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Physikalisch-Technische Bundesanstalt 1
Emission of mm-Wave and
THz Scanners
Thomas Kleine-Ostmann
Working Group 2.21 –
Electromagnetic Fields and Antenna Measuring Techniques
THz Security Workshop
Davos, Switzerland, 29th May, 2015
Physikalisch-Technische Bundesanstalt 2
• Scanners
• Measurement Campaign L3 Provision 100 and
Smith Detection Eqo at Bundespolizei Lübeck, 2011
• Measurement Campaign QPS100 at
R&S Munich, 2012 and 2014
Content
Physikalisch-Technische Bundesanstalt 3
Person scanners L3 ProVision 100
24.25 – 30 GHz
Smith Detection Eqo
24.16 GHz
Photograph: R&S
Photograph: Smith Detection
Photograph: L3
R&S QPS 100
70 – 80 GHz
Physikalisch-Technische Bundesanstalt 4
Power density measurement for person scanners
measurement of power level
correction due to cable attenuation
and calibration factor of power meter
determination of power density from
corrected power and effective area of antenna
HP power meter
Thermal Field Probes too insensitive !
Diode Field Probes not suitable for pulsed signals !
measurement with antenna and spectrum analyzer
or suitable power measurement head
spektrum analyzer
Physikalisch-Technische Bundesanstalt 5
• Scanners
• Measurement Campaign L3 Provision 100 and
Smith Detection Eqo at Bundespolizei Lübeck, 2011
• Measurement Campaign QPS100 at
R&S Munich, 2012 and 2014
Content
Physikalisch-Technische Bundesanstalt 6
Commercially Available Scanners L3 ProVision 100 Smith Detection Eqo
http://www.smithsdetection.com/eqo.php
http://images.businessweek.com/ss/10/01/0107_airp
ort_security_technology/image/018_l3_provision.jpg
• mechanically moved antenna arrays with
192 transmission antennas
• µs pulses with frequency ramp
24.25 GHz to 30 GHz
• illumination of a passive array with 2x 0 dBm
at 24.16 GHz and 10 dB antenna gain
• scanning with 107 Voxel/s
Space and time variable frequency modulated fields::
Appropriate choice of measurement parameters and positions Worst-Case Analysis
Physikalisch-Technische Bundesanstalt 7
L3 Provision 100
Physikalisch-Technische Bundesanstalt 8
L3 Provision 100: Measurements
Horn antenna measurement
Horn antenna measurement without cover
HL050 measurement
Spectrum analyzer
Physikalisch-Technische Bundesanstalt 9
L3 Provision 100: Measurements
24 25 26 27 28 29 30
0,000000
0,000005
0,000010
0,000015
0,000020
Le
istu
ng
sflu
ssdic
hte
[m
W/c
m²]
Frequenz [GHz]
160 cm
Physikalisch-Technische Bundesanstalt 10
Smith Detection Eqo
Physikalisch-Technische Bundesanstalt 11
Smith Detection Eqo: Measurements
Horn in front of illuminating horn antenna Field probe in front of illuminating horn antenna
Horn at scanning position HL050 at scanning position
Physikalisch-Technische Bundesanstalt 12
Smith Detection Eqo: Measurements
24,10 24,12 24,14 24,16 24,18 24,20 24,22
0,00000
0,00001
0,00002
0,00003
0,00004
0,00005
0,00006
0,00007
Le
istu
ng
sflu
ssdic
hte
[m
W/c
m²]
Frequenz [GHz]
144,5 cm / 20 cm Abstand
Physikalisch-Technische Bundesanstalt 13
Results
L3 Provision 100
cw test mode, distance 2.5 cm
approx. 0.1 µW/cm2
scan mode, distance 3.7 cm
approx. 0.015 µW/cm2 peak
scan mode, distance 33 cm
approx. 0.003 µW/cm2 peak
scan mode, distance 58 cm (scan position)
approx. 0.003 µW/cm2 peak
Smith Detection Eqo
cw illumination, at cover
approx. 30 µW/cm2
cw illumination, 5 cm from cover
approx. 10 µW/cm2
cw illumination, 30 cm from cover (person
distance)
approx. 1 µW/cm2
pulsed in front of array,
max. 3 µW/cm2
pulsed in front of array, at scan position)
approx. 0.4 µW/cm2
cw illumination,, at scan position)
approx. 0.025 µW/cm2
Physikalisch-Technische Bundesanstalt 14
• Scanners
• Measurement Campaign L3 Provision 100 and
Smith Detection Eqo at Bundespolizei Lübeck, 2011
• Measurement Campaign QPS100 at
R&S Munich, 2012 and 2014
Content
Physikalisch-Technische Bundesanstalt 15
Characterization of a Rohde&Schwarz QPS100
Tx Rx
Physikalisch-Technische Bundesanstalt 16
Distance dependent antenna calibration
68 69 70 71 72 73 74 7520
20.2
20.4
20.6
20.8
21
21.2
21.4
Frequenz / GHz
An
ten
na
Ga
in / d
B
30 cm
50 cm
75 cm
100 cm
75 76 77 78 79 80 81 8218
18.2
18.4
18.6
18.8
19
19.2
Frequenz / GHz
An
ten
na
Ga
in / d
B
20 cm
50 cm
75 cm
100 cm
Pcg
f
f
cg
P
A
PS
eff
2
2
2
2
4
4
Physikalisch-Technische Bundesanstalt 17
Uncertainty analysis
;30
;10
10
4
10
110
210
2
PESWDBMMixMAntACLMMP
c
fS
P
g
Quantity
Unit Definition
S mW/cm2 Determined Power Density
pi
f Hz Frequency
g dB Antenna Gain
c m/s Speed of Light
P dBW Measured Power
M dBm Power Reading before Correction
CLM dB Conversion Loss Mixer
A dB 20 dB Attenuator
MAnt dB Mismatch error between Antenna and Attenuator
MMix dB Mismatch error between Mixer and Attenuator
DB dB Correction due to deviation between measurement bandwidth 20 MHz and calibration bandwidth 3 MHz
SW dB Correction due to standing wave pattern
PE dB Correction due to positioning error
Physikalisch-Technische Bundesanstalt 18
Uncertainty budget for the V band Quantity Value Standard
Uncertainty
Distribution Sensitivity
Coefficient
Uncertainty
Contribution
Index
pi 3.1415926535898
f 74.127000·109 Hz 577·103 Hz rectangular 960·10-15 550·10-9 mW/cm2 0.0 %
g 19.240 dB 0.200 dB normal -8.2·10-3 -1.6·10-3 mW/cm2 8.5 %
c 299.8·106 m/s
P -44.120 dBW 0.655 dBW
M -60.370 dBm 0.100 dBm normal 8.2·10-3 820·10-6 mW/cm2 2.1 %
CLM 26.640 dB 0.250 dB normal 8.2·10-3 2.0·10-3 mW/cm2 13.3 %
A 19.6100 dB 0.0500 dB normal 8.2·10-3 410·10-6 mW/cm2 0.5 %
MAnt 0.0 dB 6.36·10-3 dB U 8.2·10-3 52·10-6 mW/cm2 0.0 %
MMix 0.0 dB 0.0262 dB U 8.2·10-3 210·10-6 mW/cm2 0.1 %
DB 0.0 dB 0.398 dB rectangular 8.2·10-3 3.3·10-3 mW/cm2 33.8 %
SW 0.0 dB 0.393 dB rectangular 8.2·10-3 3.2·10-3 mW/cm2 32.9 %
PE 0.0 dB 0.202 dB rectangular 8.2·10-3 1.6·10-3 mW/cm2 8.7 %
S 0.03544 mW/cm2 5.60·10-3 mW/cm2 relative expanded uncertainty of 32 %
(k=2, 95% confidence interval, same for W band)
Physikalisch-Technische Bundesanstalt 19
Measurement positions and approaches front view top view
1) maximum power densities at distinct locations using the MaxHold modus with Peak detector
(upper limit but high measurement dynamics for mapping the field, scanner in sweep mode)
2) averaged power densities as required by the ICNIRP guidelines using the RMS detector,
the 0-Hz-Span modus, sweep times of 44 s (ICNIRP requirement for 75 GHz) and Time-Domain Power
averaging at few distinct locations with less measurement dynamics (scanner at fixed frequency).
Physikalisch-Technische Bundesanstalt 20
Characterization of a Rohde&Schwarz QPS100
70 71 72 73 74 75 76 77 78 79 80
0.00
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
left 50 cm
left 105 cm
left 140 cm
left 165 cm
center 50 cm
center 105 cm
center 140 cm
center 165 cm
right 50 cm
right 105 cm
right 140 cm
right 165 cm
P
ow
er
De
nsity / m
W/c
m2
Frequency / GHz
5 cm distance to panel, MaxHold modus with Peak detector, normal operation
Physikalisch-Technische Bundesanstalt 21
Characterization of a Rohde&Schwarz QPS100
70 71 72 73 74 75 76 77 78 79 800.0000
0.0001
0.0002
0.0003
0.0004
0.0005
0.0006
0.0007
0.0008
0.0009
0.0010 left 50 cm
left 105 cm
left 140 cm
left 165 cm
center 50 cm
center 105 cm
center 140 cm
center 165 cm
right 50 cm
right 105 cm
right 140 cm
right 165 cm
Pow
er
De
nsity / m
W/c
m2
Frequency / GHz
50 cm distance to panel, MaxHold modus with Peak detector, normal operation
Physikalisch-Technische Bundesanstalt 22
Characterization of a Rohde&Schwarz QPS100
70 71 72 73 74 75 76 77 78 79 800.0000
0.0001
0.0002
0.0003
0.0004
left 50 cm
left 105 cm
left 140 cm
left 165 cm
center 50 cm
center 105 cm
center 140 cm
center 165 cm
right 50 cm
right 105 cm
right 140 cm
right 165 cm
P
ow
er
De
nsity / m
W/c
m2
Frequency / GHz
100 cm distance to panel, MaxHold modus with Peak detector, normal operation
Physikalisch-Technische Bundesanstalt 23
Characterization of a Rohde&Schwarz QPS100
75 76 77 78 79 800.00000
0.00002
0.00004
0.00006
0.00008
0.00010
0.00012
0.00014
0.00016
0.00018
0.00020
50 cm
105 cm
140 cm
165 cm
Pow
er
De
nsity / m
W/c
m2
Frequency / GHz
operator position, MaxHold modus with Peak detector, normal operation
Physikalisch-Technische Bundesanstalt 24
Characterization of a Rohde&Schwarz QPS100
0 10 20 30 40 50 60 700.000000
0.000005
0.000010
0.000015
0.000020
0.000025
Pow
er
De
nsity / m
W/c
m2
Distance to panel / cm
averaged power density according to ICNIRP directly in front of an antenna with
scanner operated in single frequency test mode
(RMS detector, 0-Hz-span at 75.396 GHz, time-domain averaging over 44 s,
noise floor correction)
Physikalisch-Technische Bundesanstalt 25
Characterization of a Rohde&Schwarz QPS100
70 71 72 73 74 75 76 77 78 79 800.00000
0.00001
0.00002
0.00003
0.00004
0.00005
0.00006
0.00007
0.00008
5.5 cm
55.5 cm
Po
we
r D
en
sity / m
W/c
m2
Frequency / GHz
averaged power density according to ICNIRP directly in front of an antenna with
scanner operated in single frequency test mode for two typical distances)
(RMS detector, 0-Hz-span at multiple frequencies, time-domain averaging over 44 s,
noise floor correction)
Physikalisch-Technische Bundesanstalt 26
• repeat selected measurements of the previous
campaign
• extend measurements to 170 GHz with external
WR06 mixer (RPG SAM-170, 20-30 dB conversion
loss):
FCC and ETSI EN 305 550 foresee emission
measurements at second harmonic
Measurement Campaign QPS100 at
R&S Munich, 2014
Physikalisch-Technische Bundesanstalt 27
Measurement Campaign QPS100 at
R&S Munich, 2014
100 110 120 130 140 150 160 170 180 190 200-64
-62
-60
-58
-56
-54
-52
Sig
na
l P
ow
er
/ d
Bm
Frequency / GHz
FSW67+
SAM-170
overrange
mode
normal scanner
operation
Physikalisch-Technische Bundesanstalt 28
Measurement Campaign QPS100 at
R&S Munich, 2014
110 120 130 140 150 160 170-80
-75
-70
-65
-60
Sig
na
l P
ow
er
/ d
Bm
Frequency / GHz
FSW67+
SAM-170
overrange
mode with
Auto-ID
scanner
at 69.895 GHz