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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

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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