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Copyright © 2016 E&R TECH. All rights reserved.
EMC & NOISEEngineering ServiceProduct / System / EFS / EMC Management Plan.
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2016 CST SI / PI / EMC Conference
Radiator for ALSE validation(By CST MICROWAVE STUDIO)
Radiator for ALSE validation
2016.9.6
• What is the ALSE?
• ALSE validation method
• Radiator for ALSE validation
• Simulation model & results
• Measurement setup & results
• Effects of 50Ω load
• ALSE influence parameters
4
6
7
8
15
21
24
What is the ALSE?
ALSE(Absorber-lined shielded enclosure)
- Shielded enclosure with radio frequency-absorbing material on its internal ceiling andwalls (CISPR 25)
CISPR25 Ed. 3.0 : 2008
What is the ALSE?
ALSE(Absorber-lined shielded enclosure)
Reference : google image (https://www.google.com)
ALSE validation method
Ground plane
Transmit
Receive
(Direct wave + Reflected wave)
Variable height
(1 m ~ 4 m)
Direct wave
Reflected wave
CISPR 16Verified by NSA
(Normalized Site Attenuation)
CISPR 25
Ground plane
TransmitReceive (Only Direct wave)
Constant height
(1 m)
Direct wave
Reflected wave
Ground plane
Verified by ???
ALSE validation method (CISPR 25 Ed. 4)
Radiator for ALSE validation
ALSE validation method (CISPR 25 Ed. 4)
Modelled long wire transmitting antenna
Radiator modelling
Front view
500mm
50mm
Top view
150mm100mm
100mm
Material : Aluminum (Lossy metal)
Material : Copper (Lossy metal)
ALSE validation method (CISPR 25 Ed. 4)
Radiator for ALSE validation (VSWR)
5
10
15
20
25
0 100 200 300 400 500 600 700 800 900 1000
VS
WR
frequency in MHz
CISPR 25 Ed.4 vs CST simulation model
without 10 dB attenuation
ALSE validation method (CISPR 25 Ed. 4)
Ground plane modelling
1m
2.5m
Ground plane
0.2m
0.129m
Straps
0.9m
0.129m
0.2m
Material : Copper (Lossy metal)
ALSE validation method (CISPR 25 Ed. 4)
Rod antenna modelling for antenna factor
• 모노폴 높이 : 1100 mm• 모노폴 직경 : 30 mm• 카운터포이즈 : 600 X 600 mm
10 kΩ 저항
1 V/mPlane wave 인가
• 안테나 팩터(dB/m) = 전계강도(dBV/m) – 10kΩ 전압값(dBV)
ALSE validation method (CISPR 25 Ed. 4)
Simulation setup & results – 0.15 ~ 30 MHz
• 전계강도(dBuV/m) = 10kΩ 전압값(dBuV) + 안테나 팩터(dB/m) – 10dB(attenuation)
Antenna configuration for reference measurement
method below 30 MHz
Conductive
floor
Radiator
Monopole
Ant.
50 ohm
Load
Excitation
1 Vrms
Simulation setup
Ant. Distance
1m
ALSE validation method (CISPR 25 Ed. 4)
E-field
Monitor
(1 m)
Test Table
(Ground)
Radiator
@ 300 MHz
50 ohm
Load
Excitation
1 Vrms
Simulation results – 30 ~ 1000 MHz
Simulation setup
ALSE validation method (CISPR 25 Ed. 4)
Simulation results
1000 ~ 1200 mm 로가변
• GND 크기에 따른 전기장 분포 변화는 거의 없음• CISPR 25 Ed.4 Draft 에서도 같은 내용 언급
Test table 의 ground plane 크기에 대한 영향도 분석
ALSE validation method (CISPR 25 Ed. 4)
Signal
Generator
50Ω
load10 dB attenuation
90 degree
connector
Antenna
(1 m height)
EMI
ReceiverALSE
1m
GND Plane (Test table)
Table height = 0.9 m
Output = 120 dBμV
MA
M0= direct connection (120 dBuV - cable loss)kAF= Antenna factor (dB(1/m))
± 6 dB, ≥ 90 %
𝐸𝑒𝑞 = 120𝑑𝐵𝜇𝑉 + 𝑀𝐴 −𝑀0 + 𝑘𝐴𝐹
Ferrite core
Ferrite core
∆𝐿𝑜𝑛𝑔 𝑊𝑖𝑟𝑒 𝑀𝑒𝑡ℎ𝑜𝑑= 𝐸𝑒𝑞,𝑚𝑎𝑥 − 𝐸𝑒𝑞,𝑚𝑎𝑥,𝑟𝑒𝑓
Measurement setup
Frequency range[MHz]
Frequency step[MHz]
Number of points
015 ~ 29.95 0.2 150
30 ~ 199 1 170
200 ~ 1000 5 161
0.15 ~ 1000 - 481
ALSE validation method (CISPR 25 Ed. 4)
Matching Unit
(Attenuation)
Attn.50Ω
load
RadiatorSignal
Generator
임피던스 매칭이란 최대 전력 전달을 의미하는 것이 아님
임피던스 불연속점에서 반사손실은 Radiation 형태로 나타나며, 측정 에러를 유발할 수 있음
이를 최소화 하기 위해 Attenuation 을 삽입
Broadband impedance matching
without attn. with attn.
Broadband
Matching
without attn.
with attn.
ALSE validation method (CISPR 25 Ed. 4)
Measurement results (해외)
ALSE validation method (CISPR 25 Ed. 4)
Measurement results (해외)
ALSE validation method (CISPR 25 Ed. 4)
Measurement results (해외)
ALSE validation method (CISPR 25 Ed. 4)
Measurement results
Dimension E&R ALSE
L (m) 6.15
W (m) 7.2
H (m) 3.15
G.P. size (m) 2.7 X 1.8
Bonding Wall
Number of straps 9
Width of straps (cm) 20
ALSE validation method (CISPR 25 Ed. 4)
Effect of 50Ω load
Ideal port
with attenuation & 50Ω load
50 ohm
Load
Attenuation
Stray inductance & capacitance
500 ~ 700 MHz 사이의 주파수 대역에서 영향이 있음
50Ω load에 대한 영향도 분석 - 시뮬레이션
ALSE validation method (CISPR 25 Ed. 4)
Effect of 50Ω load
Reference : CISPR/D/JWG A-SITE-VAL/N075
• 가장 일반 적인 형태의 B type 의 경우 600 MHz 부근 공진 발생
Vertical Polarization
Conclusion : Additional requirements for 50 ohm load or transmitting antenna should be added
50Ω load에 대한 영향도 분석 - 측정 (해외)
ALSE validation method (CISPR 25 Ed. 4)
Effect of 50Ω load
200 400 600 800 1000
40
50
60
70
80
90
100
110
120
130
dB
uV
/m
Freq [MHz]
Load A
Load BVertical Polarization
200 400 600 800 1000
40
50
60
70
80
90
100
110
120
130
dB
uV
/m
Freq [MHz]
Load A
Load BHorizontal Polarization
• Load 종류별로 기생성분에 의해 공진 발생
Emax
Emax값은상대적으로큰변화는없음
Load A
Load B
50Ω load에 대한 영향도 분석 - 측정
ALSE validation method (CISPR 25 Ed. 4)
ALSE influence parameters