yesTwo miniature low profile PIFLA antennas with a compact volume size of 30mm × 15mm × 8mm has presented in this paper. By applying the magnetic wall concept a reduced size dual-band and a wideband half PIFLAs for WLAN (2.4GHz/5.2GHz) and UWB applications are achieved. The dual-band antenna shows a relative bandwidth of 12% and 10.2% at ISM2400 and IEEE802.11a frequency bands respectively for input return loss less than 10dB. By carefully tuning the geometry parameters of the dual-band proposed antenna, the two resonant frequencies can be merged to form a wide bandwidth characteristic, to cover 3000MHz to 5400 MHz bandwidth (57%) for a similar input return loss that is fully covering the lower band UWB (3.1-4.8GHz) spectrum. The experimental and simulated return losses on a small finite ground plane of size 30mm × 15mm show good agreement. The computed and measured radiation patterns are shown to fully characterize the performance of the proposed two antennas.MSCR

Abd-Alhameed, Raed A.

Adnan, S.

Elfergani, Issa T.

Elmegri, Fauzi

Hraga, Hmeda I.

See, Chan H.

YesTwo miniature low profile PIFLA antennas with a compact volume size of 30mm × 15mm × 8mm has presented in this paper. By applying the magnetic wall concept a reduced size dual-band and a wideband half PIFLAs for WLAN (2.4GHz/5.2GHz) and UWB applications are achieved. The dual-band antenna shows a relative bandwidth of 12% and 10.2% at ISM2400 and IEEE802.11a frequency bands respectively for input return loss less than 10dB. By carefully tuning the geometry parameters of the dual-band proposed antenna, the two resonant frequencies can be merged to form a wide bandwidth characteristic, to cover 3000MHz to 5400 MHz bandwidth (57%) for a similar input return loss that is fully covering the lower band UWB (3.1-4.8GHz) spectrum. The experimental and simulated return losses on a small finite ground plane of size 30mm × 15mm show good agreement. The computed and measured radiation patterns are shown to fully characterize the performance of the proposed two antennas.MSCR

Abd-Alhameed, Raed

Bradford Scholars

 The University of Bradford Institutional Repository http://bradscholars.brad.ac.uk This work is made available online in accordance with publisher policies. Please refer to the repository record for this item and our Policy Document available from the repository home page for further information. To see the final version of this work please visit the publisher’s website. Where available access to the published online version may require a subscription. Author(s): Hraga, H. I., See, C. H., Abd-Alhameed, R. A., Adnan, S., Elfergani, I. T. E. and Elmegri, F. Title: The Compact Design of Dual-band and Wideband Planar Inverted F-L-antennas for WLAN and UWB Applications. Publication year: 2011 Conference title: Progress In Electromagnetics Research Symposium Proceedings, Marrakesh, Morocco, March 20-23, 2011. Publisher:  The Electromagnetics Academy. Link to original published version:  http://www.piers.org/piersproceedings/piers2011MarrakeshProc.php Citation: Hraga, H. I., See, C. H., Abd-Alhameed, R. A., Adnan, S., Elfergani, I. T. E. and Elmegri, F. (2011). The Compact Design of Dual-band and Wideband Planar Inverted F-L-antennas for WLAN and UWB Applications. In: Progress In Electromagnetics Research Symposium Proceedings, Marrakesh, Morocco, March 20-23, 2011. Cambridge, MA: The Electromagnetics Academy. ISBN: 978-1-934142-16-5, pp. 453-457. Copyright statement: © 2011, The Electromagnetics Academy. Reproduced in accordance with the publisher's self-archiving policy. 1The Compact Design of Dual-band and Wideband PlanarInverted F-L-antennas for WLAN and UWB ApplicationsH. I. Hraga, C. H. See, R. A. Abd-Alhameed, S. Adnan, I. T. E. Elfergani, and F. ElmegriMobile and Satellite Communications Research Centre, University of Bradford, Bradford, UKAbstract— Two miniature low profile PIFLA antennas with a compact volume size of 30mm×15mm×8mm has presented in this paper. By applying the magnetic wall concept a reduced sizedual-band and a wideband half PIFLAs for WLAN (2.4GHz/5.2GHz) and UWB applicationsare achieved. The dual-band antenna shows a relative bandwidth of 12% and 10.2% at ISM2400and IEEE802.11a frequency bands respectively for input return loss less than 10 dB. By carefullytuning the geometry parameters of the dual-band proposed antenna, the two resonant frequen-cies can be merged to form a wide bandwidth characteristic, to cover 3000MHz to 5400MHzbandwidth (57%) for a similar input return loss that is fully covering the lower band UWB (3.1–4.8GHz) spectrum. The experimental and simulated return losses on a small finite ground planeof size 30mm × 15mm show good agreement. The computed and measured radiation patternsare shown to fully characterize the performance of the proposed two antennas.1. INTRODUCTIONUWB technology is invented for short range and higher data rate communication. The lowerand upper UWB spectrums are 3100MHz to 4000MHz and 6000MHz to 10600MHz respectively.There are three overlapping target segments that could benefit from short-range wireless connec-tions enabled by UWB: PC and peripheral devices, mobile devices, and consumer electronics. Byimplementing this technology, it is believed capable of delivering 1Gbit/s data rates over cable andwireless claims to double the exiting most of wireless terminal data-rate. This makes the constanthigh demand for designing smaller and lighter internal antennas, which immune to damage and lowSAR.There were several antennas size reduction techniques have been proposed over last decadesthat investigate the use of high permittivity substrate, shorting pins, shorting walls and modifyingthe geometry of the internal antenna [1–3]. Recently, another size reduction technique is proposedin [4–6] using the magnetic wall concept. It was interestingly found that the performances in termsof return losses, gains, radiation efficiencies, radiation patterns of half size structures of the U-slot,E-shaped [5] and UWB microstrip patch antennas [6] are comparable to their full structures.2. ANTENNA DESIGN CONCEPTThe PIFLA shown in Fig. 1 is quite similar to the antenna design of the work reported in [7],but the size is reduced to half using the principle of the existing magnetic wall on the antennasurface [5, 6]. The initial geometry parameters of the antenna are stated as follows: L1 = 18.6mm,L2 = 10mm, h1 = 8mm, h2 = 4.5mm, d = 3.5mm and w = 0mm. It should be noted that thesedimensions are the same as in [7], except the width of F-shaped, L-shaped radiator and groundplane have been cropped to half, which are 7.5mm, 8.5mm and 15mm respectively. The coppermetal plate thickness of the proposed antenna and the gap distance for the feed are 0.5mm.The operation mechanism of this PIFLA is simple. As can be portrayed in Fig. 1, this antennais a combination of a planar F-shaped antenna with rectangular plate feed and a planar L-shapedantenna. The F-shaped antenna which has a longer electrical length is designed to control the lowerresonant mode (2450MHz), where as the L-shaped antenna is used to provide the higher resonantmode (5200MHz).By keeping the same geometry parameters, the return losses of the half size PIFLA are studied.As can be seen in Fig. 2, the bandwidth for lower resonant mode remains, but the bandwidth forhigher resonant mode degrades considerably in which 12.2% (5GHz to 5.65GHz) to work in [7] and3.8% (5.15GHz to 5.35GHz) to the half structure.2Figure 1: Geometry of the proposed miniature PI-FLA.Figure 2: Simulated S11 (Full size PIFLA and Halfsize).Figure 3: Practical prototype of the proposed dual-bands PIFLA.Figure 4: Measured and simulated S11.3. SIMULATED AND MEASURED RESULT DISCUSSIONSThe prototype antennas were characterised by RF and anechoic chamber measurements. The RFmeasurements were carried out using an HP-8510C VNA. The radiation patterns were measuredas follows. The fixed reference antenna was a broadband horn (EMCO 3115) and the spacing withthe antenna under test (AUT) was fixed at 4m. Two pattern cuts (H-plane and E-plane) weretaken for each design frequency covering the target bandwidth.3.1. Miniature Dual-band PIFLABy scrutinizing the variations in the geometry against the impedance bandwidth, the optimalparameters can be recognized for dual-band operation. These parameters can be given as follows:L1 = 18.6mm, L2 = 10mm, h1 = 8mm, h2 = 5mm, d = 4.5mm and w = 1.5mm.Figure 3 shows the first miniature dual-band PIFLA prototype. Fig. 4 illustrates the typicalmeasured and computed antenna performance in terms of impedance bandwidth for both full-sizeand half-size PIFLAs by using two commercial packages (HFSS [8] and SEMCAD X [9]). Thereturn loss is better than −10 dB, satisfying the desired IEEE802.11b/g frequency band (2400–2485MHz) and IEEE 802.11a (5.15–5.35GHz) bands respectively. As can be observed, simulatedand measured results for half-size PIFLA were found to be in excellent agreement. The half-sizeand full-size PIFLA seem to show identical measured impedance bandwidth at two resonant modes.Figures 5(a) and (b) show the simulated and measured co-polar and cross-polar radiation pat-terns in the x-z and y-z planes at 2400MHz and 5200MHz for the miniature PIFLA. The simulatedand measured radiation patterns of the fabricated prototype are seen to be quite similar to eachother at the two designated centre frequencies.3.2. Wideband PIFLAThe optimised geometry parameters of the proposed PIFLA for UWB application are given asfollows: L1 = 18.45mm, L2 = 8.5mm, h1 = 8mm, h2 = 5.5mm, d = 14.5mm and w = 4.5mm.3Fig. 6 describes the experimental prototype of the PIFLA with finite ground plane of 30× 15mm,while Fig. 7 shows the typical measured and computed antenna performance in term of impedancebandwidth by using two commercial packages (HFSS [8] and SEMCAD X [9]). As can be seen, thelowest and highest frequency edges, i.e., 3000MHz and 5400MHz, of an input return loss ≤ −10 dBare observed. The impedance bandwidth of the proposed antenna, for −10 dB return loss, is2400MHz or about 57% with respect to the centre frequency at 3950MHz (average of measuredlower and higher frequencies with a −10 dB return loss), which fully covers the frequency spectrumof uplink UWB (3100MHz to 4800MHz). Basic agreement is achieved between the experimentaland computed return loss over the desired operating frequency band.The far-field radiation characteristics of the prototype were also investigated at 3000MHz,4000MHz and 5000MHz, as shown in Fig. 8. It is observed that the radiation patterns at differentfrequencies are quite similar, which is expected in a wideband antenna.(a) 2400 MHz(b) 5200 MHzFigure 5: Simulated and measured normalised radiation patterns of the proposed dual-bands PIFLA fortwo planes (left: x-z plane, right: y-z plane) at (a) 2400MHz and (b) 5200MHz. ‘xxxx’ simulatedcross-polarization; ‘oooo’ simulated co-polarization; ‘- - -’ measured cross-polarization; ‘—’ measured co-polarization.Figure 6: Practical prototype of the proposed wide-band PIFLA.Figure 7: Measured and simulated S11.4(a) 3000 MHz(b) 4000 MHz(c) 5000 MHz Figure 8: Simulated and measured radiation patterns of the proposed wideband PIFLA for two planes(left: x-z plane, right: y-z plane) at (a) 3000MHz, (b) 4000MHz and (c) 5000MHz. ‘xxxx’ simulatedcross-polarization; ‘oooo’ simulated co-polarization; ‘- - -’ measured cross-polarization; ‘—’ measured co-polarization.4. CONCLUSIONIn this paper a simple geometry of a miniature planar inverted F-L antenna (PIFLA) has beenproposed and studied experimentally and theoretically. By carefully selecting different sets of opti-mal geometry parameters and applying the size reduction techniques to the proposed antenna, two50% size reduction PIFLAs have been designed and tested. By balancing the size and bandwidthconstraints, these proposed antennas have a compact envelope dimension of 30mm×15mm×8mmand covers the required operating frequency band for WLAN and UWB applications. These fea-tures make the proposed antenna an attractive candidate for application in a range of future mobileterminals.REFERENCES1. Skrivervik, A. K., J.-F. Zurcher, O. Staub, and J. R. Mosig, “PCS antenna design: Thechallenge of miniaturization,” IEEE Antennas and Propagation Magazine, Vol. 43, 12–27,August 2001.2. Lee, C. S. and K.-H. Tseng, “Size reduction of microstrip antennas,” Electron. Lett., Vol. 37,1274–1275, 2001.3. Shackelford, A. K., K. F. Lee, and K. M. Luk, “Design of small-size wideband width microstrip-patch antennas,” IEEE Antennas and Propagation Magazine, Vol. 45, No. 1, 75–83, February2003.54. Deshmukh, A. A. and G. Kumar, “Half U-slot loaded rectangular microstrip antenna,” IEEEAP-S Int. Symp. USNC/CNC/URSI National Radio Science Meeting, Vol. 2, 876–879, 2003.5. Chair, R., C.-L. Mak, K.-F. Lee, K.-M. Luk and A. A. Kishk, “Miniature wide-band half U-slot and half E-shaped patch antennas,” IEEE Transactions on AP, Vol. 53, No. 8, 2645–2651,August 2008.6. Guo, L., S. Wang, X. Chen, and C. Parini, “Miniaturised antennas for UWB communications,”Proceeding of Eucap, 3774–3778, Berlin, Germany, March 23–27, 2009.7. See, C. H., R. A. Abd-Alhameed, D. Zhou, and P. S. Excell, “Dual-frequency Planar Inverted F-L-Antenna (PIFLA) for WLAN and short range communication systems,” IEEE Transactionson AP, Vol. 56, 3318–3320, October 20088. HFSS ver.11, Ansoft. Ltd.9. SEMCAD X ver.14, Schmid & Partner Engineering AG, Zeughausstrasse 43, 8004, Zurich,Switzerland.

The Compact Design of Dual-band and Wideband Planar Inverted F-L-antennas for WLAN and UWB Applications

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