5G OTA Measurement aspects

Reiner StuhlfauthTechnology Marketing Manager, 5SWT

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Massive MIMO: There is a Principle DifferenceBelow 6 GHz versus above 24 GHz

2

< 6GHz > 24 GHz

ı Multiple configurable Base Station patterns creating multiple cells/sectors

ı Omni/Uni directional UE pattern

ı Base Stations support multiple narrow beams (dynamically steered)

ı UE uses narrow beams with steering/tracking

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Massive MIMO (Sub-6GHz)

3COMPANY RESTRICTED

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It’s all about the cables….in 5G Massive MIMO

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Massive MIMO Active Antenna System (sub 6GHz)

64 - 128 Dual-Polarized Antennas…

.64 - 128 RF Transceivers FPGA + Fiber TRx

Dig I/Q

OTA for Integrated 5G DUTs

Traditional Test & Measurement

Base

band

Base

band

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Fraunhofer distance. Near field vs. far field

Near-field region =phase & magnitude

Very near-field region

Far field=magnitude

2D2 / λ0.62 D3 / λ

Near field measurements:• values depend on phase & magnitude⇒ not simple for modulated signals (wide bandwidth,

phase coherent receiver needed)• multiple samples are needed, i.e. on a ring trajectory⇒ near-field to far-field transformation isneeded (additional time + effort)=> single probe + rotation concept (accurate positionerneeded) or multi-antenna probe (calibration complexity)• Smaller chamber sizes

Far field measurements:• values depend on magnitude only⇒ suitable for modulated signals• one sample is sufficient, no NF/FF post-processing• Larger chamber sizes required or compact range

concept (higher complexity)

Fraunhofer distance. Near field vs. far fieldBasestation 8 Element Array at 2.69 GHz

Near-field regionphase & magnitude

Required chamber size for far-field

AUT size (D) Frequency Chamber size

0.5 meters 6 GHz 10 meters

0.5 meters 30 GHz 50 meters

1.0 meter 6 GHz 40 meters

Very near-fieldregion (< 0.6m)

Near: Phase + Magnitude

Far: Magnitude

Far-field vs. near-field

Far fieldmagnitude

2D2 / λ = 4.1 m0.62 D3 / λ = 0.6 m

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What is the Quietzone (in Farfield)?

7

Quietzone: Only for Far-field measurements

Near-field does not have a “quiet zone”

+D/2

-D/2

R

R

d

Point Source(Measurement Antenna)

Qui

et Z

one

(D)

φ(R)

φ(R+d)

𝑅𝑅𝑚𝑚𝑚𝑚𝑚𝑚 =𝜋𝜋𝐷𝐷2

4𝜆𝜆Δ𝜑𝜑𝑚𝑚𝑚𝑚𝑚𝑚=𝑁𝑁𝐷𝐷2

𝜆𝜆

Quiet Zone Phase Deviation vs. Measurement Error

Rmin(N) Phase Deviation

𝐷𝐷2/𝜆𝜆 45 degrees

2𝐷𝐷2/𝜆𝜆 22.5 degrees

4𝐷𝐷2/𝜆𝜆 11.2 degrees

8𝐷𝐷2/𝜆𝜆 5.6 degrees

𝑁𝑁 = ∞

-25 dB

-30 dB

-20 dB

𝑁𝑁 = 2𝑁𝑁 = 4

High Gain Antenna Pattern

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Far-Field Measurement Systems

Device Under Test

3D Rotation of DUT

DUT-MEAS Antenna Separation: R > 2D2/λ

R&S®Signal Analyzer

R&S®Signal Generator

Active Measurements

Passive Measurements

R&S®VNA

Dual-Polarized High-Gain Antenna

Far FieldMagnitude

Single Measurement point

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Near Field to Far Field Transform Steps

3. Far-field: Generated1. Complex Wave: Measurement

E-Field

E-Field

Near field E-field measurementsover surface

b

a

2. Fourier Transform: Software

Cylindrical Planar Spherical

Radiated Near Field RegionPhase & Magnitude

How to measure the phase for Massive MIMO DUT with no test ports?

𝑓𝑓𝑚𝑚,𝑦𝑦 = 𝐴𝐴�𝐸𝐸𝑚𝑚,𝑦𝑦𝑒𝑒+𝑗𝑗𝐤𝐤�𝐫𝐫 𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑

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Near-field Systems: Phase Retrieval

Direct Device Access Two-Sphere Approach Interferometry (WPTC Spiral Scanner)

EiRP & EiS: Digital IQ and/or Test Interface

Radiated Near Field RegionPhase & Magnitude

DUT

Measurement Antenna

DUT DUT

Measurement Surface 1

Measurement Surface 2

Use Surface 1 to as phase reference for Surface 2 measurement (unproven for high-gain antennas).

Combine signal of known phase with signal of unknown phase in order to extract unknown phase (optics)

Measurement Surface

Rotating DUT

Measurement Antenna

Phase Shifterφ = [0, ± π/2, π]

Reference Antenna

Rotating DUT+ Reference Ant

EiS Test Mode: DUT Access Required

EiS Test Mode: DUT Access Required

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Massive MIMO: Near-Field Measurement System

Reference Antenna

Measurement Antenna

ActiveAntennaSystemDUT

Phase Shifterφ = [0, ± π/2, π]

R&S®VNANarrow-Band Signal

R&S®Signal Analyzer (Wide-band)

Modulated/CW

or

Each grid point measures two polarizations of E-field

Reference antenna injects 4 signals with different phase shifts

Phase Retrieval: Interferometric mixing of signal with known phase with signal of unknown phase

R&S®Signal Generator (Wide-band)R&S®Oscilloscope (Wide-band)

Results

Phase retrieval with reference antenna

Massive MIMO Array Size ~ 1 meter

Modulated LTE Signal (10MHz BW)

Measurement of 3D Gain

Measured Near Field

Far Field

𝑓𝑓𝑚𝑚,𝑦𝑦 = 𝐴𝐴�𝐸𝐸𝑚𝑚,𝑦𝑦𝑒𝑒+𝑗𝑗𝐤𝐤�𝐫𝐫 𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑

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Example resultsReference antenna method verified

12

x-y planex-z plane x-y planex-z plane

FF conditions reached at ~1m → Size of electrical active part of DUT was smaller than array size D → active part of DUT determining factor w.r.t. NF vs. FF

NF measurements NF-FF transformed

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Quiet Zone SizesBlackbox testing significantly increases chamber sizes

13

DUT

TabletD = 40cm

R = 30 meters R = 4.2 meters

UE:D = 15cm

Blackbox: Antenna Location Unknown

DUT

Tabletd = 6 cm

R = 0.67 meters R = 0.3 meters

UE:d = 4 cm

Whitebox: Antenna Location Known

Near-Field Scan with holographic back projection

𝑓𝑓𝑚𝑚,𝑦𝑦 = 𝐴𝐴�𝐸𝐸𝑚𝑚,𝑦𝑦𝑒𝑒+𝑗𝑗𝐤𝐤�𝐫𝐫 𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑

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Near-field to Far-field Transformation – FIAFTAPerformance Comparison

Probe Compensation

FeaturesEquivalent Sources

Arbitrary Grids

vs.

220 minutes 6 minutes

Transformation

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Far-field in Near-field Systems: Hardware Fourier Transforms

Complex near-field wave generated

Fresnel Lens (Fourier Optics) Reflector: Compact Antenna Test Range Other ideas

Amplitude Phase Plane wave far-field received

DUT

Measurement𝑓𝑓𝑚𝑚,𝑦𝑦 = 𝐴𝐴�𝐸𝐸𝑚𝑚,𝑦𝑦𝑒𝑒+𝑗𝑗𝐤𝐤�𝐫𝐫 𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑

Signal processing

concept

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Theory + ideas

16

Far Field situation Like in optics: generate a far field with a certain size

3GPP TSG-RAN WG4 Meeting #78 R4-161372

Plane wave generation in condensed spatial environment

Utilization of a probe antenna array: Uplink & Downlink

Array spacing dependent on wavelength

Phase + Magnitude Magnitude

Required Chamber Size

AUT Size (D) Frequency (c/λ) FF Chamber Size

0.5 meters 6 GHz 10 meters

0.5 meters 30 GHz 50 meters

1.0 meter 6 GHz 40 meters

2D2 / λ

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Hardware oriented NF-FF transformation: first results

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DUT: High-Gain ArrayDimensions: 60x60cm

Far-field Range: 8m

R&S®Signal Analyzer (Wide-band)R&S®Signal Generator (Wide-band)R&S®Oscilloscope (Wide-band)

Single RF Cable

1.5 meters

Certified Lab Results(Spain)

Results1.5m from DUT

Single Antenna1.5m from DUT

Measurement Setup

Signal processing

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Additional Challenges: Active Return Loss Measurement (Mutual Coupling)Passive Return

Loss

Active Return Loss distorted by the mutual coupling

Passive Return Loss Single

Element

Antenna Array Return Loss Measurements

Active Return LossSimultaneous

Measurements

Source: Signal Processing Magazine, IEEE, Jan 2013

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Additional Challenges: The Phase Calibration Problem

Phase/Magnitude/Frequency Tolerances (Static & Dynamic)

RFIC RFIC

LO

RF Feeding Network

Dynamic Thermal Effects in PAs

Timing Errors in ADCs Phase Error (Uniform)Comparison between ideal and non-

calibrated beam forming

Phase Shifter Tolerances

Group Delay Variations

Baseband

~20 dB

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Beamforming: antenna gain depending on temperatureR&S®ATS1000

Active or Passive

DUT

flexible size

lessons learned: antenna gain is depending on temperature

Source: IBM + Ericsson: insertion loss Tx/Rx switch and impacton beamforming gain

temperature controlled chamber

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mmWave Systems

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5G mmWave Transceiver & Antenna Measurements

mmWave Hybrid Beamforming Architecture

Analog or Switched Arrays

….

2-8 RF Transceivers

OTA measurement for mmWave DUTs

Low Frequency Test & Measurement

Base

band

Base

band

….

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How to measure EiRP/etc… for mmWave UEs?4G: 2.8 GHz UE 5G: 28GHz UE

Multiple directions

Narrow beams with beam steering/tracking

Omni/Uni-directionalSingle direction EiRP/EiS

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Cable Influences in 5G mmWave Systems3D Gain Patterns of mmWave UE antenna

No Measurement Cable With Measurement Cable

Antenna couples to all surrounding objectsConductive measurements introduce large error in RF measurements

10 20 30 40

12

9

63

Frequency (GHz)

Inser

tion L

oss (

dB/m

)

50 60

Flexible mmWave Cable Losses

24

Longer cables in measurement systems will require amplifiers or mixers…..

…..therefore need small and compact chambers for testing

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3GPP TR 38.803 NR FF Baseline Measurement Setup

25

Center of beam measurement only setup, i.e. combined link and measurement antenna

Center / off center of beam measurement setup, i.e. independent link and measurement antenna

R4-1700530 (R&S) TP NR UE RF Testability

http://www.3gpp.org/ftp/tsg_ran/WG4_Radio/TSGR4_82/Docs/R4-1700530.zip

Electromagnetic Fields: Where is the Far-field?Basestation Antenna Array at 28 GHz

Radiated Near Field RegionPhase & Magnitude

Far FieldMagnitude

Reactive Near Field Region

D

0.62 𝐷𝐷3

𝜆𝜆𝑅𝑅 =

2𝐷𝐷2

𝜆𝜆

26

DUT

Laptop

R = 16 meters? R = 4.5 meters?

UE

R = 46 meters?

DUT

R

BaseStation

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1S - 5G test solutions

NF-FF Reference Antenna Measurement: 28GHz Basestation Array

ResultsSize of electrical active part of DUT is the determining factor w.r.t. NF vs. FF~10 cm x ~10 cm array sizeMeasurement distance of ~1 m results in FF conditions!Reference antenna method verified

Reference Antenna

Measurement Antenna

ActiveAntennaSystemDUT

Phase Shifterφ = [0, ± π/2, π]

R&S®VNANarrow-Band Signal

R&S®Signal Analyzer (Wide-band)

Modulated/CW

or

Each grid point measures two polarizations of E-field

Reference antenna injects 4 signals with different phase shifts

Phase Retrieval: Interferometric mixing of signal with known phase with signal of unknown phase

R&S®Signal Generator (Wide-band)R&S®Oscilloscope (Wide-band)

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Electromagnetic Fields @ 28GHzSize of electrical active part determines FF

28

Radiated Near Field RegionPhase & Magnitude

Far FieldMagnitude

Reactive Near Field Region

D

0.62 𝐷𝐷3

𝜆𝜆 𝑅𝑅 =2𝐷𝐷2

𝜆𝜆 R = 1.87 m R = 48 cmR = 4.2 m

DUT DUT

Laptop

Rd = 10 cm d = 5 cmd = 15 cm

R = 30 m R = 4.2 mR = 92 m

D = 40 cm D = 15 cmD = 70 cm

D

D D

d

dd

November 2017

Chamber Size: Far-field or Near-field?UEs: Dant ~ DUT

DU

T=10cm

Dant=4cm28GHz UE Subarray (HPBW=15°)

Criteria Far-field Distance

2λ/HPBW2 0.30 meters

28GHz Entire UE

2D2/λ 1.86 meters

HPBW (radians)Half-power beam

width

𝑅𝑅𝐹𝐹𝐹𝐹 =2𝐷𝐷2

𝜆𝜆 𝑜𝑜𝑜𝑜2𝜆𝜆

𝐻𝐻𝐻𝐻𝐻𝐻𝐻𝐻2

3dB powerdifference

θ

Near-field far-field aspects

30

What is the size D of a UE? Shall we assume the maximumDUT size? Is this realistic according to chamber sizes?

𝐻𝐻𝑅𝑅𝑅𝑅𝐻𝐻𝑇𝑇𝑅𝑅

~1

(𝑘𝑘𝑜𝑜)2

Friis equation:𝑤𝑤𝑤𝑤𝑤𝑤𝑤 𝑘𝑘 = 2𝜋𝜋/𝜆𝜆

power measurementsidentify intersection of E/H-fieldand far-field

proof of concept: LTE band 3: known UE,far-field estimation based on power levels

source R4-1610010 and „R4-1700531

Near-field far-field aspects

31

𝐻𝐻𝑚𝑚 = 𝐺𝐺𝑅𝑅𝑅𝑅𝑚𝑚 �𝜆𝜆04𝜋𝜋𝑅𝑅

2

� 𝐷𝐷𝑇𝑇𝑅𝑅 � 𝐻𝐻𝑅𝑅 = 𝐺𝐺𝑅𝑅𝑅𝑅𝑚𝑚 �𝜆𝜆04𝜋𝜋𝑅𝑅

2

� 𝐷𝐷𝑇𝑇𝑅𝑅 � 1 − Γ𝑇𝑇𝑅𝑅 2 � 𝜂𝜂𝑇𝑇𝑅𝑅 � 𝐻𝐻𝑇𝑇𝑅𝑅

= 𝐺𝐺𝑅𝑅𝑅𝑅𝑚𝑚 �𝜆𝜆04𝜋𝜋𝑅𝑅

2

� 𝐺𝐺𝑇𝑇𝑅𝑅 � 𝐻𝐻𝑇𝑇𝑅𝑅 = 𝐺𝐺𝑅𝑅𝑅𝑅𝑚𝑚 �𝜆𝜆04𝜋𝜋𝑅𝑅

2

� 𝐸𝐸𝐸𝐸𝑅𝑅𝐻𝐻

We have learned about near-field and far-field, but where to measure?reminder. a beamforming antenna has main lobe, side lobes, nulls + noise

measured power according to gain, antenna size D and Rx power P

𝐻𝐻𝑚𝑚 > 𝐻𝐻𝑚𝑚,𝑚𝑚𝑚𝑚𝑚𝑚with Pmin following noise level aspects:

𝑘𝑘 � 𝑇𝑇 � 𝐻𝐻 � 𝑁𝑁𝑁𝑁𝑚𝑚

40

50

60

70

80

0.1 0.4 0.7 1 1.3 1.6 1.9

dB

R [m]

Measurement path loss vs. distance R

28 GHz 67 GHz

90 GHz PLmax

=>far-field assumption for power levelsare only valid for main lobe ofbeamforming antenna

source R4-1610010 and „R4-1700531

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Near-Field Scan with holographic back projection

𝑓𝑓𝑚𝑚,𝑦𝑦 = 𝐴𝐴�𝐸𝐸𝑚𝑚,𝑦𝑦𝑒𝑒+𝑗𝑗𝐤𝐤�𝐫𝐫 𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑

Quiet Zone Sizes: 3GPP Pre-Conformance

32

DUT

Tablet30x30cm

R = 16 meters R = 4.5 meters

UE: 15x15cm

Blackbox: Antenna Location Unknown

DUT

Tablet30x30cm

R = 0.5 meters R = 0.3 meters

UE: 15x15cm

Whitebox: Antenna Location Known

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Measurement Comparison – Large Chamber vs. ATS1000Peak Gain & TRP

33

WPTC-L Large Chamber: 5.2 x 4.2 x 4 meters

Peak Gain Difference1.1 dB

TRP Difference< 0.1 dB

ATS1000 Chamber: 1.9 x 1.0 x 0.85 meters

Horn: 28GHz Horn: 28GHz

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Measurement Comparison – Large Chamber vs. ATS1000Customer Device Comparison @ 28GHz

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DUTx

yz

Customer reference data: FF chamber with R = 6 meters

UE with PCB Antenna

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From Classical OTA to RF Characterization Systems… in One

R&S®ZVA

Classical OTA Measurements (CW)

EiRP, 2D/3D Gain

RF Transceiver Characterization: Tx & Rx

+

R&S®TS7830

EiRP, 2D/3D GainEVM, ACLR, SEM, …

Flexible Range Length

R&S®ATS1000 or R&S®TS8991

Signal Analysis/Generation

Clear Upgrade Path from Basic OTA Chambers to Advanced RF Conformance Systems

R&S®ATS1000 or R&S®TS8991

R&S®Mixers for higher frequencies

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Is the dynamic beamforming characteristic needed in all test cases?For efficiency reasons we should restrict this to minimum

ı Power control is an essential feature in any cellular network, however we have few test cases to ensure it’s functionality and performance

ı Dynamic beamforming is an essential feature in cm-/mm-wave spectrum, but we do not need to mimic it in any test case either

Nove

36

RF

Single (main) beam sufficient

Demodulation

Baseband performance under

fading

RRM

Beam switching / handover require some dynamic

(spatial) scenarios

Protocol

Beam switching / handover require some dynamic

(spatial) scenarios

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mmWave: EiRP Measurements for Small DUTs

DUT 2D Beam-SteeringOTA RF Digital

DUT

RF

OTA Power Sensor: Vivaldi Antenna + Power Meter

R&S®TS7124Shielded Box

R&S®NRPM-A66/81OTA Power Sensor

R&S®NRPM3Power Meter

3D Beam-Steering

OTA

DUT

37COMPANY RESTRICTED

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R&S Test SolutionNRPM - OTA power measurement systemı Vivaldi antenna with integrated diode

detector for power measurements directly on the antenna

ı Absolute power measurementı Frequency range: 27.5 – 75 GHzı Will be extended to 22 – 81 GHz

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OTA System components: Wideband Measurement AntennasPatented low RCS dual-polarized Vivaldi antenna: TC-TA85CP/LP

39

Parameter ValueFrequency range 4 - 87 GHzVSWR < 2.5Gain > 10 dBi from 20 GHzCross-polarization rejection >20 dB up to 40 GHz, >15 dBRadar Cross Section (RCS) -20 dBsm (Horn: -8 dBsm)Dimensions 76 x 48 x 34 mm3

3 6 10 20 30 40 50 60 70 85Frequency (GHz)

-6

-4

-2

0

2

4

6

8

10

12

14

16

IEEE

Gai

n (d

Bi)

IEEE Gain comparison for ANT1

Second prototype without lens

Second prototype with lensNo Lens With Lens

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Future UE OTA Measurements in Production Environment

Step 2: Failure (individual testing)

Step 1:Whole Unit

…Beam 1:

Broadside Beam 2 Beam N

T

BL RP

Gain

EVM

ACLR

OOBMeasure joint

EVM/ACLR/OOB + 5-Point Gain for each

Beam

Sequential testing of each transceiver for EVM/ACLR/OOB + individual

antenna gain

…TRx + Antenna #1

TRx + Antenna

#M

…Gain EVM

ACLR

OOB

Phase/Amplitude

Calibration

3D-MIMO Antenna Calibration Procedure M

IMO

Enc

oder

REFMEAS

Calibrated Phase Difference (σ = 0.25°)

Dig

ital B

eam

form

ing

Enc

oder

R&S®RTO2044

4 Phase Coherent Ports

Switch Matrix

phase coherent input signals

Beamforming Codebook

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Some discussion started…

ı Contribution to next ITU-R SG5 meeting (Terrestrial Services)ı It is expected that the BS location topic will step into the public when higher density of

transmitter will be discussed.

Nove

42

“In this contribution there is included information that is intended for the use in preparation ITU-T Technical Report concerning impact of the 5G mobile systems on environment.”

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Food for thoughts…ı Two international bodies; ICNIRP and IEEE developed exposure guidelines and defined exposure

limits in terms of SAR and electric and magnetic field strength

Nove

43

“A good channel of communication and information in partnership with operators associations and the help of national authorities will permit to show the benefits of 5G and to proactively answer to the public concerns.”

Basic restrictions and reference levels (average limits values shall be measured over a six minute time):

Compliance Distance for ICNIRP limits over antenna gain and input power

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R&S 5G OTA Product Matrix

Large Chambers:TS8991

OTA R&D:WPTC Spiral Scanner

OTA R&D and Production: ATS1000

OTA R&D:DST 200

OTA Production: NRPM OTA Power Sensors

DUT Size Car, TV, AppliancesBasestation, Laptops, & UE UE & CPE UE

UE & Laptops (28GHz+)

Frequency ~0.4 to 87 GHz ~0.7 to 87 GHz 18 to 87 GHz ~0.9 to 87 GHz ~22 to 81 GHz

Fields Near & Far Near & Far Near & Far Far Field Quasi-Far & Far

Signals Modulated/CW Modulated/CW Modulated/CW Modulated/CW Modulated/CW

Parameters EiRP, EiS, Gain, EVM, …EiRP, EiS, Gain, EVM, …

EiRP, EiS, Gain, EVM, …

EiRP, EiS, Gain, EVM, …

EiRP at single points

AvailabilityAvailable for purchase

Available for purchase

Available for purchase in 2017

Available for Purchase

Available for Purchase

Coming Soon

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R&S®NRPM

mmWave

mmWave Beamsteering

R&S Antenna Test Solutions SummaryMassive MIMO

Multiport Testing Production & Benchtop

PWC for Massive MIMO

R&S®ATS1000

CTIA Radiation Patterns

R&S®ZNBT

R&S®SMW200+6x R&S®SGT100

R&S®TS8991

R&S®FSV R&S®NRP

DUT

R&S®NRPM-A66

R&S®SMW200A

R&S®RTO2044

R&S®DST200

R&S®TS7124

R&S®RTO

R&S®FSV/FSP

R&S®ZVC/D

R&S®TS8991 R&S®ZVA/B/C/D

R&S®TS-F24

R&S®TS8991: WPTCRF Pre-Conformance

R&S®ATS1000

R&S®TS7830

R&S®ZVA

R&S®SMW200A

R&S®FSW

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Convergence of antenna OTA and conformance

Classical OTA & Antenna Tests

Full-dimension/3D-MIMO

Beamforming Patterns

Over-the-Air measurements

Classical Conducted Conformance TestsRF (Tx: Power, Power Dynamics, Signal Quality (EVM), Spectrum Emissions (ACLR), Timing…; Rx: Sensitivity,max. Input, ACS, Blocking, Spurious,…)

Demodulation performance

Radio Resource Management (idle and connected mobility, timing, measurement procedures and performance)

Protocol (idle mode, Layer 2, RRC, EPS mobility and session management)

LTE Core

5G NR

4G LTE

4G User & ControlPlane

4G/5G DualConnectivity

46November 2017

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“If you want to go fast, go alone. If you want to go far, go together!”

African proverb

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5G OTA Measurement aspects������Massive MIMO: There is a Principle Difference�Below 6 GHz versus above 24 GHzMassive MIMO (Sub-6GHz)It’s all about the cables….in 5G Massive MIMOFraunhofer distance. Near field vs. far field Fraunhofer distance. Near field vs. far field What is the Quietzone (in Farfield)?Far-Field Measurement SystemsNear Field to Far Field Transform StepsNear-field Systems: Phase Retrieval Massive MIMO: Near-Field Measurement SystemExample results�Reference antenna method verifiedQuiet Zone Sizes�Blackbox testing significantly increases chamber sizesNear-field to Far-field Transformation – FIAFTAFar-field in Near-field Systems: Hardware Fourier Transforms Theory + ideasHardware oriented NF-FF transformation: first resultsAdditional Challenges: Active Return Loss Measurement (Mutual Coupling)Additional Challenges: The Phase Calibration ProblemBeamforming: antenna gain depending on temperaturemmWave Systems5G mmWave Transceiver & Antenna MeasurementsHow to measure EiRP/etc… for mmWave UEs?Cable Influences in 5G mmWave Systems3GPP TR 38.803 NR FF Baseline Measurement SetupElectromagnetic Fields: Where is the Far-field?NF-FF Reference Antenna Measurement: 28GHz Basestation ArrayElectromagnetic Fields @ 28GHz�Size of electrical active part determines FFChamber Size: Far-field or Near-field?Near-field far-field aspectsNear-field far-field aspectsQuiet Zone Sizes: 3GPP Pre-ConformanceMeasurement Comparison – Large Chamber vs. ATS1000�Peak Gain & TRPMeasurement Comparison – Large Chamber vs. ATS1000�Customer Device Comparison @ 28GHzFrom Classical OTA to RF Characterization Systems… in OneIs the dynamic beamforming characteristic needed in all test cases?�For efficiency reasons we should restrict this to minimum mmWave: EiRP Measurements for Small DUTsR&S Test Solution�NRPM - OTA power measurement systemOTA System components: Wideband Measurement Antennas�Patented low RCS dual-polarized Vivaldi antenna: TC-TA85CP/LPFuture UE OTA Measurements in Production Environment3D-MIMO Antenna Calibration Procedure Some discussion started…Food for thoughts…R&S 5G OTA Product MatrixR&S Antenna Test Solutions SummaryConvergence of antenna OTA and conformanceSlide Number 47