KR101027970B1 - Power Anmplifier With Internal Matching Network Using Ferroelectrics - Google Patents

Abstract

The present invention relates to an amplifier and a package including a variable matching circuit that can have an optimum efficiency and linearity even with impedance change of an amplifier according to a surrounding environment by using a variable capacitor using a ferroelectric.

An amplifier having a variable internal matching circuit using a ferroelectric according to the present invention includes a variable capacitor and a distance between a pad and a pad, a wire thickness, and a height that can change the capacitance of the capacitor by changing the dielectric constant of the ferroelectric formed on the substrate. And a variable inductor configured in the form of a thin wire welding that can adjust an inductance value by changing at least one of materials.

The present invention can achieve miniaturization of a capacitor and an amplifier package by applying a variable capacitor using a ferroelectric material. In addition, there is an advantage that can maintain the efficiency and linearity of the amplifier by correcting the change in the impedance of the amplifier according to changes in the external environment or temperature changes.

Ferroelectrics, Ferroelectrics, Matching Circuits, Matching Networks, Power Amplifiers, Variable Circuits, Tunable Matching Networks

Description

Amplifier with Variable Internal Matching Circuit Using Ferroelectrics {Power Anmplifier With Internal Matching Network Using Ferroelectrics}

The present invention relates to an amplifier including a tunable matching network (Tunable Matching Network) that can have an optimum efficiency and linearity even in the impedance change of the amplifier according to the surrounding environment by using a variable capacitor using a ferroelectric.

Currently, researches are being actively conducted on power amplifiers of the transmitting end in the mobile communication and wireless communication markets. In particular, high-efficiency circuit design techniques such as Doherty and high power such as GaN are used to increase the efficiency and linearity of the amplifier at the maximum output power. Research on linearization techniques such as device development, digital predistortion, feedforward, etc. is ongoing.

Despite the design and device research, however, the surface of human body, car, ambient temperature, and heat generation of the amplifier may change the input / output impedance of the power amplifier in the wireless communication environment. There is a problem that causes.

In the conventional general type output matching circuit, since all L and C element values in the circuit are fixed, it is necessary to redesign and reimplement the matching circuit according to the frequency change. have.

In order to solve this problem, the interest and development of the conventional tunable matching network (Tunable Matching Network) shown in Figures 1a and 1b is increasing little by little. These current variable matching circuits are mainly formed outside the amplifier package, or made variable by applying a ferroelectric or MEMS to only a portion in the wafer state.

However, in the case of forming the variable matching circuit outside the above-described package, the size of the entire amplifier is large. In the case where the variable element is applied in the wafer state, the matching circuit or the power amplifier is limited. There are disadvantages that must be made.

In order to solve the problems described above, the present invention can provide a variable internal matching circuit using a variable capacitor using a ferroelectric, a thin wire welding type inductor, etc., thereby miniaturizing the amplifier package. In addition, the amplifier can be configured by adding a function such as an LC resonant circuit inside the package.

In order to achieve the above object, an amplifier having a variable internal matching circuit using a ferroelectric according to the present invention includes a variable capacitor and a variable inductor capable of changing the capacitance value of the capacitor by changing the dielectric constant of the ferroelectric formed on the substrate. It provides an amplifier configured by. At this time, the variable inductor is preferably configured in the form of a thin wire welding that can adjust the inductance value by changing at least one of the distance between the pad, the thickness of the wire, the height and the material.

According to another aspect of the present invention, an amplifier having a variable internal matching circuit using a ferroelectric includes a first inductor configured in a thin wire welding form using an input port and a transistor as both pads, and a conductor pattern stacked on a ferroelectric deposited on a package substrate. And a second capacitor configured as a thin wire welding using both the variable capacitor and the transistor as both pads, and an amplifier package including a third inductor configured as a thin wire welding using both the variable capacitor and the output port as both pads. To provide.

According to the present invention, since the variable matching circuit can be implemented inside the power amplifier package, the size of the power amplifier package can be reduced. In addition, since a variable capacitor using a ferroelectric material having a dielectric constant of several hundreds is applied, the capacitor and the package can be miniaturized.

In addition, according to the present invention, it is possible to provide a matching circuit that can vary according to frequency, thereby correcting an impedance change of an amplifier according to a change in an external environment or a temperature change, thereby maintaining the efficiency and linearity of the amplifier. There is an advantage.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are provided to those skilled in the art to fully understand the present invention, and may be modified in various forms, and thus the scope of the present invention is not limited to the embodiments described below. . In describing the present invention, when it is determined that description of related known functions or the like may unnecessarily obscure the subject matter of the present invention, detailed descriptions of such known functions and the like will be omitted.

2 is a block diagram illustrating a specific embodiment of an amplifier package including a variable matching circuit using a ferroelectric according to the present invention.

The interior of the amplifier package may be composed of a power device such as GaN, GaAs, Si, and the like variable capacitor, inductor and transmission line (Transmission Line) required for the input-output matching circuit according to the present invention.

As shown in FIG. 2, the amplifier package according to the present invention includes a first inductor 210 having an input port 100 and a pad having both input ports and transistors 220 as pads. ), A second inductor having a variable capacitor 240 in which a conductor pattern is stacked on the ferroelectric layer deposited on the package substrate, and a thin wire welding type using both the variable capacitor and the transistor 220 as pads. 230 and a conductor pattern formed on the ferroelectric layer, and one side of the wire is a thin wire welding using an output port 400 connected to an output part and the variable capacitor 240 and the output port 400 as both pads. And a third inductor 250 having a wire shape.

The variable capacitor is a variable capacitor capable of changing the dielectric constant of the ferroelectric substrate 300 and changing the capacitance of the capacitor 230 when an external bias voltage is applied.

In this case, it is preferable to use Barium-Strontium-titanate (BST) having high dielectric constant and low dielectric loss in the high frequency region as the ferroelectric.

The ferroelectric (for example, BST) may be deposited using a method such as MOCVD, Sputtering, PLD, etc., in which a thin film is deposited on a substrate such as magnesium oxide (MgO) or sapphire (Sapphire). can do. In addition, it is possible to implement a relatively low-cost LTCC form by depositing a thick film in the form of a green sheet.

Methods of implementing the variable capacitor include a metal insulator metal (MIM) method and an interdigital method. Metal Insulator Metal (MIM) method is a metal-based capacitor manufacturing technology that can increase the variable rate and nonlinearity of capacitors, but it is difficult to process. Interdigital method has the disadvantage of easy manufacturing process and high linearity but low variable rate. Capacitor manufacturing technology. Therefore, there is a need to effectively vary the implementation of the variable capacitor according to the application.

 The inducted wired (Bond Wire) it is preferable that the inductance value can be adjusted by varying at least one of the length, the thickness, the height and the material between the pad and the pad.

FIG. 3 is a schematic diagram showing an embodiment of a variable capacitor in which BST is deposited on sapphire, and FIG. 4 is a characteristic graph of the variable capacitor shown in FIG.

As shown in FIG. 3, a variable capacitor according to the present invention may be implemented by depositing BST on a package substrate (BST Layer) and stacking a conductor electrode (Top Electrode) thereon.

In the variable capacitor illustrated in FIG. 3, as shown in the graph of FIG. 4, as the external bias voltage is increased, the dielectric constant of BST is lowered, and the lower dielectric constant has a characteristic of reducing the capacitance of the capacitor. By varying the capacitance of the capacitor in this way, the inductance of the entire circuit can be changed.

As described above, a method of implementing such a variable capacitor includes a metal insulator metal (MIM) method and an interdigital method.

Through the above-described variable capacitor, a thin wire welded inductor, and a variable transmission line, a PI matching circuit or a T matching circuit, which is a basic matching structure, may be configured.

5 is a block diagram illustrating an embodiment of an equivalent circuit of an internal variable matching circuit using ferroelectrics.

In the matching circuit according to the present embodiment, a base end is connected to an input port and an emitter end is a grounded transistor, a first capacitor having one end connected to a collector end of the transistor, an inductor connected in series with the other end of the first capacitor, A fourth capacitor having the other end and one end of the inductor connected in series and the other end of the inductor connected to an output port, the second variable capacitor and the fourth capacitor having one end connected in parallel with the first end of the inductor and the other end of which is grounded; The inductor and one end thereof are connected in parallel, and the other end thereof includes a third variable capacitor grounded.

6 is a block diagram illustrating a second embodiment of an equivalent circuit of an internal variable matching circuit using ferroelectrics.

The configuration of the matching circuit according to the present embodiment, as shown, the base terminal is connected to the input port and the emitter terminal is grounded transistor, the first variable capacitor connected to the collector terminal and one end of the transistor, the first variable capacitor The second end is connected to one end and the other end is connected to the output port and the second capacitor and the first capacitor and the second capacitor and the other end is configured to include a grounded inductor, wherein the first capacitor and The second capacitor and the inductor are configured to form a tee network.

7 is a block diagram showing an equivalent circuit of an internal variable matching circuit using a ferroelectric including an LC resonant circuit.

An internal variable matching circuit including an LC resonant circuit includes a transistor having a base end connected to an input port and an emitter end grounded, a first inductor L1 having one end connected to a collector end of the transistor, and another end and one end of the first inductor. A first variable capacitor C1 connected to the other end and grounded, a second inductor L2 having one end connected to a collector end of the transistor, a third inductor L3 having one end connected to the other end of the second inductor, and the One end of the second inductor and the third inductor is connected, and the other end includes a second variable capacitor C2 grounded.

The first variable capacitor C1 is combined with the first inductor L1 to remove the impedance of the second harmonic to zero, and when the center frequency is changed by an external environment change such as temperature, the first variable capacitor C1 is removed. The capacitance of C1) can also be changed to eliminate the changed second harmonic.

In addition, the second variable capacitor C2 is coupled to the second inductor L2 and the third inductor L3 to match the impedance so that the maximum output of the power amplifier can be obtained. In this case, the second variable capacitor C2 is By changing, the matching of the changed bands is possible.

In addition to the implementation of the inductor through the thin wire (Bond Wire), by taking the form of a resonant circuit using an inductor and a capacitor, the variable inductor can be implemented in a form that can change the overall inductance by changing the variable capacitor.

The embodiments of the present invention have been described above in detail based on the drawings. Those skilled in the art will be able to perform various modifications and equivalent other embodiments from the foregoing detailed description and drawings, and thus the true technical protection scope of the present invention is defined based on the following claims. It will be apparent to those skilled in the art that the scope of the present invention and equivalent embodiments thereof are included.

1A and 1B are schematic diagrams showing an embodiment of a variable matching circuit according to the prior art according to the prior art.

Figure 2 is a block diagram showing a specific embodiment of the amplifier package including a variable matching circuit using a ferroelectric according to the present invention.

3 is a schematic diagram showing an embodiment of a variable capacitor in which BST is deposited on sapphire.

4 is a characteristic graph of the variable capacitor shown in FIG.

5 is a block diagram illustrating an embodiment of an equivalent circuit of an internal variable matching circuit using ferroelectrics.

6 is a block diagram illustrating a second embodiment of an equivalent circuit of an internal variable matching circuit using ferroelectrics.

7 is a block diagram showing an equivalent circuit of an internal variable matching circuit using a ferroelectric including an LC resonant circuit.

Claims (16)

Inside the package, Variable internal matching circuit consisting of a variable capacitor and a variable inductor that can change the capacitance of the capacitor by changing the dielectric constant of the ferroelectric Including, The variable capacitor, When an external bias voltage is applied, a ferroelectric material of BST material whose dielectric constant changes is stacked on a package substrate. The ferroelectric is, It is formed by any one of the method of depositing a thin film on the package substrate using any one of the method of MOCVD, PLD and Sputtering and the method of depositing a thick film in the form of a green sheet on the package substrate, The variable inductor, Fine-wire welding type that can adjust the inductance value by varying at least one of pad to pad distance, wire thickness, height and material An amplifier having a variable internal matching circuit using a ferroelectric, characterized in that consisting of. delete The method of claim 1, The ferroelectric has high dielectric constant and low dielectric loss in high frequency region An amplifier having a variable internal matching circuit using a ferroelectric. delete delete delete The method of claim 1, The package substrate is any one of an MgO substrate and a sapphire substrate An amplifier having a variable internal matching circuit using a ferroelectric. The method of claim 1, The variable capacitor is made of any one of a metal insulator metal (MIM) method for increasing the variable rate and nonlinearity of the capacitor and an interdigital method having high linearity and easy manufacturing. An amplifier having a variable internal matching circuit using a ferroelectric. delete The method of claim 1, Wherein the variable internal matching circuit, changing the value of the variable capacitor to change the inductance of the entire matching circuit. An amplifier having a variable internal matching circuit using a ferroelectric. The method of claim 1, The variable matching circuit includes a PI network including two variable capacitors and an inductor connected in series with the two variable capacitors as pads. An amplifier having a variable internal matching circuit using a ferroelectric. The method of claim 1, The variable matching circuit includes a T network including two series connected variable capacitors and an inductor connected in parallel with the two variable capacitors. An amplifier having a variable internal matching circuit using a ferroelectric. A variable internal matching circuit according to claim 1; And An LC resonant circuit configured by connecting a variable capacitor and a variable inductor in series; An amplifier having a variable internal matching circuit and LC resonant circuit using a ferroelectric comprising a. Inside the package, A first inductor 210 having a thin wire welding form using the input port 100 and the transistor 220 as both pads, A variable capacitor 240 formed by stacking a conductor pattern on the ferroelectric 300 deposited on the package substrate, A second inductor 230 having a thin wire welding form using both the variable capacitor and the transistor 220 as pads; Third inductor 250 configured in a thin wire welding form using the variable capacitor 240 and the output port 400 as both pads. Including, The variable capacitor, When an external bias voltage is applied, a ferroelectric material of BST material whose dielectric constant changes is stacked on a package substrate. The ferroelectric is, It is formed by any one of the method of depositing a thin film on the package substrate using any one of the method of MOCVD, PLD and Sputtering and the method of depositing a thick film in the form of a green sheet on the package substrate, Each of the first to third inductors, Amplifier package having a variable internal matching circuit using a ferroelectric, characterized in that the thin wire welding form that can adjust the inductance value by varying at least one of the distance between the pad, the thickness of the pad, the height and the material . delete The method of claim 14, wherein the ferroelectric, Having high permittivity and low dielectric loss in high frequency region An amplifier package having a variable internal matching circuit using a ferroelectric.

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