A Conformal CPW Folded Slot Antenna Array Printed on a

Kapton Substrate

Masud A. AzizSayan Roy*

Layne A. BergeIrfanullah

Sanjay NariyalBenjamin D. Braaten

NORTH DAKOTA STATE UNIVERSITY

APPLIED ELECTROMAGNETICS LAB

Department of Electrical and Computer Engineering

North Dakota State UniversityFargo, ND, USA

• 1) Introduction and Background

• 2) Conformal CPW Folded Slot Array

• 3) Measurement and Simulation Results

• 4) Proposed Design Guidelines

• 5) Conclusion

NORTH DAKOTA STATE UNIVERSITY

APPLIED ELECTROMAGNETICS LAB

Topics

Introduction and Background

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Schematic of the CPW (Co Planar Waveguide) –fed single folded slot antenna [1]:

[1] D. E. Anagnostou and A. A. Gheethan, “A coplanar reconfigurable folded slot antenna without bias network for WLAN applications,”, IEEE Antennas And Wireless Propagation Letters, vol. 8, pp. 1057-1060, Sep. 2009.

Conformal CPW Folded Slot Array

NORTH DAKOTA STATE UNIVERSITY

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b = 5.00 mm,

s = 61.00 mm,

ws = 21.37 mm,

Ls = 43.40 mm,

r = 41.80 mm,

d = 2.00 mm,

g = 0.63 mm,

m = 1.79 mm,

n = 0.71 mm,

Lf = 2.77 mm,

P = 43.5 mm and

Q = 160.5 mm.

Substrate Thickness : 0.05 mmDielectric Permittivity: 2.91

Measurement and Simulation ResultsNORTH DAKOTA STATE UNIVERSITY

APPLIED ELECTROMAGNETICS LAB

Printed two-element CPW folded slot antenna array on 2 mil Kapton substrate

Measurement and Simulation ResultsNORTH DAKOTA STATE UNIVERSITY

APPLIED ELECTROMAGNETICS LAB

Prototype antenna diagram with a bend angle of ϕb on a conformal surface (wedge)

Measurement and Simulation ResultsNORTH DAKOTA STATE UNIVERSITY

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The resonant frequency was measured to be 3.29 GHz with a 10dB bandwidth of 250 MHz for ϕb =0°.

A good impedance match can be observed for each bend angle.

The impedance match of the antenna is essentially independent of ϕb below 45°.

The measured and simulated normalized field patterns on a

conformal surface with ϕb = 0°

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in x-z plane in y-z plane

Measurement and Simulation ResultsNORTH DAKOTA STATE UNIVERSITY

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Prototype antenna diagram with a bend angle of ϕb on a conformal surface (wedge)

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Comparison of the

measured normalized

field pattern in the x-z

plane on a conformal

surface with ϕb =

0°

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Comparison of the

measured normalized

field pattern in the x-z

plane on a conformal

surface with ϕb =

30°

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APPLIED ELECTROMAGNETICS LAB

Comparison of the

measured normalized

field pattern in the x-z

plane on a conformal

surface with ϕb =

45°

Measurement and Simulation ResultsNORTH DAKOTA STATE UNIVERSITY

APPLIED ELECTROMAGNETICS LAB

Proposed Design GuidelinesNORTH DAKOTA STATE UNIVERSITY

APPLIED ELECTROMAGNETICS LAB

b = 5.00 mm,

s = 61.00 mm,

ws = 21.37 mm,

Ls = 43.40 mm,

r = 41.80 mm,

d = 2.00 mm,

g = 0.63 mm,

m = 1.79 mm,

n = 0.71 mm,

Lf = 2.77 mm,

P = 43.5 mm and

Q = 160.5 mm.

Changed Parameters: ws , Ls , r , one at a time

Changes in Geometry

Proposed Design GuidelinesNORTH DAKOTA STATE UNIVERSITY

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Effect of changes in ws (slot height)

Observation:

S11 can be improvised by

increasing the dimension of

the radiating slot of the

antenna.

Advantage:

A better S11 can be

obtained without changing

the overall dimension of the

antenna

Proposed Design GuidelinesNORTH DAKOTA STATE UNIVERSITY

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Effect of changes in Ls (slot width)

Observation:

A second resonance point

at 2.3 GHz has been found

without any changes of the

default characteristics of

the antenna

Advantage:

Dual-band characteristics

can be achieved without

changing the overall

dimension of the antenna

Proposed Design GuidelinesNORTH DAKOTA STATE UNIVERSITY

APPLIED ELECTROMAGNETICS LAB

Effect of changes in r (size of the dipole)

Observation:

The resonance frequency

can be changed by

decreasing the size of the

dipole exciting the radiating

slot of the antenna

Advantage:

The overall radiating frequency

can be decreased without

changing the overall dimension

of the antenna

Conclusion Introduction and Background on the CPW-fed slot

antenna has been discussed.

Conformal CPW-fed slot antenna array has been introduced.

Measurement and Simulation Results are compared for different bend angles of the surface of the antenna.

New design guidelines have been proposed for the improvisation of the antenna characteristics.

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APPLIED ELECTROMAGNETICS LAB

Questions?

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Thank you for listening!