First Results of the DEBoRA Project

Dataset 1 Dataset 2 Dataset 3 Dataset 4 Dataset 5 Dataset 6
First Results of the DEBoRA Project
Mathias Magdowski
August 4, 2017

Details of the measurement
Device under test:
cell phone
GSM 1800 band
Parameters:
angle steps: 45°
polarization: horizontal and vertical
DUT size: ?
environment: semi?/fully? anechoic
height scan: ?
measurement distance: ?
ﬁle name: 119540-5 Directivity GSM1800

Measured Directivity versus Frequency
1 500 1 550 1 600 1 650 1 700 1 750 1 800 1 850 1 900 1 950 2 000
2
4
6
8
10
Frequency, f in MHz
Directivity,Dmax

Comparison with the Analytical Approximation
1 500 1 550 1 600 1 650 1 700 1 750 1 800 1 850 1 900 1 950 2 000
2
4
6
8
10
Frequency, f in MHz
Directivity,Dmax
Measured
Unintentional radiator

Analytical Approximation for an Unintentional Radiator
Maximum directivity:
Dmax ≈
1.55 ka ≤ 1
0.5 0.577 + ln 4(ka)2 + 8ka + 1
8(ka)2+16ka
ka > 1
k is the wave number
radius of the smallest surrounding sphere is approx. a = 5 cm
Source:
P. F. Wilson, D. A. Hill, and C. Holloway, “On determining the
maximum emissions from electrically large sources”, IEEE
Transactions on Electromagnetic Compatibility, vol. 44, no. 1,
pp. 79–86, Feb. 2002, Eq. (9)

Discussion of Results
Frequencies below 1690 MHz and above 1810 MHz:
seems to be only noise
ﬂuctuation −→ uncertainty of the measurement
either too low or to large compared to the analytical result
Frequencies between 1690 MHz and 1810 MHz:
rapid changes −→ not very physical
larger frequency correlation expected
in general higher than the analytical result
cell phone −→ intentional emitter

Device under test:
WiFi camera
ISM 2.4 GHz band
Parameters:
angle steps: ?
polarization: ?
DUT size: ? (8 cm radius assumed)
height scan: ?
ﬁle name: Kopie von Directivity Test

Measured Directivity versus Frequency
2 400 2 410 2 420 2 430 2 440 2 450 2 460 2 470 2 480
1
2
3
4
5
6
7
8
Frequency, f in MHz
Directivity,Dmax

2 400 2 410 2 420 2 430 2 440 2 450 2 460 2 470 2 480
1
2
3
4
5
6
7
8
Frequency, f in MHz
Directivity,Dmax
Measured

much better agreement in general
some ﬂuctuation −→ uncertainty of the measurement
two stronger outliers at 2411 MHz and 2476 MHz

Device under test:
Small transmitter
ISM 2.4 GHz band for Bluetooth
Parameters:
angle steps: ?
polarization: ?
DUT size: ? (7.75 cm to 8.5 cm radius measured)
height scan: ?
ﬁle name: 140803-1 Directivity Bluetooth

1 000 2 000 3 000 4 000 5 000 6 000 7 000
1
2
3
4
5
6
7
8
Frequency, f in MHz
Directivity,Dmax
Measured

Zoom at around 2.4 GHz
2 300 2 350 2 400 2 450 2 500 2 550 2 600
1
2
3
4
5
6
7
8
Frequency, f in MHz
Directivity,Dmax
Measured

measured data in general too high (wrong eﬀective radius)?
very noise, low frequency correlation
very limited frequency band from 2400 MHz to 2484 MHz
two additional peaks around 1685.25 MHz and 1784.5 MHz

Device under test:
Small transmitter
ISM 2.4 GHz band for WiFi
Parameters:
angle steps: ?
polarization: ?
DUT size: ? (7.75 cm to 8.5 cm radius measured)
height scan: ?
ﬁle name: 140953-3 Directivity W-lan 2,4GHz

1 000 2 000 3 000 4 000 5 000 6 000 7 000
1
2
3
4
5
6
7
Frequency, f in MHz
Directivity,Dmax
Measured

2 300 2 350 2 400 2 450 2 500 2 550 2 600
1
2
3
4
5
6
7
Frequency, f in MHz
Directivity,Dmax
Measured

quite good agreement in general
some ﬂuctuation −→ uncertainty of the measurement
two stronger outliers around 2400 MHz and 2474 MHz
some additional peak at 1336.75 MHz
(very small) harmonics of the WiFi band at 4762.75 MHz

Device under test:
Small transmitter
Parameters:
angle steps: ?
polarization: ?
height scan: ?
ﬁle name: 141868-3 Directivity WLAN 2,4GHz

1 000 2 000 3 000 4 000 5 000 6 000 7 000
1
2
3
4
5
Frequency, f in MHz
Directivity,Dmax
Measured

2 300 2 350 2 400 2 450 2 500 2 550 2 600
1
2
3
4
5
Frequency, f in MHz
Directivity,Dmax
Measured

very similar to data set 4
two stronger outliers around 2392.25 MHz and 2478.5 MHz
other peaks around 887.025 MHz and 1341.75 MHz
harmonics at 4874 MHz

Device under test:
Small transmitter
Parameters:
angle steps: ?
polarization: ?
height scan: ?
ﬁle name: 142759-1 Direktivity W Lan 2,4 GHz

three separable bands
1. from 2362 MHz to 2367.75 MHz: somehow noisy
2. from 2400 MHz to 2402.75 MHz: somehow noisy
3. from 2412 MHz to 2423.75 MHz: strong frequency correlation
−→ reasonable data
measured data in general too high (wrong eﬀective radius or
intentional radiator)?
no other peaks or harmonics

Acknowledgment
The author would like to thank
Dr. Bernd Sisolefsky,
Frank Siebert,
Manfred Schmidt, and
Eric Brüsewitz
from the Federal Network Agency, Measuring Laboratory Kolberg
Bundesnetzagentur für Elektrizität, Gas, Telekommunikation, Post
und Eisenbahnen
Messlabor Kolberg, Ring 58
15754 Heidesee, Germany
for their kind cooperation and support in collection the measured
data.

Acknowledgment 2
The author would also like to thank
Prof. Dr. Hans Georg Krauthäuser and
André Manicke
from the Technical University of Dresden
Technische Universität Dresden
Elektrotechnisches Institut
Lehrstuhl für Theoretische Elektrotechnik und Elektromagnetische
Vertäglichkeit
Helmholtzstraße 9, 01069 Dresden, Germany
for initially starting this project.

Thanks for your attention!
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First Results of the DEBoRA Project

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