KR20210044366A - Nonlinear Modeling Method of Power Amplifier - Google Patents

Abstract

The present invention relates to an apparatus and a method for nonlinear modeling of a power amplification element, in which a nonlinear modeling result of a unit element constituting a large-area element is scaled up in parallel to model the large-area element. The apparatus includes: a plurality of low-current unit elements, which are power amplification elements; a parameter measurement unit for measuring linear and nonlinear characteristic parameters of the unit element; a parameter extraction unit for completing the nonlinear modeling by extracting a nonlinear model parameter based on a measurement result of a characteristic parameter in linear and nonlinear regions of the unit element; a unit element modeling verification unit for verifying unit element modeling by comparing a measured scattering parameter according to an IV curve in the linear and nonlinear regions of the unit element; a parallel expansion unit for modeling a large-area element by expanding a nonlinear modeling result of the unit element in parallel; an embedding performing unit for performing embedding for adding wire bonding and a lead frame of a package to a nonlinear model on the modeled large-area element; and a large-area element modeling verification unit for verifying the modeling by using load-pull data of the large-area element by evaluating an actual element characteristic in a nonlinear region of the large-area element and comparing a load-pull measurement result for obtaining an optimal impedance.

Description

Nonlinear Modeling Method of Power Amplifier {Nonlinear Modeling Method of Power Amplifier}

The present invention relates to an apparatus and method for nonlinear modeling of a power amplification device in which a nonlinear modeling result of a unit device is scaled up in parallel to model a large area device.

In general communication and broadcasting systems, a high power amplifier is essentially used to transmit a transmission signal over a wide area.

In general, the high power amplifier has a non-linear characteristic in the magnitude and phase of the output signal depending on the magnitude of the input signal. The present invention relates to a predistortion compensation technology for compensating for nonlinear characteristics that occur when using such a high power amplifier (HPA). In general, a high power amplifier is used to amplify the signal when transmitting communication signals such as satellite, mobile communication, radio relay link, and radar.

Semiconductor power amplifiers currently applied to commercial and military systems have superior advantages over conventional vacuum tube type high-power amplifiers (Traveling Wave Tube) in terms of life time, maintenance and operation of the amplifier.

The semiconductor power amplification device technology that should be basically equipped to implement a semiconductor high-power amplifier is a silicon-based LDMOS (Laterally Diffused Metal Oxide Semiconductor) device, a Gallium Arsenide (GaAs)-based HEMT (High Electron Mobility Transistor) device, and gallium nitride. There is a HEMT device technology based on (GaN: Gallium Nitride).

Among them, the GaN-based HEMT device (GaN HEMT device) technology is implemented with GaN material, and the GaN material can operate at high voltage due to the wide energy gap of 3.4 eV, and the carrier concentration using polarized charges is 10 times higher than that of GaAs. Therefore, high current density and high power density can be obtained, making it suitable as a high output, high efficiency, and compact power amplifier element.

Accordingly, GaN HEMT devices that are small and capable of obtaining high power output are in the spotlight as a next-generation power amplification device that can replace the existing semiconductor devices used in not only civilians, but also military, especially radars.

In order to manufacture a GaN HEMT-based power amplifier, modeling of device characteristics is essential. For accurate modeling, it is important to select an appropriate model and reproduce device characteristics based on accurate measurement data.

The small signal model is distinguished from the large-signal model in which model parameters change according to the bias condition. The large-signal model can exhibit nonlinear characteristics in which intrinsic components are changed by the gate and drain voltage, and the small-signal model is used when modeling the linear frequency characteristics due to the values of the extracted components according to the bias conditions.

Therefore, for devices used in the RF domain, these linear and nonlinear characteristics can have a great influence over the entire system. Therefore, it is important to have a nonlinear model that can be reproduced in a simulation without error about the actual measured value.

In the conventional large-area device modeling technology, it is difficult to measure an on-wafer probe due to a large consumption current, and modeling was performed based on the measured data by packaging a large-area device. Compared to the method of measuring and modeling characteristics using an on-wafer probe without packaging the power device, this method achieves accurate nonlinear modeling of the large-area device itself due to the effects of additional circuit components and parasitics due to packaging. It is difficult.

Therefore, in order to obtain a nonlinear modeling of a large area device itself, a de-embedding process is required in which additional circuit components are measured and the measurement reference plane is transferred to the device input/output reference plane. This de-embedding process not only includes a measurement error, but also requires a lot of time and cost for manufacturing and measurement.

An object of the present invention is to model a large-area device by scaling up the result of nonlinear modeling of the unit device constituting the large-area device in parallel, thereby eliminating the effect of additional circuits and parasitic components according to the package. In addition, it is to provide a device and method for nonlinear modeling of a power amplification device that can drastically reduce the manufacturing and measurement cost and time required by de-embedding for the modeling of the device itself. .

A nonlinear modeling apparatus of a power amplification device according to an embodiment of the present invention for achieving the above object includes a plurality of low-current unit devices as a power amplification device, and a parameter measuring unit that measures linear and nonlinear characteristic parameters of the unit device. And, a parameter extraction unit for completing nonlinear modeling by extracting a nonlinear model parameter based on a measurement result of a characteristic parameter in the linear and nonlinear regions of the unit device, and measured according to the IV curve in the linear and nonlinear regions of the unit device. A unit device modeling verification unit that compares scattering parameters to verify unit device modeling, a parallel expansion unit that models a large area device by expanding the nonlinear modeling result of the unit device in parallel, and the modeled large area device is nonlinear. Compare the wire bonding to the model and the embedding execution unit that performs embedding to add the lead frame of the package, and the load-pull measurement result to evaluate the actual device characteristics in the nonlinear region of the large-area device and obtain the optimum impedance. And a large-area device modeling verification unit that verifies the modeling using the load-pull data of the large-area device.

In this case, the parameter measuring unit may measure the pulsed IV of the unit device and the scattering parameter according to each pulsed IV point according to temperature using an on-wafer probe.

In addition, the parameter measurement unit may include a measurement for a long pulse for thermal analysis according to the GaN HEMT power amplification device, and a measurement for analyzing the effect of output reduction due to a decrease in the drain current of the gate-leg and the drain-leg. Do.

In addition, the unit device modeling verification unit may verify nonlinear unit device modeling using load-pull data of the unit device.

On the other hand, according to an embodiment of the present invention, a method for nonlinear modeling of a power amplification device includes: preparing a plurality of low power unit devices as a power amplification device; Measuring linear and nonlinear characteristic parameters of the unit device; Completing nonlinear modeling by extracting nonlinear model parameters based on measurement results of linear and nonlinear characteristic parameters of the unit device when measurement of linear and nonlinear parameters of the unit device is completed; When the nonlinear modeling of the unit device is completed, verifying the unit device by comparing the measured scattering parameters according to the IV curve in the linear and nonlinear regions; Modeling a large-area device by extending the nonlinear modeling result of the verification of the unit device in parallel; Performing wire bonding of the modeled large-area device according to a non-linear model and embedding to add a lead frame of the package; And comparing and verifying a load-pull measurement result for obtaining an optimum impedance and evaluating an actual device characteristic in the nonlinear region of the large-area device.

According to the present invention, compared to the method of packaging and modeling a large-area device by modeling a large-area device by scaling up a nonlinear modeling result of a unit device constituting a large-area device in parallel, an additional circuit according to the package In addition to being able to exclude the influence of the device and the influence of parasitic components, it is possible to drastically reduce the manufacturing and measurement cost and time required by de-embedding for modeling of the device itself.

In addition, according to the present invention, a high-power large-area device consumes a large amount of current and requires a measuring device with a relatively high specification, and the risk of oscillation due to a large current during measurement is high, but in a unit device that consumes a relatively low current, such You can easily solve the problem.

1 is a block diagram schematically showing a nonlinear modeling apparatus of a power amplification device according to the present invention,
2 is a modeling flow chart of a large-area power amplification device for explaining a nonlinear modeling method of a power amplification device according to an embodiment of the present invention.
3 is a configuration diagram of packaging a large-area unit power amplification device,
4 is a conceptual diagram modeling a large-area power amplifying device using a unit power amplifying device,
5 is a reference diagram showing de-embedding using a T-parameter and a conversion equation of a T-parameter and an S-parameter.

First, general terms used in the specification and claims are selected in consideration of functions in various embodiments of the present invention. However, these terms may vary depending on the intention of a technician in the field, legal or technical interpretation, and the emergence of new technologies. In addition, some terms may be terms arbitrarily selected by the applicant. These terms may be interpreted as the meanings defined in the present specification, and if there is no specific term definition, they may be interpreted based on the general contents of the present specification and common technical knowledge in the art.

In addition, the same reference numerals or numerals in each drawing attached to the present specification indicate parts or components that perform substantially the same function. For convenience of description and understanding, different embodiments will be described using the same reference numerals or reference numerals. That is, even if all of the components having the same reference numerals are shown in the plurality of drawings, the plurality of drawings do not mean one embodiment.

In addition, in the specification and claims, terms including ordinal numbers such as'first' and'second' may be used to distinguish between components. These ordinal numbers are used to distinguish the same or similar constituent elements from each other, and the meaning of the term should not be limitedly interpreted due to the use of such ordinal numbers. For example, the order of use or arrangement of components combined with these ordinal numbers should not be limited and interpreted by the number. If necessary, each ordinal number may be used interchangeably.

In the present specification, expressions in the singular include plural expressions unless the context clearly indicates otherwise. In the present application, terms such as'comprise' or'comprise' are intended to designate the existence of features, numbers, steps, actions, components, parts, or a combination thereof described in the specification, but one or more other It is to be understood that it does not preclude the presence or addition of features, numbers, steps, actions, components, parts, or combinations thereof.

Further, in an embodiment of the present invention, when a part is connected to another part, this includes not only a direct connection but also an indirect connection through another medium. In addition, the meaning that a part includes a certain component means that other components may be further included rather than excluding other components unless specifically stated to the contrary.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

1 is a block diagram schematically showing a nonlinear modeling apparatus of a power amplification device according to the present invention.

As shown in FIG. 1, the device for nonlinear modeling of a power amplification device according to the present invention includes a low current unit device 110, a parameter measurement unit 120, a parameter extraction unit 130, and a unit device modeling verification unit 140. , A parallel expansion unit 150, an embedding performing unit 160, and a large area device modeling verification unit 170.

Here, the low current unit device 110 is a power amplification device, a silicon-based LDMOS (Laterally Diffused Metal Oxide Semiconductor) device, a Gallium Arsenide (GaAs)-based HEMT (High Electron Mobility Transistor) device, and gallium nitride. It is a (GaN: Gallium Nitride) based HEMT device. In an embodiment of the present invention, it is a GaN-based HEMT device (GaN HEMT power amplification device).

High-electron mobility transistor (HEMT) is a high-power, highly integrated transistor, switch, power amplifier, and microwave monolithic integrated circuit (MMIC) by heterojunction of compound semiconductors such as gallium arsenide (GaAs). ), etc. In addition, the transistor is required to be capable of operating at high power, high frequency and high temperature for a high-power microwave monolithic integrated circuit, and gallium nitride (Gallium Nitride) having a larger energy bandgap than that of a group III-V material. It is possible to have a high threshold voltage by using.

Here, in order to improve the breakdown voltage of gallium nitride, a structure using a single electric field electrode on a gate in a high electron mobility transistor is used, which is a structure in which another electrode is formed between the gate and the drain, This electric field electrode structure widens the electric field between the gate and the drain, thereby reducing the peak value.

The parameter measuring unit 120 uses an on-wafer probe for the unit device 110 to measure the pulsed IV for the unit device 110 and a scattering parameter according to each pulsed IV point according to temperature. Measure. That is, the linear and nonlinear characteristic parameters of the unit device are measured.

At this time, the parameter measurement unit 120 measures a long pulse for thermal analysis according to the GaN HEMT power amplification device, according to the gate-leg and drain-lag. Measurements are also included to analyze the effect of power reduction due to drain current reduction.

When the measurement of linear and nonlinear parameters for the unit device 110 is completed, the parameter extraction unit 130 selects an appropriate nonlinear model (Physic model, Behavioral model, compact model), and then selects a linear/nonlinear, thermal and trapping (Trapping) model. effect) Extract parameters to describe the effect. That is, nonlinear modeling is completed by extracting nonlinear model parameters based on the measurement results of the linear and nonlinear characteristic parameters of the unit device 110.

When the nonlinear modeling of the unit device 110 is completed, the unit device modeling verification unit 140 verifies the unit device modeling by comparing the measured scattering parameters according to the IV curve in the linear and nonlinear regions. . At this time, the nonlinear unit device modeling is verified using load-full data of the unit device 110.

The parallel expansion unit 150 models a large area device by scaling up a nonlinear modeling result for which modeling verification of the unit device is completed in parallel.

The embedding execution unit 160 performs packaging effects of the modeled large-area device according to a nonlinear model, that is, wire bonding and embedding to add a lead frame of the package.

The large-area device modeling verification unit 170 evaluates actual device characteristics in a non-linear region and compares the load-pull measurement results for obtaining an optimum impedance, and verifies the modeling using load-pull data of the large-area device.

2 is a modeling flow chart of a large-area power amplification device for explaining a nonlinear modeling method of a power amplification device according to an embodiment of the present invention. As shown in FIG. 2, a plurality of low power units for configuring a large-area device Prepare the device (S110).

Here, the low-current unit device is a power amplification device, a silicon-based LDMOS (Laterally Diffused Metal Oxide Semiconductor) device, a Gallium Arsenide (GaAs)-based HEMT (High Electron Mobility Transistor) device, and a gallium nitride (GaN: Gallium Nitride) based HEMT device. In an embodiment of the present invention, it is a GaN-based HEMT device (GaN HEMT power amplification device).

Subsequently, the unit device is measured according to the temperature of the pulsed IV and the scattering parameter according to each pulsed IV point using an on-wafer probe (S120). That is, the linear and nonlinear characteristic parameters of the unit device are measured.

In this case, measurements for long pulses for thermal analysis according to GaN HEMT power amplification devices and measurements to analyze the effect of output reduction due to drain current reduction due to gate-lag and drain-lag are also included.

Subsequently, when measurement of linear and nonlinear parameters for the unit device is completed, a suitable nonlinear model (Physic model, Behavioral model, compact model) is selected, and parameters for describing linear/nonlinear, thermal and trapping effects are extracted. Do (S130). That is, nonlinear modeling is completed by extracting nonlinear model parameters based on the measurement results of the linear and nonlinear characteristic parameters of the unit device.

Subsequently, when the nonlinear modeling of the unit device is completed, the scattering parameters measured according to the IV curve in the linear and nonlinear regions are compared and verified (S140). At this time, the nonlinear modeling is verified using the load-pull data of the unit device.

Subsequently, a large-area device is modeled by scaling up the verified nonlinear modeling result in parallel (S150).

Subsequently, the modeled large-area device is subjected to packaging effect according to the nonlinear model, that is, wire bonding and embedding to add a lead frame of the package (S160).

In addition, the actual device characteristics in the nonlinear region are evaluated and the load-pull measurement results for obtaining the optimum impedance are compared (S170). At this time, the modeling is verified using the load-pull data of the large-area device.

3 is a configuration diagram of a large-area unit power amplifier packaged.

As shown in FIG. 3, the unit device 110 is a GaN HEMT power amplification device, and is connected to a chip 111, a gold wire 112 bonded to both sides of the chip 111, and the gold wire 112 A lead frame 113 that supplies electricity to and supports the chip 111, _{ceramics 114 made of Al 2} O ₃ to mount the chip 111, and both ends of the ceramics 114 It consists of a flanger 115 connected to.

4 is a conceptual diagram modeling a large-area power amplifying device using a unit power amplifying device, and FIG. 5 is a reference diagram showing de-embedding using a T-parameter and a conversion equation of a T-parameter and an S-parameter.

When the nonlinear model for the unit device is verified in FIG. 2, the result of the nonlinear modeling of the unit device is scaled up in parallel as shown in FIG. 4 to describe a large area device.

In this way, the large-area device described as a unit device model performs packaging effects, that is, wire bonding, and embedding to add a lead frame of the package for verification.

In this embedding process, in the case of a power amplification device that consumes a large current, it is impossible to measure the on-wafer due to the current limitation of the probe. Therefore, it is performed because load-pull data can be obtained through packaging.

Meanwhile, wire bonding for embedding and lead frame data of the package can be obtained through 3D EM simulation or measurement.

As described above, when the load-pull result of the unit device-based large-area device nonlinear modeling matches the measurement results, the modeling process ends. If not, the nonlinear modeling parameters of the unit device are modified to repeat a series of processes.

Meanwhile, in the above, preferred embodiments of the present invention have been illustrated and described, but the present invention is not limited to the specific embodiments described above, and the technical field to which the present invention belongs without departing from the gist of the present invention claimed in the claims. In addition, various modifications are possible by those of ordinary skill in the art, and these modifications should not be individually understood from the technical spirit or prospect of the present invention.

110: low current unit device 120: parameter measuring unit
130: parameter extraction unit 140: unit device modeling verification unit
150: parallel expansion unit 160: embedding execution unit
170: large area device modeling verification unit

Claims (8)

As a power amplification device, a number of low-current unit devices,
A parameter measuring unit for measuring linear and nonlinear characteristic parameters of the unit device,
A parameter extraction unit for completing nonlinear modeling by extracting a nonlinear model parameter based on a measurement result of a characteristic parameter in the linear and nonlinear regions of the unit device;
A unit device modeling verification unit for verifying unit device modeling by comparing the measured scattering parameters according to the IV curve in the linear and nonlinear regions of the unit device,
A parallel expansion unit for modeling a large-area device by expanding the result of nonlinear modeling of the unit device in parallel,
An embedding performing unit performing wire bonding of the modeled large area device to a nonlinear model and embedding to add a lead frame of the package,
A large-area device modeling verification unit that evaluates the actual device characteristics in the nonlinear region of the large-area device and compares the load-pull measurement results to obtain an optimal impedance, and verifies the modeling using the load-pull data of the large-area device. Nonlinear modeling device of a power amplification device including. The method of claim 1,
The parameter measuring unit measures the pulsed IV of the unit device and the scattering parameter according to each pulsed IV point according to temperature using an on-wafer probe. The method of claim 1,
The parameter measurement unit also includes a measurement for a long pulse for thermal analysis according to the GaN HEMT power amplification device, and a measurement for analyzing an effect of output reduction due to a decrease in the drain current of the gate-leg and the drain-leg. Nonlinear modeling device of power amplifier. The method of claim 1,
The unit device modeling verification unit verifies the nonlinear unit device modeling using load-pull data of the unit device. Preparing a plurality of low power unit devices as power amplification devices;
Measuring linear and nonlinear characteristic parameters of the unit device;
Completing nonlinear modeling by extracting nonlinear model parameters based on measurement results of linear and nonlinear characteristic parameters of the unit device when measurement of linear and nonlinear parameters of the unit device is completed;
When the nonlinear modeling of the unit device is completed, verifying the unit device by comparing the measured scattering parameters according to the IV curve in the linear and nonlinear regions;
Modeling a large-area device by extending the nonlinear modeling result of the verification of the unit device in parallel;
Performing wire bonding of the modeled large-area device according to a nonlinear model and embedding to add a lead frame of the package;
And comparing and verifying a load-pull measurement result for obtaining an optimum impedance and evaluating an actual device characteristic in a nonlinear region of the large-area device. The method of claim 5,
The unit device is a nonlinear modeling method of a power amplification device, characterized in that the pulsed IV of the unit device and the scattering parameter according to each pulsed IV point are measured according to temperature using an on-wafer probe. The method of claim 5,
The unit device also includes a measurement for a long pulse for thermal analysis according to the GaN HEMT power amplification device, and a measurement for analyzing the effect of output reduction due to a decrease in drain current of the gate-leg and the drain-leg. Nonlinear modeling method of power amplification device. The method of claim 5,
The unit device or the large area device is a nonlinear modeling method of a power amplification device, characterized in that the modeling of the nonlinear unit device or the large area device is verified using load-pull data.

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