1. A Parametric Analysis of Small Planar Inverted-F Antenna (PIFA) for USB Dongle Applications
Authors:
Hardeep Singh Saini
Akhil Sharma
Abhishek Thakur
Rajesh Kumar
Naveen Kumar
28 April 2017

2. Outline Introduction Antennas for Mobile Handheld Devices
Planar Inverted-F Antenna (PIFA) Structure
Comparison between various antenna structures
Problem Definition
Objectives
Design Methodology
Simulations & Results
Conclusion
Future Scope
References
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3. Introduction
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4. Introduction
An Antenna converts electromagnetic radiation into electric current, or vice versa.
Need of Antenna :
For transmission and reception of the radio signal.
Antennas are required by any radio receiver or transmitter to couple its electrical connection to the electromagnetic field. 
For electromagnetic waves carry signals through the air (or through space) at the speed of light with almost no transmission loss.
Wireless performance is completely dependent on a high performance antenna design and implementation. 
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5. Antennas for USB devices
Internal Antennas
Microstrip antennas (MSA)
Meander line antennas (loaded/unloaded)
Planar inverted-F antennas (PIFA)
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6. Antenna Type/ Parameters
Comparison Table
Antenna Type/ Parameters
Monopole
Microstrip Patch
PIFA
Radiation Pattern
Omnidirectional
Directional
Gain
High
Moderate to high
Modeling & Fabrication
Modeling is somewhat difficult
Easier to fabricate and model
Easier fabrication using PCB
Applications
Radio Broadcasting, vehicular antenna
Satellite Communication, Aircrafts
Internal antennas of Mobile phones
Merits
Compact size,
Low fabrication cost and simple to manufacture, Large bandwidth support
Low cost, Low weight, Easy in integration
Small size, Low cost, Reduced backward radiation for minimizing SAR
Problems
Difficult fabrication at higher frequencies (>3GHz)
No bandpass filtering effect, surface-area requirement
Narrow bandwidth characteristic
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7. Planar Inverted-F Antenna (PIFA)
PIFA is also referred to as short-circuited microstrip antenna due to the fact that its structure resembles to short-circuit MSA.
The shorting post near the feed point of PIFA structure is a good method for reducing the antenna size, but this result into the narrow impedance bandwidth which is one of the limitations.
By varying the size of the ground plane, the bandwidth of a PIFA can be adjusted and optimized.
The location and spacing between two shorting posts can be adjusted accordingly. L W
Ground Plane
Radiating Patch
Feed point h Lp Wp
Typical PIFA Structure
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8. Effect of Parameter Variation in PIFA
Parameters
Effects
Length
Determines resonance frequency
Width
Control impedance matching
Height
Control Bandwidth
Width of shorting plate
Effect on the anti-resonance and increase bandwidth
Feed position from shorting plate
Effect on resonance frequency and bandwidth
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9. Simulation Results
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10. Proposed Design 3D View in of Proposed Antenna 28 April 2017 Lp Wg WpLg Wg
RT Duroid Substrate
Radiating Patch
Shorting Plate
Ground Plane Slot
Ground Plane
Feed
Pin h Wp Lp
3D View in of Proposed Antenna
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11. Detailed Dimensions Parameter Value (mm) Lg 44 h 0.8 Wg 25 Lgs 17 Lp18
Wgs 3 Wp 20 Ls 4 Ws 8
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12. PARAMETRIC ANALYSIS Length of Ground Plane
It is seen that as the length of the ground plane increases, the value of return loss reduces on the lower side of frequency range.

13. PARAMETRIC ANALYSIS Length of Ground Slot
From the results it is clear that as the length of the slots is increased (14mm, 15mm, 16mm, 17mm), the return loss parameter also shows good results. Therefore the optimum size of the ground slot selected is 14mm.

14. PARAMETRIC ANALYSIS Width of Ground Slot
. It is seen that as the width of the slot increases, the return loss plot shows poor results. Therefore the optimum size of the width of the slot should be 3 mm.

15. PARAMETRIC ANALYSIS Length of Shorting Plate
It is clear that as the length of shorting plate increases the return loss plot shows better results. Therefore the optimum length of the shorting plate should be 9 mm.

16. Return Loss (S11)
Resonant frequencies achieved are 2.54 GHz and 3.76 GHz with return loss of dB and dB respectively.
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17. Radiation Pattern
It can be seen from the plot that the antenna is a good radiator with almost omni directional radiation
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18. A peak gain of 3.22 dB is observed at resonance.
Gain (dB)
A peak gain of 3.22 dB is observed at resonance.
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19. Voltage Standing Wave Ratio (VSWR)
The value of VSWR can be seen in the plot and has to be less than 3 dB at both resonant frequencies which is desirable for USB dongle applications
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20. Conclusion
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21. Conclusion
There are few conclusions that can be drawn from this thesis work:
The designed 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 Bandwidth & radiation efficiencies at obtained resonant frequencies.
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22. References
Kin-Lu Wong, “Planar Antennas for Wireless Communication”, Published by John Wiley & Sons, Inc., Chapter: 2, Pages: 26-65, 2003.
C. Rowell, E.Y. Lam, “Mobile-phone antenna design”, IEEE Antennas and Propagation Magazine, Vol. 54, No. 4, Page(s): 14 – 34, 2012.
W. Geyi, Q. Rao, S. Ali, and D. Wang, “Handset Antenna Design: Practice and Theory”, Progress in Electromagnetic Research Journal (PIER), Vol. 80, Pages: 123–160, 2008.
Hang Wong, Kwai-Man Luk, Chi Hou Chan, Quan Xue, Kwok Kan So, Hau Wah Lai, “Small antennas in Wireless Communications”, Proceedings of the IEEE Journal, Vol. 100,  No. 7, Page(s): 2109 – 2121, 2012.
R. Vaughan, “Model and results for single mode PIFA antenna”, IEEE Antennas and Propagation Society International Symposium, Vol. 4, Page(s): 4028 – 4031, 2004.
Taeho Son, “Feeding point determination for PIFA type mobile phone handset internal antenna”, IEEE Antennas and Propagation Society International Symposium, Vol. 1A, Page(s): 475 – 478, 2005.
J.A. Ray, S.R.B. Chaudhuri, “A review of PIFA technology”, IEEE Indian Antenna week (IAW), Page(s): 1 – 4, 2011.
Y. Belhadef, N. Boukli Hacene, “PIFAs antennas design for mobile communications”, 7th IEEE International Workshop on Systems, Signal Processing and their Applications, Page(s): 119 – 122, 2011.
Hassan Tariq Chattha, Yi Huang, Xu Zhu, and Yang Lu, “An empirical equation for predicting the resonant frequency of planar inverted-F antennas”, IEEE Antennas and Wireless Propagation Letters, Vol.8, Page(s): 856 – 860, 2009.
Sun, X.L.; Cheung, S.W.; Yuk, T.I., "A dual-band antenna for wireless USB dongle applications," Antenna Technology (iWAT), 2013 International Workshop on , vol., no., pp.307,310, 4-6 March 2013
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