KR102537967B1 - Method for extracting relative permeability of ferrite core and em simulating method using the same - Google Patents

Abstract

A method for extracting the relative permeability of a ferrite core according to an embodiment of the present invention is a method for extracting the relative permeability of a ferrite core included in a probe used for a Bulk Current Injection (BCI) test. Converting the equivalent circuit into a second equivalent circuit, calculating the impedance of the second equivalent circuit, extracting the relative permeability of the ferrite core using the impedance of the second equivalent circuit, and proportional to the relative permeability of the ferrite core and calculating the corrected relative permeability of the ferrite core by applying the constant. The second equivalent circuit is a circuit in which a resistor and an inductor are connected in parallel.

Description

Relative permeability extraction method of ferrite core and electromagnetic simulation method using the same

The present invention relates to a method for extracting relative permeability of a ferrite core and an electromagnetic simulation method using the same.

The BCI (Bulk Current Injection) test system is a standard immunity test that is commonly used in areas where electrical components such as automobiles and aircraft are introduced. When modeling such a BCI test system by replacing it with an equivalent circuit, it is necessary to reflect the electromagnetic phenomena included in the actually measured test setup, such as the coupling that exists between the probe and cable included in the BCI test system. There are limits. Therefore, it is necessary to model the structure of each component included in the BCI test system in 3D shape to perform full wave-EM simulation.

On the other hand, in order to perform EM simulation, it is necessary to secure the permeability of the ferrite core included in the probe in advance, and to accurately extract the permeability for each frequency in the entire frequency band (eg, 1 MHz to 400 MHz). there is.

An object to be solved by the present invention is to provide a method for extracting the relative permeability of a ferrite core capable of accurately calculating the relative permeability that changes according to the frequency of the ferrite core and an electromagnetic simulation method using the same.

Another problem to be solved by the present invention is to provide a method for extracting the relative permeability of a ferrite core that can more easily calculate the relative permeability and an electromagnetic simulation method using the same.

Another problem to be solved by the present invention is a ferrite core capable of improving the consistency between the electromagnetic simulation (EM simulation) result and the measurement result by implementing the BCI (Bulk Current Injection) test system as an electromagnetic model (EM model). It is to provide a relative permeability extraction method and an electromagnetic simulation method using the same.

The tasks of the present invention are not limited to the tasks mentioned above, and other tasks not mentioned will be clearly understood by those skilled in the art from the following description.

In order to solve the above problems, a method for extracting the relative permeability of a ferrite core according to embodiments of the present invention is a relative permeability of a ferrite core included in a probe used for a Bulk Current Injection (BCI) test. In the extraction method, converting a first equivalent circuit corresponding to the probe into a second equivalent circuit, calculating an impedance of the second equivalent circuit, and using the impedance of the second equivalent circuit to determine the relative value of the ferrite core. The method may include extracting magnetic permeability and calculating a corrected relative magnetic permeability of the ferrite core by applying a proportional constant to the relative magnetic permeability of the ferrite core. The second equivalent circuit may be a circuit in which a resistor and an inductor are connected in parallel.

In order to solve the above problems, the electromagnetic simulation method according to embodiments of the present invention uses the relative permeability of a ferrite core included in a probe used for a Bulk Current Injection (BCI) test, The method of implementing electromagnetic simulation by implementing the probe as an electromagnetic model may include extracting a relative magnetic permeability of the ferrite core, and implementing an electromagnetic model of the probe using the relative magnetic permeability of the ferrite core. there is. The extracting of the relative permeability of the ferrite core may include converting a first equivalent circuit corresponding to the probe into a second equivalent circuit, calculating an impedance of the second equivalent circuit, and impedance of the second equivalent circuit. The method may include extracting the relative permeability of the ferrite core using , and calculating a corrected relative permeability of the ferrite core by applying a proportional constant to the relative permeability of the ferrite core. The second equivalent circuit may be a circuit in which a resistor and an inductor are connected in parallel.

In order to solve the above problems, a computer program according to embodiments of the present invention is a computer program stored in a computer readable medium, the computer program includes instructions, and when executed by a computer system, the instructions may cause the computer system to perform any one of the ferrite core relative permeability extraction method and the electromagnetic simulation method.

The method for extracting the relative permeability of a ferrite core and the electromagnetic simulation method using the method according to embodiments of the present invention substantially calculate the relative permeability of the ferrite core, except for components to be reflected by modeling the probe in a 3D shape when performing the EM simulation. Since the relative permeability is extracted using an equivalent circuit (second equivalent circuit) using components contributing to , it is possible to extract the relative permeability for each frequency of the ferrite core more simply and accurately than in the conventional method.

In addition, in the case of the relative permeability extraction method of the ferrite core and the electromagnetic simulation method using the method according to the embodiments of the present invention, the extracted relative permeability is corrected using a proportional constant corresponding to the error to additionally calculate the corrected relative permeability, It is possible to more accurately extract the relative magnetic permeability for each frequency of the ferrite core.

Effects according to the present invention are not limited by the contents exemplified above, and more various effects are included in the present invention.

1 is a block diagram schematically illustrating an example of a Bulk Current Injection (BCI) test system.
FIG. 2A is a diagram illustrating an example of a first probe included in the BCI test system of FIG. 1 .
FIG. 2B is a diagram illustrating an example of a second probe included in the BCI test system of FIG. 1 .
FIG. 3A is a graph showing an example of the magnitude of impedance per frequency for the first probe of FIG. 2A.
FIG. 3B is a graph showing an example of a phase of impedance per frequency for the first probe of FIG. 2A.
FIG. 4A is a graph showing an example of the magnitude of impedance per frequency for the second probe of FIG. 2B.
FIG. 4B is a graph showing an example of a phase of impedance per frequency for the second probe of FIG. 2B.
5 is a circuit diagram showing an example of a first equivalent circuit.
6 is a block diagram schematically illustrating a system for extracting relative permeability of a ferrite core according to embodiments of the present invention.
7 is a flowchart illustrating a method of extracting relative magnetic permeability of a ferrite core according to embodiments of the present invention.
8 is a circuit diagram showing an example of a second equivalent circuit.
FIG. 9 is a graph showing an example of impedance per frequency for the second equivalent circuit of FIG. 8 .
10 is a diagram showing an example of a ferrite core.
FIG. 11A is a graph showing an example of relative permeability for each frequency of the first probe extracted by the method of extracting the relative permeability of the ferrite core of FIG. 7 .
FIG. 11B is a graph showing an example of the relative permeability for each frequency of the second probe extracted by the method of extracting the relative permeability of the ferrite core of FIG. 7 .
12A and 12B are graphs for explaining an example of calculating a corrected relative permeability by applying a proportional constant to the relative permeability extracted by the method for extracting the relative permeability of the ferrite core of FIG. 7 .
FIG. 13 is a graph for explaining the consistency of transfer characteristics of a probe when a corrected relative permeability calculated by applying a proportional constant to the relative permeability extracted by the method of extracting the relative permeability of the ferrite core of FIG. 7 is used.
14 is a flowchart illustrating an electromagnetic simulation method according to embodiments of the present invention.

Like reference numerals have been used for like elements throughout the description of each figure. In the accompanying drawings, the dimensions of the structures are shown enlarged than actual for clarity of the present invention. Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. These terms are only used for the purpose of distinguishing one component from another. For example, a first element may be termed a second element, and similarly, a second element may be termed a first element, without departing from the scope of the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise.

In this application, the terms "include" or "have" are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that it does not preclude the possibility of the presence or addition of numbers, steps, operations, components, parts, or combinations thereof.

In addition, when a part is said to be "connected" to another part, this includes not only the case where it is directly connected but also the case where it is connected with another element interposed therebetween.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in more detail. The same reference numerals are used for the same components in the drawings, and redundant descriptions of the same components are omitted.

1 is a block diagram schematically illustrating an example of a Bulk Current Injection (BCI) test system.

FIG. 2A is a diagram illustrating an example of a first probe included in the BCI test system of FIG. 1 .

FIG. 2B is a diagram illustrating an example of a second probe included in the BCI test system of FIG. 1 .

The BCI test system (BCIT) uses a current injection probe (eg, the first probe (PRB1)) to inject current into a device under test (DUT) (eg, IC (Integrated Circuit)) to be measured. (also referred to as "bulk current injection"), a test for electromagnetic compatibility (EMC) characteristics may be performed.

In general, a test is performed using such a BCI test system (BCIT) for an IC test in a field where electrical components such as automobiles and aircraft using high power voltages are introduced. In particular, as the degree of integration of ICs has recently increased, the importance of tests related to electromagnetic wave immunity has increased.

To describe the BCI test system (BCIT) in more detail, referring to FIG. 1, the BCI test system (BCIT) includes a power supply (PS), a first artificial network (AN) (AN1), and a second AN (AN2). ), a first probe (PRB1) (eg, a current injection probe or BCI probe), a second probe (PRB2) (eg, a monitoring probe or measurement probe), an RF generator (RFG), and a device under test ( DUT) may be included. Meanwhile, the BCI test system BCIT connects the first probe PRB1 and the second probe PRB2 and the device under test DUT, and may further include a cable through which current flows.

The power supply (PS) supplies power to the first AN (AN1), the second AN (AN2), the first probe (PRB1), and the RF generator (RFG) so that the BCI test can be performed. For example, the power supply PS may be a DC supply, but this is merely illustrative and not limited thereto.

The first AN(AN1) and the second AN(AN2) may be a (+) terminal and a (-) terminal constituting an artificial network, respectively. The first AN (AN1) and the second AN (AN2) may provide power supplied from the power supply (PS) to the first probe (PRB1) and the RF generator (RFG).

The first probe PRB1 (eg, a current injection probe) may have a structure in which a donut-shaped ferrite core is disposed inside an external metal case. For example, further referring to FIG. 2A , the first probe PRB1 may include a first outer metal case OMC1 and a first ferrite core RFC1 included in the first outer metal case OMC1. can

The first probe PRB1 may generate a magnetic induction phenomenon so that a BCI test may be performed in the device under test (DUT). For example, the first probe PRB1 may be electrically connected to the RF generator RFG and receive an RF signal generated from the RF generator RFG. Here, when the RF signal generated by the RF generator RFG is provided to the first probe PRB1, the first probe PRB1 may generate an induced current according to a magnetic induction phenomenon. Also, the first probe PRB1 may inject a corresponding current into the device under test (DUT) connected through a cable.

The second probe PRB2 (eg, monitoring probe) may have a structure in which a donut-shaped ferrite core is disposed inside an external metal case. For example, further referring to FIG. 2B , the second probe PRB2 may include a second outer metal case OMC2 and a second ferrite core RFC2 included in the second outer metal case OMC2. can Meanwhile, the first probe PRB1 and the second probe PRB2 may have similar structures, but may have different sizes, shapes, and structures depending on their functions and characteristics.

The second probe PRB2 may serve to monitor (or measure) the generated current.

Meanwhile, although not shown in FIG. 1 , according to an embodiment, the BCI test system (BCIT) may further include an optical converter and a data acquisition unit. For example, the current (or voltage) generated by the device under test (DUT) may be provided to the optical converter through the cable and the second probe PRB2, and may be provided to the data acquisition unit via the optical converter. The data acquisition unit may determine electromagnetic compatibility characteristics of the device under test (DUT) by monitoring a generated current (or output voltage) of the device under test (DUT).

FIG. 3A is a graph showing an example of the magnitude of impedance per frequency for the first probe of FIG. 2A.

FIG. 3B is a graph showing an example of a phase of impedance per frequency for the first probe of FIG. 2A.

FIG. 4A is a graph showing an example of the magnitude of impedance per frequency for the second probe of FIG. 2B.

FIG. 4B is a graph showing an example of a phase of impedance per frequency for the second probe of FIG. 2B.

5 is a circuit diagram showing an example of a first equivalent circuit.

Referring to FIGS. 1 to 4B, FIG. 3A shows a first graph showing the magnitude of impedance per frequency measured for the first probe PRB1, which is a current injection probe (or BCI probe), and FIG. 3B shows A second graph showing the phase of the impedance per frequency measured for the first probe PRB1, which is a current injection probe (or BCI probe), is shown. In FIG. 4A, the second probe, which is a monitoring probe (or measuring probe), is shown. A third graph showing the magnitude of impedance per frequency measured for PRB2 is shown, and FIG. 4B shows the phase of impedance per frequency measured for the second probe PRB2, which is a monitoring probe (or measurement probe). A fourth graph is shown. For example, the first to fourth graphs shown in FIGS. 3A to 4B show the magnitude and phase of the impedance of the first probe PRB1 and the impedance of the second probe PRB2 for a frequency band of 1 MHz to 400 MHz, respectively. represents the magnitude and phase of

Meanwhile, both the magnitude and phase of the impedances of the first and second probes PRB1 and PRB2 shown in FIGS. 3A to 4B may be measured values. For example, the magnitude and phase of the impedance of each of the first and second probes PRB1 and PRB2 shown in FIGS. 3A and 4B are determined by using a Vector Network Analyzer (VNA). It may be derived by measuring S-parameters (eg, scattering coefficients) of each of PRB1 and the second probe PRB2 and converting them into impedances.

For example, the impedance of each of the first probe PRB1 and the second probe PRB2 may be derived using Equation 1 below.

[Equation 1]

In [Equation 1], “Z _probe ” represents the impedance of the first probe PRB1 or the second probe PRB2, and “S11” represents the first probe PRB1 measured by the vector network analyzer. may indicate an S-parameter (eg, S11 parameter) of or an S-parameter (eg, S11 parameter) of the second probe PRB2.

On the other hand, a vector network analyzer is an analysis device used to verify design simulation, and is an analysis device capable of measuring S-parameters, for example, reflected and transmitted signals. For example, the vector network analyzer can measure the S11 parameter (eg, reflection coefficient) and the S21 parameter (eg, transmission coefficient), but this is merely exemplary, and the vector network analyzer can measure various S-parameters (eg, For example, S12 parameter, S22 parameter, etc.) may be measured.

As shown in FIGS. 3A to 4B , the magnitude and phase of the impedances of the first and second probes PRB1 and PRB2 may vary according to frequency. For example, as shown in FIGS. 3A and 4A, the impedance of each of the first and second probes PRB1 and PRB2 varies from a low frequency band to a specific frequency band. It is included in each probe (PRB2), and increases linearly as a whole due to the characteristics of the inductor, whose impedance increases with frequency. ) may show a decreasing trend. In addition, as shown in FIGS. 3B and 4B, the impedance phase of each of the first probe PRB1 and the second probe PRB2 is maintained at 90° as a whole from a low frequency band to a specific frequency band, and then In the exceeding high frequency band, the impedance phase may tend to decrease as a whole due to a component corresponding to ferrite loss.

In this way, a probe (eg, the first probe PRB1 or the second probe PRB2) used in the BCI test system BCIT may have an impedance that changes according to a frequency.

Here, further referring to FIG. 5 , FIG. 5 illustrates an equivalent circuit ECT_C (hereinafter, referred to as a “first equivalent circuit ECT1”) for a probe used in the BCI test system BCIT. Here, as described above, the probes used in the BCI test system (BCIT) include the first probe PRB1 as a current injection probe (or BCI probe) and the second probe PRB2 as a monitoring probe (or measurement probe). can be any one of That is, a “probe” referred to below is a probe used in the BCI test system (BCIT), and may be understood as referring to the above-described first probe PRB1 or second probe PRB2.

Referring to FIG. 5 , a first equivalent circuit ECT1 corresponding to a probe may have a circuit structure in which a probe resistance unit DC_C, a ferrite core unit FRC_C, and a connector unit CNT_C are connected in series.

Here, the probe resistance part DC_C is a DC resistance component of the probe and may represent a DC resistance component by members included in the probe. For example, the probe resistance unit DC_C may include a DC resistance Rdc.

In addition, the ferrite core part FRC_C may represent the impedance of the toroidal ferrite core included in the probe. For example, the ferrite core part (FRC_C) includes a toroid resistance (Rt), a toroid inductor (Lt), and a toroid capacitor (Ct) of a ferrite core having a toroid structure included in the probe. may have a circuit structure in which a toroid resistor (Rt), a toroid inductor (Lt), and a toroid capacitor (Ct) are connected in parallel.

Also, the connector part CNT_C may indicate impedance of a connector of a probe to be connected to a cable. For example, the connector unit CNT_C may include a connector inductor Lc and a connector capacitor Cc, and may have a circuit structure in which the connector inductor Lc and the connector capacitor Cc are connected in parallel.

Accordingly, the impedance of the probe used in the BCI test system (BCIT) can be expressed as in [Equation 2] below.

[Equation 2]

In [Equation 2], “Z _probe ” represents the impedance of the probe (eg, the first probe PRB1 or the second probe PRB2), and “Z _DC ” represents the resistance of the probe resistance unit DC_C. It may represent impedance (eg, DC resistance Rdc), “Z _toroid ” may represent the impedance of the ferrite core part FRC_C, and “Z _con ” may represent the impedance of the connector part CNT_C. In addition, in [Equation 2], "R _toroid ", "L _toroid ", and "C _toroid " respectively represent the toroid resistance (Rt) of the ferrite core part (FRC_C), the toroid inductor (Lt), and the toroid Indicates components of the Lloyd capacitor Ct, and “L _con ” and “C _con ” may respectively represent components of the connector inductor Lc and the connector capacitor Cc of the connector unit CNT_C.

In this way, one probe may include various components due to the above-described structure, shape, and the like of the probe.

On the other hand, as described above, when modeling by replacing the BCI test system (BCIT) with an equivalent circuit, actually measured test setup such as coupling between probes and cables included in the BCI test system (BCIT) There is a limit to reflecting the electromagnetic phenomena included in Therefore, it is necessary to model the structure of each component included in the BCI test system (BCIT) in a 3D shape to perform full wave-EM simulation.

Here, in order to model the structure of each component included in the BCI test system (BCIT) in 3D shape and perform the full wave-EM simulation, the ferrite core included in the probe used in the BCI test system (BCIT) In a frequency band (eg, 1 MHz to 400 MHz), it is necessary to secure relative magnetic permeability for each frequency in advance.

To this end, in the past, research on various methods has been conducted in order to extract the relative magnetic permeability with respect to the frequency of the ferrite core. For example, by performing iterative fitting based on the 5th-order Debye model, a method of deriving the inherent permeability of ferrite among all components included in the measured probe impedance, a method of performing this process through the Lorentz model, and a connector , the measurement data including all components, such as the shape of the toroid, was applied to the Lorentz model to extract the magnetic permeability, and based on this, the specific magnetic permeability of ferrite was derived through the first-order Debye model, and the two results were compared and analyzed. .

However, these existing methods substitute various parasitic components such as resistors, inductors, and capacitors in various ways for the impedance data measured for the probe used in the BCI test system, and convert the replaced components into variables by frequency again. Since it uses a numerical analysis method such as That is, in the case of the existing methods, it is complicated and takes a relatively long time to extract the relative permeability because the above-mentioned various methods must be performed, and the resultant value may be relatively inaccurate in extracting the relative permeability for each frequency of the ferrite core. there is.

Accordingly, the method for extracting the relative permeability of a ferrite core and the system for extracting the relative permeability of a ferrite core according to embodiments of the present invention include a probe (eg, a first probe PRB1 or With respect to the equivalent circuit (eg, the first equivalent circuit ECT1) corresponding to the second probe PRB2), the DC resistance component of the probe, the impedance component of the connector, and the toroidal ferrite core included in the probe Relative magnetic permeability for each frequency of the ferrite core is calculated using an equivalent circuit converted by excluding the toroidal capacitor component (ie, the capacitance component due to the coil shape of the probe) for (eg, the second equivalent circuit ECT2). can be extracted.

In addition, here, in relation to the components that affect the relative magnetic permeability of the ferrite core, that is, the toroid inductor (Lt) and the toroid resistance (Rt), as shown in [Equation 3] below, the toroid inductor (Lt) The impedance value of may be determined by the characteristics of an inductor in which impedance increases with frequency in a linearly increasing frequency band (eg, 1 MHz to 10 MHz), and the value of the toroid resistance (Rt) is such that the value of reactance becomes zero. It can be approximated with the value of maximum impedance (ie, the impedance value at the time of impedance matching).

[Equation 3]

In [Equation 3], "L _toroid " represents the inductor component of the toroid inductor Lt, "Z _inductive " represents the impedance value of the toroid inductor Lt, and "R _toroid " represents the toroid resistance ( Rt), "Zmax" may represent a maximum impedance value, and "f" may represent a frequency.

Hereinafter, a method for extracting relative permeability of a ferrite core and a system for extracting relative permeability of a ferrite core according to embodiments of the present invention will be described in more detail with reference to FIGS. 6 to 13 .

6 is a block diagram schematically illustrating a system for extracting relative permeability of a ferrite core according to embodiments of the present invention.

Referring to FIG. 6 , a ferrite core relative permeability extraction system 100 according to embodiments of the present invention may include a communication unit 110 , a processor 120 and a database 130 . Meanwhile, in FIG. 6 , the system 100 for extracting relative permeability of a ferrite core is illustrated as including the database 130, but this is merely illustrative, and embodiments of the present invention are not limited thereto. For example, according to embodiments, the relative permeability extraction system 100 of a ferrite core may be configured without including the database 130 .

The ferrite core relative permeability extraction system 100 may transmit and receive information with the outside through the communication unit 110 . To this end, the communication unit 110 may be implemented with various communication technologies. For example, in the communication unit 110, WIFI, Wideband CDMA (WCDMA), High Speed Downlink Packet Access (HSDPA), High Speed Uplink Packet Access (HSUPA), High Speed Packet Access (HSPA), Mobile WiMAX WiMAX), WiBro, LTE (Long Term Evolution), 5G, Bluetooth, infrared data association (IrDA), NFC (Near Field Communication), Zigbee, and wireless LAN technologies will be applied. can In addition, when the ferrite core relative permeability extraction system 100 is connected to the Internet to provide a corresponding service, the communication unit 110 may follow TCP/IP, which is a standard protocol for information transmission on the Internet, and GPS (Global Positioning System) technology may be used. Meanwhile, according to embodiments, the communication unit 110 may be omitted.

The database 130 may store information for extracting the relative magnetic permeability of the ferrite core. For example, the database 130 may store information on various formulas used in extracting the relative magnetic permeability of the ferrite core.

The processor 120 may access the database 130 through the communication unit 110 . Meanwhile, when the system 100 for extracting the relative permeability of a ferrite core uses an external database without including the database 130 as described above, the system for extracting the relative permeability of a ferrite core 100 via the communication unit 110 You will be able to access external databases.

The ferrite core relative permeability extraction system 100 may perform the operation of the ferrite core relative permeability extraction method described below. For example, the ferrite core relative permeability extraction method of FIG. 7 may be performed on the processor 120 of the ferrite core relative permeability extraction system 100 .

7 is a flowchart illustrating a method of extracting relative magnetic permeability of a ferrite core according to embodiments of the present invention.

8 is a circuit diagram showing an example of a second equivalent circuit.

FIG. 9 is a graph showing an example of impedance per frequency for the second equivalent circuit of FIG. 8 .

10 is a diagram showing an example of a ferrite core.

FIG. 11A is a graph showing an example of relative permeability for each frequency of the first probe extracted by the method of extracting the relative permeability of the ferrite core of FIG. 7 .

FIG. 11B is a graph showing an example of the relative permeability for each frequency of the second probe extracted by the method of extracting the relative permeability of the ferrite core of FIG. 7 .

12A and 12B are graphs for explaining an example of calculating a corrected relative permeability by applying a proportional constant to the relative permeability extracted by the method for extracting the relative permeability of the ferrite core of FIG. 7 .

FIG. 13 is a graph for explaining the consistency of transfer characteristics of a probe when a corrected relative permeability calculated by applying a proportional constant to the relative permeability extracted by the method of extracting the relative permeability of the ferrite core of FIG. 7 is used.

1 to 7, in the method for extracting the relative permeability of a ferrite core according to embodiments of the present invention, a first equivalent circuit corresponding to a probe is converted into a second equivalent circuit (S710), and the second equivalent circuit The impedance is calculated (S720), the relative permeability of the ferrite core is extracted using the impedance of the second equivalent circuit (S730), and the corrected relative permeability of the ferrite core is calculated by applying a proportional constant to the relative permeability of the ferrite core (S740). )can do.

For example, further referring to FIGS. 5 and 8 , first, the first equivalent circuit corresponding to the probe of the method for extracting the relative magnetic permeability of a ferrite core according to embodiments of the present invention is converted into a second equivalent circuit (S710) The step of doing is, for the first equivalent circuit ECT1 corresponding to the probe (eg, the first probe PRB1 or the second probe PRB2 described with reference to FIG. 1), the DC resistance component (eg, For example, the DC resistance (Rdc) of the probe resistance part (DC_C)), the impedance component of the connector part (CNT_C) (eg, the impedance component of a circuit in which the connector inductor (Lc) and the connector capacitor (Cc) are connected in parallel), The first equivalent circuit ECT1 may be converted into the second equivalent circuit ECT2 by excluding the capacitance component of the toroid capacitor Ct of the ferrite core FRC_C.

Accordingly, as shown in FIG. 8 , the second equivalent circuit ECT2 may have a circuit structure including only the ferrite core part FRC. That is, the second equivalent circuit ECT2 may have a circuit structure in which the toroidal resistance Rt of the ferrite core part FRC and the toroidal inductor Lt are connected in parallel.

More specifically, in the case of the probe's DC resistance component (eg, the DC resistance (Rdc) of the probe resistance part DC_C) among the impedance components of the probe, in the entire frequency band (eg, 1 MHz to 400 MHz) It can have a value small enough to be ignored. That is, in extracting the relative permeability, the DC resistance component of the actual probe (eg, the DC resistance (Rdc) of the probe resistance part DC_C) has a value small enough not to affect the value, The impedance value of the probe may be expressed as the sum of the impedance value of the ferrite core part FRC_C and the impedance value of the connector part CNT_C as shown in [Equation 4] below.

[Equation 4]

In [Equation 4], “Z _probe ” represents the impedance of the probe (eg, the first probe PRB1 or the second probe PRB2), and “Z _DC ” represents the resistance of the probe resistance unit DC_C. It may represent impedance (eg, DC resistance Rdc), “Z _toroid ” may represent the impedance of the ferrite core part FRC_C, and “Z _con ” may represent the impedance of the connector part CNT_C.

In addition, among the impedance components of the probe, the capacitor component of the ferrite core part FRC_C (for example, the capacitance of the toroid capacitor Ct) is a parasitic component generated due to the shape of the gap between the coils surrounding the ferrite core of the probe. , and among the impedance components of the probe, the impedance component of the connector part CNT_C (for example, the impedance component of a circuit in which the connector inductor Lc and the connector capacitor Cc are connected in parallel) is independent of the ferrite core. It may be a component due to the probe's connector.

Here, among the impedance components of the probe, the loss component of the ferrite core part (FRC_C) included in the probe, that is, the component of the toroid resistance (Rt) and the impedance value of the ferrite core part (FRC_C) are changed according to the frequency. Only the components of the Loid inductor Lt may correspond to components that affect the relative magnetic permeability per frequency of the actual ferrite core. That is, among the impedance components of the probe, the impedance component of the connector part (CNT_C) and the capacitance component of the toroid capacitor (Ct) excluding the component of the toroid resistance (Rt) and the toroid inductor (Lt) excluding the ferrite core of the probe It is caused by various constituent components, and may correspond to a component that does not affect the value of the relative permeability per frequency of the actual ferrite core.

In other words, in the case of the impedance component of the connector unit CNT_C and the capacitance component of the toroid capacitor Ct, including the DC resistance component (eg, DC resistance Rdc) of the probe among the impedance components of the probe, , may be a component to be reflected by modeling the probe in a 3D shape when performing EM simulation using the extracted relative permeability of the ferrite core. That is, when the probe is modeled in a 3D shape, the impedance component of the connector part CNT_C and the capacitance component of the toroid capacitor Ct, including the DC resistance component (eg, DC resistance Rdc) of the probe, are ferrite When modeling in 3D shape regardless of the relative permeability of the core, it is due to the shape or structure of various components constituting the probe except for the ferrite core, and may correspond to a component reflected in 3D modeling. Accordingly, when modeling is performed by setting the shape and structure of the probe to be the same as that of the actual probe during 3D modeling, the impedance of the connector part CNT_C including the DC resistance component (for example, DC resistance Rdc) of the probe The component and the capacitance component of the toroid capacitor Ct may correspond to components that always have the same value regardless of the relative magnetic permeability of the ferrite core.

Accordingly, in the method of extracting the relative permeability of a ferrite core according to embodiments of the present invention (eg, converting a first equivalent circuit corresponding to the probe of FIG. 7 into a second equivalent circuit (S710)), first , DC resistance component (eg, DC resistance (Rdc )), the impedance component of the connector unit CNT_C and the capacitance component of the toroid capacitor Ct may be excluded to convert into the second equivalent circuit ECT2.

Thereafter, the step of calculating the impedance of the second equivalent circuit of the method for extracting the relative permeability of the ferrite core according to embodiments of the present invention (S720) is the ferrite core using component values included in the second equivalent circuit ECT2. (For example, the impedance value of the ferrite core part (FRC) of FIG. 8 ) may be calculated.

For example, as shown in FIG. 8 , the second equivalent circuit ECT2 may express the impedance of the ferrite core included in the probe as shown in [Equation 5] below.

[Equation 5]

In [Equation 5], “Z _ferrite ” represents the impedance of the ferrite core (eg, the ferrite core part (FRC) of FIG. 8), and “R _toroid ” represents the toroid resistance of the ferrite core part (FRC). (Rt), and "L _toroid " may indicate a component of the toroid inductor (Lt) of the ferrite core (FRC).

That is, the impedance of the ferrite core, for example, the _ferrite core part (FRC) included in the second equivalent circuit (ECT2) of FIG. ) can be expressed as a value of Here, the value of the toroid inductor (Lt) and the value of the toroid resistance (Rt) can be calculated in [Equation 3], so when the corresponding values are applied to [Equation 5], the ferrite core part ( It is possible to extract the value of "Z _ferrite ", which is the impedance of the ferrite core part (FRC) (ie, extract both real and imaginary part values for "Z _ferrite ", which is the impedance of the ferrite core part (FRC)).

Accordingly, the step of calculating the impedance of the second equivalent circuit (S720) is the impedance value of the second equivalent circuit ECT2, that is, the second equivalent circuit, using [Equation 3] and [Equation 5]. The "Z _ferrite " value, which is the impedance of the ferrite core part (FRC) included in the circuit (ECT2), can be extracted.

For example, further referring to FIG. 9 , when the probe is the aforementioned first probe PRB1 (eg, current injection probe, BCI probe), the value of the toroid inductor (Lt) and the toroid resistance (Rt) The values of are extracted as 0.6 μH and 259.17 Ω, respectively, and accordingly, the value of the impedance of the ferrite core part (FRC) (shown as “Z _ferrite ” in FIG. 9) as shown in the graph shown by the dotted line in FIG. 9 is extracted. can do. As another example, when the probe is the aforementioned second probe PRB2 (eg, monitoring probe, measurement probe), the value of the toroid inductor (Lt) and the value of the toroid resistance (Rt) are 1.6 μH and 2.75 KΩ, respectively. , and accordingly, the value of the impedance (shown as “Z _ferrite ” in FIG. 9) of the ferrite core part (FRC) as shown in the graph shown by the solid line in FIG. 9 can be extracted. However, here, the values of the toroid inductor (Lt) and the toroid resistance (Rt) are simply illustrative, and the values may vary depending on the model, shape, and structure of the probe.

Thereafter, in the step of extracting the relative permeability of the ferrite core using the impedance of the second equivalent circuit of the method for extracting the relative permeability of the ferrite core according to the embodiments of the present invention (S730), the [Equation 3] and the [ The relative magnetic permeability for each frequency of the ferrite core may be extracted through the impedance value of the second equivalent circuit ECT2, that is, the ferrite core part FRC, calculated using Equation 5.

For example, as shown in FIG. 9, in both the first probe PRB1 and the second probe PRB2, the impedance value of the ferrite core part FRC depends on the characteristics of the toroid inductor Lt in the low frequency band. Although the magnitude increases linearly as the frequency increases, the slope gradually decreases due to the characteristics of the toroid resistance (Rt), which is a component corresponding to ferrite loss, in the high-frequency band above a certain frequency (eg, tens of MHz) is showing a tendency to

The relative magnetic permeability reflecting only the characteristics of the toroid inductor Lt excluding such a loss can be developed as an impedance value of the toroid inductor Lt as shown in [Equation 6] below.

[Equation 6]

In [Equation 6], "L _toroid " represents the inductance component of the toroid inductor (Lt), "μ" represents the absolute magnetic permeability, "μ ₀ " represents the magnetic permeability of vacuum, "μ _r " Represents the relative magnetic permeability for each frequency of the ferrite core, "N" represents the number of windings of the coil wound around the toroid core, and "h" represents the thickness of the ferrite core part (FRC) (ie, ferrite core) shown in FIG. 10 (h), "a" and "b" respectively represent the inner diameter (a) and outer diameter (b) of the ferrite core portion (FRC) (ie, ferrite core) shown in FIG. 10, and "w" is 2πf (Here, "f" represents frequency), and "Z _inductive " may represent the impedance of the toroid inductor (Lt).

Here, in the case of "Z _inductive " representing the impedance of the toroid inductor Lt included in [Equation 6], as described above, only the characteristics of the toroid inductor Lt excluding the component corresponding to ferrite loss are reflected. It may correspond to impedance. Here, when “Z _inductive ” included in [Equation 6] is replaced with “Z _ferrite ” representing the impedance of the ferrite core (ie, the ferrite core part (FRC)), the loss component (eg, toroid resistance The relative permeability per frequency of the ferrite core may be expressed as an impedance value in which all components substantially contributing to the relative permeability per frequency of the ferrite core, including the component of (Rt), are reflected. [Equation 7] derived accordingly is as follows.

[Equation 7]

In the above equation, “μ _r (w)” represents the relative permeability of the ferrite core, “Z _ferrite” represents the impedance of the second equivalent circuit ECT2 (eg, the ferrite core part FRC), and “ "w" represents 2π* frequency, "μ ₀ " represents the magnetic permeability of vacuum, "N" represents the number of windings of the coil wound around the toroid core, and "h" represents the ferrite core portion shown in FIG. 10 ( FRC) (ie, ferrite core) represents the thickness (h), and "a" and "b" are respectively the inner diameter (a) and outer diameter ( b) can be represented.

Here, as described above, in the step of calculating the impedance of the second equivalent circuit (S720), the value of the impedance of the ferrite core (eg, the ferrite core part (FRC) of FIG. 8) corresponds to the already calculated value. do.

Accordingly, in the step of extracting the relative magnetic permeability of the ferrite core using the impedance of the second equivalent circuit (S730), the value of the impedance of the ferrite core (eg, the ferrite core portion FRC of FIG. 8) (eg, For example, by substituting “Z _ferrite ” into Equation 7, the relative permeability value of the ferrite core (eg, the ferrite core part (FRC)) can be extracted. Accordingly, a relative magnetic permeability value for each frequency including a real part and an imaginary part may be extracted.

For example, further referring to FIGS. 11A and 11B , real and imaginary parts of the relative permeability for each frequency of the ferrite core extracted by the method for extracting the relative permeability of the ferrite core according to embodiments of the present invention are shown. . For example, in FIG. 11A, the real part (shown as 'REL1' in FIG. 11A) and the imaginary part (shown as 'REL1' in FIG. In FIG. 11a, 'IMA1') is shown, and in FIG. 11b, the real part of the extracted ferrite core for the second probe PRB2 (eg, monitoring probe, measurement probe) ('REL2' in FIG. 11b) is shown. ) and an imaginary part (shown as 'IMA2' in FIG. 11B) are shown.

As such, in the case of the relative permeability extraction method of the ferrite core according to the embodiments of the present invention, relatively simple and more accurate relative permeability can be extracted without using a complicated numerical analysis method.

Meanwhile, even if the 3D shape is modeled using the relative extraction rate of the ferrite core extracted in this way, some errors may occur between S-parameters (eg, S21 parameters) between the EM model of the probe and the actual model. Here, in the case of the error, it is due to the difference between the EM model and the real model for the probe, and the error may occur at a constant rate on the S-parameter.

For example, further referring to FIG. 13, the size of the S-parameter (S21) for the EM model of the probe and the size of the S-parameter (S21) measured for the real model may change depending on the frequency. (For example, it changes according to the influence of the toroidal inductor (Lt) and toroidal resistance (Rt) of the ferrite core part (FRC) according to the above description). Here, the ratio of the size of the S-parameter (S21) measured for the real model to the size of the S-parameter (S21) for the EM model for the probe in the entire frequency band (eg, 1 MHz to 400 MHz) In the case of calculation, it may be set as a proportional constant for the size of the S-parameter (S21) for the EM model of the probe and the size of the measured S-parameter (S21) for the real model.

Accordingly, calculating the corrected relative permeability of the ferrite core by applying a proportional constant to the relative permeability of the ferrite core in the method of extracting the relative permeability of the ferrite core according to the embodiments of the present invention (S740), the second equivalent circuit By applying (for example, by multiplying) the proportional constant to the real part and imaginary part of the relative permeability of the ferrite core extracted in the step of extracting the relative permeability of the ferrite core using the impedance of (S730), respectively, the correction relative permeability can be calculated.

For example, as shown in FIG. 12A, the real part (shown as “REL_1” in FIG. 12A) corrected by multiplying the real part of the relative permeability (shown as “REL” in FIG. 12A) by a proportional constant is It can be calculated, and as shown in FIG. 12B, the corrected imaginary part (shown as “IMA_1” in FIG. 12B) by multiplying the imaginary part of the relative permeability (shown as “IMA” in FIG. 12B) by a proportional constant ) can be calculated.

In this case, further referring to FIG. 13, in the case of the size of the S-parameter (S21) for the probe of the EM model, a graph of the EM model modeled using the relative permeability before correction (in FIG. 13, "EM Consistency with S-parameters (S21) measured for the real model in the case of a graph (shown as "EM_1" in FIG. You can see that it is better than this. That is, the relative permeability extraction method of the ferrite core according to the embodiments of the present invention is proportional to correct the error range having a certain ratio to the value of the relative permeability (eg, the real part and the imaginary part of the relative permeability). By applying a constant, a more accurate relative permeability of the ferrite core can be extracted.

14 is a flowchart illustrating an electromagnetic simulation method according to embodiments of the present invention.

1 to 14, the electromagnetic simulation method according to embodiments of the present invention uses the relative permeability of a ferrite core included in a probe used for a Bulk Current Injection (BCI) test to model the probe as an electromagnetic model ( EM) to perform electromagnetic simulation (EM simulation).

For example, the electromagnetic simulation method according to embodiments of the present invention may extract the relative magnetic permeability of the ferrite core (S1410) and implement an electromagnetic model of the probe using the relative magnetic permeability of the ferrite core (S1420).

Here, the step of extracting the relative permeability of the ferrite core (S1410) is substantially the same as or similar to the method of extracting the relative permeability of the ferrite core described with reference to FIGS. do.

Embodiments according to the present invention described above may be implemented in the form of program instructions that can be executed through various computer components and recorded on a computer-readable recording medium. The computer readable recording medium may include program instructions, data files, data structures, etc. alone or in combination. Program instructions recorded on the computer-readable recording medium may be specially designed and configured for the present invention, or may be known and usable to those skilled in the art of computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks and magnetic tapes, optical recording media such as CD-ROMs and DVDs, and magneto-optical media such as floptical disks. media), and hardware devices specially configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include high-level language codes that can be executed by a computer using an interpreter or the like as well as machine language codes such as those produced by a compiler. The hardware device may be configured to act as one or more software modules to perform processing according to the present invention and vice versa.

As described above, the relative permeability extraction method of the ferrite core and the electromagnetic simulation method using the same according to the embodiments of the present invention, except for components to be reflected by modeling the probe in a 3D shape when performing the EM simulation, substantially Since the relative permeability is extracted using an equivalent circuit (second equivalent circuit) using components contributing to the relative permeability of the ferrite core, the relative permeability per frequency of the ferrite core can be extracted more simply and accurately than the conventional method. .

In addition, in the case of the relative permeability extraction method of the ferrite core and the electromagnetic simulation method using the method according to the embodiments of the present invention, the extracted relative permeability is corrected using a proportional constant corresponding to the error to additionally calculate the corrected relative permeability, It is possible to more accurately extract the relative magnetic permeability for each frequency of the ferrite core.

A method for extracting relative permeability of a ferrite core according to various embodiments of the present invention can be described as follows.

In order to solve the above problems, a method for extracting the relative permeability of a ferrite core according to embodiments of the present invention is a relative permeability of a ferrite core included in a probe used for a Bulk Current Injection (BCI) test. In the extraction method, converting a first equivalent circuit corresponding to the probe into a second equivalent circuit, calculating an impedance of the second equivalent circuit, and using the impedance of the second equivalent circuit to determine the relative value of the ferrite core. The method may include extracting magnetic permeability and calculating a corrected relative magnetic permeability of the ferrite core by applying a proportional constant to the relative magnetic permeability of the ferrite core. The second equivalent circuit may be a circuit in which a resistor and an inductor are connected in parallel.

In one embodiment, the ferrite core of the toroid structure included in the probe has an equivalent circuit structure in which a toroid resistor, a toroid inductor, and a toroid capacitor are connected in parallel, and the second equivalent circuit includes the toroid A resistor and the toroid inductor may have a circuit structure connected in parallel.

In an embodiment, in the step of calculating the impedance of the second equivalent circuit, the impedance of the second equivalent circuit may be calculated using the following equation.

[mathematical expression]

In the above equation, Zferrite is the impedance of the second equivalent circuit, Rtoroid is the resistance value of the toroid resistance, and Ltoroid is the inductance of the toroid inductor.

In one embodiment, the first equivalent circuit has a circuit structure in which a probe resistance part, a ferrite core part, and a connector part are connected in series, the probe resistance part includes a DC resistance of the probe, and the ferrite core part comprises the A toroid resistor, a toroid inductor, and a toroid capacitor for the ferrite core of the toroid structure included in the probe have an equivalent circuit structure connected in parallel, and the connector unit includes a connector inductor and a connector for the connector included in the probe. Capacitors may have an equivalent circuit structure connected in parallel.

In one embodiment, in the step of extracting the relative permeability of the ferrite core, the relative permeability may be extracted using the following equation.

[mathematical expression]

In the above equation, μ _r (w) is the relative permeability, Z _ferrite is the impedance of the second equivalent circuit, w is 2π*frequency, μ0 is the permeability of vacuum, N is the number of turns of the ferrite core, , h is the thickness of the ferrite core, a is the inner diameter of the ferrite core, and b is the outer diameter of the ferrite core.

In an embodiment, in the calculating of the corrected relative permeability of the ferrite core, the corrected relative permeability may be calculated by multiplying a real part and an imaginary part included in the relative permeability of the ferrite core by the proportional constant, respectively.

In one embodiment, the probe may be any one of a BCI probe used for the BCI test and a monitoring probe used for the BCI test.

An electromagnetic simulation method according to various embodiments of the present invention can be described as follows.

In order to solve the above problems, the electromagnetic simulation method according to embodiments of the present invention uses the relative permeability of a ferrite core included in a probe used for a Bulk Current Injection (BCI) test, The method of implementing electromagnetic simulation by implementing the probe as an electromagnetic model may include extracting a relative magnetic permeability of the ferrite core, and implementing an electromagnetic model of the probe using the relative magnetic permeability of the ferrite core. there is. The extracting of the relative permeability of the ferrite core may include converting a first equivalent circuit corresponding to the probe into a second equivalent circuit, calculating an impedance of the second equivalent circuit, and impedance of the second equivalent circuit. The method may include extracting the relative permeability of the ferrite core using , and calculating a corrected relative permeability of the ferrite core by applying a proportional constant to the relative permeability of the ferrite core. The second equivalent circuit may be a circuit in which a resistor and an inductor are connected in parallel.

A computer program according to various embodiments of the present invention may be described as follows.

In order to solve the above problems, a computer program according to embodiments of the present invention is a computer program stored in a computer readable medium, the computer program includes instructions, and when executed by a computer system, the instructions may cause the computer system to perform any one of the ferrite core relative permeability extraction method and the electromagnetic simulation method.

Although the above has been described with reference to the embodiments of the present invention, those skilled in the art will understand that the present invention can be variously modified and changed without departing from the spirit and scope of the present invention described in the claims. You will be able to.

100: relative permeability extraction system of ferrite core
110: communication department
120: processor
130: database
BCIT: BCI Test System
DUT: device under test
ECT1: first equivalent circuit
ECT2: second equivalent circuit
FRC: ferrite core
RFG: RF Generator
PRB1: first probe
PRB2: second probe
PS: power supply

Claims (8)

In the relative permeability extraction method of the ferrite core included in the probe used for the BCI (Bulk Current Injection) test,
converting a first equivalent circuit corresponding to the probe into a second equivalent circuit;
calculating an impedance of the second equivalent circuit;
extracting the relative magnetic permeability of the ferrite core using the impedance of the second equivalent circuit; and
Calculating a corrected relative permeability of the ferrite core by applying a proportional constant to the relative permeability of the ferrite core;
The second equivalent circuit is a circuit in which a resistor and an inductor are connected in parallel, a relative permeability extraction method of a ferrite core. The method of claim 1, wherein the ferrite core of the toroid structure included in the probe has an equivalent circuit structure in which a toroid resistor, a toroid inductor, and a toroid capacitor are connected in parallel,
The second equivalent circuit has a circuit structure in which the toroid resistor and the toroid inductor are connected in parallel. The method of claim 2, wherein the calculating of the impedance of the second equivalent circuit calculates the impedance of the second equivalent circuit using the following equation.
[mathematical expression]

In the above equation, Z _ferrite is the impedance of the second equivalent circuit, R _toroid is the resistance value of the toroid resistance, and L _toroid is the inductance of the toroid inductor. The method of claim 1, wherein the first equivalent circuit has a circuit structure in which a probe resistor unit, a ferrite core unit, and a connector unit are connected in series,
The probe resistance part includes a DC resistance of the probe,
The ferrite core part has an equivalent circuit structure in which a toroid resistor, a toroid inductor, and a toroid capacitor are connected in parallel to the ferrite core of the toroid structure included in the probe,
The connector part has an equivalent circuit structure in which a connector inductor and a connector capacitor for a connector included in the probe are connected in parallel. The method of claim 1 , wherein in the extracting of the relative permeability of the ferrite core, the relative permeability is extracted using the following equation.
[mathematical expression]

In the above equation, μ _r (w) is the relative permeability, Z _ferrite is the impedance of the second equivalent circuit, w is 2π*frequency, μ ₀ is the permeability of vacuum, and N is the number of turns of the ferrite core , h is the thickness of the ferrite core, a is the inner diameter of the ferrite core, and b is the outer diameter of the ferrite core. The ferrite core of claim 1 , wherein the calculating of the corrected relative permeability of the ferrite core calculates the corrected relative permeability by multiplying a real part and an imaginary part included in the relative permeability of the ferrite core by the proportional constant, respectively. Relative permeability extraction method of . The method of claim 1 , wherein the probe is any one of a BCI probe used in the BCI test and a monitoring probe used in the BCI test. In a method of performing electromagnetic simulation by implementing the probe as an electromagnetic model using the relative permeability of a ferrite core included in a probe used for a Bulk Current Injection (BCI) test,
extracting the relative magnetic permeability of the ferrite core; and
Implementing an electromagnetic model of the probe using the relative permeability of the ferrite core,
The step of extracting the relative magnetic permeability of the ferrite core,
converting a first equivalent circuit corresponding to the probe into a second equivalent circuit;
calculating an impedance of the second equivalent circuit;
extracting the relative magnetic permeability of the ferrite core using the impedance of the second equivalent circuit; and
Calculating a corrected relative permeability of the ferrite core by applying a proportional constant to the relative permeability of the ferrite core;
The second equivalent circuit is a circuit in which a resistor and an inductor are connected in parallel.

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