Publication number Publication date
JPH0577211B2 (en) 1993-10-26

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