Broadband pifa

BROADBAND PLANAR INVERTED F ANTENNA

TANJIR ALAMECE124007

WHAT IS PIFA The inverted F Antenna (IFA) typically consists of a

rectangular planar element located above a ground plane, a short circuiting plate or pin, and a feeding mechanism for the planar element.

The inverted F antenna is a variant of the monopole

where the top section has been folded down so as to be parallel with the ground plane.

This is done to reduce the height of the antenna.

PIFA can be considered as a kind of linear inverted F antenna (IFA) with the wire radiator element replaced by a plate to expand the bandwidth.

Fig.1, Inverted F Antenna

Fig.2. Basic Planar Inverted F-Antenna The shape of the antenna appears like an inverted F, and hence named Planar Inverted F Antenna (PIFA) .

WHY PIFA?

The antenna is small in size, easy to manufacture and has low fabrication cost.

Planar Inverted F Antenna has an omnidirectional pattern and provides high gain in vertical and horizontal direction.

The structure of PIFA is simple and can be easily hidden in handsets when compared to other conventional antennas.

The antenna not only shows improved performance but also reduces backward radiation towards user’s body and head i.e., it minimizes SAR.

Fig.3 Fabricated PIFA

Fig.4. Gain of a PIFA

OBJECTIVE OF PIFA In wireless communication a low profile antenna that supports multiband and

wideband operations is required. In order to meet these requirements Planar Inverted F Antenna designs are needed.

These antennas are compact and support multiband and wideband operations. Therefore such antennas are suitable for the devices where space is a major issue.

PIFA has low backward radiation and hence it minimizes electromagnetic wave absorption.

It has a self resonating structure.

Height of radiator and variation of distance, location and length affects the performance of the antenna.

Therefore Planar Inverted F Antennas (PIFA) can be used for variety of applications such as in mobile and radio communication because of its compact size, reduced length and easy integration.

Fig.5. 3D Radiation pattern of a PIFA.

TYPES OF PIFA

A. Slotted Patch PIFA Design

B. Tapered T-PIFA design

C. Reconfigurable PIFA Design

D. Defected Ground Plane PIFA Design

E. Fractal Circular PIFA Design

F. Square Patch PIFA Design

Fig.A slotted patch PIFA(4 slots) Fig. B. Tapered T-PIFA design

Fig.C.Reconfigurable PIFA Fig.D. Defected Ground Plane PIFA

Fig.E. Fractal Circular PIFA Fig.F. Square Patch PIFA

APPLICATIONS OF PIFA

a) Planar Inverted F-Antenna for Handheld Devices

b) Planar Inverted F-Antenna array for MIMO application

c) Planar Inverted F-Antenna for Medical Applications

Fig.8. Isometric view of PIFA structure for medical application

Fig.6. 3D Layout of a antenna

Fig.7. Layout of the MIMO design

ADVANTAGES OF PIFA

It can be hiding into the housing of the mobile while comparable to whip/rod/helix antennas.

It reduces the backward radiation toward the user’s head, minimizing specific absorption rate (SAR).

Third advantage is that PIFA it exhibits moderate to high gain in both vertical and horizontal states of polarization.

DISADVANTAGES OF PIFA Narrow bandwidth characteristic of PIFA is one of the limitations for its commercial

application for wireless mobile.

DESIGN AND RESULTS USING HFSS

W2

Proposed Design

Fig.9. detailed dimension Fig.10. 3D view of proposed design in HFSS

Paramete

r

Value (mm) Parameter Value (mm)

L 100 W 60

L1 61 W1 40

L2 23 W2 30

h 8

Return Loss (S11)

10 dB Bandwidth

= 5.35%B.W=

10 dB Bandwidth of u-slotted PIFA around 1st Resonance frequency 2.24 GHz

, here, f2=2.3GHz and f1=2.18 GHz

10 dB Bandwidth of u-slotted PIFA around 2nd Resonance frequency 2.9 GHz%B.W=6.89, here, f2=3 GHz and f1=2.8 GHz

Fig.12. u-slotted pifa

Fig.13.Bandwidth calculation of u-slotted

PIFA

Fig.11. Return loss curve of u-slotted PIFA

ObjectiveOur objective is to increase the Bandwidth of the PIFA.

Fig.14. Bandwidth

calculation of u-slotted PIFA

Techniques to improve the Bandwidth of the PIFA Bandwidth is affected very much by the size of the ground plane. By varying

the size of the ground plane, the bandwidth of a PIFA can be adjusted. For example, reducing the ground plane can effectively broadened the bandwidth of the antenna system.

Use of thick air substrate to increase the bandwidth.

Using parasitic resonators with resonant lengths close to main resonant frequency.

Adjusting the location and the spacing between two shorting posts.

In order to increase the Bandwidth we modified the design-

Here we have used nine horizontal slots of dimension 1mm and length 7mm each across W2 and three vertical slots of width 1mm and length 35 mm to meet our requirements while maintaining all other dimensions unchanged..

Fig.15. Proposed u-slotted PIFA

Fig.16. modified Broadband PIFA

Return Loss (S11) of Broadband PIFA

Fig.18. Return loss curve of modified Broadband PIFA

Fig.17. Return loss curve of u-slotted PIFA

we observed that the bandwidth increases, which is our aim and its resonance frequency we get, is 2.99 GHz.

Radiation Pattern

Fig.19. Radiation pattern of u-slotted PIFA at resonance Frequency 2.24 GHz, phi 0 deg.

Fig.20. Radiation pattern of u slotted PIFA at resonance Frequency 2.24 GHz, phi 90 deg.



Fig.23. Radiation pattern of Broadband PIFA at resonance Frequency 2.99 GHz, phi 0 deg.

Fig.24. Radiation pattern of Broadband PIFA at resonance

Frequency 2.99 GHz, phi 90 deg.

3D Polar Plot

Fig.25. Polar plot of U-slotted PIFA Fig.26. Polar plot of broadband PIFA

Impedance Matching The impedance matching of the PIFA is obtained by positioning of the

single feed and the shorting pin within the shaped slot, and by optimizing the space between feed and shorting pins.

The main idea designing a PIFA is to don’t use any extra lumped components for matching network, and thus avoid any losses due to that.

Radiation Pattern The radiation pattern of the PIFA is the relative distribution of radiated power as a

function of direction in space.

In the usual case the radiation pattern is determined in the far-field region and is represented as a function of directional coordinates. Radiation properties include power flux density, field strength, phase, and polarization.

Conclusion

There are few conclusions that can be drawn from this thesis work:

The designed Broadband antenna, built on PIFA structure, is very sensitive to any

changes to the dimensions of the structure including the ground plane.

Ground plane of the antenna is used as a radiator resulting in overall size reduction

and improvement in the operating bandwidth.

Also there is significant improvement in gain and radiation efficiencies at obtained

resonant frequencies.

May 2, 2023National Institute of Technical Teacher's Training & Research, Chandigarh

REFERENCES[1] Balanis, Constantine. "Antenna Theory: A Review", Proceedings of the IEEE, vol. 80, January 1992. [2] G. R. Kadambi, K. D. Simmons, J. L. Sullivan, and T. Hebron, “SingleNfeed multiband PIFA for cellular and non cellular applications,” Centurion Wireless Technologies, Inc., 2002.[3] Bluetooth. [Online]. Available: www.anycom.com; Bluetooth@ anycom.com[4] M. Sanad and N. Hassan, “A compact dual band microstrip antenna forNportable GPS/cellular phones,” presented at the Proc. IEEE Antennas Propagation Int. Symp., Salt Lake City, UT, Jul. 1999.[5] P. Salonen, M. Keskilammi, and M. Kivikoski, “Single-feed dual planar inverted-F antennas with U-slot,” IEEE Trans. Antennas Propag., vol.N48, no. 8, pp. 1262–1264, Aug. 2000.[6] D. Nashhat, H. Elsadek, and H. Ghali, “Dual-Band reduced size PIFA antenna with U-slot for bluetooth and WLANapplications,” presented at the Proc. IEEE Antennas Propagation Int. Symp., Columbus, OH, Jun. 22–27, 2003[7] W2AEE Antenna History. Arthur M. Kay (?), scanned by Alan Crosswell. http://www.w2aee.columbia.edu/history/antenna-history.html[9] IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL. 53, NO. 8, AUGUST 2005 2631Single Feed Compact Quad-Band PIFA Antenna for Wireless Communication Applications. Dalia Mohammed Nashaat, Hala A. Elsadek, Member, IEEE, and Hani Ghali, Member, IEEE[10] Journal of Electromagnetic Analysis and Applications, 2011, 3, 406-411 doi:10.4236/jemaa.2011.310064 Published Online October 2011 (http://www.SciRP.org/journal/jemaa)

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