new

2013 6th International Congress on Image and Signal Processing (CISP 2013)

A Compact Triband Fractal PIFA Antenna for Mobile Handset Applications

Yuming Nie Lizhong Song Department of Electronics and Information Engineering

Harbin Institute of Technology Harbin,China 150001 School of Information and Electrical Engineering

Harbin Institute of Technology(Weihai) Weihai,China 264209

Abstract-A compact fractal planar inverted F antenna (PIFA) for personal communication handset appfications is proposed. The antenna covers GSM (O.89-0.96GHz), DeS (1.71-1.88GHz) and WLAN (2.445-2.455GHz) frequency bands. Overall size of the antenna is less than 48mm*21mm*1.5mm (1.51 cm3) makes it suitable for 4G handsets and can be easily designed inside commercial mobile handsets. The antenna is designed and optimized by using commercially available software-High Frequency Structure Simulator (HFSS) based on fiuite element method algorithm. Simulated return loss and radiation performance of the antenna meet the requirements of practical mobile phones well.

Index Terms-Triband planar inverted-F antenna(PIFA); internal mobile handset antenna; multiband antenna

I. INTRODUCTION

The tremendous advancement in wireless communication technologies together with the growing on consumer are leading the creation of mobile handsets which are smaller, lighter and more multifunctional [l,2].In order to satisfy the various demands for wireless services,multiband antenna is a good candidate [3]. The types of internal antennas have been proposed as ceramic chip antenna (CCA) with meander lines [4,5], monopole antennas [6]-[8] and planar inverted-F antenna (PIFA). Multiband antennas are required to support multiple standards [4]. Owing to the advantages of low profile and compact size, designs compact and light-weighted PIFA antennas are reported in many open literatures [9]-[17].

Thick radiation element with hole is used to reduce the size of PIFA for personal communication services [9]. Varactor diode is used to get tuning over the wide frequency range for personal communication handsets [10].The application of multiple folded radiator to independent frequency control of a compact tri-band planar inverted-F antenna (PIFA) composed of three resonant frequencies, global system for mobile communication (GSM900, 880-960 MHz)/digital communication system (DCS1800, 1710-1880 MHz)/Satellite Digital Mobile Broadcasting (Satellite DMB, 2605-2655 MHz) are treated with the optimized parameter values [3].A compact PIFA suitable for dual-frequency at 900 and 1800MHz has been proposed [18].U-shaped slits are inserted within the antennaradiating surface and a capacitive plate is loaded between the radiating surface and the ground plane are illustrated to reduce the antenna physical size [19].

The advantage of PIFA is compact, low profile and easy to manufacture [9]. PIFA which first appeared in the IEEE

978-1-4799-2764-7/13/$31.00 2013 IEEE

literature by the year 1987 emerged as one of the most promising candidate in this category of low profile antennas in last three decades [10,20]. However it has a narrow bandwidth and needs a height from ground to substrate for matching and additional shorting pins near the feed to reduce the size of antenna [9,11]. Literature [2] presents a PIFA antenna for mobile handsets. The proposed antenna has three resonant frequencies including 0.92GHz, 2GHz and 2.33GHz. Limited to the space, fractal technic is used to make the last two frequencies lower in this paper.

In Section II and m, the entire structure of the proposed antenna is described in detail and the simulated results are shown. Finally, conclusions are briefly shown in Section IV.

II. ANTENNA CONFIGURATION

The configuration of the proposed antenna is illustrated in Fig.1 which including two parts the copper patch and the substrate part. For easy fabrication, commercially cheap FR4 substrates with r=4.4, tan =0.019, and h=1.5mm are adopted in the antenna design. The length and width of the substrate are 60mm and 50mm respectively.

III. ANTENNA DESIGN PROCEDURE

In this section, the design procedures for the proposed antenna are described. First of all, the basic resonant structure without fractal part is analyzed, and then the affection of fractal part is discussed.

A. The effects of basic patch

Fig.2 depicts the basic part of proposed antenna. The basic part has two resonant frequencies which are 0.99Ghz and 2.24Ghz. The total length of patch decides the resonant frequencies. Fig.3 delineates the simulated reflection coefficients relative to changes of Ld which affects the whole length of basic antenna. As Ld lengthens, the resonant frequencies decrease.

B. The Effects of the added regular part

To introduce the third resonant frequency, a regualr part is added in the middle as Fig.4. The simulated return loss with variations of the length of added part is shown as Fig. 5.

1468 "IEEE

(a) 3D structure of the proposed antenna

(b) Top view of the antenna structure

(c) Top view of the antenna substrate with microstrip feed line

Figure 1. Antenna structure

Figure 2. The main part of proposed antenna

C. The Antenna with fractal part

As discussed above, the reflection coefficients decrease as the Wf lengthens. Limited to the antenna space, fractal technic is used to lengthen Wf. The antenna with fractal part is shown as Fig.6. The parameters are optimized by commercial finite method solver for electromagnetic structures

-5

-10

-15 -If- Ld = 1 nun

....... Ld = 4 nun -Ld = 9 nun --- -6

-.5----------1.5----2--2.5 ---- Frequency (GHz)

Figure 3. Simulated reflection coefficients relative to changes in length of Ld

Figure 4. The antenna with a regular part

----Wf = 32mrn --- -6 dB curve -.5----------1.5-----2-----2. 5 ----

Frequency (GHz)

Figure 5. Simulated return loss as a function of the length Wf

form Ansys HFSS( High Frequency Structure Simulator ). The detail parameters are explained as table I.

D. Reflection coefficients relative to changes of different parameters

Figs.7-9 depict simulated reflection coefficients as a function of XcI, Xc2, and Hf respectively. Figs.7-9 show Xc2 is critical parameters to the antenna performance. The final optimized length of Xc2 is 23.5 mm.

E. SIMULATED RESULTS

The simulated return loss is shown as Fig. 10. At GSM and DeS frequency bands 811

-5

-10

-15

-20 U)

-25

-30

Figure 6. The antenna with fractal part

TABLE I EXPLANATION OF PARAMETERS

,

Parameters Dimension(mm) W L

WeI Wc2 Xci Xc2 LL Ld Lfl Lf2 Hf

--Xcl=2mm Xcl=4mm

Xcl=6mm --- -6dB curve

48 21 1 2

1.5 23.5 11.2

3 1.9 1.9 5

-3Qi.5 1.5 2 2.5

-10 -15

00 -20 "0

-25 U; -30

-35 -40

-45

Frequency (GHz)

Figure 7. 811 relative to the length variation of Xci

Xc2=10mm Xc2=20mrn

Xc3=30mrn --- -6dB curve

-5B. 5-------7-------1. 5------2-------2 .5------ Frequency (GHz)

Figure 8. 811 relative to the length variation of Xc2

IV. CONCLUSION A small-size PIFA covers GSM (O.89-0.96GHz), DCS

(1.71-1.88GHz) and WLAN (2.445-2.455GHz) bands suit-

-20 Hf = 5 mm --- -6 dB curve

-2Qi.5-----7------1.5----2-------2.5---- Frequency (GHz)

-5

Figure 9. Sl1 relative to the length variation of Hf

-10

;; -15 -S11 of proposed antenna

---'-6dB curve

-20

-2Qi.5----------1.5----2------2.5---- Frequency (GHz)

Figure 10. Simulated reflection coefficients

270

Figure 11. Simulated radiation patterns at O.925GHz for XZ plane

270

Figure 12. Simulated radiation patterns at O.925GHz for YZ plane

able for internal mobile phone antenna applications has been proposed. A parametric study of the antenna dimensions is described,which permits the design of the antenna according to size,bandwidth,and radiation requirements for applications.The antenna is easily fabricated at low cost. The antenna exhibits good impedance matching performance-reflection coefficients less than -6dB at GSM frequency, less than -6dB in

1470

270

Figure 13. Simulated radiation patterns at 0.925GHz for XY plane

"of"; ; ::t ; ,>'"

270

Figure 14. Simulated radiation patterns at 1.795GHz for XZ plane

Figure 15. Simulated radiation patterns at 1.795GHz for YZ plane

90 40

"o f , :::k .;

270


90 5

Figure 17. Simulated radiation patterns at 2.45GHz for XZ plane

'" 5 120 60

150 . _'" ._,.\:.::""'T""./ ,:.. _ , . . "

. ' _ 3 0

210 m 240 300

270

Figure 18. Simulated radiation patterns at 2.45GHz for YZ plane


the GSM and DCS bands, less than -10 dB at the WLAN band. Good radiation characteristics for frequencies over the three operating bands have also been observed.

ACKNOWLEDGMENT

This work is supported by the National Natural Science Foundation of China (Grant No. 61271118) and Open Research Program of State Key Laboratory of Millimeter Waves(Grant No. K201328).

REFERENCES

[1] R. A. Bhatti and S. O. Park, "Hepta-band internal antenna for personal communication handsets," Antennas and Propagation, IEEE Transactions on, vol. 55, no. 12, pp. 3398-3403,2007.

[2] D. G. Kang and Y. Sung, "Compact hexaband pifa antenna for mobile handset applications," Antennas and Wireless Propagation Letters, IEEE, vol. 9, pp. 1127-1130, 2010.

[3] D. y. Kim, J. W. Lee, C. S. Cho, and T. K. Lee, "Design of a compact tri-band pifa based on independent control of the resonant frequencies," Antennas and Propagation, IEEE Transactions on, vol. 56, no. 5, pp. 1428-1436,2008.

[4] J. I. Moon and S. O. Park, 'The design of small size chip ceramic dielectric antenna for bluetooth application," in Antennas and Propagation Society International Symposium, 2003. IEEE, vol. 2, pp. 954-957, IEEE,2003.

[5] W. Choi, S. Kwon, and B. Lee, "Ceramic chip antenna using meander conductor lines:' Electronics Letters, vol. 37, no. 15, pp. 933-934,2001.

[6] K. L. Wong, G. Y. Lee, and T. W. Chiou, "A low-profile planar monopole antenna for multiband operation of mobile handsets," Antennas and Propagation, IEEE Transactions on, vol. 51, no. I, pp. 121-125,2003.

[7] F. S. Chang, S. H. Yeh, and K. L. Wong, "Planar monopole in wrapped structure for low-profile gsmJdcs mobile phone antenna:' Electronics Letters, vol. 38, no. 11, pp. 499-500, 2002.

[8] K. Tong, K. Luk, C. Chan, and E. Yung, "A miniature monopole antenna for mobile communications," Microwave and Optical Technology Letters, vol. 27, no. 4, pp. 262-263, 2000.

[9] Y. B. Kwon, J. I. Moon, and S. O. Park, "An internal triple-band planar inverted-f antenna," Antennas and Wireless Propagation Letters, IEEE, vol. 2, no. I, pp. 341-344, 2003.

1471

[10] V. A. Nguyen, R. A. Bhatti, and S. O. Park, "A simple pifa-based tunable internal antenna for personal communication handsets," Antennas and Wireless Propagation Letters, IEEE, vol. 7, pp. 130-133,2008.

[11] H. Lai, P. Li, and K. Luk, "Wideband small patch antenna:' Electronics Letters, vol. 39, no. 8, pp. 641---642, 2003.

[12] D. U. Sim and J. I. Choi, "A compact wideband modified planar inverted f antenna (pifa) for 2.4/5-ghz wlan applications:' Antennas and Wireless Propagation Letters, IEEE, vol. 5, no. 1, pp. 391-394, 2006.

[13] I. G. Zuazola and J. Batchelor, "Compact multiband pifa type antenna," Electronics letters, vol. 45, no. 15, pp. 768-769, 2009.

[14] R. A. Bhatti, Y. T. 1m, and S. O. Park, "Compact pifa for mobile tenninals supporting multiple cellular and non-cellular standards," Antennas and Propagation, IEEE Transactions on, vol. 57, no. 9, pp. 2534-2540, 2009.

[15] C. H. Wu and K. L. Wong, "Ultrawideband pifa with a capacitive feed for penta-band folder-type mobile phone antenna," Antennas and Propagation, IEEE Transactions on, vol. 57, no. 8, pp. 2461-2464, 2009.

[16] H. Elsadek and D. M. Nashaat, "Multiband and uwb v-shaped antenna configuration for wireless communications applications," Antennas and Wireless Propagation Letters, IEEE, vol. 7, pp. 89-91,2008.

[17] D. Kearney, M. John, and M. J. Ammann, "Miniature ceramic dualpifa antenna to support band group 1 uwb functionality in mobile handset," Antennas and Propagation, IEEE Transactions on, vol. 59, no. 1, pp. 336-339, 2011.

[18] C. R. Rowell and R. D. Murch, "A compact pifa suitable for dualfrequency 900/1800-mhz operation:' Antennas and Propagation, IEEE Transactions on, vol. 46, no. 4, pp. 596-598, 1998.

[19] D. M. Nashaat, H. A. Elsadek, and H. Ghali, "Single feed compact quadband pifa antenna for wireless communication applications," Antennas and Propagation, IEEE Transactions on, vol. 53, no. 8, pp. 2631-2635, 2005.

[20] J. A. Ray and S. Chaudhuri, "A review of pifa technology," in Antenna Week (lAW), 2011 Indian, pp. 1-4, IEEE, 2011.

1472

Documents

new