KR101069407B1 - Voltage controlled oscillstor based transformer and multiband voltage controlled oscillstor including the same - Google Patents

Abstract

The multi-band oscillator is connected to a power supply for supplying a first voltage and supplies a current source for supplying current, a switching unit for selecting an oscillation mode through the current supplied from the current source, and an oscillation frequency of different bands according to the oscillation mode selected in the switching unit. A multi-mode resonator includes a plurality of resonators to output, a multi-mode resonator includes a plurality of transistors and a plurality of inductors connected in a forward or reverse direction to operate as a high frequency oscillator for outputting a high frequency or low frequency oscillator for outputting a low frequency It works.

Transformers, Voltage Controlled Oscillators, Multiband Oscillators

Description

VOLTAGE CONTROLLED OSCILLSTOR BASED TRANSFORMER AND MULTIBAND VOLTAGE CONTROLLED OSCILLSTOR INCLUDING THE SAME}

The present invention relates to a transformer-based voltage controlled oscillator and a multiband oscillator including the same.

With the recent development of tuner, software defined radio (SDR) terminal, and multi-band receiver technology, a voltage-controlled oscillator that satisfies the phase noise performance while being a broadband band. ) 'S research is also developing rapidly.

The voltage-controlled oscillator is a LC-Tank voltage-controlled oscillator which has a low noise performance among various types, but the amount of capacitors or variable capacitors constituting the tank may increase widely at a fixed frequency. It was difficult to generate wideband frequency output.

In order to solve this problem, a voltage controlled oscillator using a switch inductor and a switch capacitor is used. The technology of the inductor controlled by the switch has the advantage of increasing the output range of the resonant frequency of the oscillator by connecting the switch to the inductor to adjust the overall inductance to the switch to obtain the wideband output of the oscillator.

On the other hand, the LC-Tank voltage controlled oscillator is also used as a broadband oscillator by applying a switch inductor and a switch capacitor. In such a wideband oscillator, a fixed capacitance that is variable with a plurality of binary controls along with a variable capacitor produces a wideband frequency output. However, inductors and capacitors controlled by the switch have parasitic components of the control element, and when the switch transistor is turned on, channel resistance appears, thereby reducing the Q factor indicating resonance of the resonance part, thereby hampering phase noise characteristics. Occurs.

The technical problem to be achieved by the present invention is to provide a transformer-based voltage-controlled oscillator and a multi-band oscillator including the same that can improve the phase noise characteristics, can operate in a wide band.

In the transformer-based voltage controlled oscillator according to a feature of the present invention for achieving the above object,

By using a first transistor having a source electrode connected to a first power supply for supplying a first power source, a first inductor forward connected to the first transistor and a second inductor forward connected to the first transistor A transformer-based resonator for outputting a high frequency, and a drain electrode is connected to the first inductor of the transformer-based resonator, and a second transistor having a gate electrode connected to the second inductor.

In the transformer-based voltage controlled oscillator according to another aspect of the present invention,

Low frequency is obtained by using a first transistor having a source electrode connected to a first power supply for supplying a first power source, a first inductor connected forward with the first transistor, and a second inductor connected backward with the first transistor. A transformer-based resonator and a drain electrode are connected to the first inductor of the transformer-based resonator and a second transistor having a gate electrode connected to the second inductor.

In a multi-band oscillator according to another feature of the present invention,

An oscillation frequency of a different band according to a current source connected to a power supply for supplying a first voltage to supply a current, a switching unit to select an oscillation mode through the current supplied from the current source, and the oscillation mode selected by the switching unit And a multimode resonator for outputting, wherein the multimode resonator includes a plurality of transistors and a plurality of inductors connected in a forward or reverse direction to the plurality of transistors.

In a multi-band oscillator according to another feature of the present invention,

Selecting an oscillation mode through a current source connected to a first power supply for supplying a first voltage, the first and second switches connected in parallel, a first transistor having a source electrode connected to the first switch, and the first transistor A second transistor having a source electrode connected to a second switch, a first inductor having one end connected to a first node to which a drain electrode of the first transistor and a gate electrode of the second transistor are connected, and the other end of the first inductor A third transistor having a drain electrode connected to the second electrode and a source electrode connected to a second power supply for supplying a second voltage, and a gate at a second node connected with the other end of the first inductor and the drain electrode of the third transistor A fourth transistor having an electrode connected thereto, and a source electrode connected to the second power source; a drain electrode of the second transistor, and the third transistor; And a second inductor having one end connected to a third node to which the gate electrode of the gate is connected and the other end connected to a fourth node to which the gate electrode of the first transistor and the drain electrode of the fourth transistor are connected. .

In a multi-band oscillator according to another feature of the present invention,

The oscillation mode is selected through a current source connected to a first power supply for supplying a first voltage, and source electrodes are connected to the first and second switches and the first and second switches that are connected in parallel, respectively, The first and second transistors connected to each other, the source electrodes are connected to the first and second switches, respectively, and the third and fourth transistors having gate electrodes connected to each other, and the gate electrodes of the first transistors. A first inductor having one end connected to a first node to which the gate electrode of the third transistor is connected, and another end connected to a second node to which the gate electrode of the second transistor and the gate electrode of the fourth transistor are connected; One end is connected to a third node to which the drain electrodes of the first and second transistors are connected, and the drain electrodes of the third and fourth transistors. And a second inductor that is connected to the other end of the fourth node is connected.

As described above, according to the present invention, a transformer-based inverter-type multi-band oscillator may operate in a mode of outputting two different frequency bands by selecting a feedback direction for two ports of a transformer. . This allows the generation of both low and high frequencies simultaneously, eliminating the problem of narrowband frequency output and improving broadband and low power performance.

In addition, according to the present invention, by outputting different frequency bands using one transformer-based resonator, chip size may be significantly reduced, and implementation costs may be reduced.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is "connected" to another part, this includes not only "directly connected" but also "electrically connected" with another element in between. . In addition, when a part is said to "include" a certain component, which means that it may further include other components, except to exclude other components unless otherwise stated.

1 is a diagram illustrating a general transformer-based resonator.

As shown in FIG. 1, the general transformer-based resonator 100 includes an inductor L ₁ , a capacitor C ₁ , and a resistor R ₁ of the first port and an inductor L ₂ of the second port, and a capacitor. (C ₂ ) and resistor (R ₂ ).

The inductor L ₁ and the inductor L ₂ , which determine the resonance frequency in the transformer-based resonator 100, are coupled to each other by a coupling constant k to generate a mutual inductance M. At this time, if the inductor L ₁ and the capacitor C _{1 of} the first port and the inductor L ₂ and the capacitor C ₂ of the second port are the same, respectively, of the first port of the transformer-based resonator 100 Voltage V ₁ and voltage of the second port V ₂ ) Are the same size and have two modes of phase in two steady-states.

That is, the transformer-based resonator 100 may have a voltage V ₁ of the first port and a voltage V ₂ of the second port. ) Odd Mode (V ₁ / V ₂ = -1) is the opposite operation, the oscillation frequency is determined by the equation (1).

는 오드 모드(Odd Mode)에서 동작하는 발진주파수이고, M은 상호인덕턴스이고, L은 인덕턴스이며, C는 커패시턴스이다.

Is the oscillation frequency operating in odd mode, M is the mutual inductance, L is the inductance, and C is the capacitance.

In addition, the transformer-based resonator 100 operates in an even mode in which the phase (V ₁ / V ₂ = 1) of the voltage V ₁ of the first port and the voltage V ₂ of the second port are the same. The oscillation frequency is determined by Equation 2.

는 이븐 모드(Even Mode)에서 동작하는 발진주파수이고, M은 상호인덕턴스이고, L은 인덕턴스이며, C는 커패시턴스이다.

Is the oscillation frequency operating in Even Mode, M is mutual inductance, L is inductance, and C is capacitance.

As described above, the transformer-based resonator 100 may have different frequency bands in two phase modes as the value of the inductor changes by the amount of mutual inductance M in two phase modes. That is, the transformer-based resonator 100 has a resonant frequency of a high frequency band in an odd mode, and has a resonant frequency of a low frequency band in an even mode.

Hereinafter, with reference to FIGS. 2A to 5, the transformer-based resonator 100 having the two phase modes may operate in a wide band, and the transformer according to the embodiment of the present invention may improve phase noise characteristics. Based on the voltage controlled oscillator and the multi-band oscillator including the same will be described in detail.

2A is a diagram schematically illustrating a transformer-based high frequency voltage controlled oscillator according to an embodiment of the present invention, and FIG. 2B is a diagram illustrating an inverter type high frequency voltage controlled oscillator as an example of the high frequency voltage controlled oscillator shown in FIG. 2A. .

Referring to FIG. 2A, the transformer-based high frequency voltage controlled oscillator 200 according to the embodiment of the present invention is a high frequency oscillator operating in an odd mode, and the transformer-based resonator 210 and the active element 220 are provided. ).

The high frequency voltage controlled oscillator 200 forms a positive feed-back loop by adding a phase delay (180 °) of the active element 220 and a phase delay (180 °) of the transformer-based resonator 210. . Since the transformer-based resonator 210 in the high frequency voltage controlled oscillator 200 operates in an odd mode with phase inversion, the differential stage and the active element 220 of the transformer-based resonator 210 are operated. Connect in the forward direction. In this case, the forward direction refers to a connection direction in which a phase change does not occur when the active device 220 is connected to the transformer-based resonator 210.

For example, as shown in FIG. 2B, the high frequency voltage controlled oscillator 200 according to the embodiment of the present invention may be formed as an inverter type high frequency voltage controlled oscillator 200 ′.

The inverter type high frequency voltage controlled oscillator 200 'includes transistors M11 and M12 and a transformer based resonator 210'. In the high frequency voltage controlled oscillator 200 ', the gate and the drain of the inverter type including the transistor M11 and the transistor M12 are connected in a forward direction through the transformer-based resonator 210'.

That is, the source of the transistor M11 is connected to the power supply VDD, and the drain thereof is connected to one end of the inductor L11. The other end of the inductor L11 is connected to the drain electrode of the transistor M12, and the source electrode of the transistor M12 is connected to the ground terminal GND. In this case, one end of the inductor L12 is connected to the gate electrode of the transistor M11, and the other end is connected to the gate electrode of the transistor M12.

Since the phases of the gate electrodes and the drain electrodes of the transistors M11 and M12 of the inverter-type high frequency voltage controlled oscillator 200 'are inversely related to each other, the phase delay of the loop is a transformer-based resonator 210'. Except for the phase difference between two ports of), it occurs by 180 °. When a phase difference of 180 ° of the transformer-based resonator 210 'is generated, the inverter-type high frequency voltage controlled oscillator 200' operates as a high frequency oscillator operating in an odd mode.

3A schematically illustrates a transformer-based low frequency voltage controlled oscillator according to an embodiment of the present invention. 3B is a view showing an inverter type low frequency voltage controlled oscillator which is an example of the low frequency voltage controlled oscillator shown in FIG. 3A.

Referring to FIG. 3A, the transformer-based low frequency voltage controlled oscillator 300 according to the embodiment of the present invention is a low frequency oscillator operating in an even mode, and the transformer-based resonator 310 and the active element 320 are provided. It includes.

The low frequency voltage controlled oscillator 300 includes a phase delay (180 °) of the active device 320 and a phase delay (180 °) through a cross connection between the differential stage of the transformer-based resonator 310 and the active device 320. This adds up to a positive feed-back loop. At this time, since the transformer-based resonator 210 operates in an even mode, phase delay does not occur. Since the transformer-based resonator 310 of the low frequency voltage controlled oscillator 300 operates in an even mode without phase inversion, the differential stage and the active element 320 of the transformer-based resonator 310 are operated. Connect in reverse direction to reverse phase. In this case, the reverse direction refers to a connection direction in which a phase change occurs when the active element 320 and the transformer-based resonator 310 are connected.

For example, as shown in FIG. 3B, the low frequency voltage controlled oscillator 300 according to the embodiment of the present invention may be formed as an inverter type low frequency voltage controlled oscillator 300 ′.

The inverter type low frequency voltage controlled oscillator 300 'includes transistors M21 and M22 and a transformer based resonator 310'. In the low frequency voltage controlled oscillator 300 ', the gate electrode and the drain electrode of the inverter type including the transistor M21 and the transistor M22 are connected in the opposite direction through the transformer-based resonator 310'.

That is, the source of the transistor M21 is connected to the power supply VDD, and the drain thereof is connected to one end of the inductor L21. The other end of the inductor L21 is connected to the drain electrode of the transistor M22, and the source electrode of the transistor M22 is connected to the ground terminal GND. At this time, one end of the inductor L22 is connected to the gate electrode of the transistor M22, and the other end is connected to the gate electrode of the transistor M21.

Phases of the gate and drain electrodes of the transistors M21 and M22 of the inverter-type low frequency voltage controlled oscillator 300 ′ are inverted with each other by 180 °, and the inductor L22 has a phase difference. One end is connected to the gate electrode of the transistor M22, the other end is cross-connected to the gate electrode of the transistor M21, and a phase difference of 180 ° occurs to generate a total phase delay of 360 °. Thus, the inverter type low frequency voltage controlled oscillator 300 'operates as a low frequency oscillator operating in an even mode.

4 is a diagram schematically illustrating a multi-mode voltage controlled oscillator combining a transformer based high frequency voltage controlled oscillator and a transformer based low frequency voltage controlled oscillator shown in FIGS. 2A and 3A.

In FIG. 4, transistors M ₄₁ and M ₄₃ of the multi-mode voltage controlled oscillator 400 are illustrated as p-channel metal oxide semiconductor (PMOS) transistors, and transistors M ₄₂ and M ₄₄ are referred to as n-channel metal. oxide semiconductor), the present invention is not limited thereto, and other transistors having similar functions may be used as transistors M ₄₁ and M ₄₃ instead of PMOS transistors, and other transistors having similar functions instead of NMOS transistors. May be used as the transistors M ₄₂ and M ₄₄ .

As shown in FIG. 4, the multi-mode voltage controlled oscillator 400 according to the embodiment of the present invention includes a power supply unit 410, a switching unit 420, and a multi-mode resonator 430.

The power supply unit 410 includes a current source I ₄₁ and a current source I ₄₂ connected to one end of the power source VDD, respectively.

The switching unit 420 includes a switch SW ₁₁ connected at one end to a current source I ₄₁ of the power supply unit 410 and a switch SW ₁₂ connected at one end to a current source I ₄₂ , and for outputting a high frequency. Select an oscillation mode such as oscillation or low frequency oscillation to output low frequency. At this time, the switch SW ₁₁ is turned on and off by the bias voltage VB1 applied, and the switch SW ₁₂ is turned on and off by the bias voltage VB2 applied.

The multi-mode resonator 430 includes transistors M ₄₁ , M ₄₂ , M ₄₃ , M ₄₄ , inductors L ₄₁ , L ₄₂ , and capacitors C ₄₃ , C ₄₄ .

The source of the transistor M ₄₁ is connected to the other end of the switch SW ₁₁ of the switching unit 420, and the drain electrode is connected to one end of the inductor L ₄₁ . The other end of the inductor L ₄₁ is connected to the drain electrode of the transistor M ₄₂ , and the source electrode is connected to the ground terminal GND. Here, at one end and the other end of the inductor (L ₄₁ ), the variable capacitor (C _V1 ) and the variable capacitor (C _V2 ) connected in series are connected in parallel, and the output frequency of the oscillator is adjusted according to the applied voltage (V _C1 ). .

The source of the transistor M ₄₃ is connected to the other end of the switch SW ₁₂ of the switching unit 420, and the drain electrode is connected to one end of the inductor L ₄₂ . The other end of the inductor L ₄₂ is connected to the drain electrode of the transistor M ₄₄ , and the source electrode is connected to the ground terminal GND. Here, at one end and the other end of the inductor (L ₄₂ ), the variable capacitor (C _V3 ) and the variable capacitor (C _V4 ) connected in series are connected in parallel, and the output frequency of the oscillator is adjusted according to the applied voltage (V _C2 ). .

In this case, the gate electrode of the transistor M ₄₁ is connected to a node N4 to which the other end of the inductor L ₄₂ and the drain electrode of the transistor M ₄₄ are connected, and the gate electrode of the transistor M ₄₃ is an inductor ( One end of L ₄₁ and the drain electrode of transistor M ₄₁ are connected to node N1. Then, the transistor gate electrode (M ₄₂₎ is connected to one end of the capacitor (C _43), the other end of the capacitor (C ₄₃₎ is that one end of the drain electrode and the inductor (L ₄₂₎ of the transistor (M ₄₃₎ connected It is connected to node N3. Node that is the gate electrode of the transistor (M ₄₄₎ is connected to one end of the capacitor (C _44), the drain electrode of the other end transistor (M ₄₂₎ of the capacitor (C ₄₄₎ the other end of the inductor (L ₄₁₎ of the connection ( N2).

Here, capacitor C ₄₃ and capacitor C ₄₄ operate as DC blocking capacitors for independent biasing of transistor M ₄₂ and transistor M ₄₄ , respectively. The gate voltages of the transistors M ₄₂ and M ₄₄ are respectively adjusted according to VB3 and the bias voltage VB4. The capacitor C ₄₁ and the capacitor C ₄₂ are positioned between the switching unit 420 and the multi-mode resonator 430, and one end of the capacitor C ₄₁ is a switch SW ₁₁ of the switching unit 420. ) of which is connected to a contact in which a source electrode is connected to the other end of the multi-mode resonator portion 430 transistor (M ₄₁ a) and the other end is connected to one end of the capacitor (C _42), the other end of the capacitor (C ₄₂₎ Is connected to a contact point between the other end of the switch SW ₁₂ of the switching unit 420 and the source electrode of the transistor M ₄₃ to operate as an AC ground.

Referring to the operation of the multi-mode voltage controlled oscillator 400, when a current is applied through the current source I ₄₁ or the current source I ₄₂ of the power supply unit 410, the bias of the switch SW ₁₁ and the switch SW ₁₂ . Current is only applied to the switch turned on by the voltage.

If the switch SW ₁₁ is turned on, in the multi-mode resonator 430, the transistor M ₄₁ and the transistor M ₄₂ are turned on so that the drain electrode of the transistor M ₄₁ is connected to one end of the inductor L ₄₁ . The drain electrode of the transistor M ₄₂ is connected to the other end thereof. The gate electrode of the transistor M ₄₁ is connected to the node N4, and the gate electrode of the transistor M ₄₂ is connected to the node N3 through a capacitor C ₄₃ . That is, in the multi-mode resonator 430, the other end of the inductor L ₄₂ is connected in the reverse direction to the gate electrode of the transistor M ₄₁ like the inverter type low frequency voltage controlled oscillator 300 ′ shown in FIG. 3B. One end of the inductor L ₄₂ is connected to the gate electrode of the transistor M _{42 in a} reverse direction to operate as a low frequency oscillator operating in an even mode.

On the other hand, when the switch SW ₁₂ is turned on, in the multi-mode resonator 430, the transistors M ₄₃ and M ₄₄ are turned on so that one end of the inductor L ₄₂ has a drain electrode of the transistor M ₄₃ . Is connected, and the drain electrode of the transistor M ₄₄ is connected to the other end thereof. The gate electrode of the transistor M ₄₃ is connected to the node N1, and the gate electrode of the transistor M ₄₄ is connected to the node N2 through the capacitor C ₄₄ . That is, in the multi-mode resonator 430, one end of the inductor L ₄₁ is forwardly connected to the gate electrode of the transistor M ₄₃ like the inverter type high frequency voltage controlled oscillator 200 ′ shown in FIG. 2B. The other end of the inductor L ₄₁ is connected to the gate electrode of the transistor M ₄₄ in the forward direction to operate as a high frequency oscillator operating in odd mode.

5 is a diagram schematically illustrating a multi-mode voltage controlled oscillator according to another embodiment of the present invention.

In FIG. 5, transistors M ₅₁ , M _{52 ,} M ₅₃ , and M ₅₄ of the multi-mode voltage controlled oscillator 500 are illustrated as p-channel metal oxide semiconductor (PMOS) transistors, but the present invention is not limited thereto. Other transistors with similar functions may be used as the transistors M ₅₁ , M _{52 ,} M ₅₃ , M ₅₄ instead of transistors.

As shown in FIG. 5, the multi-mode voltage controlled oscillator 500 according to another embodiment of the present invention includes a power supply unit 510, a switching unit 520, and a multi-mode resonator 530.

The power supply unit 510 includes a current source I ₅₁ and a current source I ₅₂ , respectively, one end of which is connected to the power source VDD.

The switching unit 520 includes a switch SW ₂₁ having one end connected to the current source I ₅₁ of the power supply unit 510 and a switch SW ₂₂ connected to one end of the current source I ₅₂ , and for outputting high frequency. Select an oscillation mode such as oscillation or low frequency oscillation to output low frequency. At this time, the switch SW ₂₁ is turned on and off by the bias voltage VB1 applied, and the switch SW ₂₂ is turned on and off by the bias voltage VB2 applied.

The multi-mode resonator 530 includes two pairs of transistors M ₅₁ and M ₅₂ , a transistor M ₅₃ and M ₅₄ , an inductor L ₅₁ and L ₅₂ , and a capacitor C ₅₁ , in which drain electrodes are connected to each other. C ₅₂ ).

Transistor, two pairs of (M _51, M ₅₂₎ and a transistor (M _53, M _54), respectively, and the drain electrode are each connected to a node (N5) and a node (N6), a transistor (M ₅₁₎ and a transistor (M ₅₄ The other end of the switch SW ₂₁ of the switching unit 520 is connected to the node N1 to which the source electrodes of the second electrode are connected to each other, and the source electrodes of the transistors M ₅₂ and M ₅₃ are connected to each other. The other end of the switch SW ₂₂ of the switching unit 520 is connected to N2. In this case, the gate electrode of the transistor M ₅₁ and the gate electrode of the transistor M ₅₃ are connected to each other, and the gate electrode of the transistor M ₅₂ and the gate electrode of the transistor M ₅₄ are connected to each other.

One end of the inductor L ₅₁ is connected to a node N3, which is connected to the gate electrode of the transistor M ₅₁ and the gate electrode of the transistor M ₅₃ , and the other end thereof is a gate electrode and a transistor of the transistor M ₅₂ . The gate electrode of M ₅₄ is connected to a node N4 connected to each other. At this time, the bias voltage VB3 is supplied to one end of the inductor L ₅₁ , and the bias voltage VB4 is supplied to the other end. One end of the inductor L ₅₂ is connected to the node N5, and the other end is connected to the node N6. Here, one end of the inductor L ₅₂ and the other end of the capacitor C ₅₁ and the capacitor C ₅₂ connected in series are connected in parallel.

Referring to the operation of the multi-mode voltage controlled oscillator 500, when a current is applied through the current source I ₅₁ or the current source I ₅₂ of the power supply unit 510, the bias of the switch SW ₁₁ and the switch SW ₁₂ . The current is only applied to the switch that is turned on with the voltage applied.

If the switch SW ₂₁ is turned on, in the multi-mode resonator 530, the transistor M ₅₁ and the transistor M ₅₄ are turned on so that the gate of the transistor M ₅₁ is connected to one end of the inductor L ₅₁ . The electrode is connected, and the other end of the gate electrode of the transistor M ₅₄ is connected. At this time, one end of the inductor L ₅₂ is connected to the node N5 connected to the drain electrode of the turned on transistor M ₅₁ , and the other end thereof is connected to the node N6 connected to the drain electrode of the turned on transistor M ₅₄ . Is connected to. Therefore, the multi-mode resonator 530 is forwardly connected to one end of the inductor L ₅₁ to the gate electrode of the transistor M ₅₁ , like the inverter type high frequency voltage controlled oscillator 200 ′ shown in FIG. 2B. The other end of the inductor L ₅₁ is connected to the gate electrode of the transistor M ₅₄ in the forward direction to operate as a high frequency oscillator operating in odd mode.

On the other hand, when the switch SW ₂₁ is turned on, in the multi-mode resonator 530, the transistors M ₅₂ and M ₅₃ are turned on so that one end of the inductor L ₅₁ has a gate electrode of the transistor M ₅₃ . Is connected, and the other end of the gate electrode of the transistor M ₅₂ is connected. At this time, one end of the inductor L ₅₂ is connected to the node N5 connected to the drain electrode of the turned on transistor M ₅₂ , and the other end thereof is connected to the node N6 connected to the drain electrode of the turned on transistor M ₅₃ . Is connected to. Accordingly, in the multi-mode resonator 530, the gate electrode of the transistor M ₅₃ is connected to one end of the inductor L ₅₁ in a reverse direction, like the low frequency voltage controlled oscillator 300 ′ of the inverter type shown in FIG. 3B. The gate electrode of the transistor M ₅₂ is connected to the other end of the inductor L ₅₁ in a reverse direction to operate as a low frequency oscillator operating in an even mode.

As described above, the inverter-type multimode voltage controlled oscillator 400 and the multimode voltage controlled oscillator 500 using transistors having different output phases have a low power structure because of low current consumption. Since the high frequency oscillation and the low frequency oscillation are possible using the multi-mode resonators 430 and 530, the chip size may be reduced. In addition, the phase noise performance may be improved by the interaction of the PMOS transistor or the NMOS transistor as a single-ended structure, and the Q factor for displaying resonance of the multi-mode resonators 430 and 530 may be improved.

In the exemplary embodiment of the present invention, the circuit structure of the multi-mode voltage controlled oscillator 400 of the inverter type and the multi-mode voltage controlled oscillator 500 using transistors having different output phases has been described as an example, but the present invention is not limited thereto. Other structures that can operate as a high frequency oscillator and a low frequency oscillator by converting a structure connecting the respective ports of the transformers of the multimode resonators 430 and 530 may also be included in the multimode voltage controlled oscillator of the present invention.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

1 is a diagram illustrating a general transformer-based resonator.

2A schematically illustrates a transformer-based high frequency voltage controlled oscillator according to an embodiment of the present invention.

FIG. 2B is a diagram showing an inverter type high frequency voltage controlled oscillator which is an example of the high frequency voltage controlled oscillator shown in FIG. 2A.

3A schematically illustrates a transformer-based low frequency voltage controlled oscillator according to an embodiment of the present invention.

3B is a view showing an inverter type low frequency voltage controlled oscillator which is an example of the low frequency voltage controlled oscillator shown in FIG. 3A.

4 is a diagram schematically illustrating a multi-mode voltage controlled oscillator combining a transformer based high frequency voltage controlled oscillator and a transformer based low frequency voltage controlled oscillator shown in FIGS. 2A and 3A.

5 is a diagram schematically illustrating a multi-mode voltage controlled oscillator according to another embodiment of the present invention.

Claims (13)

In a transformer-based voltage controlled oscillator, A first transistor having a source electrode connected to a first power supply for supplying a first power supply, A transformer-based resonator including a first inductor connected to the first transistor and a second inductor connected to the first transistor, and A second transistor having a drain electrode connected to the first inductor of the transformer-based resonator and a gate electrode connected to the second inductor Including, One end of the first inductor is connected to the drain electrode of the first transistor, the other end is connected to the drain electrode of the second transistor, One end of the second inductor is connected to the gate electrode of the first transistor, and the other end is connected to the gate electrode of the second transistor. delete delete delete delete delete delete In a multiband oscillator, First and second switches connected in parallel to select an oscillation mode through a current source connected to a first power supply for supplying a first voltage; A first transistor having a source electrode connected to the first switch, A second transistor having a source electrode connected to the second switch, A first inductor having one end connected to a first node to which the drain electrode of the first transistor and the gate electrode of the second transistor are connected; A third transistor having a drain electrode connected to the other end of the first inductor and having a source electrode connected to a second power supply for supplying a second voltage; A fourth transistor having a gate electrode connected to a second node connected to the other end of the first inductor and a drain electrode of the third transistor, and having a source electrode connected to the second power source, and One end is connected to a third node that connects the drain electrode of the second transistor and the gate electrode of the third transistor, and is connected to a fourth node that connects the gate electrode of the first transistor and the drain electrode of the fourth transistor Second inductor with the other end connected Multiband oscillator comprising a. The method of claim 8, When the first switch is turned on, The first transistor and the third transistor are turned on so that one end of the first inductor is connected to the drain electrode of the first transistor, and the other end is connected to the drain electrode of the third transistor, One end of the second inductor is connected to the gate electrode of the third transistor, and the other end is connected to the gate electrode of the first transistor to operate as a low frequency oscillator. The method of claim 8, When the second switch is turned on, The second transistor and the fourth transistor are turned on so that one end of the second inductor is connected to the drain electrode of the second transistor, and the other end is connected to the drain electrode of the fourth transistor, One end of the first inductor is connected to the gate electrode of the second transistor, and the other end is connected to the gate electrode of the fourth transistor to operate as a high frequency oscillator. In a multiband oscillator, First and second switches connected in parallel to select an oscillation mode through a current source connected to a first power supply for supplying a first voltage; First and second transistors having a source electrode connected to the first and second switches, respectively, and a drain electrode connected to each other; Third and fourth transistors having a source electrode connected to the first and second switches, and a drain electrode connected to each other; One end is connected to a first node to which the gate electrode of the first transistor and the gate electrode of the third transistor are connected, and to a second node to which the gate electrode of the second transistor and the gate electrode of the fourth transistor are connected. A first inductor connected to the other end, and A second inductor having one end connected to a third node to which the drain electrodes of the first and second transistors are connected, and another end connected to a fourth node to which the drain electrodes of the third and fourth transistors are connected; Multiband oscillator comprising a. The method of claim 11, When the first switch is turned on, The first transistor and the fourth transistor are turned on so that one end of the first inductor is connected to the gate electrode of the first transistor, and the other end is connected to the gate electrode of the fourth transistor, One end of the second inductor is connected to the third node, and the other end is connected to the fourth node to operate as a high frequency oscillator. The method of claim 11, When the second switch is turned on, The second transistor and the third transistor are turned on so that one end of the first inductor is connected to the gate electrode of the third transistor, and the other end is connected to the gate electrode of the second transistor, One end of the second inductor is connected to the third node, and the other end is connected to the fourth node to operate as a low frequency oscillator.

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