Ncc Hemant Ppt

Gain Enhancement of Microstrip Patch Antenna using Near-Zero Index

Metamaterial (NZIM) Lens

Hemant Suthar, Debdeep Sarkar*, Kushmanda Saurav

and Kumar Vaibhav Srivastava

Department of Electrical Engineering,

Indian Institute of Technology Kanpur, India

*[email protected] (Corresponding Author)

Outline of the Presentation

March 1, 2015 C10: Antennas, Paper ID: 168 2

I. Near Zero Index Metamaterials (NZIM)

II. Design of compact NZIM unit cell

III. Gain Enhancement of Microstrip Patch Antenna

with NZIM Lens

Near Zero Index Metamaterial (NZIM)


NZIM is a special class of

metamaterial in which refractive

index remains zero over a desired

frequency range

NZIM is capable of converting

diverging wave into planar wave

Enoch, Stefan, et al. "A metamaterial for directive emission." Physical Review Letters 89.21 (2002): 213902.

Unit Cell : Design and Characterization


Top View Bottom View HFSS Model

ax = ay = 4.5 mm, L1 = 4.2 mm, L2 =1.725 mm, L3 =1.2 mm, W1 = 4.3 mm, W2 = 3.5 mm, W = 0.25 mm

Evolution of the unit cell


H. S. Chen et al, Left-handed materials composed of only S-shaped resonators, Physical Review

E, vol. 70, 057605, 2004.

Design Procedure of the proposed

miniaturized NZIM unit cell: Stage-1


H. S. Chen et al, Left-handed materials composed of only S-shaped resonators, Physical Review

E, vol. 70, 057605, 2004.

X. Chen et al, Robust Method to retrieve the constitutive effective parameters of metamaterials,

Physical Review E, vol. 70, 016608, 2004.


miniaturized NZIM unit cell: Stage-2



miniaturized NIM unit cell: Stage-3


Effect of Design Parameters on Zero

Index Frequency Region


Variation with L3

Reference Microstrip Patch Antenna


Top View Side View

Lp = 16.5 mm, Wp = 12.6 mm, Ls = 60

mm, Ws = 50 mm, S1 = 3 mm

Bandwidth

Peak Gain

4.25 % 5.6 dBi

Substrate: FR4-Epoxy

(r = 4.4, tan = 0.02)

Thickness = 1.6 mm


Variation with W2

Effect of Design Parameters on Zero

Index Frequency Region (Contd.)

Beamwidth of Reference Microstrip

Patch Antenna


E Plane

H Plane

3D Gain Pattern

E

H

900 720

Patch Antenna with NZIM Lens


Top View Side View

3-D View

h ~ 0.5patch

J. P. Turpin, Q. Wu, D. H. Werner, B. Martin, M. Bray and E. Lier, Near-Zero-Index Metamaterial Lens

Combined With AMC Metasurface for High-Directivity Low-Profile Antennas, IEEE Transactions on

Antennas and Propagation, Vol. 62, No. 4, pp. 1928-1935, 2014.

Comparison of Simulated Results


Beamwidth of Proposed Antenna


E Plane H Plane

Antenna E H

Reference 900 720

Proposed 580 510

Fabricated prototypes


Top View Bottom View

Top View Side View


(r = 4.2, tan = 0.02)

Thickness = 1.6 mm


(r = 4.4, tan = 0.02)

Thickness = 0.8 mm

Measured Parameters


Antenna Bandwidth Peak Gain

(dBi)

Reference 4.66 5.32

Proposed 5.28 7.43

2D radiation Pattern


E Plane H Plane

Reference

Antenna

Proposed

Antenna

Measured Beamwidth


E Plane H Plane

Antenna E H

Reference 860 820

Proposed 500 520

Conclusion


A compact NZIM unit cell has been proposed.

As compared to a simple mirrored S-shaped unit cell, the proposed unit-cell

exhibits 51.72% reduction in electrical size.

The near-zero index frequency band is tuned to overlap with the operating

band of a WLAN band MPA.

An array of 7 7 such NZIM unit cells is used as superstrate over the MPA.

The simulated and measurement results confirm that the introduction of

superstrate significantly increases the gain of patch antenna and reduces the

HPBW in both E-plane and H-plane.

Ncc Hemant Ppt

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