IEC 61967 8 Edition 1 0 2011 08 INTERNATIONAL STANDARD NORME INTERNATIONALE Integrated circuits – Measurement of electromagnetic emissions – Part 8 Measurement of radiated emissions – IC stripline met[.]
General
The test conditions shall meet the requirements as described in IEC 61967-1 In addition, the following test conditions shall apply.
Supply voltage
The supply voltage shall be as specified by the IC manufacturer If the users of this procedure agree to other values, they shall be documented in the test report.
Frequency range
The effective frequency range for the IC stripline is 150 kHz to 3 GHz The range is limited by its Voltage Standing Wave Ratio (VSWR) characteristics (≤ 1,25)
General
The test equipment shall meet the requirements as described in IEC 61967-1 In addition, the following test equipment requirements shall apply.
RF measuring instrument
A spectrum analyzer or EMI receiver shall be used The resolution bandwidth shall be 9 kHz for EMI receivers or 10 kHz for spectrum analyzers in the frequency range from 150 kHz to
30 MHz and respectively 120 kHz or 100 kHz above 30 MHz according to IEC 61967-1
Measurements should be conducted using a peak detector and reported in dBàV units, where for a 50 Ω system, dBm readings can be converted by adding 107 Spectrum analyzers must sweep the frequency band of interest in either calibrated or coupled mode (auto sweep).
Preamplifier
A low noise preamplifier with a gain of 20 dB to 30 dB can be optionally utilized When employed, it should be directly connected to the measurement port of the IC stripline using the suitable 50 Ω coaxial adapter.
IC stripline
A TEM waveguide features an active conductor positioned at a specified distance above an enlarged ground plane, with port structures at both ends and an optional shielded enclosure The standard spacing between the active conductor and the ground plane of the integrated circuit (IC) stripline is 6.7 mm, although alternative spacings may be utilized, provided they are documented in the test report.
NOTE A conversion factor allows comparisons between IC stripline arrangements with different spacing between active conductor and ground plane (see Annex A)
The IC stripline arrangement facilitates wave propagation in the transverse electromagnetic mode, creating a specific field for testing between the active conductor and the enlarged ground plane, ideally aligned with the ground plane of a standard EMC test board as per IEC 61967-1 This test board manages the geometry and orientation of the operating IC in relation to the IC stripline, while eliminating any connecting leads within the stripline, which are located on the board's backside Additionally, an optional shielding enclosure can be employed to secure the IC stripline configuration and provide shielding, resulting in a closed version of the IC stripline compared to the open version without the enclosure.
For further information, see Annex A
A 50 Ω termination with a VSWR less than 1,1 over the frequency range of measurement is recommended for the IC stripline 50 Ω port not connected to the RF measuring instrument.
System gain
The measuring equipment's gain or attenuation, excluding the IC stripline, must be accurately determined to within ±0.5 dB Additionally, the gain of the RF measurement system should consistently fall within a 6 dB envelope across the specified frequency range.
General
The test set-up shall meet the requirements as described in IEC 61967-1 In addition, the following test set-up requirements shall apply.
Test configuration
See Figure 1 for IC stripline test configuration One of the 50 Ω ports is terminated with a
50 Ω load The remaining 50 Ω port is connected to the spectrum analyzer through the optional preamplifier For further information and cross section view of the IC stripline arrangement, see Annex A
Figure 1 – IC stripline test set-up
EMC test board (PCB)
The Device Under Test (DUT) must be installed on a printed circuit board (PCB) in accordance with IEC 61967-1 In instances where there is a conflict between IEC 61967-1 and this standard, the provisions of this standard take precedence.
The EMC test board is designed with specific measurement and monitoring points to guarantee the proper operation of the Device Under Test (DUT) It manages the geometry and orientation of the DUT in relation to the active conductor, and in the case of a closed IC stripline version, it removes any connecting leads located on the backside of the board, which are outside the housing.
General
These default test conditions are intended to assure a consistent test environment If the users of this procedure agree to other conditions, they shall be documented in the test report.
Ambient conditions
The definitions for ambient temperature and general condition of IEC 61967-1 are valid
The ambient RF noise level must be confirmed to be at least 6 dB lower than the lowest emission levels to be measured Additionally, the Device Under Test (DUT) should be properly installed in the testing setup used for the evaluation.
DUT shall not be activated (e.g power supply voltage disabled) A scan shall be made to measure the ambient noise A description of the ambient shall be a part of the test report
To address excessive noise floor measurements caused by external ambient sounds or the inherent noise of the measurement system, it is advisable to utilize a shielded enclosure Additionally, enhancing the noise floor measurement system can be achieved by incorporating a lower noise preamplifier.
Operational check
Energize the DUT and complete an operational check to assure proper function of the device
Verification of IC stripline RF characteristic
To verify the RF characteristics of the IC stripline, the Voltage Standing Wave Ratio (VSWR) of the empty stripline with a 50 Ω load termination at the second port must be measured and recorded in the test report, ensuring that the value is below 1.25.
Optionally it is recommended to check the DUT-loaded IC stripline In this case, the IC stripline resonances shall be verified with unpowered DUT in accordance to IEC 61000-4-20
A P fwd output fwd refl tloss 10 lg ≤ 1
A tloss is the transmission loss of loaded IC stripline (dB);
P ref l is the reflected power at input port (W);
P fwd is the forward power at input port (W);
P output is the measured power at output port (W)
Measurements carried out at frequencies where the VSWR and losses A tloss exceed the maximum tolerated values shall be ignored.
Test technique
With the EMC test board energized and the DUT being operated in the intended test mode, measure the RF emissions over the desired frequency band
To effectively use a spectrum analyzer, activate the "Max Hold" function and conduct at least three sweeps while the IC code loop is running Ensure that the sweep time significantly exceeds the execution time of the IC code loop.
The "Max Hold" feature on a spectrum analyzer captures and retains the highest level of each trace data point, updating these points whenever a new maximum is identified during subsequent sweeps.
When operating a receiver, ensure that the dwell time for each test frequency is at least twice the IC code loop execution time, and document the highest level detected.
Four emissions measurements were conducted, yielding four distinct data sets The initial measurement involved the EMC test board positioned in a random orientation The second measurement was taken after rotating the EMC test board 90 degrees from its initial position The third and fourth measurements followed a similar protocol.
EMC test board is rotated again to ensure emissions are measured from all four possible orientations The four sets of data shall be documented in the test report
General
The test report shall be in accordance with the requirements of IEC 61967-1 In addition, the following test report requirements shall apply.
Measurement conditions
All measurement conditions shall be documented in the test report
Acceptance levels for IC emissions must be mutually agreed upon by manufacturers and users, utilizing the reference level scheme outlined in Annex B These reference levels are applicable for measurements within the frequency range of 150 kHz to 3 GHz, expressed in units of dBµV.
The IC stripline offers a broadband method of measuring either immunity of a DUT to fields generated within the IC stripline or radiated emission from a DUT placed within the IC stripline
The IC stripline technology overcomes the limitations of conventional antennas, such as bandwidth restrictions, non-linear phase, directivity, and polarization issues It functions as a specialized transmission line that propagates a transverse electromagnetic (TEM) wave, characterized by orthogonal electric (E) and magnetic (H) fields that are perpendicular to the propagation direction This configuration mimics a planar field found in free space, maintaining an impedance of 377 Ω Notably, the TEM mode does not have a low-frequency cut-off, enabling the IC stripline to operate effectively at very low frequencies.
TEM mode also has linear phase and constant amplitude response as a function of frequency
The IC stripline enables precise generation and detection of field intensity However, its upper frequency limit is constrained by signal distortion due to resonances and multi-moding, which are influenced by the physical dimensions and configuration of the stripline.
The IC stripline is designed with impedance matching at the input and output feed points, ensuring a VSWR of less than 1.25 up to its rated frequency There are two versions of the IC stripline: the open version, which follows a standard stripline configuration, and the closed version, which includes a shielding case The active conductor is tapered at both ends to connect with conventional 50 Ω coaxial connectors For EMC testing, the board can be based on a TEM cell board in accordance with IEC 61967-1 The first resonance is indicated by a high VSWR within a narrow frequency range, and an IC stripline validated for field generation at maximum frequency is also suitable for emission measurements at that frequency.
RF connector DUT IC stripline active conductor
Figure A.1 – Cross section view of an example of an unshielded IC stripline
EMC test board à-stripline housing
DUT IC stripline active conductor
Figure A.2 – Cross section view of an example of an IC stripline with housing
The maximum usable Device Under Test (DUT) size is constrained by the dimensions of the IC stripline According to IEC 61000-4-20, the recommended ratio of DUT package height to IC stripline height is one third, with a maximum limit of one half Additionally, in the x-y dimension, the package width should not exceed the active conductor width by more than 10%.
3D field simulations indicate that a uniform field, ranging from +0 dB to -3 dB, exists outside the geometrical boundary of the active conductor width This uniformity extends to a package size that is 10% larger than the active conductor width at half the height of the active conductor.
The limitation values for the 6,7 mm IC stripline for example are given in Table A.1 and Table
A.2 The active conductor width for the closed version is dependent on the distance between active conductor and housing The complete setup has to fulfill the requirements of 8.4
Table A.1 – Maximum DUT dimensions for 6,7 mm IC stripline open version
IC stripline open version DUT z dimension (height) 6,7 mm ≤3,35 mm x-y dimension (width) 33 mm ≤36,3 mm
Table A.2 – Maximum DUT dimensions for 6,7 mm IC stripline closed version
IC stripline closed version DUT z dimension (height) 6,7 mm ≤3,35 mm x-y dimension (width) 24 mm ≤26,4 mm
NOTE The 24 mm width of the closed version stripline is related to the stripline height and shielding design with shape and distance to achieve the stripline characteristic defined in 8.4
A.2 Characteristic impedance of stripline arrangements
The nominal, characteristic impedance of an open version of IC stripline can be calculated as follows [3], if 1 < w/h ≤ 10
1 Figures in square brackets refer to the Bibliography
Z is the characteristic impedance (Ω), typical 50 Ω; w is the width (m) of active conductor ; h is the height (m) between the active conductor and ground plane
For the closed version of the IC stripline the influence of housing has to be taken into account
The correction is influenced by the geometry of the housing For spherical housing surfaces, an analytical formula for characteristic impedance is not available, necessitating empirical investigations Therefore, the characteristic impedance of stripline arrangements must be confirmed through measurement.
A.3 Conversion for different active conductor heights
A conversion factor (X) to correlate measuring results of IC striplines with different heights to the default IC stripline height of 6,7 mm can be calculated by:
X is the conversion factor (dB) to IC stripline 6,7 mm height type results; h 1 is the active conductor height of specific type; h 2 is the active conductor height of 6,7 mm type
The conversion factor for an 8 mm IC stripline is X = 1.54 dB, indicating that 1.54 dB must be added to the measured voltage in dBµV at the measurement port of the 8 mm height.
A.4 Example for IC stripline arrangement
Figure A.3 illustrates an example of an IC stripline with housing, where the x-y dimensions are determined by the EMC test board specifications (IEC 61967-1: 100 mm × 100 mm) It is essential to position the housing in the z direction as far as possible from the active conductor to minimize resonances and multi-moding within the relevant frequency range.
Figure A.3 – Example of IC stripline with housing
This annex provides a method of specifying the emission level profiles of integrated circuits
This annex serves as a guideline rather than a product specification By applying the concepts outlined in this standard and through mutual agreement between the manufacturer and the user, it is feasible to create a detailed description of the RF emissions behavior for a specific integrated circuit in one of three field orientations (x-y-z).
Figure B.1 illustrates a scheme for classifying emission levels in integrated circuits (ICs) To utilize the classification outlined in IEC 61967-2, values must be computed using Equation (B.1).
A is the converted result for comparison with reference levels;
B is the measurement result ; h àTEM is the septum height àTEM cell 45 mm (default); h IC stripline is the active conductor height 6,7 mm (default)
The maximum emission level is typically represented by a combination of two letters followed by a number, adhering to a consistent sequence If any of the three components are unnecessary, the respective letter or number will be excluded.
The first character represents the location of the horizontal line with a zero dB/decade slope, while the second character denotes the position of the -20 dB/decade slope Lastly, the third character indicates the position of the -40 dB/decade slope.
Such defined maximum emission levels with the described notation offer a standardized way to communicate maximum emission levels unambiguously
[1] Kửrber, Klotz, Mueller, Trebeck, IC- Stripline – A new Proposal for Susceptibility and
Emission Testing of ICs, EMC COMPO 2007
[2] Kửrber, Mueller, Trebeck, IC- Streifenleitung – Neues Messverfahren zur Bewertung der
EMV- Eigenschaften von Halbleitern, EMV Düsseldorf 2008
[3] M V Schneider, Microstrip Lines for Microwave Integrated Circuits The Bell System
Technical Journal, vol 48, pp 1421–1444, May 1969
[4] Kửrber, Klotz, Mỹller, Mỹllerwiebus, Trebeck, IC- Stripline for Susceptibility and
Emission Testing of ICs, EMC COMPO 2009
6.4 Ligne TEM à plaques (stripline) pour CI 24
8.4 Vérification des caractéristiques RF de la ligne TEM à plaques (stripline) pour CI 26
10 Niveaux de référence des émissions du CI 27
Annexe A (normative) Description de la ligne TEM à plaques (stripline) pour CI 28
Annexe B (informative) Spécification des niveaux d’émission 32
Figure 1 – Montage d’essai de la ligne TEM à plaques (stripline) pour CI 25
Figure A.1 – Vue en coupe d’un exemple de ligne TEM à plaques (stripline) pour CI non blindée 28
Figure A.2 – Vue en coupe d’un exemple de ligne TEM à plaques (stripline) pour CI comportant une enceinte d’essai 29
Figure A.3 – Exemple de ligne TEM à plaques (stripline) pour CI comportant une enceinte d’essai 31
Figure B.1 – Niveaux de caractérisation des émissions 33
Tableau A.1 – Dimensions maximales du DEE pour la version ouverte de la ligne TEM à plaques (stripline) pour CI de 6,7 mm 29
Tableau A.2 – Dimensions maximales du DEE pour la version fermée de la ligne TEM à plaques (stripline) pour CI de 6,7 mm 29
CIRCUITS INTÉGRÉS – MESURE DES ÉMISSIONS ÉLECTROMAGNÉTIQUES –
Partie 8: Mesure des émissions rayonnées – Méthode de la ligne TEM à plaques (stripline) pour CI
The International Electrotechnical Commission (IEC) is a global standards organization comprising national electrotechnical committees Its primary goal is to promote international cooperation on standardization in the fields of electricity and electronics To achieve this, the IEC publishes international standards, technical specifications, technical reports, publicly accessible specifications (PAS), and guides, collectively referred to as "IEC Publications." The development of these publications is entrusted to study committees, which allow participation from any national committee interested in the subject Additionally, international, governmental, and non-governmental organizations collaborate with the IEC in its work The IEC also works closely with the International Organization for Standardization (ISO) under conditions established by an agreement between the two organizations.
Official decisions or agreements of the IEC on technical matters aim to establish an international consensus on the topics under consideration, as each study committee includes representatives from the relevant national IEC committees.
Généralités
Les conditions d’essai doivent satisfaire aux exigences décrites dans la CEI 61967-1 De plus, les conditions d’essai suivantes doivent s’appliquer.
Tension d’alimentation
The power supply voltage must match the specifications provided by the IC manufacturer If users of this procedure agree on different values, these should be included in the test report.
Plage de fréquences
The effective frequency range for the stripline transmission line in integrated circuits (ICs) is between 150 kHz and 3 GHz, constrained by its voltage standing wave ratio (VSWR) characteristics, which should be less than or equal to 1.25.
Généralités
L’appareillage d’essai doit satisfaire aux exigences décrites dans la CEI 61967-1 De plus, les exigences suivantes relatives à l’appareillage d’essai doivent s’appliquer.
Appareil de mesure RF
An EMI receiver or spectrum analyzer is essential for accurate measurements The resolution bandwidth should be set to 9 kHz for EMI receivers and 10 kHz for spectrum analyzers within the frequency range of 150 kHz to 30 MHz.
120 kHz ou 100 kHz au-dessus de 30 MHz selon la CEI 61967-1 Des mesures doivent être effectuộes avec un dộtecteur de crờte et prộsentộes en unitộs de dBàV [pour systốme 50 Ω:
(indications en dBm) + 107 = dBàV] Pour les analyseurs de spectre, la bande de frộquences étudiée doit être balayée en mode étalonné ou couplé (balayage automatique).
Préamplificateur
Optionally, a low-noise preamplifier with a gain of 20 dB to 30 dB can be utilized If employed, the preamplifier should be directly connected to the measurement access of the stripline for the circuit board, using the appropriate 50 Ω coaxial adapter.
Ligne TEM à plaques (stripline) pour CI
Guide d’ondes TEM, comprenant un conducteur actif placé sur un espacement défini sur un plan de masse agrandi, connecté à une structure d’accès à chaque extrémité et une cage de
Faraday facultative L’espacement entre le conducteur actif et le plan de masse de la ligne
TEM à plaques (stripline) pour CI a une valeur par défaut de 6,7 mm Un autre espacement peut être utilisé mais il doit être noté dans le rapport d’essai
NOTE Un facteur de conversion permet des comparaisons entre les agencements de ligne TEM à plaques
(stripline) pour CI avec différents espacements entre le conducteur actif et le plan de masse (voir l’Annexe A)
The stripline configuration of the TEM line guides wave propagation in the transverse electromagnetic mode, creating a specific field for testing between the active conductor and the enlarged ground plane, preferably the ground plane of the standardized EMC test board according to IEC 61967-1 This EMC test board controls the geometry and orientation of the integrated circuit (IC) in operation relative to the stripline, while eliminating all connection conductors within the stripline, which are located on the back side of the board, opposite the stripline.
Faraday facultative peut être utilisée pour fixer la configuration de la ligne TEM à plaques
(stripline) pour CI, ainsi qu’à des fins de blindage Cela donne une version fermée de la ligne
TEM à plaques (stripline) pour CI par opposition à la version ouverte sans enveloppe de blindage
Pour des informations complémentaires, voir l'Annexe A.
Terminaison de 50 Ω
A 50 Ω termination with a VSWR of less than 1.1 is recommended for the 50 Ω access of the stripline to the integrated circuit (IC) that is not connected to the RF measurement device within the measurement frequency range.
Gain du système
The gain or attenuation of the measurement device, without the stripline TEM line for integrated circuits, must be accurately known within ±0.5 dB Additionally, the RF measurement system's gain should remain within a 6 dB envelope across the frequency range being studied.
Généralités
Le montage d’essai doit satisfaire aux exigences décrites dans la CEI 61967-1 De plus, les exigences suivantes relatives au montage d’essai doivent s’appliquer.
Configuration d’essai
Voir la Figure 1 pour la configuration d’essai de la ligne TEM à plaques (stripline) pour CI
One end of the 50 Ω connection is terminated with a 50 Ω load, while the other end is linked to the spectrum analyzer through an optional preamplifier For additional information and a cross-sectional view of the stripline configuration for integrated circuits (IC), please refer to Appendix A.
Stimulation et contrôle du DEE
Figure 1 – Montage d’essai de la ligne TEM à plaques ( stripline ) pour CI
Carte d'essai CEM (CCI)
The DEE must be installed on a CCI in accordance with IEC 61967-1 and this standard In cases where there is a conflict between IEC 61967-1 and this standard, the requirements of this standard shall take precedence.
The CEM test card includes appropriate measurement or monitoring points to ensure the correct operation of the DEE It checks the geometry and orientation of the DEE in relation to the active conductor and eliminates all connection conductors inside the test enclosure in the case of a closed version of the TEM line with plates (stripline) for integrated circuits, as these conductors are located on the back side of the card, which is outside the test enclosure.
Généralités
Default testing conditions are designed to ensure uniformity in the testing environment If users of this procedure agree on alternative conditions, these must be included in the test report.
Conditions ambiantes
Les définitions relatives à la température ambiante et les conditions générales figurant dans la CEI 61967-1 sont valables
It is essential to ensure that the ambient RF noise level is at least 6 dB lower than the lowest emission levels to be measured The DEE should be installed in the test setup as used during the trials, but it must remain deactivated (for instance, with the power supply disconnected) Ambient noise should be measured using a sweep, and the test report must include a description of the ambient conditions.
If the measured background noise is excessive due to external ambient sounds or the noise from the measurement system itself, it is advisable to use a Faraday cage.
Le système de mesure du bruit de fond peut être amélioré en utilisant un préamplificateur de bruit inférieur.
Vérification opérationnelle
Mettre le DEE sous tension et procéder à une vérification opérationnelle complète afin de s'assurer du bon fonctionnement du dispositif (c'est-à-dire exécution du code d'essai du CI).
Vérification des caractéristiques RF de la ligne TEM à plaques (stripline)
For the verification of RF characteristics of the stripline TEM line for integrated circuits (ICs), the return loss (ROS) of the empty stripline TEM line with a 50 Ω load termination at the second access point must be measured and included in the test report The value should be less than 1.25.
Additionally, it is advisable to check the stripline TEM line for integrated circuits (IC) with a powered-down differential electromagnetic environment (DEE) In this case, according to IEC 61000-4-20, the resonances of the stripline TEM line for ICs with the DEE in a powered-off state must be verified.
A P fwd output fwd refl tloss 10 lg ≤ 1
A tloss est la perte de transmission de la ligne TEM à plaques (stripline) pour CI chargée
P refl est la puissance réfléchie au niveau de l’accès d’entrée (W) ;
P fwd est la puissance directe au niveau de l’accès d’entrée (W) ;
P output est la puissance mesurée au niveau de l’accès de sortie (W)
Les mesures effectuées à des fréquences pour lesquelles le ROS et les pertes dépassent les valeurs maximales tolérées doivent être ignorées.
Technique d’essai
Avec la carte d’essai CEM sous tension et le DEE mis en fonctionnement dans le mode d’essai prévu, mesurer les émissions RF sur la bande de fréquences souhaitée
To utilize a spectrum analyzer, activate the "Max Hold" function and allow the analyzer to perform at least three scans while the CI code loop is running The scan duration should significantly exceed the execution time of the CI code loop.
The "Max Hold" setting on a spectrum analyzer retains the maximum level of each data point and updates it whenever a new maximum level is detected during successive scans.
When using a receiver, the hold time for each test frequency must be at least twice the execution time of the microcontroller's code loop, and the maximum detected level should be recorded.
Four distinct emission measurements are conducted, resulting in four data sets The first measurement is taken with the EMC test board mounted in an arbitrary orientation on the cell wall The second measurement is performed with the EMC test board rotated 90 degrees from the orientation of the first measurement For the third and fourth measurements, the EMC test board is rotated again to ensure emissions are measured from all four possible orientations All four data sets must be included in the test report.
Généralités
Le rapport d’essai doit être conforme aux exigences de la CEI 61967-1 De plus, les exigences suivantes du rapport d’essai doivent s’appliquer.
Conditions de mesure
Toutes les conditions de mesure doivent figurer dans le rapport d’essai
10 Niveaux de référence des émissions du CI
The potential acceptance levels for CI emissions must be agreed upon by manufacturers and CI users, utilizing the reference level scheme outlined in Annex B These reference levels apply to measurements within the frequency range of 150 kHz to 3 GHz and are expressed in dBµV.
Description de la ligne TEM à plaques ( stripline ) pour CI
A.1 Ligne TEM à plaques ( stripline ) pour CI
The stripline TEM line for integrated circuits offers a wideband method for measuring the immunity of electronic devices to fields generated within the stripline TEM line, as well as the radiated emissions from an electronic device located in the stripline TEM.
The stripline for integrated circuits (ICs) eliminates the need for conventional antennas, addressing inherent limitations in bandwidth, nonlinear phase, directivity, and polarization This specialized type of transmission line propagates a transverse electromagnetic (TEM) wave, characterized by orthogonal electric (E) and magnetic (H) fields that are perpendicular to the direction of propagation along the stripline The field generated simulates a planar field in free space with an impedance of 377 Ω, and the TEM mode does not exhibit a low-frequency cutoff.
The stripline TEM line can operate at desired low frequencies, offering a linear phase and a constant amplitude response across frequencies This capability enhances the usability of the stripline TEM line.
(stripline) pour CI en vue de générer ou de détecter une intensité de champ d’une manière définie
The upper useful frequency for a stripline TEM line for integrated circuits (ICs) is constrained by signal distortion caused by resonances and multiple modes occurring within the stripline These effects depend on the physical dimensions and shape of the stripline used for ICs.
For instance, the stripline TEM line for integrated circuits has a specific size and shape, featuring impedance matching at the input and output feed points of the line.
TEM stripline for integrated circuits (ICs) limits the return loss (ROS) to less than 1.25 up to its assigned frequency There are two possible versions of the TEM stripline: the open version, which utilizes a common configuration, and the closed version, which includes a shielding test enclosure The active conductor of the TEM stripline is tapered at both ends to accommodate standard 50 Ω coaxial connectors The required electromagnetic compatibility (EMC) test board can be based on a TEM cell board, in accordance with IEC 61967-1 The first resonance is demonstrated by a specific configuration.
High ROS on a narrow frequency band A stripline for integrated circuits (IC) verified for field establishment up to a maximum frequency will also be suitable for emission measurements at this frequency.
Connecteur RF DEE Conducteur actif du stripline pour CI
Figure A.1 – Vue en coupe d’un exemple de ligne TEM à plaques ( stripline ) pour CI non blindée
Boợtier du à-stripline pour CI
DEE Conducteur actif du stripline pour CI Connecteur RF
Figure A.2 – Vue en coupe d’un exemple de ligne TEM à plaques ( stripline ) pour CI comportant une enceinte d’essai
The maximum usable size of the DEE is constrained by the dimensions of the stripline TEM line for integrated circuits (ICs) It is recommended that the ratio of the height of the test chamber for the Device Under Test (DUT) to the height of the stripline TEM line should be one-third, but it must not exceed one-half, in accordance with IEC 61000-4-20 Additionally, based on the x-y dimensions, the test chamber should not exceed the width of the active conductor by more than 10%.
3D field simulations have demonstrated that a uniform field (ranging from -3 dB to +0 dB) exists outside the geometric boundaries of the active conductor's width, extending to a test chamber size that exceeds the active conductor's width by 10% at half the height of the active conductor.
The limitation values for the stripline TEM line for a 6.7 mm CI are provided in Tables A.1 and A.2 The width of the active conductor in the closed version is influenced by the distance between the conductor and the test enclosure.
L’installation complète doit satisfaire aux exigences de 8.4
Tableau A.1 – Dimensions maximales du DEE pour la version ouverte de la ligne TEM à plaques ( stripline ) pour CI de 6,7 mm
Conducteur actif 6,7 mm version ouverte de la ligne TEM à plaques (stripline) pour CI
DEE dimension z (hauteur) 6,7 mm ≤ 3,35 mm dimension x-y (largeur) 33 mm ≤36,3 mm
Tableau A.2 – Dimensions maximales du DEE pour la version fermée de la ligne TEM à plaques ( stripline ) pour CI de 6,7 mm
Conducteur actif 6,7 mm version fermée de la ligne TEM à plaques (stripline) pour CI
DUT dimension z (hauteur) 6,7 mm ≤ 3,35 mm dimension x-y (largeur) 24 mm ≤ 26,4 mm
2 Les chiffres entre les crochets se référent à la Bibliographie
The 24 mm width of the closed version of the TEM line with plates (stripline) is associated with the height of the TEM line and the shielding design, including its shape and spacing, to achieve the specified characteristics of the TEM line defined in section 8.4.
A.2 Impédance caractéristique des agencements de la ligne TEM à plaques
L’impédance nominale, caractéristique d’une version ouverte de ligne TEM à plaques
(stripline) pour CI peut être calculée comme suit en [3], si 1 < w/h ≤ 10
Z est l’impédance caractéristique (Ω), 50 Ω typiques ; w est la largeur (m) du conducteur actif ; h est la hauteur (m) située entre le conducteur actif et le plan de masse
For the closed version of the stripline TEM line, the influence of the test enclosure must be considered, as this correction is dependent on the geometry of the housing An analytical formula for the characteristic impedance cannot be provided for a spherical enclosure; empirical investigations are necessary The characteristic impedance of these stripline TEM configurations should be verified through measurements.
A.3 Conversion pour différentes hauteurs de conducteurs actifs
Un facteur de conversion (X) pour corréler les résultats de mesure des lignes TEM à plaques
(striplines) avec différentes hauteurs à la hauteur de la ligne TEM à plaques (stripline) par défaut de 6,7 mm peut être calculé par:
X est le facteur de conversion (dB) en résultats de type de hauteur de 6,7 mm de la ligne
TEM à plaques (stripline) ; h 1 est la hauteur de conducteur actif de type spécifique ; h 2 est la hauteur de conducteur actif de type 6,7 mm
For a stripline TEM line with a height of 8 mm, the conversion factor is X = 1.54 dB This means that an additional 1.54 dB must be added to the voltage measured in dBV at the measurement access point of the stripline TEM line.
A.4 Exemple d’agencement d’une ligne TEM à plaques ( stripline ) pour CI
Un exemple de ligne TEM à plaques (stripline) pour CI est fourni à la Figure A.3 Les dimensions x-y de l’enceinte d’essai sont définies par la carte d’essai CEM utilisée
The test enclosure, measuring 100 mm × 100 mm according to CEI 61967-1, should be positioned as far as possible from the active conductor in the z-direction to minimize resonances and multiple modes within the studied frequency range.
Ligne TEM à plaques (stripline) pour CI
Figure A.3 – Exemple de ligne TEM à plaques ( stripline ) pour CI comportant une enceinte d’essai
La présente annexe fournit une méthode de spécification des profils de niveau d’émission des circuits intégrés