3.1.2 probe factor ratio of electric or magnetic field strength at a specified location in near-field evaluation to the signal level measured at the output connection or applied to the
Terms and definitions
For the purpose of this document, the terms and definitions given in IEC 61967-1,
IEC 60050-131 and IEC 60050-161, as well as the following apply
3.1.1 altitude distance between the tip of the near-field probe and the reference plane of the scan (e.g the
PCB, the upper surface of the package)
Note 1 to entry: The term “altitude” refers to the vertical direction in a Cartesian coordinate system (Z-axis) in this document
The probe factor is defined as the ratio of the electric or magnetic field strength at a specific location during near-field evaluation to the signal level recorded at the output connection or applied to the input connection of a probe.
3.1.3 spatial resolution aptitude of a probe to distinguish measured field between two points
Abbreviations
Measuring the electric and magnetic fields across the surface of the integrated circuit (IC) provides insights into the relative strength of emission sources within the IC package This data allows for comparisons between various architectures, aiding in the reduction of RF emissions.
The electric and magnetic field patterns on the surface of an integrated circuit (IC) are indicative of its electromagnetic radiation potential and that of its electronic components This process aims to offer a comparative assessment of ICs rather than to forecast far-field levels for the IC or its circuit board.
Characterizing an integrated circuit (IC) requires precise magnitude and phase measurements at designated frequencies or times, resulting in substantial data collection based on the number of scanned locations and measurement points To ensure accuracy and repeatability, a computer-controlled probe-positioning and measurement system is essential, utilizing optical precision stepper motors Additionally, dedicated software programs are necessary for analyzing and managing the extensive data generated The overall scanning duration is influenced by the number of frequencies or times measured, the locations scanned, and the efficiency of the data collection system.
This document does not define the designs of probe-positioning systems or near-field probes due to the diverse range of IC processes, packaging technologies, and their physical dimensions The design choices for the positioning system and probes are influenced by factors such as the required measurement frequency range, spatial resolution, field type, and the performance of available components like stepper motors.
The spatial resolution depends on the physical dimensions and construction of the probe If the spatial resolution is known, it shall be included in the test report
The altitude of the probe above the IC surface is not specified The actual probe height shall be included in the test report
To optimize spatial resolution while minimizing measurement points, the probe position's step size should be carefully selected In specific areas of the die or package, a smaller step size can enhance resolution Additionally, post-processing data for improved resolution enables a reduction in spatial resolution during measurement, allowing for a larger step size.
General
Test conditions shall meet the requirements of IEC 61967-1 In addition, the following test conditions shall apply.
Supply voltage
A supply voltage should follow the IC manufacturer's specification If the user uses other voltage, it shall be documented in the test report.
Frequency range
An effective frequency range of this radiated emission measurement procedure is 150 kHz to
To effectively cover the entire frequency range up to 6 GHz, it may be necessary to divide the range into sub-ranges This approach allows for the use of multiple probes, with each probe specifically designed to suit an individual frequency sub-range.
General
The test equipment shall meet the requirements as described in IEC 61967-1 In addition, the following test equipment requirements shall apply.
Shielding
For optimal interconnections between the probe and measuring equipment, it is advisable to use double shielded or semi-rigid coaxial cable Additionally, depending on the surrounding environmental conditions, conducting measurements in a shielded room may be necessary.
RF measuring instrument
The choice of RF measuring instrument for this test method is determined by the selected probe type and the need for phase or time information When measuring only emission amplitude with an electric or magnetic field probe, a one-input device like a spectrum analyzer, EMI receiver, or oscilloscope is appropriate For time domain measurements, an oscilloscope is recommended.
To measure both emission amplitude and phase using an electric or magnetic field probe, it is essential to employ a vector signal measuring instrument with two input capabilities.
To accurately measure phase and amplitude using a vector signal measuring instrument, it is essential to utilize the reference input (R) alongside another input (A or B) It is important to note that S-parameter ports are typically not suitable for this type of measurement.
To ensure a sufficient noise margin exceeding 6 dB, the resolution bandwidth of the spectrum analyzer or receiver must be properly adjusted, taking into account the required sweep time based on the selected test procedure Additionally, the video bandwidth should be at least three times greater than the resolution bandwidth Both the resolution bandwidth and video bandwidth will be detailed in the test report.
Preamplifier
A low noise, high gain preamplifier is essential for improving sensitivity and meeting ambient requirements To minimize the noise floor during measurements, it is crucial to connect the preamplifier to the probe using the shortest cable possible.
(e.g gain, noise figure, etc.) should be included in the test report
Near-field probes often exhibit low return loss, which can adversely affect the system's noise figure and gain if there is a poor impedance match To prevent issues like oscillations or damage to the preamplifier, it is crucial to carefully select a preamplifier that ensures stability in a near-field scanning environment.
Cables
The probe's scanning motion necessitates the use of flexible cables connecting various components of the setup It is essential to select durable cables that can withstand the probe's movement while ensuring optimal high-frequency performance Additionally, the test report must include cable losses as a function of frequency.
Owing to the repeated movement of the cables, which can accelerate their deterioration, calibration of the cables shall be carried out regularly When the test frequency is higher than
1 GHz or phase measurements are to be carried out, the cables shall be calibrated before each test.
Near-field probe
General
Near-field probes for surface scanning vary based on user preferences, the type of field being measured, measurement equipment capabilities, and the required spatial resolution Calibration details can be found in Annex A Some probes are designed to receive fields from specific directions, while others may require rotation or replacement to capture fields from multiple angles A summary of the probes utilized in the measurement will be included in the test report The following sections will discuss different types of near-field probes.
NOTE The structures of magnetic and/or electric probes are shown in Annexes B and C However, the applicable frequency range depends on the probe structure and calibration method.
Magnetic (H) field probe
For magnetic field measurements, a single turn, miniature magnetic loop probe is often used
The typical probe is composed of wire, coaxial cable, PCB traces, or any other suitable material An example of a magnetic field probe is shown in Annex B and in IEC 61967-6 [1] 1
Electric (E) field probe
For measuring electric fields, a compact electric field probe is commonly utilized, which can be made from materials such as wire, coaxial cable, or PCB traces An example of such an electric field probe is illustrated in Annex B.
Combined electric and magnetic (E/H) field probe
A miniature magnetic loop probe, often made from wire, coaxial cable, PCB traces, or other appropriate materials, is commonly utilized for measuring combined electric and magnetic fields An example of such an electromagnetic field probe can be found in Annex C.
Probe-positioning and data acquisition system
A precise probe-positioning and data acquisition system is essential, capable of moving the probe in at least two axes parallel to the DUT surface The system must position the probe with a mechanical step size at least ten times smaller than the minimum required step size While Cartesian scanning (X, Y, and optionally Z-axis) is specified, polar and cylindrical scanning methods are also applicable.
Annex D outlines the three coordinate systems and the methods for converting position information among them The preferred system is the right-hand Cartesian coordinates, while any use of the left-hand system must be noted in the test report Additionally, some probe-positioning systems feature a mechanical structure that allows for the rotation of the probe to adjust its orientation, which can be managed by the data acquisition system.
The x, y and z position of the near-field probe may be out of alignment after the rotation Care should be taken to compensate the resulting offset by repositioning the probe
Figure 1 illustrates a probe-positioning system, which is designed to enhance stability by mounting the Device Under Test (DUT) on a printed circuit board (PCB) that is typically secured to a test fixture.
A data acquisition system consists of a computer equipped with software that sets the scan parameters, manages the measuring instrument, and operates the probe scanning system to collect data The configurations of the system and the controlling software will be detailed in the test report.
Figure 1 – Example of probe-positioning system
General
Test setup shall meet the requirements as described in IEC 61967-1 In addition, the following test setup requirements shall apply.
Test configuration
The general test setups are shown in Figures 2, 3 and 4
Figure 2 – One-input RF measurement setup
The setup of Figure 2 allows measurement of only magnitude The setups of Figures 3 and 4 allow magnitude measurements with phase or time domain measurements
Figure 3 – Two-input RF measurement setup with reference probe
For accurate phase or time domain measurements, a reference signal is essential This signal can be applied externally to a device pin, obtained from the device's output pin, or captured using a stationary auxiliary probe.
Figure 4 – Two-input RF measurement setup with reference signal
Reference signal from DUT or external Vector signal measuring instrument or oscilloscope
Control and data acquisition system
Probe positioning system Fixed reference probe
Vector signal measuring instrument or oscilloscope
Control and data acquisition system
Spectrum analyser, EMI receiver or oscilloscope
Control and data acquisition system
Phase information is needed in order to calculate the current distribution on the DUT (see 9.5)
If only the magnitude of the radiated field is required, phase information is not needed.
Test circuit board
The test circuit board used for mounting and scanning the Device Under Test (DUT) can be any board that the scanning probe can access For comparative evaluation of integrated circuits (ICs), it is essential to test them on identical printed circuit boards (PCBs) These PCBs can either be application-specific or standardized test circuit boards designed according to IEC 61967-1 standards.
To improve test reproducibility, the test circuit board must be securely mounted in the probe-positioning system This can be achieved by utilizing a test fixture that minimally affects the radiated field.
Probe-positioning system software setup
Once the DUT and test PCB are established, confirm that the probe-positioning system software is configured with the correct scan parameters, especially regarding the target scan area Check for any obstacles that could potentially harm the probe within this area Additionally, some scanner software necessitates reference points to address alignment errors and origin offsets, enhancing measurement reproducibility Tools such as cameras and lasers can aid in achieving precise alignment.
Images of the DUT may also be recorded and used as a background for the field measurements (see 9.4) A brief description of such procedures shall be included in the test report.
DUT software
Appropriate software shall be implemented in the DUT during the measurement to meet the requirements of IEC 61967-1 The description of the software shall be included in the test report
General
The test procedure will follow IEC 61967-1, with modifications as specified These default test conditions ensure a consistent testing environment Any alternative conditions agreed upon by users must be documented in the test report.
Ambient conditions
The ambient RF noise level shall be measured to establish the noise floor of the test setup
Only measurement results, at least 6 dB above the noise floor, are considered reliable The
DUT shall be installed in the test set-up, as used for testing The DUT shall not be activated
The test equipment must be configured for an operational scan to measure ambient noise levels, and the findings will be documented in the test report.
Excessive ambient RF noise can compromise the integrity of the measurement system, particularly affecting interconnecting cables and connectors To mitigate this issue, it may be necessary to utilize a shielded enclosure, implement a lower noise or higher gain preamplifier, or adjust to a narrower resolution bandwidth.
Test technique
– Annex A – Calibration of near-field probes
The text of this technical specification is based on the following documents:
Enquiry draft Report on voting
Full information on the voting for the approval of this technical specification can be found in the report on voting indicated in the above table
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2
A list of all parts in the IEC 61967 series, published under the general title Integrated circuits – Measurement of electromagnetic emissions,can be found on the IEC website
The committee has determined that the publication's content will stay the same until the stability date specified on the IEC website at "http://webstore.iec.ch" for the relevant publication data.
• transformed into an International standard,
• replaced by a revised edition, or
The 'colour inside' logo on the cover of this publication signifies that it includes essential colors for a proper understanding of the content Therefore, it is recommended that users print this document using a color printer.
Techniques for scanning the near-fields emitted by integrated circuits and their environments can pinpoint radiation areas that may interfere with nearby devices By correlating magnetic or electric field strengths to specific locations on a device, valuable insights can be gained to enhance both the functionality and electromagnetic compatibility (EMC) performance of integrated circuits.
Recent advancements in near-field scan techniques have significantly enhanced the sensitivity, bandwidth, and spatial resolution of probes, enabling the analysis of integrated circuits operating in the gigahertz range These techniques allow for the measurement of radiation in both frequency and time domains, facilitating the examination of fields generated by integrated circuits as well as externally applied disturbances Additionally, post-processing methods can greatly improve the resolution of near-field scan measurements, with the flexibility to present the data in various formats according to user preferences.
INTEGRATED CIRCUITS – MEASUREMENT OF ELECTROMAGNETIC EMISSIONS –
Part 3: Measurement of radiated emissions –
IEC 61967 outlines a test procedure for evaluating the near electric, magnetic, or electromagnetic field components at the surface of integrated circuits (ICs) This diagnostic method is designed for architectural analysis of ICs, focusing on aspects like floor planning and power distribution optimization The procedure is applicable to measurements taken on ICs mounted on any circuit board that can be accessed by a scanning probe.
In certain situations, it is beneficial to examine not just the integrated circuit (IC) but also its surrounding environment To facilitate the comparison of surface scan emissions across various ICs, a standardized test board has been established.
This measurement technique maps the electric or magnetic near-field emissions over integrated circuits (ICs) and is effective up to 6 GHz The resolution depends on the measurement probe's capabilities and the precision of the probe-positioning system While existing probe technology allows for extending the frequency limit, this is not covered in the current specification Measurements can be conducted in either the frequency domain or the time domain.
This document references essential documents that are crucial for its application For references with specific dates, only the cited edition is applicable In the case of undated references, the most recent edition of the referenced document, including any amendments, is relevant.
IEC 60050(all parts), International Electrotechnical Vocabulary (available at
IEC 61967-1, Integrated circuits – Measurement of electromagnetic emissions, 150 kHz to
1 GHz – Part 1: General conditions and definitions
For the purpose of this document, the terms and definitions given in IEC 61967-1,
IEC 60050-131 and IEC 60050-161, as well as the following apply
3.1.1 altitude distance between the tip of the near-field probe and the reference plane of the scan (e.g the
PCB, the upper surface of the package)
Note 1 to entry: The term “altitude” refers to the vertical direction in a Cartesian coordinate system (Z-axis) in this document
The probe factor is defined as the ratio of the electric or magnetic field strength at a specific location during near-field evaluation to the signal level measured at the output connection or applied to the input connection of a probe.
3.1.3 spatial resolution aptitude of a probe to distinguish measured field between two points
Measuring the electric and magnetic fields across the surface of the integrated circuit (IC) provides insights into the relative strength of emission sources within the IC package This data allows for comparisons between various architectures, aiding in the reduction of RF emissions.
The electric and magnetic field patterns on the surface of an integrated circuit (IC) are indicative of its electromagnetic radiation potential and that of its electronic components This process aims to offer a comparative assessment of ICs rather than to forecast far-field levels for the IC or its circuit board.
Characterizing an integrated circuit (IC) requires precise magnitude and phase measurements at designated frequencies or times, resulting in extensive data collection based on the number of scanned locations and measurement points To ensure accuracy and repeatability, a computer-controlled probe-positioning and measurement system is essential, utilizing optical precision stepper motors Additionally, dedicated software programs are necessary for analyzing and managing the substantial data generated The duration of the scanning process is influenced by the number of frequencies or times measured, the locations assessed, and the efficiency of the data collection system.
This document does not define the designs of probe-positioning systems or near-field probes due to the diverse range of IC processes, packaging technologies, and physical dimensions The design choices for the positioning system and probes are influenced by factors such as the required measurement frequency range, spatial resolution, field type, and the performance of available components like stepper motors.
The spatial resolution depends on the physical dimensions and construction of the probe If the spatial resolution is known, it shall be included in the test report
The altitude of the probe above the IC surface is not specified The actual probe height shall be included in the test report
To optimize spatial resolution while minimizing measurement points, the probe position's step size should be carefully selected In specific areas of the die or package, a smaller step size can enhance resolution Additionally, by employing post-processing techniques for improved resolution, the spatial resolution during measurement can be decreased, enabling the use of a larger step size.
Test conditions shall meet the requirements of IEC 61967-1 In addition, the following test conditions shall apply
A supply voltage should follow the IC manufacturer's specification If the user uses other voltage, it shall be documented in the test report
An effective frequency range of this radiated emission measurement procedure is 150 kHz to
To effectively cover the entire frequency range up to 6 GHz, it may be necessary to divide the range into sub-ranges This approach allows for the use of multiple probes, with each probe specifically designed to suit an individual frequency sub-range.
The test equipment shall meet the requirements as described in IEC 61967-1 In addition, the following test equipment requirements shall apply
General
The test report shall meet the requirements of IEC 61967-1 In addition, the following test report requirements shall apply.
Measurement conditions
All measurement conditions must be recorded in the test report, including scan frequency, scan area, probe altitude, step size, and orientation Additionally, relevant details about the data acquisition software and alignment aids should be documented.
Data exchange
– Annex D – Coordinate systems c) Expansion of:
– Annex A – Calibration of near-field probes
The text of this technical specification is based on the following documents:
Enquiry draft Report on voting
Full information on the voting for the approval of this technical specification can be found in the report on voting indicated in the above table
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2
A list of all parts in the IEC 61967 series, published under the general title Integrated circuits – Measurement of electromagnetic emissions,can be found on the IEC website
The committee has determined that the publication's content will stay the same until the stability date specified on the IEC website at "http://webstore.iec.ch" for the relevant publication data After this date, the publication will be updated.
• transformed into an International standard,
• replaced by a revised edition, or
The 'colour inside' logo on the cover of this publication signifies that it includes essential colors for a proper understanding of the content To fully grasp the material, users are advised to print this document using a color printer.
Techniques for scanning the near-fields emitted by integrated circuits and their environments can pinpoint radiation areas that may interfere with nearby devices By correlating magnetic or electric field strengths to specific locations on a device, valuable insights can be gained to enhance both the functionality and electromagnetic compatibility (EMC) performance of integrated circuits.
Recent advancements in near-field scan techniques have significantly enhanced sensitivity, bandwidth, and spatial resolution, enabling the analysis of integrated circuits operating in the gigahertz range These techniques allow for the measurement of radiation in both frequency and time domains, facilitating the examination of fields generated by integrated circuits as well as externally applied disturbances Additionally, post-processing methods can greatly improve the resolution of near-field scan measurements, with the flexibility to present the data in various formats according to user preferences.
INTEGRATED CIRCUITS – MEASUREMENT OF ELECTROMAGNETIC EMISSIONS –
Part 3: Measurement of radiated emissions –
IEC 61967 outlines a test procedure for evaluating the near electric, magnetic, or electromagnetic field components at the surface of integrated circuits (ICs) This diagnostic method is designed for architectural analysis of ICs, including floor planning and power distribution optimization The procedure is applicable to measurements taken on ICs mounted on any circuit board that can be accessed by a scanning probe.
In certain situations, it is beneficial to examine not just the integrated circuit (IC) but also its surrounding environment To facilitate a comparison of surface scan emissions across various ICs, a standardized test board has been established.
This measurement technique maps the electric or magnetic near-field emissions over integrated circuits (ICs) and is effective up to 6 GHz The measurement resolution relies on the capabilities of the probe and the accuracy of the probe-positioning system While existing probe technology allows for extending the frequency limit, this is not covered in the current specification Measurements can be conducted in either the frequency domain or the time domain.
This document references essential documents that are crucial for its application For references with specific dates, only the cited edition is applicable In the case of undated references, the most recent edition of the referenced document, including any amendments, is relevant.
IEC 60050(all parts), International Electrotechnical Vocabulary (available at
IEC 61967-1, Integrated circuits – Measurement of electromagnetic emissions, 150 kHz to
1 GHz – Part 1: General conditions and definitions
For the purpose of this document, the terms and definitions given in IEC 61967-1,
IEC 60050-131 and IEC 60050-161, as well as the following apply
3.1.1 altitude distance between the tip of the near-field probe and the reference plane of the scan (e.g the
PCB, the upper surface of the package)
Note 1 to entry: The term “altitude” refers to the vertical direction in a Cartesian coordinate system (Z-axis) in this document
The probe factor is defined as the ratio of the electric or magnetic field strength at a specific location during near-field evaluation to the signal level recorded at the output connection or applied to the input connection of a probe.
3.1.3 spatial resolution aptitude of a probe to distinguish measured field between two points
Measuring the electric and magnetic fields across the surface of the integrated circuit (IC) provides insights into the relative strength of emission sources within the IC package This approach allows for comparisons between various architectures, aiding in the reduction of RF emissions.
The electric and magnetic field patterns on the surface of an integrated circuit (IC) are linked to its electromagnetic radiation potential and the electronic modules it comprises This process aims to offer a comparative assessment of ICs rather than to forecast far-field levels for the IC or its circuit board.
Characterizing an integrated circuit (IC) requires precise magnitude and phase measurements at designated frequencies or times, resulting in substantial data collection based on the number of scanned locations and measurement points To ensure accuracy and repeatability, a computer-controlled probe-positioning and measurement system is essential, utilizing optical precision stepper motors managed by specialized control software Additionally, the analysis and management of the extensive data collected typically necessitate dedicated software programs The overall scanning duration is influenced by the number of frequencies or times measured, the locations assessed, and the efficiency of the data collection system.
This document does not define the designs of probe-positioning systems or near-field probes due to the diverse range of IC processes, packaging technologies, and physical dimensions The design choices for the positioning system and probes are influenced by factors such as the required measurement frequency range, spatial resolution, field type, and the performance of available components like stepper motors.
The spatial resolution depends on the physical dimensions and construction of the probe If the spatial resolution is known, it shall be included in the test report
The altitude of the probe above the IC surface is not specified The actual probe height shall be included in the test report
To optimize spatial resolution while reducing the number of measurement points, the probe position's step size should be carefully selected In specific areas of the die or package, a smaller step size can enhance resolution Additionally, by employing post-processing techniques for improved resolution, the spatial resolution during measurement can be decreased, enabling the use of a larger step size.
Test conditions shall meet the requirements of IEC 61967-1 In addition, the following test conditions shall apply
A supply voltage should follow the IC manufacturer's specification If the user uses other voltage, it shall be documented in the test report
An effective frequency range of this radiated emission measurement procedure is 150 kHz to
To effectively cover the entire frequency range up to 6 GHz, it may be necessary to divide the range into sub-ranges This approach allows for the use of multiple probes, with each probe specifically designed to suit an individual frequency sub-range.
The test equipment shall meet the requirements as described in IEC 61967-1 In addition, the following test equipment requirements shall apply
General
Calibration of a probe compensates variations of sensitivity with frequency and allows conversion of the signal level at its output to magnetic or electric field strength
The relationship between measured signal level and field strength is determined by the probe factor of the probe Various equations are available and widely utilized to express this relationship This specification does not favor any particular equation, and thus, all are presented for consideration.
When measuring voltage or current at the output of the probe, the probe factor may be calculated according to one of the following equations:
F PA and F PB are the probe factors;
M F is the measured signal level in volts (V) or amperes (A);
F is the field strength in volts per metre (V/m) or amperes per metre (A/m)
F PA and F PB are simply reciprocals of each other
When the power at the output of the probe is measured, the equations for calculating the probe factor become:
F PC and F PD are the probe factors;
M F is the measured signal level in watts (W);
F is the field strength in volts per metre (V/m) or amperes per metre (A/m);
F PC and F PD are simply reciprocals of each other
The probe factor may also be expressed in dB
The relationship between units and the probe factor is clearly identifiable, as demonstrated in Tables A.1 and A.2, which outline the allowed unit combinations To prevent misunderstandings, it is essential to refrain from using scaling factors such as k, m, or à Additionally, employing parentheses in unit expressions helps distinguish between similar units, such as dBm for decibels relative to milliwatts and dB(m) for decibels relative to meters.
Table A.1 – Probe factor linear units
Probe factor F PA or F PC F PB or F PD Field strength units ( F ) A/m V/m A/m V/m
W Ω⋅m 2 (A.3) S⋅m 2 (A.3) S/m 2 (A.4) Ω/m 2 (A.4) NOTE The number in brackets refers to the appropriate equation
Table A.2 – Probe factor logarithmic units
Probe factor F PA or F PC F PB or F PD Field strength units
Measured signal units ( M F ) dBV dB(Ω⋅m)
(A.1) dB(m) (A.1) dB(S/m) (A.2) dB(1/m) (A.2) dBA dB(m)
(A.1) dB(S⋅m) (A.1) dB(1/m) (A.2) dB(Ω/m) (A.2) dBW dB(Ω⋅m 2 )
(A.3) dB(S⋅m 2 ) (A.3) dB(S/m 2 ) (A.4) dB(Ω/m 2 ) (A.4) NOTE The number in brackets refers to the appropriate equation
For an emission scan, the probe measures the field (electrical or magnetic) surrounding it
The probe factor is defined solely as a function of frequency, making the distance from the source irrelevant It is essential to include a sufficient range of frequencies to accurately describe the characteristic As illustrated in Figure A.1, the graph of probe factor (voltage measured at the probe's output) versus frequency shows a slope of 20 dB per decade at lower frequencies, while at higher frequencies, the measured probe factor diverges from theoretical values.
Figure A.1 – Typical probe factor against frequency
Suppliers may include calibration data with the probe, eliminating the need for the calibration method outlined below However, periodic verification using the specified method is still necessary.
The calibration of measurement probes is essential and follows a specific procedure A microstrip line method is employed to determine the probe factor, as it accurately represents actual measurements This involves measuring the output signal level of the probe and comparing it with the field strength derived from either a 3D electromagnetic simulator or theoretical analysis per IEC 61967-6 The probe factor is defined as the ratio of the measured signal level to the calculated field strength To minimize measurement errors and enhance repeatability, this calibration should be conducted using the specified surface scan measurement setup.