5G Radio Exposure Measurements...EM Safety Guidelines / Regulations MIC MRA International Workshop 2019, March 7, 2019 3 110GHz 10MHz IT’IS 3GHz 10GHz ART-FI SATIMO 10 kHz 0.6GHz

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

2MIC MRA International Workshop 2019, March 7, 2019

EM Safety Guidelines / Regulations


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


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.


Whole-Body Phantoms


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


5G mmWave: 6 (10) – 110 GHz


Safety Guidelines: Open Issues


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


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)


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!


mmWave Assessment Methods


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


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


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


Accurate E-Field Measurements <10 to >100 GHz


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



EUmmWV2 Probe: Minimization of Reflections


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


EUmmW Probe: System Integration in DASY6 and ICEyBenefits1st method to assess power density in the near-field of sources


Probe Calibration 10 – 110 GHz


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


Calibration System: ISO17025 Accreditation

calibration uncertainty: < ±1.0 dB frequency range: 750 MHz – 100 GHz ISO/IEC 17025 accreditation - received in May 2018


Scanning and Field Reconstruction


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


South Korea Workshop, Seoul, 20171027 29

MIC MRA International Workshop 2019, March 7, 2019 30

Demonstrator: H-Field Reconstruction from E-Field Magnitudes


\

|Hx| |Hy| |Hz|

reference (simulation)

reconstruction

Verification Sources


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


Uncertainty Budget


Preliminary Uncertainty Budget\


System Validation


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)



10 GHz Cavity Backed Array of Dipoles


2 mm 10 mm


10 GHz Cavity Backed Array of Dipoles (cont.)normalized to 0-dBm radiated power


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


90 GHz Cavity Backed Array of Dipoles


2 mm 10 mm


90 GHz Cavity Backed Array of Dipoles (cont.)normalized to 0-dBm radiated power



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


90 GHz Pyramidal Horn with Slot Array


2 mm 10 mm


90 GHz Pyramidal Horn with Slot Array (cont.)



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


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


Validation of FTE: 30 GHz Cavity Backed Array of Dipoles


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


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


Conformal Assessmentsmeasurement on fully conformal surfaces (e.g., concave surface of virtual reality (VR) devices) full functionality of IEC TR 63170 available 3Q19


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


Conclusions: 5G Radio Exposure Measurement


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


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


5G Radio Exposure Measurements...EM Safety Guidelines / Regulations MIC MRA International Workshop 2019, March 7, 2019 3 110GHz 10MHz IT’IS 3GHz 10GHz ART-FI SATIMO 10 kHz 0.6GHz

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