immunity analysis & test results via bulk current … 0 frequency, mhz b teseq cip-9136a notes:...

IEEE 802.3bp RTPGE Task Force– May 14, 2013 Version 1.0

Mehmet Tazebay

[email protected]

Immunity Analysis & Test Results

via Bulk Current Injection Method

for 1-pair UTP Channels

Victoria, BC, Canada

May 15, 2013

IEEE P802.3 Maintenance report – July 2008 Plenary Version 1.0 IEEE 802.3bp RTPGE Task Force– May 14, 2013 Version 1.0 Page 2

Contributors

Ahmad Chini, Broadcom Mehmet Tazebay, Broadcom

Supporters Sasha Babenko, Molex

Mike Gardner, Molex


Overview

• Objective & Setup Information

• Bulk Current Injection (BCI) Test Setup

• CM/DM BCI Transfer Functions

• Mode Transfer Impedance

• CM/DM Noise Calculation

• Conclusions


Objective & Setup Information

1. Utilize Bulk Current Injection (BCI) test method to quantify and

measure the common mode (CM) & differential mode (DM) transfer

function

2. Compute the CM & DM noise for a given BCI Immunity Test Profile

Setup Information:

2m 1-pair UTP AWG22 prototype cable is used

Current Injection Probe (CIP) is used to couple and measure the

common mode and differential mode signals

Well-balanced(!) UTP-to-SMA test heads were utilized to connect the

cable under test with measurement equipment

3-port Network Analyzer measurements were conducted


Bulk Current Injection Test Setup

CIP

Network

Analyzer

1-pair, 2m UTP

5-cm

Foam

2 x 50 Ω

Termination

Test Head


Test Head

Note: Test Head is critical for imbalance and has to be properly designed,

manufactured and measured.


Background Noise

0 50 100 150 200 250 300 350 400-120

-100

-80

-60

-40

-20

0

Frequency, MHz

Sds21 a

nd S

cs21, dB

Note: Background Noise is well below measurement values for

both CM and DM Transfer function measurements.

Common Mode

Differential Mode


CM & DM BCI Transfer Functions

0 50 100 150 200 250 300 350 400-100

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

Frequency, MHz

Sds21 a

nd S

cs21, dB

HCM(f)

HDM(f)

Notes: 3 x 1-pair UTP channels were measured (6 different test

heads). The variations in DM noise seen is due to

test head soldering process variation.


Current Injection Probe Calibration

0 50 100 150 200 250 300 350 400-20

-18

-16

-14

-12

-10

-8

-6

-4

-2

0

Frequency, MHz

S31 in d

B

Teseq CIP-9136A

Notes: * Current Injection Probe (CIP) transfer function has a few

dB variation in coupling factor across the frequency band.

* The 2-port S31 measurement with calibration tool is

used to calibrate noise measurements.

HCIP(f)


Mode Transfer Impedance

• Let a common mode transfer impedance be defined as

• Let a differential mode transfer impedance be defined as

• Then for a given peak BCI current, the input referred common mode

and differential mode noise can be calculated as the following:

ZCM[Ω] = 50 Ω

2 *

HCM(f)

HCIP(f) (1)

ZDM[Ω] = 50 Ω * 2 * HDM(f)

HCIP(f) (2)

VCM[mV] = IBCI[mA] * ZCM[Ω] (3)

VDM[mV] = IBCI[mA] * ZDM[Ω] (4)


ZCM[Ω] (as measured)

0 50 100 150 200 250 300 350 400 0

10

20

30

40

50

60

70

80

90

100

Frequency, MHz

,

ZC

M[Ω

]

Notes: * Common Mode Transfer Impedance, ZCM([Ω], is shown for 3

cable samples of the same type, 6 ends.

* The results shown are for all 6 ends of the cables.

* All cables show same impedance values.


ZDM[Ω] (as measured)

0 50 100 150 200 250 300 350 400 0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0.5

Frequency, MHz

ZD

M[Ω

]

Notes: * Differential Mode Transfer Impedance, ZDM[Ω], is shown

for 3 cable samples of the same type, 6 ends.

* The results shown are for all 6 ends of the cables.


VCM for a constant level BCI (200mA)

0 50 100 150 200 250 300 350 400 0

5

10

15

20

25

30

35

40

Frequency, MHz

VC

M[𝑽

]


VDM for a constant level BCI (200mA)

0 50 100 150 200 250 300 350 400 0

50

100

150

200

Frequency, MHz

VD

M[𝒎

𝑽]


VCM & VDM for a constant level BCI (200mA)

0 50 100 150 200 250 300 350 400 10

0

10 1

10 2

10 3

10 4

10 5

Frequency, MHz

VCM

VDM

VC

M &

VD

M, [

mV

]


VCM for a BCI Profile (max 350mA)

0 50 100 150 200 250 300 350 400 0

5

10

15

20

25

30

35

40

Frequency, MHz

101

102

0

100

200

300

400

Frequency, MHz

BC

I te

st le

vel, m

A

VC

M(𝑽

)


VDM for a BCI Profile (max 350mA)

0 50 100 150 200 250 300 350 400 0

20

40

60

80

100

120

140

160

180

200

Frequency, MHz

VD

M[𝒎

𝑽]

101

102

0

100

200

300

400

Frequency, MHz

BC

I te

st le

vel, m

A


Conclusions

• In this contribution, we demonstrate

1. BCI is an effective technique for analyzing and quantifying the

ingress model for EMC immunity

2. It is feasible to characterize the mode-conversion channel

transfer functions via BCI

3. Given BCI levels & #2, it is also feasible to calculate the CM and

DM noise levels at the input of receiver

4. There exist 1-pair UTP channels which can yield DM noise as

low as 55mV-pp

immunity analysis & test results via bulk current … 0 frequency, mhz b teseq cip-9136a notes:...

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