KR101207960B1 - Variable active inductor, phase shifter and voltage controlled oscillator using the same - Google Patents

Abstract

The present invention relates to a variable active inductor, a phase shifter and a voltage controlled oscillator using the same, and more particularly, to a variable active inductor and a phase shifter and a voltage controlled oscillator using the same to extend a frequency range of use by adding a lumped element. . The present invention can provide a variable active inductor having an extended use frequency, a phase shifter, and a voltage controlled oscillator using the lumped element. In addition, the present invention can provide a variable active inductor, a phase shifter and a voltage controlled oscillator using the cascode structure to improve the Q-factor and operate in a stable region.

Description

Variable active inductors, phase shifters and voltage controlled oscillators using the same {VARIABLE ACTIVE INDUCTOR, PHASE SHIFTER AND VOLTAGE CONTROLLED OSCILLATOR USING THE SAME}

The present invention relates to a variable active inductor, a phase shifter and a voltage controlled oscillator using the same, and more particularly, to a variable active inductor and a phase shifter and a voltage controlled oscillator using the same to extend a frequency range of use by adding a lumped element. .

An inductor is a device that induces a voltage in proportion to the change in current. Recently, an inductor has a demand for a function of changing an inductor's value in various applications. The most common application is a frequency synthesizer in a communication system, which is used in a voltage-controlled oscillator to adjust the bandwidth to be transmitted and received. In general, the operating frequency of the voltage controlled oscillator is changed by using a varactor, but the operating frequency range can be extended by using a variable inductor.

Another important application is the phase shifter, which constitutes a phased array antenna widely used in high performance radar systems. Various methods of constructing a phase shifter have been proposed in the past, but a method of implementing a phase shifter using a left-handed metamaterial has recently been proposed. Negative permittivity and permeability can be realized by using the lefting material, and various new functions are realized by extending existing physical properties. Previously published literature has demonstrated that the lefting metamaterial can be used as a phase shifter in combination with the previously known characteristics of right-handed transmission lines. In addition, these phase shifters can be miniaturized and precisely controlled by using semiconductor integrated circuit processes. However, in the conventional structure of the phase shifter published, the varistor is mainly used to obtain the phase shift. However, these structures have been limited by the relatively large loss of the varactor and limited capacitor range. In addition, the method of tuning the frequency using the varactor has a disadvantage in that the tuning range is limited and the loss is large over the microwave band. To address these shortcomings, new attempts have been made to apply an active variable inductor to a meta-phase phase shifter consisting of a left-handed and right-handed transmission line in the RF frequency band. Is still limited to use below the RF frequency band.

An object of the present invention is to provide a variable active inductor capable of extending the use frequency, a phase shifter and a voltage controlled oscillator using the same.

Another object of the present invention is to provide a variable active inductor capable of improving the Q-factor and operating in a stable region, a phase shifter and a voltage controlled oscillator using the same.

In order to achieve the above object, the present invention provides a second transistor having a drain and a gate connected to a driving power supply, a concentrating element connected between the drain and the gate of the second transistor, and a drain connected to the gate of the second transistor. And a first transistor having a source connected to the source of the second transistor, and a current source connected between the source of the second transistor and the source of the first transistor.

The present invention may further include a third transistor connected to the first transistor in a cascode form. In this case, the source of the third transistor is connected to the drain of the first transistor, and the drain of the third transistor is connected to the gate of the second transistor. Here, the concentrator includes a passive inductor.

The present invention also includes a left transmission line including a capacitance and a first inductor, and a right transmission line coupled to the left transmission line and including a varactor and a second inductor. It provides a phase shifter characterized in that to obtain a phase shift.

The present invention also provides a second transistor having a drain and a gate connected to a driving power supply, a lumped element connected between the drain and the gate of the second transistor, a drain connected to a gate of the second transistor, and a source of the second transistor. And a variable active inductor having a first transistor connected to the source of the second transistor and a current source connected between the source of the second transistor and the source of the first transistor to vary the operating frequency. Provide an oscillator. The display device may further include a third transistor connected to the first transistor in a cascode form. In this case, the source of the third transistor is connected to the drain of the first transistor, and the drain of the third transistor is connected to the gate of the second transistor.

The present invention can provide a variable active inductor having an extended use frequency, a phase shifter, and a voltage controlled oscillator using the lumped element.

In addition, the present invention can provide a variable active inductor, a phase shifter and a voltage controlled oscillator using the cascode structure to improve the Q-factor and operate in a stable region.

1 is a circuit diagram of a variable active inductor according to a first embodiment of the present invention.
2 is a small signal equivalent model of a variable active inductor according to a first embodiment of the present invention.
3 is a simplified equivalent circuit diagram of FIG.
4 is a circuit diagram of a variable active inductor according to a second embodiment of the present invention.
5 is a small signal equivalent model of a variable active inductor according to a second exemplary embodiment of the present invention.
6 is a simplified equivalent circuit diagram of FIG.
7 is a circuit diagram of a meta-material phase shifter using a variable active inductor according to the present invention.
8 and 9 are circuit diagrams of a voltage controlled oscillator using a variable active inductor according to the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

It will be apparent to those skilled in the art that the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, It is provided to let you know. Like reference numerals refer to like elements throughout.

1 is a circuit diagram of a variable active inductor according to a first embodiment of the present invention.

)과 접속된 제 2 트랜지스터(

)와, 제 2 트랜지스터(

)의 드레인과 게이트 사이에 접속된 집중 소자(

)와, 드레인이 제 2 트랜지스터(

)의 게이트와 접속되고, 소스가 제 2 트랜지스터(

)의 소스와 접속된 제 1 트랜지스터(

)와, 제 2 트랜지스터(

)의 소스와 제 1 트랜지스터(

)의 소스 사이에 접속된 전류원을 포함한다.In the variable active inductor according to the first embodiment of the present invention, as shown in FIG.

And a second transistor connected to

) And the second transistor (

A concentrated element connected between the drain and the gate of

) And the drain has a second transistor (

Is connected to the gate of the source, and the source is the second transistor (

A first transistor connected with a source of

) And the second transistor (

Source and the first transistor (

A current source connected between the sources.

)를 추가하여 사용 가능한 주파수를 마이크로파 대역 이상으로 확장할 수 있다.The present invention is a passive element inductor (

), You can extend the available frequencies beyond the microwave band.

FIG. 2 is a small signal equivalent circuit of the variable active inductor according to the first embodiment of the present invention, and FIG. 3 is an equivalent circuit diagram of FIG.

)의 등가회로는 트랜스컨덕턴스(

), 게이트-소스 커패시턴스(

), 그리고 출력 임피던스(

)로 표현되고, 제 2 트랜지스터(

)의 표현도 이와 유사하다. 이 회로에 대한 소신호 등가회로 분석을 통해서 도 3에 나타낸 간략화된 등가회로를 얻을 수 있으며, 이를 통해 튜닝 인덕터 값에 대한 해석적인 수식을 얻는다. 출력 임피던스(

)가

인 조건을 이용하면, 도 2에 나타낸 회로의 입력 임피던스

을 다음의 수학식1과 같이 얻는다.As shown in FIG. 2, the first transistor (

The equivalent circuit of) is the transconductance (

), Gate-source capacitance (

), And the output impedance (

) And the second transistor (

) Is similar. By analyzing the small-signal equivalent circuit for this circuit, the simplified equivalent circuit shown in FIG. Output impedance (

)end

When the phosphorus condition is used, the input impedance of the circuit shown in FIG.

Is obtained as in Equation 1 below.

Here, each parameter of Equation 1 is equal to Equation 2 to Equation 5 below.

은

인 범위에서는 인덕턴스 특성을 나타내는 것을 알 수 있다. 또한,

인 조건을 선택하고,

인 주파수 영역에서 동작한다면 수학식5는

로 근사화되어, 기존의 gyrator-C 구조의 능동형 인덕터로 간소화됨을 알 수 있다. 그러므로, 본 발명에서 제시하는 가변 능동 인덕터는 집중 소자(

)를 기존의 gyrator-C 구조에 추가함으로서

인 주파수 영역에서 동작 가능한 능동형 인덕터 특성을 갖는 것을 알 수 있다.
here,

silver

It can be seen that the phosphorus range shows inductance characteristics. Also,

Select the condition

Equation 5 in the frequency domain

It is approximated by, which simplifies the conventional gyrator-C structure active inductor. Therefore, the variable active inductor proposed in the present invention is a lumped element (

) To the existing gyrator-C structure

It can be seen that it has an active inductor characteristic that can operate in the in-frequency region.

Next, a variable active inductor according to a second embodiment of the present invention implemented in the form of a cascode will be described with reference to the drawings. In the following description, the overlapping description of the variable active inductor according to the first embodiment of the present invention described above will be omitted or briefly described.

2 is a circuit diagram of a variable active inductor according to a second embodiment of the present invention.

As shown in FIG. 2, the variable active inductor according to the second embodiment of the present invention includes a second transistor having a drain and a gate connected to a driving power supply, a concentrating element connected between the drain and the gate of the second transistor, A first transistor having a drain connected to the gate of the second transistor and a source connected to the source of the second transistor, a current source connected between the source of the second transistor and the source of the first transistor, and the drain of the gate of the second transistor And a third transistor connected to the source and connected to the drain of the first transistor.

)의 게이트에 입력되는 전압(

)을 가변함으로서 능동형 인덕터가 안정되게 동작하도록 한다. 즉, 본 실시예에 따른 가변 능동 인덕터는 캐스코드 구조의 높은 출력 임피던스 특성에 의해 Q-팩터가 향상되는 장점이 있고, 능동형 인덕터가 안정된 영역에서 동작되도록 튜닝할 수 있다.This embodiment shows a structure using a cascode to improve the quality factor (Q-factor) of the variable active inductor. This structure not only improves the Q-factor due to the high output impedance characteristic of the cascode structure, but also the third transistor (

Voltage at the gate of

) To make the active inductor operate stably. That is, the variable active inductor according to the present embodiment has the advantage that the Q-factor is improved by the high output impedance characteristic of the cascode structure, and the active inductor can be tuned to operate in a stable region.

5 is a small signal equivalent model of a variable active inductor according to a second embodiment of the present invention, and FIG. 6 is a simplified equivalent circuit diagram of FIG.

인 조건을 이용하면, 도 5에 나타낸 회로의 입력 임피던스

을 다음의 수학식6과 같이 얻는다.By analyzing the small signal equivalent circuit for the variable active inductor according to the present embodiment, a simplified equivalent circuit as shown in FIG. 6 can be obtained, and through this, an analytical formula for the tuning inductor value is obtained. Output impedance

If the phosphorus condition is used, the input impedance of the circuit shown in FIG.

Is obtained as in Equation 6 below.

Here, each parameter of Equation 6 is equal to Equation 7 to Equation 10 below.

은

인 범위에서는 인덕턴스 특성을 나타내는 것을 알 수 있다. 또한,

인 조건을 선택하고,

인 주파수 영역에서 동작한다면 전술된 수학식10은

로 근사화되어, 기존의 gyrator-C 구조의 능동형 인덕터로 간소화됨을 알 수 있다. 그러므로, 본 발명에서 제시하는 가변 능동 인덕터는 집중 소자(

)를 기존의 gyrator-C 구조에 추가함으로서

인 주파수 영역에서 동자가하는 능동형 인덕터 특성을 갖는 것을 알 수 있다. 또한, 이 구조에서는 도 2에 도시된 본 발명의 제 1 실시예에 따른 가변 능동 인덕터 구조에서 얻은

의 값보다 도 5에 도시된 본 실시예에 따른 가변 능동 인덕터 구조에서 얻은

의 값이 캐스코드 구조에 의해서 감소되는 것을 확인할 수 있다. 그러므로, 본 발명은 캐스코드 구조를 사용함으로서 Q-팩터를 향상시킬 수 있음을 알 수 있다.
here,

silver

It can be seen that the phosphorus range shows inductance characteristics. Also,

Select the condition

If it operates in the in frequency domain described above Equation 10

It is approximated by, which simplifies the conventional gyrator-C structure active inductor. Therefore, the variable active inductor proposed in the present invention is a lumped element (

) To the existing gyrator-C structure

It can be seen that the active inductor has a characteristic of a pupil in the in-frequency region. In addition, in this structure, the variable active inductor structure according to the first embodiment of the present invention shown in FIG.

Obtained from the variable active inductor structure according to the present embodiment shown in FIG.

It can be seen that the value of is reduced by the cascode structure. Therefore, it can be seen that the present invention can improve the Q-factor by using a cascode structure.

Next, a meta-material phase shifter according to the present invention which can be used in microwave and millimeter wave bands using the variable active inductor according to the first embodiment of the present invention described above will be described with reference to the accompanying drawings.

7 is a circuit diagram of a meta-material phase shifter using a variable active inductor according to the present invention.

이 전술된 본 발명의 제 1 실시예에 따른 가변 능동 인덕터로 구현된다. 또한, 집중 소자 커패시턴스

은

과 함께 좌형 전송 선로를 구성하며, 집중 소자 인덕턴스

은 버렉터

와 함께 우형 전송 선로를 구성한다. 여기서, 위상 가변은

과 버렉터

를 가변하여 위상 변위를 얻을 수 있다.As shown in FIG. 7, the meta-material phase shifter according to the present invention is a meta-material structure in which a right transmission line and a left transmission line coupled with the right transmission line are combined. In this embodiment,

This is implemented with the variable active inductor according to the first embodiment of the present invention described above. In addition, lumped element capacitance

silver

Together with the left transmission line, lumped element inductance

Silver collector

Together with this, it constructs a right transmission line. Where the phase variable is

And collector

The phase shift can be obtained by varying.

Although described above with reference to the drawings and embodiments, those skilled in the art can be variously modified and changed within the scope of the invention without departing from the spirit of the invention described in the claims below. I can understand. That is, the meta-material phase shifter according to the present invention described above is just one example of the variable active inductor according to the first embodiment of the variable active inductor according to the present invention. It can be applied to the frequency variable function of microwave and millimeter wave band voltage controlled oscillator to extend the frequency variable range. In addition, the variable active inductor according to the present invention may be applied to the phase variable function of the RF, microwave, and millimeter wave band frequency shifters to extend the frequency variable range. For example, in the case of a conventionally used voltage controlled oscillator, since the inductor has a fixed value, the operating frequency is changed using the varactor, but the present invention is illustrated in FIGS. 8 and 9. The active inductor according to the present invention can extend the frequency variable range. Of course, in FIG. 8, the third transistor M13 may be omitted.

M1: first transistor M2: second transistor
M3: third transistor L1: inductor

Claims (8)

A second transistor having a drain and a gate connected to a driving power supply;
A passive inductor connected between the drain and the gate of the second transistor;
A first transistor having a drain connected to the gate of the second transistor and a source connected to the source of the second transistor;
And a current source connected between the source of the second transistor and the source of the first transistor. The method according to claim 1,
And a third transistor connected in cascode form with the first transistor. The method according to claim 2,
And wherein the third transistor has a source connected to a drain of the first transistor and a drain connected to a gate of the second transistor. delete A left transmission line comprising a capacitance and a first inductor,
A right transmission line coupled to the left transmission line and including a varactor and a second inductor,
Phase shifter, characterized in that for obtaining a phase shift by varying the collector and the first inductor. A second transistor having a drain and a gate connected to a driving power supply, a passive inductor connected between the drain and the gate of the second transistor, a drain connected to a gate of the second transistor, and a source of the second transistor. And a variable active inductor having a first transistor connected to the first transistor and a current source connected between the source of the second transistor and the source of the first transistor. The method of claim 6,
And a third transistor connected to the first transistor in the form of a cascode. The method of claim 7,
And the third transistor has a source connected to a drain of the first transistor and a drain connected to a gate of the second transistor.

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