5g radio exposure measurements...em safety guidelines / regulations mic mra international workshop...
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MIC MRA International Workshop 2019, March 7, 2019
5G Radio Exposure MeasurementsMyles Capstick, IT’IS Foundation Serge Pfeifer, IT’IS Foundation Sven Kühn, IT’IS Foundation Jingtian Xi, IT’IS Foundation Leif Klysner, SPEAG Romain Meyer, SPEAG Katja Pokovic, SPEAG Niels Kuster, IT’IS Foundation & ETH Zurich
Content5G Sub6: 600 MHz – 6 GHz 5G mmWave: 6 – 110 GHz - Safety Guidelines: Open Issues - mmWave Assessment Methods - Accurate E-Field Measurements <10 to >100 GHz - Probe Calibration 10 – 110 GHz - Scanning and Field Reconstruction - Verification Sources - Uncertainty Budget - System Validation
Solutions in Research & Development - Forward Transformation Evaluation - Maximum Exposure Evaluation - Combining SAR and Power Density - Conformal Assessments - Assessment of Transmitted Power
Conclusions
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EM Safety Guidelines / Regulations
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110GHz10MHz
IT’IS
10GHz3GHz
ART-FI
SATIMO
6GHz0.6GHz10 kHz
FCC
IEEE
ICNIRP
10GHz6GHz3GHz
SAR power density
100kHz 300GHz
5G sub6 5G mmWave
5G sub6: 600 MHz – 6 GHz
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Gold SAR Standard: DASY6IIEC 62209 FCC KDB 865664 … IEEE 1528 ANSI-C63.19 IEC 62232 EN 50385 EN 50383:2010 EU Directive RED 2014/53/EU AS/NZS 2772-2:2011 ARIB STD T-56 3.1 IS16133 DT-IFT-007-2015 IEEE/IEC 1528-62209 etc.
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Whole-Body Phantoms
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Latest Developments: IEC 1528-62209 Ready for 5Gsub6extended frequency: 4 MHz – 10 GHz enables MIMO - SAR combiner for correlated & uncorrelated signals - specific phantoms - wrist - goggles
no missing gaps for sub6 cDASY V6.10 ready for all sub6
release 3Q19
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5G mmWave: 6 (10) – 110 GHz
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Safety Guidelines: Open Issues
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Regulation: Safety Guidelines Being Currently Revised / Equipment Developed
incident power density poorly defined in the reactive near-field Re(S)
transmitted power instrumentation ready by now
correlation w/ temperature averaging area averaging time combination w/ SAR
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Recent Publications with Detailed Analysis & Proposed Solutions for StandardsPfeiffer S et al., Total Field Reconstruction in the Near-Field Using Pseudo-Vector E-Field Measurements: IEEE Transactions on Electromagnetic Compatibility, 61 (2) , 2018 Carrasco E et al, Exposure Assessment of Portable Wireless Devices Above 6 GHz, Radiation Protection Dosimetry, ncy177, 2018 Neufeld E et al., Theoretical and Numerical Assessment of Maximally Allowable Power-Density Averaging Area for Conservative 5G Exposure Assessment: Bioelectromagnetics, 39 (8), 2018 Neufeld E, et al., Systematic Derivation of Safety Limits for Time-Varying 5G Radio Frequency Exposure Based on Analytical Models and Thermal Dose. Health Phys 115:705-711; 2018.
- Foster KR Comments on Neufeld and Kuster. "Systematic Derivation of Safety Limits for Time-Varying 5G Radiofrequency Exposure Based on Analytical Models and Thermal Dose." Health Phys. 115.6 (2018): 705-711 (submitted)
- Neufeld et al, Response to Prof. Foster's Comments on Our Paper "Systematic Derivation of Safety Limits for Time-Varying 5G Radiofrequency Exposure Based on Analytical Models and Thermal Dose." Health Phys. 115.6 (2018): 705-711 (submitted)
Foster KR, et al. Thermal Analysis of Averaging Times in Radio-Frequency Exposure Limits Above 1GHz. IEEE Access 6:74536-74546; 2018 Samaras T et al, Theoretical Evaluation of the Power Transmitted to the Body as a Function of Angle of Incidence and Polarization at Frequencies >6 GHz and its Relevance for Standardization. Bioelectromagnetics, 2019 (published online) Christ A, et al., RF-Induced Temperature Increase in Layered Skin Tissue for Frequencies from 6 to 100 GHz: Bioelectromagnetics, 2019 (revision submitted) Neufeld E, et al. Discussion on Consistent Spatial and Time Averaging Restrictions within the Electromagnetic Exposure Safety Framework in the Frequency Range Above 6GHz for Pulsed and Localized Exposures. Bioelectromagnetics 2019 (revision submitted)
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Incident Power Density (PD) versus SAR and Transmitted Power (Str)power density has not meaning and cannot be determined in the highly reactive near-field in particular below 10 GHz instead SAR or Str should be used!
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mmWave Assessment Methods
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By Direct Measurement in the Near-FieldE-field probes
challenges field distortions by substrates / probe body directionality
H-field probes challenges
field distortion / scattering by probe body E-field sensitivity
elctro-/magneto-optical probes challenges
spatial resolutions sensitivity
wave-guide challenges
large field distortions fixed impedance
Near-Field Assessment Methods Via Measurement in the Far-Fieldmeasurement with horn antennas in the far field + backward transformation to the near-field
challenges error < a few dBs
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Backward Transformation (Towards the Source)
information about reactive fields and evanescence fields are missing backward propagation falls apart very close to the source - example from 2mm to 0.1 mm
unreliable with uncertainties >10 dB cannot be used for compliance testing
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By Direct Measurement in the Near-FieldE-field probes
challenges ‣ field distortions by substrates / probe body ‣ directionality
H-field probes challenges
field distortion/scattering by probe body E-field sensitivity
elctro-/magneto-optical probes challenges
spatial resolutions sensitivity
wave-guide challenges
large field distortions fixed impedance
Near-Field Assessment MethodsVia Measurement in the Far-Fieldmeasurement with horn antennas in the far field + backward transformation to the near-field
challenges ‣ error < a few dBs
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Accurate E-Field Measurements <10 to >100 GHz
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EUmmWV2 Probe: Pseudo-Vector Design
probe - 2 dipoles (one each side of the quartz substrate) - ≈0.9 mm long and diode loaded - typical distance between physical tip and sensor
center: 1.5 mm
quartz substrate - 0.9 mm wide - 20 mm long - 0.18 mm thick - dipole sensors present - 𝜀r = 3.8 (quartz) homogeneous
measurement: three rotations around axis, (i.e., six E-field measurements in total) reconstruction of ellipse and elimination of mechanical tolerances
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EUmmWV2 Probe: Minimization of Reflections
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EUmmWV2 Probe Performancefrequency range: 750 MHz – 110 GHz dynamic range: <20 – 10,000 V/m with PRE-10 (minimum <50 – 3000 V/m) deviation from hemispherical isotropy: <0.5 dB at 60 GHz linearity: <0.2 dB compatibility: 5G-Module 1.0+ (DASY6) V1, mmW-Module 1.0+ (ICE V2.0+) ISO17025 Calibrated
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EUmmW Probe: System Integration in DASY6 and ICEyBenefits1st method to assess power density in the near-field of sources
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Probe Calibration 10 – 110 GHz
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Calibration Method & Proceduresensor model (f): 6 parameters known calibration field: 3-antenna method calibration points: 25 + 8 frequencies and different inclination determination of the sensor model parameters with a least square fit assessing deviation at 33 frequencies determination of isotropy at x frequencies
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Calibration System: ISO17025 Accreditation
calibration uncertainty: < ±1.0 dB frequency range: 750 MHz – 100 GHz ISO/IEC 17025 accreditation - received in May 2018
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Scanning and Field Reconstruction
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Reconstruction
knowledge of E-field distribution on two planes allows reconstruction of phase plane wave decomposition in infinite plane by Fourier transformation and subsequent reconstruction of full-wave 3D distributions our solution for phase reconstruction
novel and improved algorithm based on Gerchberg–Saxton (GS) (R. W. Gerchberg and W. O. Saxton, “A practical algorithm for the determination of the phase from image and diffraction plane pictures,” Optik 35, 237 (1972))
measurement requirement: 2 planes (grid-step λ/4): 2 × 24 × 24 points
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South Korea Workshop, Seoul, 20171027 29
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Demonstrator: H-Field Reconstruction from E-Field Magnitudes
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\
|Hx| |Hy| |Hz|
reference (simulation)
reconstruction
Verification Sources
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5G System Verification Packages: 10, 30, 60, and 90 GHz10 GHz: 8.2 – 12.4 GHz horn, SMA female interface, enclosed 30, 60, and 90 GHz: stand-alone fixed-frequency sources integrated with horns, enclosed, 12 V DC supply compliant with IEC106 AHG10 released
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Uncertainty Budget
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Preliminary Uncertainty Budget\
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System Validation
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Validation Sources (Compliant with IEC106 AHG10 Report)two fundamental EM sources - electric dipoles - magnetic dipoles (slots)
complex arrays but well defined for simulations
Cavity Backed Array of DipolesPyramidal Horn with Slot Array frequencies: 10, 30, 60 90 GHz round-robin (12 labs)
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10 GHz Cavity Backed Array of Dipoles
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2 mm 10 mm
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10 GHz Cavity Backed Array of Dipoles (cont.)normalized to 0-dBm radiated power
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simulated measured deviation
distance (mm)
Etotal(V/m)
Savg1cm2 (W/m2)
Etotal(V/m)
Savg1cm2 (W/m2)
Etotal(dB)
Savg1cm2 (dB)
2 49.1 1.09 42.1 1.45 -1.3 1.2
5 23.0 0.804 22.5 0.738 -0.2 -0.4
10 14.3 0.451 15.7 0.420 0.8 -0.3
20 14.5 0.468 15.4 0.391 0.5 -0.8
50 13.2 0.456 14.3 0.456 0.7 0.0
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90 GHz Cavity Backed Array of Dipoles
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2 mm 10 mm
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90 GHz Cavity Backed Array of Dipoles (cont.)normalized to 0-dBm radiated power
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simulated measured deviation
distance (mm)
Etotal(V/m)
Savg1cm2 (W/m2)
Etotal(V/m)
Savg1cm2 (W/m2)
Etotal(dB)
Savg1cm2 (dB)
2 125 7.29 113 6.32 -0.8 -0.6
5 114 5.13 112 4.47 -0.2 -0.6
10 78.6 3.83 79.0 4.00 0.0 0.2
20 43.2 2.92 44.3 2.97 0.2 0.1
50 18.4 0.829 18.9 0.829 0.3 0.0
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90 GHz Pyramidal Horn with Slot Array
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2 mm 10 mm
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90 GHz Pyramidal Horn with Slot Array (cont.)
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simulated measured deviation
distance (mm)
Etotal(V/m)
Savg1cm2 (W/m2)
Etotal(V/m)
Savg1cm2 (W/m2)
Etotal(dB)
Savg1cm2 (dB)
2 82.2 8.31 80.0 8.82 -0.2 0.3
5 71.7 7.18 79.3 7.58 0.9 0.2
10 50.7 5.57 55.0 5.77 0.7 0.2
20 45.0 3.78 47.6 3.80 0.5 0.0
50 26.2 1.65 26.8 1.65 0.2 0.0
normalized to 0-dBm radiated power
Solutions Under DevelopmentR&D Partners- IT'IS Foundation - SPEAG
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Forward Transformation Evaluation (FTE)measurements on two or three planes for each side of the phone conservative averaged PD evaluator for pSnavgxcm2 and pSnavgxcm2 based on either - validated simulations - measurements of each antenna group separately
(can be controlled individually with a code book)
evaluation of the exposures in 3D based on advanced forward propagation techniques evaluation of PD distribution on any virtual surface (e.g., SAM head, ELI phantoms, face-down) available 1Q19
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Validation of FTE: 30 GHz Cavity Backed Array of Dipoles
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Simulated vs. Measured Plane at 2 mm Simulated vs. Reconstructed XZ Plane
Maximum Exposure Evaluationmeasurements on two or three planes for each side of the phone conservative averaged PD evaluator for pSnavgxcm2 and pSnavgxcm2 based on either - validated simulations - measurements of each antenna group separately
(can be controlled individually with a code book)
evaluation of the exposures in 3D based using advanced forward propagation techniques evaluation of PD distribution on any virtual surface (e.g., SAM head, ELI phantoms, face-down) B-release available 2Q19
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Combining SAR and Power Densitymeasurements on two or three planes for each side of phone conservative averaged PD evaluator for pSnavgxcm2 and pSnavgxcm2 based on either - validated simulations - measurements of each antenna group separately (can
be controlled individually with a code book)
evaluation of the exposures in 3D based on advanced forward propagation techniques evaluation of PD distribution on any virtual surface (e.g., SAM head, ELI phantoms, face-down) combination of PD and SAR
available 2Q19
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Conformal Assessmentsmeasurement on fully conformal surfaces (e.g., concave surface of virtual reality (VR) devices) full functionality of IEC TR 63170 available 3Q19
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Assessment of Transmitted Power (Str )evaluation of transmitted PD Str for frequencies below 24 GHz cDASY6/7 module for measuring transmitted power Str in phantoms no overestimation in the very near-field of transmitters (<λ/2pi)
fully compatible with ICNIRP/IEEE available 4Q19
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Conclusions: 5G Radio Exposure Measurement
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Conclusions: 5Gsub6 (IEC 1528-62209) extended frequency: 4 MHz - 10 GHz enables MIMO - SAR combiner for correlated & uncorrelated signals - specific phantoms - wrist - goggles - etc.
no missing gaps for sub6 cDASY V6.10 release: 2Q19
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Conclusion: 5G mmWave (>6 GHz)PD has no meaning and cannot be assessed below10 GHz (SAR or Str should be used instead) EUmmW probe novel reconstruction algorithm validated (λ/5) traceable ISO 19025 calibration system check sources validation sources uncertainty: ~0.7 dB (k=1) ready for compliance testing
option: FTE 1Q19 option: Optimizer 2Q19 option: Combiner SAR and Power Density 2Q19 option: Conformal Evaluator 3Q19 module: Transmitted Power Density (Str) 4Q19
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