Designing a Band Notch Filter for a UWB Antenna Using CST MWS

Designing a band notch filter for a UWB antenna using CST MWS Optimization or not?

Ad Reniers

Introduction • • • •

Ultra Wide-Band filter structures and analysis Simulation setup and results Conclusions

/ Electrical Engineering

9-4-2010

PAGE 1

Ultra Wide-band • Ultra wide-band frequencies between 3.1 GHz and 10.6 GHz • To avoid interference between 5 GHz and 6 GHz reserved for WLAN we where asked to design a filter

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9-4-2010

PAGE 2

Ultra Wide-band antenna • A compact antenna was needed • Evolution from a thin wire dipole to a printed pseudo monopole

D H3

H2

H1

Ws W

Top layer copper Bottom layer copper Substrate

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PAGE 3

• • • •

Ultra Wide-Band filter structures and analysis Simulation setup and results Conclusions

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9-4-2010

PAGE 4

Notch filter analyses • An ‘U’ shaped gap for Notch filter characterization

BI BII

AI

AII AIII

Top layer copper Bottom layer copper Substrate Gap in the copper

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PAGE 5

Spur filter analyses • Spur line filter in the transmission line =

DII

DI

CII

Top layer copper Bottom layer copper Substrate Gap in the copper

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PAGE 6

Notch and spur filter results • Results with the filters combined BI BII

S11 PARAMATERS HP8510 Ad Reniers, 27 juni 2007 0

DII -5

DI

-10

Amplitude (dB)

-15

AI

-20

AII AIII CII

-25

Top layer copper -30

Bottom layer copper -35

Substrate

UWB Antenne U notch Spur Simulatie Notch & Spur

Gap in the copper

Ideaal 12.0

11.8

11.5

11.3

11.1

10.8

10.6

10.4

9.9

10.1

9.6

9.4

9.2

8.9

8.7

8.5

8.2

8.0

7.8

7.5

7.3

7.1

6.8

6.6

6.4

6.1

5.9

5.7

5.4

5.2

5.0

4.7

4.5

4.3

4.0

3.8

3.6

3.3

3.1

2.9

2.6

2.4

2.2

1.9

1.7

1.5

1.2

1.0

-40

Ferquency (GHz)

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PAGE 7

• • • •

Ultra Wide-Band filter structures and analysis Simulation setup and results Conclusions

/ Electrical Engineering

9-4-2010

PAGE 8

Simulation setup in CST using the optimizer (1) • Optimizer only used for the notch filter • Parameter and goal settings:

BI BII

AI

AII AIII

Top layer copper Bottom layer copper Substrate Gap in the copper

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PAGE 9

Simulation setup in CST using the optimizer (2) Reflectie Parameters Simulatie CST Microwave Studio Door Ad Reniers, Datum 6 juni 2007

0

BI -5

BII

-10

S11 (dB)

-15

-20

-25 B C -30

D E

-35

F

AI

Geen Filter

AII

Ideaal -40 0.000

1.000

AIII 2.000

3.000

4.000

5.000

6.000

7.000

8.000

9.000

10.000

11.000

12.000

Frequency (GHz)

Top layer copper

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Sim.

AI, AII and BII (mm)

BI + BII (mm)

AIII (mm)

BW (GHz @ -10dB)

Ampl. (dB)

Bottom layer copper

B

1.31

5.99 mm

7.30

4.34 ..6.28

-1.72

Substrate

C

1.19

5.93

7.46

4.38 .. 6.19

-1.83

Gap in the copper

D

1.22

5.96

7.16

4.56 .. 5.96

-2.72

E

0.99

5.96

8.60

4.28 .. 6.35

-1.68

F

1.33

5.39

7.18

4.61 .. 5.75

-5.86

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PAGE 10

Simulation setup in CST not using the optimizer Reflectie Parameters Simulatie CST Microwave office Door Ad Reniers, 23 juni 2007

0

BI BII

-5

-10

S11 (dB)

-15

DII -20

DI

-25

-30

-35

-40 0.000

Ideaal 1r 1ra 1rb 1rc 1rd

1.000

AI

AII AIII

2.000

3.000

4.000

5.000

6.000

7.000

8.000

9.000

10.000

11.000

12.000

CII

Frequentie (GHz)

Top layer copper

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Sim.

AI, AII and BII (mm)

BI + BII (mm)

AIII (mm)

BW (GHz @ -10dB)

Ampl. (dB)

1ra

1.20

7.20

8.00

4.42 .. 5.80

-2.63

1rb

1.20

7.20

6.80

4.85 .. 6.00

-3.51

1rc

1.20

7.20

6.40

5.04 .. 6.08

-3.95

1rd

1.20

7.20

6.00

5.22 .. 6.16

-4.49

Bottom layer copper Substrate Gap in the copper

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Results using the optimizer/iterative process Reflectie Parameters S11 PARAMATERS

Simulatie CST Microwave office HP8510 DoorAd AdReniers, Reniers,2723juni juni2007 2007

00

BI BII

-5 -5

-10 -10

S11 (dB)

Amplitude (dB)

-15 -15

DII -20 -20

DI

-25 -25

-30 -30

AI

AIII

Frequentie (GHz) Ferquency (GHz)

12.0

11.8

11.000

11.5

11.3

11.1

10.8

10.000

10.6

10.4

9.9

10.1

9.000

9.6

9.4

9.2

8.9

8.000

8.7

8.5

8.2

8.0

7.000

7.8

7.5

7.3

7.1

6.000

6.8

6.6

6.4

6.1

5.000

5.9

5.7

5.4

5.2

4.000

5.0

4.7

4.5

4.3

3.000

4.0

3.8

3.6

2.000

AII CII

3.3

3.1

2.9

2.6

1.000

2.4

2.2

1.9

1.5

1.2

1.0

-40 -40 0.000

1.7

Ideaal UWB Antenne U notch Spur 1rk Simulatie Notch & Spur 1rl Ideaal

-35 -35

12.000

Top layer copper Bottom layer copper Substrate

Sim.

AI, AII and BII (mm)

BI + BII (mm)

AIII (mm)

CI + CIII (mm)

CII (mm)

DI + DII (mm)

BW (GHz @ -10dB)

Ampl. (dB)

1rk

1.20

7.20

6.00

0.84

0.6

5.6

4.70 .. 6.24

-2.36

1d

1.22

5.96

7.16

NA

NA

NA

4.56 .. 5.96

-2.72

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Gap in the copper

9-4-2010

PAGE 12

• • • •

Ultra Wide-Band filter structures and analysis Simulation setup and results Conclusions

/ Electrical Engineering

9-4-2010

PAGE 13

Conclusions • Using the optimizer is a good starting point if there is no analytical model • You should know what to expect • Not the ultimate tool • The iterative process gives more inside in the working of the filter itself • Combination of using the optimizer and a iterative process is the most efficient way to design.

Top layer copper Bottom layer copper Substrate

• Thank you for your attention / Electrical Engineering

Gap in the copper

9-4-2010

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