KR20070092356A - Wide-band low noise amplifier - Google Patents

Abstract

A wide-band low noise amplifier is provided to reduce a power consumption of the LNA by parallel-coupling a component gate LNA(Low Noise Amplifier) with a common source LNA. A wide-band low noise amplifier includes a common gate LNA and a common source LNA. The common gate LNA amplifies a signal from an input terminal and outputs the amplified result through an output terminal. The common source LNA is parallel-coupled with the common gate LNA and amplifies a signal from an input terminal to output the amplified result through an output terminal. A pair of common gate LNAs(800) amplify signals from two input terminals and output the amplified result through two output terminals. A pair of resistors supply bias voltages to the common gate LNAs. A pair of common source LNAs(810) are parallel-coupled with the common gate LNAs. The common source LNAs amplify the signals from two input terminals and outputs the amplified result through two output terminals.

Description

Wide-band low noise amplifier

1 is a circuit diagram showing the configuration of a common source low noise amplifier having a resistance feedback;

2 is a circuit diagram showing a configuration of a common gate low noise amplifier;

3 is a circuit diagram showing a configuration of a common source low noise amplifier having a drain feedback;

4 is a circuit diagram showing a configuration of a common source low noise amplifier having a resistance feedback with reduced noise;

5 is a circuit diagram showing a configuration of a low noise amplifier boosting mutual conductance;

6 is a circuit diagram illustrating a configuration of a common gate low noise amplifier in which capacitors are cross-coupled;

7 is a circuit diagram showing the configuration of a common gate hybrid low noise amplifier having a resistance feedback;

8 is a block diagram showing the configuration of a low noise amplifier of the present invention;

9 is a circuit diagram showing a configuration of a first embodiment of a low noise amplifier of the present invention;

10 is a circuit diagram showing a configuration of a second embodiment of a low noise amplifier of the present invention;

11 is a circuit diagram showing a configuration of a third embodiment of a low noise amplifier of the present invention;

12 is a circuit diagram showing a configuration of a fourth embodiment of a low noise amplifier of the present invention;

13 is a circuit diagram showing a configuration of a fifth embodiment of the low noise amplifier of the present invention;

14 is a circuit diagram showing a configuration of a first embodiment in which the low noise amplifier of the present invention is configured differentially;

15 is a circuit diagram showing a configuration of a second embodiment in which the low noise amplifier of the present invention is configured differentially;

16 is a circuit diagram showing a configuration of a third embodiment in which the low noise amplifier of the present invention is configured differentially;

17 is a circuit diagram showing a configuration of a fourth embodiment in which the low noise amplifier of the present invention is configured differentially;

18 is a circuit diagram showing the configuration of the fifth embodiment in which the low noise amplifier of the present invention is configured differentially.

The present invention relates to a wideband low noise amplifier for use in amplifying a wideband signal.

More particularly, the present invention relates to a broadband low noise amplifier having a low power consumption, easy matching to a wide band, low noise and high linearity by combining a common gate low noise amplifier and a common source low noise amplifier in parallel.

In general, low noise amplifiers are widely used to amplify a low level noise input signal received through an antenna in a receiver.

In particular, a television receiver employs a wideband low noise amplifier capable of amplifying an input signal having a very wide frequency band of 45 to 860 MHz.

In designing a low noise amplifier, a low noise amplifier capable of realizing wide-band input matching characteristics is divided into a common source low noise amplifier with a resistive feedback and a common gate low noise amplifier (Common) Gate Low Noise Amplifier and Common Source Low Noise Amplifier With Common Drain Feedback.

Based on the three broadband low noise amplifiers described above, a common source low noise amplifier having a resistance feedback with reduced noise is a wideband low noise amplifier having improved input matching characteristics, noise characteristics, and linearity performance. Feedback Low Noise Amplifier With Noise Canceling Technique, Gm-Boosted Common Gate Low Noise Amplifier with mutual conductance boost, Capacitor Cross-Coupled Common Gate Low Noise Amplifier And the Shunt-Feedback & Common Gate Hybrid Low Noise Amplifier having resistance feedback are known.

In such a low noise amplifier, it is very important to be able to easily match the broadband, low power consumption, low noise and high linear characteristics.

It is therefore an object of the present invention to provide a wideband low noise amplifier having low power consumption, easy matching with wide bandwidth, and low noise and high linearity.

According to the broadband low noise amplifier of the present invention having such a purpose, a common gate low noise amplifier and a common source low noise amplifier are combined and configured in parallel.

The common gate low noise amplifier amplifies a signal of an input terminal with an NMOS transistor which is a common gate amplifier, and a current mirror amplifies the signal amplified by the common gate amplifier to output the output terminal.

In the common source low noise amplifier, a capacitor separates the bias from the common gate low noise amplifier and passes only an AC signal, and the common source amplifier amplifies the AC signal passing through the capacitor and outputs the output terminal.

Therefore, the broadband low noise amplifier of the present invention comprises: a common gate low noise amplifier for amplifying a signal of an input terminal and outputting it to an output terminal; And a common source low noise amplifier connected in parallel to the common gate low noise amplifier and amplifying a signal of an input terminal and outputting the signal to an output terminal.

In addition, the broadband low noise amplifier of the present invention can be configured as a differential type, a pair of common gate low noise amplifier to amplify the signals of the two input terminals and output to the two output terminals, respectively; And a pair of common source low noise amplifiers connected to the pair of common gate low noise amplifiers in parallel and amplifying signals of two input terminals and outputting the two output terminals to two output terminals, respectively. .

The common gate low noise amplifier; A common gate amplifier for amplifying the signal at the input terminal; A current source for supplying a bias to the common gate amplifier; And a current mirror which transfers the signal amplified by the common gate amplifier to the output terminal.

The common gate amplifier; An NMOS transistor is characterized by the above-mentioned.

The current source; It is characterized by a high frequency choke reactor.

The current mirror; Amplify the output signal of the common gate amplifier to 1: N and output to the output terminal.

In addition, the current mirror; It is composed of a PMOS transistor, characterized in that the drain is connected to the output terminal.

The common source low noise amplifier; A capacitor separating the common gate low noise amplifier and a bias and passing only an AC signal; And a common source amplifier for amplifying the AC signal passing through the capacitor and outputting the amplified AC signal to the output terminal.

The common source amplifier; The NMOS transistor is characterized in that the drain is connected to the output terminal.

In addition, the common source low noise amplifier of the present invention is characterized in that it further comprises a feedback unit for supplying a bias by feeding back the signal of the output terminal to the common source amplifier.

The feedback unit; A low pass filter for filtering an AC signal from the signal of the output terminal and passing only a DC component; And an operational amplifier for amplifying an output signal of the low pass filter and supplying a bias to the common source amplifier.

The operational amplifier; A bias is supplied to the common source amplifier by amplifying a predetermined reference voltage and an output signal of the low pass filter.

The common source low noise amplifier may further include a capacitor at an output terminal of the operational amplifier, the AC signal being grounded and only a DC signal is supplied to the common source amplifier as a bias.

The apparatus may further include a resistor for preventing a reverse flow of the signal between the operational amplifier and the common source amplifier.

In addition, the feedback unit; And a resistor connected between the attractive force and the output of the common source amplifier.

Hereinafter, a wideband low noise amplifier of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 illustrates a configuration of a common source low noise amplifier with a resistive shunt-feedback having a resistance feedback. Referring to FIG. 1, an input terminal Vin is connected to a gate of an NMOS transistor NM ₁₀₁ , and a source is grounded. The drain of the NMOS transistor NM ₁₀₁ is connected to the output terminal Vout, the load resistor R ₁₀₁ is connected between the power supply terminal V _DD and the drain of the NMOS transistor NM ₁₀₁ , and the NMOS The feedback resistor R ₁₀₂ is connected between the drain of the transistor NM ₁₀₁ and the gate.

In the common source low noise amplifier having the resistance feedback of this configuration, the NMOS transistor NM ₁₀₁ amplifies the signal input to the input terminal Vin and outputs it to the output terminal Vout, which is output to the output terminal Vout. The signal is fed back to the gate of the NMOS transistor NM ₁₀₁ through the feedback resistor R ₁₀₂ , and the input impedance Rs of the input terminal Vin is represented by Equation 1 by the feedback resistor R ₁₀₂ .

Here, g _m101 is the mutual conductance of the NMOS transistor NM ₁₀₁ .

When the value of the input impedance of Equation 1 is set equal to the output impedance of the signal input unit (not shown) connected to the input terminal Vin, the common source low noise amplifier having resistance feedback is a broadband input. It has a matching characteristic.

In addition, considering only noise of the NMOS transistor NM ₁₀₁ , the noise figure NF is represented by Equation 2 below.

는 엔모스 트랜지스터(NM₁₀₁)의 채널 길이가 서브 마이크론 단위일 경우의 잡음계수(noise factor)로서 1＜

＜2이고,

로서,

은 엔모스 트랜지스터(NM₁₀₁)의 드레인과 소스 사이의 전압이 0V일 경우에 상호 컨덕턴스이며, Rs는 입력 임피던스이다.here,

Is a noise factor when the channel length of the NMOS transistor NM ₁₀₁ is in submicron units.

<2,

as,

Is the mutual conductance when the voltage between the drain and the source of the NMOS transistor NM ₁₀₁ is 0V, and Rs is the input impedance.

Therefore, the minimum noise figure that can be obtained in the low noise amplifier of FIG. 1 is 3 ㏈ or more, and when considering the noise index of the load resistor R ₁₀₁ and the feedback resistor R ₁₀₂ , the actual noise The exponent becomes even larger, making it difficult to obtain a noise figure of less than 3 dB.

In addition, the feedback resistor R ₁₀₂ is likely to make the operation of the low noise amplifier unstable, and the output impedance is also reduced by the loop gain, making it difficult to use in a receiver or the like requiring a high output impedance.

2 is a circuit diagram showing the configuration of a common gate low noise amplifier. 2, the NMOS transistor (NM ₂₀₁₎ of the gate is applied with a bias voltage (V _B201), the NMOS transistor (NM ₂₀₁₎ of the source, the input terminal (Vin) and a constant current source (I ₂₀₁₎ is connected do.

A drain of the NMOS transistor NM ₂₀₁ is connected to the output terminal Vout, and a load resistor R ₂₀₁ is connected between the drain of the NMOS transistor NM ₂₀₁ and the power supply terminal V _DD . .

In the common gate low noise amplifier having such a configuration, the NMOS transistor NM ₂₀₁ operates by the bias voltage V _B201 , and the NMOS transistor NM ₂₀₁ receives a signal applied to the source of the NMOS transistor NM ₂₀₁ through the input terminal Vin. The transistor NM ₂₀₁ is amplified and output to the output terminal Vout, and the input impedance Rs of the input terminal Vin is expressed by Equation 3 below.

은 엔모스 트랜지스터(NM₂₀₁)의 상호 컨덕턴스이다.here,

Is the mutual conductance of the NMOS transistor NM ₂₀₁ .

When the value of the input impedance of Equation 3 is set equal to the output impedance of the signal input unit (not shown) connected to the input terminal Vin, the common gate low noise amplifier provides a wide bandwidth input matching characteristic. Will have

In addition, considering only noise of the NMOS transistor NM ₂₀₁ , the noise figure NF is expressed by Equation 4 below.

는 엔모스 트랜지스터(NM₂₀₁)의 채널 길이가 서브 마이크론 단위 일 경우의 잡음계수로서 1＜

＜2이고,

로서,

은 엔모스 트랜지스터(NM₂₀₁)의 상호 컨덕턴스이며,

은 엔모스 트랜지스터(NM₂₀₁)의 드레인과 소스 사이의 전압이 0V일 경우에 상호 컨덕턴스이다.here,

Is the noise coefficient when the channel length of the NMOS transistor NM ₂₀₁ is in submicron units.

<2,

as,

Is the mutual conductance of the NMOS transistor NM ₂₀₁ ,

Is the mutual conductance when the voltage between the drain and the source of the NMOS transistor NM ₂₀₁ is 0V.

Therefore, the minimum noise figure that can be obtained in the common gate low noise amplifier of FIG. 2 is 3 ㏈ or more, and when considering the noise figure of the current source I ₂₀₁ and the feedback resistor R ₂₀₁ , the actual noise figure is even larger. It is difficult to obtain a noise figure of 3 dB or less.

3 is a circuit diagram showing the configuration of a common source low noise amplifier having drain feedback. 3, the NMOS transistor ₍₃₀₁ NM) and of the input terminal (Vin) and a current source (I ₃₀₁₎ connected to the gates, NMOS transistors (NM ₃₀₁₎ of the source is grounded.

Yen, the drain of the MOS transistor (NM ₃₀₁₎ is connected to the output terminal (Vout), it is also a power supply terminal (VDD) and the NMOS transistor (NM ₃₀₁₎ a load resistor (R ₃₀₁₎ to the drain connection.

And the NMOS transistor (NM ₃₀₁₎ the drain of NMOS transistor are feedback connected to the gate of the source is a NMOS transistor (NM ₃₀₁₎ in connected to the gate NMOS transistor (NM ₃₀₂₎ of (NM _302), NMOS transistor A drain of the NM ₃₀₂ is connected to the power supply terminal V _DD .

In the common source low noise amplifier having the drain feedback of this configuration, the NMOS transistor NM ₃₀₁ amplifies the signal input to the input terminal Vin and outputs the output terminal Vout to the output signal of the output terminal Vout. Accordingly, the NMOS transistor NM ₃₀₂ operates so that the power supply of the power supply terminal V _DD is fed back to the gate of the NMOS transistor NM ₃₀₁ through the NMOS transistor NM ₃₀₂ , so that the input impedance of the input terminal Vin is increased. Rs is the same as Equation 5.

및

는 엔모스 트랜지스터(NM₃₀₁)(NM₃₀₂)의 상호 컨덕턴스이다.here,

And

Is the mutual conductance of the NMOS transistor NM ₃₀₁ (NM ₃₀₂ ).

When the value of the input impedance of Equation 5 is set equal to the output impedance of the signal input unit connected to the input terminal Vin, the common source low noise amplifier having the drain feedback has a wide input matching characteristic.

In addition, considering only the noise of the NMOS transistor NM ₃₀₁ and the NMOS transistor NM ₃₀₂ , the noise figure NF is expressed by Equation 6 below.

는 엔모스 트랜지스터(NM₃₀₁)(NM₃₀₂)의 채널 길이가 서브 마이크론 단위일 경우의 잡음계수로서 1＜

＜2이고,

이며,

로서,

및

는 각기 엔모스 트랜지스터(NM₃₀₁)(NM₃₀₂)의 상호 컨덕턴스이며,

및

는 각기 엔모스 트랜지스터(NM₃₀₁)(NM₃₀₂)의 드레인과 소스 사이의 전압이 0V일 경우에 상호 컨덕턴스이다.here,

Is the noise coefficient when the channel length of the NMOS transistor NM ₃₀₁ (NM ₃₀₂ ) is in submicron units, and 1 <

<2,

Is,

as,

And

Are mutual conductances of the NMOS transistors NM ₃₀₁ and NM ₃₀₂ , respectively.

And

Are mutual conductance when the voltage between the drain and the source of the NMOS transistor NM ₃₀₁ (NM ₃₀₂ ) is 0V, respectively.

Equation 6 is simplified to Equation 7.

The gain Av of the common source low noise amplifier having the drain feedback of FIG. 3 is expressed by Equation (8).

Therefore, when considering the actual values of the components constituting the common source low noise amplifier having the drain feedback of FIG. 3, it is difficult to obtain a noise figure of 3 dB or less, and to the noise of the current source I ₃₀₁ and the load resistor R ₃₀₁ . If taken into account, the actual noise figure becomes larger.

In addition, the common source low noise amplifier having the drain feedback of FIG. 3 is likely to operate unstable by the feedback of the common drain, and the output impedance is also reduced by the loop gain, making it difficult to use in a receiver or the like requiring a high output impedance. .

4 is a circuit diagram illustrating a configuration of a common source low noise amplifier having a resistance feedback with reduced noise. Referring to FIG. 4, an input terminal Vin is connected to a gate of an NMOS transistor NM ₄₀₁ (NM ₄₀₂ ) and a gate of a PMOS transistor PM ₄₀₁ , and a source of the NMOS transistor NM ₄₀₁ is grounded. The current source I ₄₀₁ is connected between the source of the PMOS transistor PM ₄₀₁ and the power supply terminal VDD.

The NMOS transistor (NM ₄₀₁₎ and a PMOS transistor (PM ₄₀₁₎ of the drain NMOS transistor (NM ₄₀₁₎ (NM ₄₀₂₎ the gate and the PMOS transistor (PM ₄₀₁₎ through a feedback resistor (R ₄₀₁₎ for the Feedback is connected to the gate.

In addition, the drains of the NMOS transistor NM ₄₀₁ and the PMOS transistor PM ₄₀₁ are connected to the gate of the NMOS transistor NM ₄₀₃ through a capacitor C ₄₀₁ , and the power supply terminal V _{DD is} connected to the resistor R. ₄₀₂ is connected to the gate of the NMOS transistor NM ₄₀₃ .

The yen drain of the MOS transistor (NM ₄₀₃₎ is connected to a power supply terminal (VDD), a source of enmo switch transistor (NM ₄₀₃₎ is connected to the output terminal (Vout), also the output terminal (Vout) and a power supply terminal ( The current source I ₄₀₂ is connected between V _DD ).

And the yen source of the MOS transistor (NM ₄₀₂₎ is grounded, and the drain NMOS transistor through (NM ₄₀₄₎ is connected to the output terminal (Vout), NMOS transistors (NM ₄₀₄₎ a gate bias voltage (V _B401 of ) Is connected to be applied.

In the common source low noise amplifier having the resistance feedback which reduces the noise of such a configuration, the NMOS transistor NM ₄₀₁ and the PMOS transistor PM ₄₀₁ amplify the signal of the input terminal Vin and output it to the drain.

The signal amplified by the NMOS transistor NM ₄₀₁ and the PMOS transistor PM ₄₀₁ is amplified through the NMOS transistor NM ₄₀₃ after passing through the capacitor C401 and output to the output terminal Vout.

The input impedance Rs of the input terminal Vin is determined by the mutual conductance of the NMOS transistor NM ₄₀₁ and the PMOS transistor PM ₄₀₁ as shown in equation (9).

및

는 엔모스 트랜지스터(NM₄₀₁) 및 피모스 트랜지스터 (PM₄₀₁)의 상호 컨덕턴스이다.here,

And

Is the mutual conductance of the NMOS transistor NM ₄₀₁ and the PMOS transistor PM ₄₀₁ .

When the value of the input impedance of Equation 9 is set equal to the output impedance of the signal input unit connected to the input terminal Vin, the low noise amplifier of FIG. 4 has a wide input matching characteristic.

The noise generated by the input matching (the noise caused by the NMOS transistor NM ₄₀₁ and the PMOS transistor PM ₄₀₁ ) is inverted and amplified by the NMOS transistor NM ₄₀₂ and then the NMOS transistor NM ₄₀₄ . Through the output terminal (Vout) through the non-inverted amplification through the NMOS transistor (NM ₄₀₃ ) and then output to the output terminal (Vout) is synthesized.

Therefore, NMOS transistor (NM ₄₀₂₎ is offset from the non-inversion amplified via the inversion noise between the noise and the amplification NMOS transistor (NM _403), but to obtain a low noise figure of about 2.4㏈, the high power consumption There is a problem.

5 is a circuit diagram showing a configuration of a low noise amplifier boosting mutual conductance. Referring to FIG. 5, an input terminal Vin and a current source I ₅₀₁ are connected to a source of the NMOS transistor NM ₅₀₁ . In addition, NMOS transistors, the source of the (NM ₅₀₁₎ is connected to the gate of the NMOS transistor (NM ₅₀₁₎ through the amplifier 501, the NMOS transistor is connected to the output terminal (Vout), the drain of the (NM _501), also The load resistor R ₅₀₁ is connected between the drain of the NMOS transistor NM ₅₀₁ and the power supply terminal V _DD .

(여기서, A는 증폭기(501)의 증폭도이고,

은 엔모스 트랜지스터(NM₅₀₁)의 상호 컨덕턴스이다.)의 값에 의하여 입력단자(Vin)의 입력 임피던스가 결정되며, 그 입력 임피던스의 값을 상기 입력단자(Vin)에 접속되는 신호 입력부의 출력 임피던스와 동일하게 설정하면, 광대역의 입력 매칭특성을 갖게 된다.The low noise amplifier boosting the mutual conductance of such a configuration has a tradeoff relationship between the input matching and the noise figure, so that the input matching characteristic must be sacrificed to some extent in order to obtain a low noise characteristic. In a way to improve the trade-off relationship

(Where A is the amplification degree of the amplifier 501,

Is the mutual conductance of the NMOS transistor NM ₅₀₁ ). The input impedance of the input terminal Vin is determined, and the output impedance of the signal input unit connected to the input terminal Vin is determined by the value of the input impedance Vin. When set equal to, the wide bandwidth input matching characteristic is obtained.

When the low noise amplifier boosting the mutual conductance considers only the noise of the NMOS transistor NM ₅₀₁ , the noise figure NF is expressed by Equation 10 below.

는 엔모스 트랜지스터(NM₅₀₁)의 채널 길이가 서브 마이크론 단위일 경우에 잡음계수로서 1＜

＜2이고,

로서,

은 엔모스 트랜지스터(NM₅₀₁)의 상호 컨덕턴스이며,

은 엔모스 트랜지스터(NM₅₀₁)의 드레 인과 소스 사이의 전압이 0V일 경우에 상호 컨덕턴스이다.here,

Is the noise coefficient when the channel length of the NMOS transistor NM ₅₀₁ is in the submicron unit.

<2,

as,

Is the mutual conductance of the NMOS transistor (NM ₅₀₁ ),

Is the mutual conductance when the voltage between the drain and the source of the NMOS transistor NM ₅₀₁ is 0V.

만큼 감소됨을 알 수 있다.That is, the low noise amplifier boosting the mutual conductance of FIG. 5 is lower than that of the common gate low noise amplifier of FIG. 2.

It can be seen that the decrease.

5 described above is an example of a differential type using a low noise amplifier boosting mutual conductance to configure a common gate low noise amplifier in which the capacitor shown in FIG. 6 is cross-coupled.

Referring to FIG. 6, an input terminal Vin + (Vin−) and a current source I ₆₀₁ (I ₆₀₂ ) are connected to a source of an NMOS transistor NM ₆₀₁ (NM ₆₀₂ ). In addition, NMOS transistors (NM ₆₀₁₎ the source of (NM ₆₀₁₎ and the capacitor (C ₆₀₁₎ (C ₆₀₂₎ to be connected to each gate of the NMOS transistor (NM ₆₀₂₎ (NM ₆₀₁₎ through, NMOS transistor (NM ₆₀₁ The drain of NM ₆₀₂ is connected to the output terminal Vout- (Vout +), and the current source I ₆₀₃ between the drain of the NMOS transistor NM ₆₀₁ (NM ₆₀₂ ) and the power supply terminal V _DD . (I ₆₀₄ ) are respectively connected.

In the common gate low noise amplifier in which such a differential capacitor is cross-coupled, the signal of the input terminal Vin + and Vin- is connected to the gate of the NMOS transistor NM ₆₀₂ and NM ₆₀₁ through the capacitor C ₆₀₁ and C ₆₀₂ . It is applied to operate the NMOS transistor NM ₆₀₂ (NM ₆₀₁ ), and the signal of the input terminal Vin + (Vin-) is amplified through the NMOS transistor NM ₆₀₁ (NM ₆₀₂ ) and the output terminal Vout- Output as (Vout +).

만큼 감소되나, 증폭기(501)의 증폭 이득 A에 의해 더해지는 잡음이 있다.The low-noise amplifier boosting the mutual conductance of FIG. 5 and the common gate low-noise amplifiers of which the capacitor of FIG. 6 is cross-coupled are compared to the common gate low-noise amplifier of FIG. 2 as described above.

Reduced by, but there is noise added by the amplification gain A of the amplifier 501.

(여기서, f₀은 저잡음 증폭기가 증폭하는 신호의 주파수이고, f_t는 이득이 1로 되는 단위 이득 주파수이다.)가 되는 주파수 대역 특히 텔레비전 수상기에 구비되는 튜너부가 텔레비전 방송신호를 수신하는 주파수 대역에서는 3㏈ 이하의 잡음지수를 획득하기는 어렵다.therefore

(Where f ₀ is the frequency of the signal amplified by the low noise amplifier and f _t is the unity gain frequency where the gain is 1). In particular, the frequency band in which the tuner portion provided in the television receiver receives the television broadcast signal. It is difficult to obtain a noise figure of less than 3 dB at.

7 is a circuit diagram showing the configuration of a common gate hybrid low noise amplifier having resistance feedback. Referring to FIG. 7, an input terminal Vin + (Vin−) is connected to a gate of an NMOS transistor NM ₇₀₁ (NM ₇₀₂ ) and a gate of a PMOS transistor PM ₇₀₁ (PM ₇₀₂ ) to form an NMOS. The drains of the transistors NM ₇₀₁ and PMOS transistors PM ₇₀₁ and the drains of the NMOS transistors NM ₇₀₂ and PMOS transistors PM ₇₀₂ are connected to the output terminals Vout- (Vout +). The drain of the MOS transistor NM ₇₀₁ and the PMOS transistor PM ₇₀₁ and the drain of the NMOS transistor NM ₇₀₂ and the PMOS transistor PM ₇₀₂ are connected to each other through the feedback resistor R ₇₀₁ (R ₇₀₂ ). The gates of the MOS transistor NM ₇₀₁ and the PMOS transistor PM ₇₀₁ and the gates of the NMOS transistor NM ₇₀₂ and the PMOS transistor PM ₇₀₂ are respectively connected.

The input terminal Vin- (Vin +) and the constant current source I ₇₀₁ (I ₇₀₂ ) are connected to a source of an NMOS transistor NM ₇₀₁ (NM ₇₀₂ ), and a PMOS transistor PM ₇₀₁ (PM ₇₀₂ ). The input terminal Vin- (Vin +) is connected to the drain of the _C1 ), and the constant current source I ₇₀₃ (I) is connected between the drain of the PMOS transistor PM ₇₀₁ (PM ₇₀₂ ) and the power supply terminal V _DD . ₇₀₃ ) is connected.

(여기서,

은 엔모스 트랜지스터(NM₇₀₁)(NM₇₀₂)의 상호 컨덕턴스이고,

는 피모스 트랜지스터(PM₇₀₁)(PM₇₀₂)의 상호 컨덕턴스이다)의 값에 의해 결정되는 것으로서 입력 임피던스를 상기 입력단자(Vin)에 접속되는 신호 입력부의 출력 임피던스와 동일하게 설정하면, 광대역의 입력 매칭특성을 갖게 된다.The common gate hybrid low noise amplifier having such a resistance feedback is a kind of low noise amplifier boosting the mutual conductance shown in FIG.

(here,

Is the mutual conductance of the NMOS transistor NM ₇₀₁ (NM ₇₀₂ ),

Is determined by the value of the PMOS transistor PM ₇₀₁ (the mutual conductance of the PM ₇₀₂ ). When the input impedance is set equal to the output impedance of the signal input unit connected to the input terminal Vin, a wideband input is obtained. It has a matching characteristic.

Since the common gate hybrid low noise amplifier having the resistance feedback of FIG. 7 can implement input matching as a small current, it is suitable for the case where the power consumption is less than 1 kHz.

In addition, the noise index of the common gate hybrid low noise amplifier having the resistance feedback of FIG. 7 has the same value as that of the common gate low noise amplifier of FIG.

However, there is no trade-off between input matching and noise figure.

8 is a block diagram showing the configuration of a wideband low noise amplifier of the present invention. Referring to FIG. 8, the broadband low noise amplifier of the present invention includes a common gate low noise amplifier 800 and a common source low noise amplifier 810.

The common gate low noise amplifier 800 and the common source low noise amplifier 810 are connected in parallel between the input terminal Vin and the output terminal Vout, and the signal of the input terminal Vin is connected to the common gate low noise amplifier 800. The common source low noise amplifier 810 is amplified and output to the output terminal Vout.

9 is a circuit diagram showing a configuration of a first embodiment of a low noise amplifier of the present invention. Referring to FIG. 9, in the low noise amplifier of the present invention, the common gate low noise amplifier 800 has an input terminal Vin connected to a source and a bias voltage V _B901 applied to a gate to _receive a signal of the input terminal Vin. of the NMOS transistor (NM ₉₀₁₎ and the NMOS transistor current source (I ₉₀₁₎ and a PMOS transistor (PM ₉₀₁ for supplying a bias voltage to the source of the (NM _901), the common gate amplifier 901 for amplifying, PM ₉₀₂ and a current mirror 903 that amplifies the current output to the drain of the NMOS transistor NM ₉₀₁ to 1: N and outputs it to the output terminal Vout.

In the low noise amplifier of the present invention, the common source low noise amplifier 810 includes a capacitor C ₉₀₁ which blocks direct current and passes only an AC signal of the input terminal Vin, a source is grounded, and a drain thereof is output terminal Vout. NMOS transistor NM _{902, which} is a common source amplifier 905, amplifying an AC signal passing through the capacitor C ₉₀₁ and outputting the same to an output terminal Vout, and the NMOS transistor NM ₉₀₂ . It _consists of a resistor (R ₉₀₁ ) for supplying a bias voltage (V _B902 ) to the gate of.

The first embodiment of the broadband low noise amplifier of the present invention configured as described above is input to the input terminal Vin while the operating power is applied to the power supply terminal V _DD and the bias voltages V _B901 and V _B912 are applied. The input signal is amplified by the NMOS transistor NM _{901 which} is the common gate amplifier 901 in the common gate low noise amplifier 800 and output to the drain of the NMOS transistor NM ₉₀₁ .

The signal output to the drain of the NMOS transistor NM ₉₀₁ is output to the output terminal Vout through the PMOS transistor PM ₉₀₁ (PM ₉₀₂ ) of the current mirror 903.

Here, the channel size of the PMOS transistor PM ₉₀₁ and the PMOS transistor PM ₉₀₂ is 1: N, and the signal output to the drain of the NMOS transistor NM ₉₀₁ is amplified to 1: N in the current mirror 903. And output to the output terminal Vout.

In addition, the input signal from the input terminal (Vin), a drain of the NMOS transistor (NM ₉₀₂₎ after being applied yen to the gate of the MOS transistor (NM ₉₀₂₎ through the capacitor (C ₉₀₁₎ of the common source low-noise amplifier 810 amplifies It is output to the output terminal (Vout) through.

(여기서, g_m901은 엔모스 트랜지스터(NM₉₀₁)의 상호 컨덕턴스임)이 되고, 그 입력 임피던스 Rs의 값을 상기 입력단자(Vin)에 접속되는 신호 입력부(도면에 도시되지 않았음)의 출력 임피던스와 동일하게 설정하면, 본 발명의 광대역 저잡음 증폭기는 광대역의 입력 매칭특성을 갖게 된다.In the present invention, the input impedance Rs of the input terminal Vin is similar to the common gate low noise amplifier of FIG.

(Where g _m901 is the mutual conductance of the NMOS transistor NM ₉₀₁ ), and the output impedance of a signal input unit (not shown) connected to the input terminal Vin whose value of the input impedance Rs is connected to the input terminal Vin. When set equal to, the wideband low noise amplifier of the present invention has wideband input matching characteristics.

The gain Av is multiplied by the gain of the current mirror 903 by the gain of the NMOS transistor NM _{901 which} is the common gate amplifier 901 as shown in Equation 11 below, and the NMOS of the common source low noise amplifier 810. The gain of the transistor NM ₉₀₂ is added up.

Where N is the ratio of the channel sizes of the PMOS transistors PM ₉₀₁ (PM ₉₀₂ ) in the current mirror 903, g _m901N and g _m902N are mutual conductances of the NMOS transistors NM ₉₀₁ (NM ₉₀₂ ), R _L is a load resistor connected to the output terminal Vout.

Therefore, according to the present invention, it can be seen that the input signal can be amplified with high gain while having a wide input matching characteristic.

In addition, the present invention has a relatively high linear characteristic because a high gain can be obtained by amplifying the current by the current mirror 903 in amplifying the input signal.

In addition, when considering only the NMOS transistor NM ₉₀₁ (NM ₉₀₂ ) and the PMOS transistor PM ₉₀₁ (PM ₉₀₂ ), the noise figure NF is expressed by Equation 12 below.

이고,

는 엔모스 트랜지스터(NM₉₀₁)(NM₉₀₂) 및 피모스 트랜지스터(PM₉₀₁)(PM₉₀₂)의 채널 길이가 서브 마이크론 단위일 경우에 잡음계수로서 1＜

＜2이며,

로서 g_m901N은 엔모스 트랜지스터(NM₉₀₁)의 상호 컨덕턴스이며, g_do901N은 엔모스 트랜지스터(NM₉₀₁)의 드레인과 소스 사이의 전압이 0V일 경우의 상호 컨덕턴스이며, g_m902N은 엔모스 트랜지스터(NM₉₀₂)의 상호 컨덕턴스이며, g_m902P는 피모스 트랜지스터(PM₉₀₂)의 상호 컨덕턴스이다.here,

ego,

Is the noise coefficient when the channel length of the NMOS transistor NM ₉₀₁ (NM ₉₀₂ ) and the PMOS transistor PM ₉₀₁ (PM ₉₀₂ ) is in submicron units.

<2,

As g _m901N the yen and the transconductance of the MOS transistor (NM _901), g _do901N are NMOS transistors, and the transconductance of when the voltage is 0V between (NM ₉₀₁₎ the drain and source of the, g _m902N is NMOS transistor (NM ₉₀₂ ), and g _m902P is the mutual conductance of the PMOS transistor PM ₉₀₂ .

의 값이

로 스케일링(scaling)됨을 알 수 있다. 여기서,

이고, 통상적으로 N의 값을 3이라고 할 경우에

가 된다.Looking at the first term and the second term of Equation 12, the noise figure of the common gate low noise amplifier of FIG.

Has a value of

It can be seen that it is scaled to. here,

In general, when the value of N is 3

Becomes

가 존재하고, g_m902N이 g_m901N 및 g_m902P에 비하여 상당히 크므로 전체 잡음에 큰 영향을 주지 않아 낮은 전력으로 2㏈ 근처의 잡음 지수를 얻을 수 있다.And the denominator of the last term in

It is present and, g _m902N yi _m901N g and g does not have a significant effect on the total noise in considerably larger than the _m902P to obtain the noise figure of around 2㏈ with low power.

In the present invention, since the drains of the NMOS transistor NM ₉₀₂ and the PMOS transistor PM ₉₀₂ are connected to the output terminal Vout, the output impedance is very high. Therefore yen to the feedback signal of the output terminal (Vout) can supply a bias voltage to the gate of the MOS transistor (NM _902).

10 is a circuit diagram showing the configuration of a second embodiment of a wideband low noise amplifier of the present invention. Referring to FIG. 10, a second embodiment of the low noise amplifier according to the present invention includes a common source low noise amplifier 810 including an NMOS transistor NM _{902 which} is a capacitor C ₉₀₁ and a common source amplifier 905, and an output. the terminal (Vout) having a MOS transistor by yen-rate feedback unit 1000 for supplying a bias voltage to the gate of the (NM ₉₀₂₎ further feeds back a signal.

The feedback unit 1000 has a resistor R ₁₀₀₀ and a capacitor C ₁₀₀₀ connected in series with the output terminal Vout, and a connection point of the resistor R ₁₀₀₀ and the capacitor C ₁₀₀₀ is connected to the operational amplifier OP. It is connected to the non-inverting input terminal (+), the reference voltage (V _REF ) is applied to the inverting input terminal (-) of the operational amplifier (OP). The output terminal of the operational amplifier OP is connected to the gate of the NMOS transistor NM ₉₀₂ through a ground capacitor C ₁₀₀₂ and a resistor R ₁₀₀₂ .

In the second embodiment of the low noise amplifier of the present invention configured as described above, the output signal of the output terminal Vout is connected to the non-inverting input terminal (+) of the operational amplifier OP through the resistor R ₁₀₀₀ and the capacitor C ₁₀₀₀ . Is entered.

Here, the resistor R ₁₀₀₀ and the capacitor C ₁₀₀₀ operate as a low pass filter, and an AC voltage is not input to the non-inverting input terminal (+) of the operational amplifier OP, and only a DC voltage is input.

The reference voltage V _REF is applied to the inverting input terminal (-) of the operational amplifier OP, and the operational amplifier OP is applied to the DC voltage and the inverting input terminal (-) applied to the non-inverting input terminal (+). The amplified reference voltage V _REF is amplified and output.

The output signal of the operational amplifier OP is fed back to the gate of the NMOS transistor NM ₉₀₂ through the ground capacitor C ₁₀₀₂ and the resistor R ₁₀₀₂ .

이하의 주파수를 가지는 신호를 차단하게 된다.In this case, the ground capacitor C ₁₀₀₂ serves to ground an AC component, and only the DC component is fed back to the gate of the NMOS transistor NM ₉₀₂ . The resistor R ₁₀₀₂ prevents the signal from flowing backward to the output terminal of the operational amplifier OP, and the capacitor C ₉₀₁ controls the bias of the common gate low noise amplifier 800 and the common source low noise amplifier 810. It operates for the DC blocking to separate each other, and the capacitor (C ₉₀₁ ) and the resistor (R ₁₀₀₂ ) acts as a high pass filter

Signals having the following frequencies are blocked.

In the present invention, the feedback unit 1000 includes a feedback resistor R ₁₁₀₁ connected between the drain and the gate of the NMOS transistor NM ₉₀₂ as in the third embodiment shown in FIG. 11. The unit 1000 may be configured.

As described above, since the broadband low noise amplifier of the present invention can obtain a low noise figure near 2 kHz as described above, the current source I ₉₀₁ is similar to the fourth and fifth embodiments shown in FIGS. 12 and 13. May be configured using a high frequency choke inductor (L). Even when a bias is supplied to the high frequency choke inductor L, a low noise figure of 3 dB or less can be obtained.

On the other hand, the broadband low noise amplifier of the first to fifth embodiments of the present invention as described above may be configured to be differential as shown in Figs.

In the differential configuration, a pair of common source low noise amplifiers 810 and 810a are connected in parallel to a pair of common gate low noise amplifiers 800 and 800a, respectively.

The bias voltage V _B1400 is applied to the gates of the NMOS transistors NM ₉₀₁ and NM _901a of the pair of common gate low noise amplifiers 800 through the resistors R ₁₄₀₀ and R ₁₄₀₁ . Connect. In addition, a capacitor C ₁₄₀₀ is connected between the connection point of the gate of the resistor R ₁₄₀₀ and the NMOS transistor NM ₉₀₁ and the source of the NMOS transistor NM _901a , and the resistor R _1400a and the _NMOS transistor NM. _A capacitor C ₁₄₀₁ is connected between the connection point of the gate of _901a and the source of the NMOS transistor NM ₉₀₁ .

The resistor R ₁₄₀₀ and R ₁₄₀₁ serve to supply the bias voltage V _B1400 to the gate of the NMOS transistor NM ₉₀₁ and NM _901a .

The capacitors C ₁₄₀₀ and C ₁₄₀₁ boost the mutual conductance of the NMOS transistors NM ₉₀₁ and NM _901a to increase the gain and improve the noise figure.

On the other hand, while the present invention has been shown and described with respect to specific preferred embodiments, various modifications and changes of the present invention without departing from the spirit or field of the invention provided by the claims below It can be easily understood by those skilled in the art.

As described in detail above, the present invention can implement a wideband low noise amplifier having a wideband input matching characteristic using only the advantages of the common gate low noise amplifier and the common source low noise amplifier, and provides low noise, high gain, and high linearity with low power. You can get it.

In addition, the present invention is suitable for the application of a CMOS circuit, and can be configured as a wideband low noise amplifier having a single input and a single output as well as a differential wideband low noise amplifier having two inputs and two outputs. The amplified broadcast signal can be amplified in a low noise over a wide band.

In addition, the present invention can be easily used in a portable receiving device due to low power consumption.

Claims (16)

A common gate low noise amplifier for amplifying a signal of an input terminal and outputting the signal to an output terminal; And And a common source low noise amplifier connected in parallel to the common gate low noise amplifier and amplifying a signal of an input terminal and outputting the signal to an output terminal. A pair of common gate low noise amplifiers amplifying signals of two input terminals and outputting the two output terminals, respectively; A pair of resistors for supplying a bias voltage to the pair of common gate low noise amplifiers; And And a pair of common source low noise amplifiers connected to the pair of common gate low noise amplifiers in parallel and amplifying signals of two input terminals and outputting the two output terminals to two output terminals, respectively. 3. The apparatus of claim 2, further comprising: between the pair of common gate low noise amplifiers; And a capacitor for increasing the mutual conductance of the input transistor. 3. The device of claim 1 or 2, wherein the common gate low noise amplifier; A common gate amplifier for amplifying the signal at the input terminal; A current source for supplying a bias to the common gate amplifier; And a current mirror configured to transfer the signal amplified by the common gate amplifier to the output terminal. The apparatus of claim 4, wherein the common gate amplifier comprises: a common gate amplifier; A broadband low noise amplifier characterized by being an NMOS transistor. The method of claim 4, wherein the current source; A broadband low noise amplifier characterized by being a high frequency choke reactor. The method of claim 4, wherein the current mirror; And amplifying the output signal of the common gate amplifier to 1: N and outputting the same to an output terminal. The method of claim 4, wherein the current mirror; A wideband low noise amplifier comprising a PMOS transistor, wherein a drain is connected to the output terminal. 3. The apparatus of claim 1 or 2, wherein the common source low noise amplifier; A capacitor separating the common gate low noise amplifier and a bias and passing only an AC signal; And And a common source amplifier configured to amplify an AC signal passing through the capacitor and output the amplified AC signal to the output terminal. 10. The apparatus of claim 9, wherein the common source amplifier; And a drain connected to the output terminal by an NMOS transistor. The method of claim 9, And a feedback unit for supplying a bias by returning the signal of the output terminal to the common source amplifier. The method of claim 11, wherein the feedback unit; A low pass filter for filtering an AC signal from the signal of the output terminal and passing only a DC component; And an operational amplifier configured to amplify an output signal of the low pass filter and supply a bias to the common source amplifier. 13. The system of claim 12, wherein the operational amplifier; And a bias is supplied to the common source amplifier by amplifying a predetermined reference voltage and an output signal of the low pass filter. The method of claim 11, And an output terminal of the operational amplifier further comprises a capacitor which grounds an AC signal and supplies only a DC signal to the common source amplifier as a bias. The method of claim 11, And a resistor for preventing backflow of the signal between the operational amplifier and the common source amplifier. The method of claim 11, wherein the feedback unit; And a resistor connected between the attraction and the output of the common source amplifier.

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