Teddy Purnamirza, -

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Progress In Electromagnetics Research Letters, Vol. 64, 21–28, 2016A Design of Compact Radial Line Slot Array (RLSA) Antennasfor Wi-Fi Market NeedsTeddy Purnamirza1, *, Donny Kristanto1, and Imran M. Bin Ibrahim2Abstract—This paper proposes a compact Radial Line Slot Array (RLSA) antenna for 5.8 GHz Wi-Fidevices, which meets market needs. Various small RLSA antenna models with radius of 140 mm, weredesigned using extreme beamsquint technique. The models then were simulated to result in a bestmodel. A prototype of the best model was then fabricated and measured to verify the simulation. Themeasured parameters are: a gain of 18 dBi, bandwidth of 1GHz, beamwidth of 20◦, and mainlobe tosidelobe ratio of 15 dB, which meet antenna specifications for market needs. The prototype was testedas an antenna for a Wireless Fidelity (Wi-Fi) device in order to show its performance. The test showedthat the prototype worked properly. Lastly, we compared the size of the prototype with the averagesize of various antennas available in markets. We found that the prototype had the advantage of smallsize and flat, with similar performance.1. INTRODUCTIONInitially, RLSA antennas were developed for satellite signal reception antennas with diameter of notless than 600 mm [1–3]. Due to the advantages of RLSA antennas, such as high gain, flat and highefficiency [2–4], RLSA antennas were also developed for other applications, such as for Wi-Fi [5–14].In contrast to satellite applications, Wi-Fi needs much smaller antennas. However, the design of smallRLSA antennas was not easy since small size RLSA antennas normally had high reflection coefficient [14–16].Several papers introduced several designs of RLSA antennas for Wi-Fi applications. In 2004, Imranintroduced a 5.8 GHz RLSA antenna with gain of 26 dBi and successfully used it as an antenna for pointto point links [17–19]. However, this design utilized a beamsquint technique similar to a technique usedto design RLSA antennas for satellite applications. Hence, the diameter of this antenna is still consideredlarge with diameter of 650 mm, so that it is not applicable to small Wi-Fi devices.In 2008, Islam developed RLSA antennas using materials of a Flame Retardant (FR4) board [20, 21].The antennas were designed by still using the beamsquint technique same as the technique used to designRLSA antennas for a satellite. This antenna was quite small with a diameter of 150 mm since it wasdesigned using small slots. However, there are some drawbacks in designing this antenna, such as adesign of overlap slots, a loss cavity due to the use of several FR4 boards, and the use of loss materialof FR4. These all lead to low gain (only 8 dB) and low bandwidth (75 MGHz).Purnamirza and Rahman, in 2012, introduced a design of RLSA antennas using a 3-layer cavity,which are one polypropelene layer and two FR4 layers [13]. This design has successfully reduced theproblem of high reflection coefficient in small RLSA antennas. However, this design has a weakness ofcomplex fabrication process since it consists of three layers. As far as the authors’ knowledge, sinceReceived 31 August 2016, Accepted 26 October 2016, Scheduled 18 November 2016* Corresponding author: Teddy Purnamirza (tptambusai.purnamirza@gmail.com).1 Department of Electrical Engineering, Faculty of Science and Technology, Universitas Islam Negeri Sultan Syarif Kasim, Pekanbaru,Riau, Indonesia. 2 Faculty of Electronic and Computer Engineering, Universiti Teknikal Malaysia Malaka, Malaysia.22 Purnamirza, Kristanto, Ibrahim2012, there have been no other efforts to bring RLSA antennas as a potential antenna for Wi-Fi point topoint applications. Some researches after year of 2012 only discuss the theory of RLSA antenna [22–24].In year of 2013, we introduced a new simple technique called extreme beamsquint technique todesign high performance small RLSA antennas [14]. This technique is quite interesting comparedto other previous techniques developed for RLSA antennas since it can obtain small antennas withhigh gain, wide bandwidth and low reflection coefficient. As a continuation, in this paper, using thistechnique, we try to realize a small RLSA antenna as a potential antenna that meets market needs forWi-Fi point to point applications. Our work was started by finding the specification of antennas used bypoint to point Wi-Fi devices usually available in markets, including gain, beamwidth, and bandwidth.Based on the specifications, we then designed and fabricated a small RLSA antenna using the extremebeamsquint technique. The fabricated antenna was measured and tested. Lastly, to show the advantageof the small RLSA antenna, we compared the size of the RLSA antenna with the average size of variousantennas available in market. We found that the designed RLSA antenna has the advantage of smallsize and flat, with the performance comparable to other types of available antennas in markets.2. SPECIFICATIONS OF DESIGNED RLSA ANTENNASIn this research, information about the specifications of various antennas used in point to point Wi-Fidevices usually available in markets is collected and analyzed. The average values of the specificationsare shown in Table 1 below. Based on these values, RLSA antenna models are designed as explained inSection 4.Table 1. Average values of the specification of various antennas for 5.8 GHz point to point links thatavailable in markets.Gain (dBi) Beamwidth (Degree) Bandwidth (MHz)14–18 ±25 150–2003. STRUCTURE AND PARAMETERS OF DESIGNED RLSA ANTENNASIn this research, the structure of designed RLSA antennas consists of a copper radiating element, acopper background element, a polypropylene cavity, and a Sub-miniature version A (SMA) feeder, asshown in Figure 1. The SMA feeder is an ordinary SMA feeder available in market, modified by addinga copper head, as shown in Figure 1(b). The head serves to transform Transverse Electric Mode (TEM)coaxial mode signal within coaxial cable into TEM cavity mode signal within the cavity structure, sothat the signal from the feeder will propagate in radial directions within the cavity of the antenna.Table 2 and Table 3 show design parameters of the designed RLSA antenna and the feeder.4. STEPS OF ANTENNA DESIGNIn this research, using the parameters listed in Table 2 and Table 3, various RLSA antenna models aredesigned using following steps:a. Develop a computer program: Every single RLSA antenna has about 130 slots, which is unique inpositions and tilts. Therefore, in order to ease and fasten the calculation of slots position and thedrawing time of slots, we develop a Visual Basic Application (VBA) macro program that functionsto calculate the slots positions and draw them automatically in accurate positions.b. Parameterization: In order to obtain an antenna which meets the specification listed in Table 1, wecarry out a parameterization by varying two design parameters: beamsquint angle (Φ varies from60◦ to 89◦) and the number of slot pairs in first ring (n varies from 12 to 16). Hence, we developabout 100 RLSA antenna models for each value of Φ and n.c. Simulations: We simulate the 100 antenna models using CST STUDIO SUITETM Software andobtain a best antenna model.d. Fabrication: The best antenna model is then fabricated to yield a prototype.Progress In Electromagnetics Research Letters, Vol. 64, 2016 23(b)diameter of the disc height of thedisclower air gap (a)Background Cavity Radiating element Figure 1. (a) Structure of RLSA antennas. (b) Structure of antenna feeders [13, 14].Table 2. Design parameters of the RLSA antenna [13, 14].Specification Parameters Symbols ValuesCentre frequency f 5.8 GHzBeamsquint angle Φ Vary from 60 ◦ to 89 ◦Wavelength inside the cavity λg 33.88 mmSlot length l 0.5λgSlot width w 1mmRadius of antenna r 140 mmNumber of slot pair in first ring n Vary from 12 to 16Cavity thickness d1 8mmThe thickness of radiating element and background d 0.05 mmThe permittivity of cavity εr1 2.33Cavity material PolypropyleneThe material of radiating element and the background copperTable 3. Design parameters of feeder [13, 14].Specification Parameters Symbol ValuesThe height of disc h 3mmThe radius of disc ra 1.4mmThe lower air gap b1 4mmThe upper air gap b2 1mmThe material of the disc CopperThe type of the feeder SMA Feeder24 Purnamirza, Kristanto, Ibrahim5. RESULTS AND DISCUSSIONSThe simulation of 100 RLSA antenna models obtains the best antenna model that meets the specificationshown in Table 1. Moreover, the best antenna model also has a best performance in term of gain,bandwidth, and S11, compared to other 99 models. This best model has parameter of Φ = 78◦ andn = 14. The design of slots configuration is shown in Figure 2(a). The best model and its feeder arethen fabricated, and their prototypes are shown in Figures 2(b) and 2(c).(a) (b) (c)Figure 2. (a) Design of RLSA antenna model. (b) Fabricated antenna model. (c) Fabricated Fedeer.The prototype antenna was measured in an Anechoic Chamber to get its radiation pattern,beamwidth, ratio of mainlobe to sidelobe, and gain. The S11 was obtained by measuring the prototypeantenna using a Network analyzer.Figure 3 shows the measured and simulated S11 of the prototype antenna. From this figure, it canbe observed that the prototype antenna has a bandwidth about 1 GHz at the centre frequency around5.8 GHz. This bandwidth is more than enough for Wi-Fi signal which typically needs bandwidth onlyaround 150 MHz.Frequency (GHz)5.0 5.2 5.4 5.6 5.8 6.0 6.2 6.4 6.6S11 (dB)-35-30-25-20-15-10-50SimulationsMeasurements-10 dB LineBandwidth of about 1 GHzFigure 3. Measured and simulated S11 of the RLSA antenna.Progress In Electromagnetics Research Letters, Vol. 64, 2016 25-30 -25 -20 -15 -10 -5 0-30-25-20-15-10-50-25-20-15-10-50-25-20-15-10-500306090120150180210240270300330SimulationsMeasurementsMainlobe directions of about 600Beamwidth ofabout 290Figure 4. Measurement and simulation result of radiation pattern.Figure 4 shows the measured and simulated radiation patterns of the prototype antenna. From thisfigure, it can be observed that the antenna has a beamwidth of 29◦ and mainlobe direction of about 60◦.Other measured performance parameters of the antenna are listed in Table 4. Based on the values ofgain, bandwidth and beamwidth, which are 18.4 dBi, 1GHz, and 29◦, respectively, it can be concludedthat the performance of the RLSA antenna meets the need of market specification performance as listedin Table 1.Table 4. Performance parameters.Performance Parameters ValuesGain 18.4 dBi3 dB Bandwidth ±1GHz3 dB Beamwidth 29◦Mainlobe to Sidelobe Ratio about 16 dBMainlobe directions 60◦ from boresight directionEfficiency −0.123 dBFrom Figure 3 and Figure 4, it can be observed that the simulation result shows a comparablereading to the measurement result. The difference between them is due to the imperfections duringthe fabrication process of the antenna model. The causes of imperfections are as follows. Firstly, theradiating element, cavity and background are separated elements, so when they were combined duringthe fabrication process, there was a slight shift from the correct position. Secondly, the permittivity ofthe cavity is slightly increased due to the use of glue to stick the radiating element and the backgroundto the cavity. Thirdly, there is an imperfection in soldering the head disc at the SMA feeder at thecorrect position.26 Purnamirza, Kristanto, Ibrahim"RLSA AntennaAccessPoint (AP)ComputerComputerAccessPoint (AP)(a) (b) (c)Figure 5. (a) Transmitter (front view). (b) Transmitter (back view). (c) Testbed System.In order to test the performance of the antenna in real conditions, we have built a testbed systemas shown in Figure 5(c). The testbed consists of two 5.8 GHz radio Access Point (AP) as transceivers,the RLSA antenna connected to one of the transceivers, a microstrip AP antenna connected to the othertransceiver, and two computers connected to the two APs.There are two scenarios of the test. Firstly, one transceiver is connected to the RLSA antenna,and the other transceiver is connected to the microstrip antenna. Secondly, we use two microstrip APantennas, and each is connected to one transceiver.In the first and second scenarios, we send an amount of data from one transceiver to the other,thus measure the transfer data rate for about ten times. From this test, the averagely measured datarate for the first scenario is about two times higher than the data rate for the second scenario. Thishigher rate of the first scenario is due to the wider bandwidth and higher gain of the RLSA antennathan the bandwidth of the embedded microstrip AP antenna.To show the advantage of RLSA antenna, we compare the size of prototype and the size of variousantennas available in markets. We find that our RLSA prototype is attractive due to its flat shape,whereas the other antennas usually have the shape of convex (like parabolic or grid). So, in term ofvolume, the RLSA prototype is smaller than other antennas with averagely same performance. The onlyflat antenna available in market is microstrip antenna. However, microstrip antennas have weakness oflow efficiency and low gain.6. CONCLUSIONSA new small 5.8 GHz RLSA antenna for Wi-Fi point to point devices is designed and fabricated. Thesimulation, measurement, and test results show that this antenna is able to perform at industrialspecification. We also find that this antenna is attractive compared to other types of antennas due toits flat shape and small size.ACKNOWLEDGMENTWe would like to thank Computer Simulation Technology Malaysia Sdn. Bhd, for giving a temporarylicence to use CST STUDIO SUITETM Software as simulation software in our research. Appreciationalso goes to Advance Microwave Laboratory, Faculty of Electronic and Computer Engineering, UniversitiTeknikal Malaysia Malaka for their assistances in conducting antenna measurement.Progress In Electromagnetics Research Letters, Vol. 64, 2016 27REFERENCES1. Ando, M., et al., “Radial line slot antenna for 12 GHz satellite TV reception,” IEEE Transactionson Antennas and Propagation, Vol. 33, 1347–1353, 1985.2. Davis, P. W., “Experimental investigations into a linearly polarized radial slot antenna for DBSTV in Australia,” IEEE Transactions on Antennas and Propagation, Vol. 45, 1123–1129, 1997.3. Fernández González, J. M., et al., “Lightweight portable planar slot array antenna for satellitecommunications in x-band,” IEEE Antennas and Wireless Propagation Letters, Vol. 10, 1409–1412,2011.4. Wang, Y., et al., “The investigation for a circularly polarized radial line slot antenna with low sidelobes and high gain,” Microwave and Millimeter Wave Technology (ICMMT), 1226–1227, 2012.5. Bialkowski, K. S. and S. Zagriatski, “A dual band 2.4/5.2 GHz antenna including a radial lineslot array and a patch,” IEEE Antennas and Propagation Society, AP-S International Symposium(Digest), 3095–3098, 2004.6. Jamlos, M. F., O. A. Aziz, T. A. Rahman, M. R. Kamarudin, P. Saad, M. T. Ali, and M. N. Md Tan,“A beam steering Radial Line Slot Array (RLSA) antenna with reconfigurable operating frequency,”Journal of Electromagnetic Waves and Applications, Vol. 24, Nos. 8–9, 1079–1088, 2010.7. Jamlos, M. F., O. A. Aziz, T. A. Rahman, M. R. Kamarudin, P. Saad, M. T. Ali, andM. N. Md Tan, “A reconfigurable Radial Line Slot Array (RLSA) antenna for beam shape andbroadside application,” Journal of Electromagnetic Waves and Applications, Vol. 24, Nos. 8–9,1171–1182, 2010.8. Jamlos, M. F. B., T. A. Rahman, M. R. Kamarudin, P. Saad, O. Abdul Aziz, and M. A. Shamsudin,“Adaptive beam steering of RLSA antenna with RFID technology,” Progress In ElectromagneticsResearch, Vol. 108, 65–80, 2010.9. Jamlos, M. F. B., T. A. Rahman, M. R. Kamarudin, P. Saad, M. A. Shamsudin, andA. M. M. Dahlan, “A novel adaptive Wi-Fi system with RFID technology,” Progress InElectromagnetics Research, Vol. 108, 417–432, 2010.10. Bialkowski, K. S. and S. Zagriatski, “Investigations into a dual band 2.4/5.2 GHz antennafor WLAN applications,” 15th International Conference on Microwaves, Radar and WirelessCommunications, MIKON 2004, 660–663, 2004.11. Zagriatski, S. and M. E. Bialkowski, “Circularly polarised radial line slot array antenna forwireless LAN access point,” 15th International Conference on Microwaves, Radar and WirelessCommunications, MIKON 2004, 649–652, 2004.12. Rahman, T. A., et al., “A study on effectiveness of FR4 as a dielectric material for radial line slotarray antenna for wireless backhaul application,” 17th Asia Pacific Conference on Communication(APCC), 385–388, 2011.13. Purnamirza, T. and T. A. Rahman, “A novel technique in simplifying the fabrication process andin improving the reflection coefficient of the Linear Polarized Radial Line Slot Array (LP-RLSA)antennas,” Journal on Electromagnetic Wave and Application, Vol. 26, No. 4, 535–548, 2012.14. Purnamirza, T., T. A. Rahman, and M. H. Jamaluddin, “The extreme beamsquint technique tominimize the reflection coefficient of very small aperture radial line slot array antennas,” Journalof Electromagnetic Waves and Applications, Vol. 26, Nos. 17–18, 2267–2276, 2012.15. Hirokawa, J., et al., “Matching slot pair for a circularly-polarised slotted waveguide array,” IEEProceedings H: Microwaves, Antennas and Propagation, Vol. 137, 367–371, 1990.16. Herranz, J. I., et al., “Optimization of beam-tilted linearly polarized radial-line slot-arrayantennas,” IEEE Antennas and Wireless Propagation Letters, Vol. 9, 1165–1168, 2010.17. Imran, M. I. and A. R. Tharek, “Radial line slot antenna development for outdoor point to pointapplication at 5.8 GHz band,” 2004 RF and Microwave Conference, RFM 2004 Proceedings, 103–105, 2004.18. Imran, M. I., et al., “An optimization of beam squinted radial line slot array antenna design at5.8 GHz,” 2008 IEEE International RF and Microwave Conference, RFM 2008, 139–142, Sabah,2008.28 Purnamirza, Kristanto, Ibrahim19. Imran, M. I., et al., “Beam squinted Radial Line Slot Array Antenna (RLSA) design for point-to-point WLAN application,” 2007 Asia-Pacific Conference on Applied Electromagnetics Proceedings,APACE2007, 2007.20. Islam, M. R. U. and T. A. Rahman, “Novel and simple design of multi layer Radial Line SlotArray (RLSA) antenna using FR-4 Substrate,” 2008 Asia-Pacific Symposium on ElectromagneticCompatibility and 19th International Zurich Symposium on Electromagnetic Compatibility, APEMC2008, 843–846, 2008.21. Islam, M. R. U., et al., “Simple integrated system for wireless backhaul networks,” Proceedingsof the International Conference on Computer and Communication Engineering 2008, ICCCE08:Global Links for Human Development, 341–345, 2008.22. Ibrahim, I. M., T. A. Rahman, M. I. Sabran, and M. F. Jamlos, “Comparison of polypropyleneand FR4 dielectric cavity for RLSA Antenna design at 5.8 GHz,” IEEE TENSYMP 2014 — 2014IEEE Region 10 Symposium, Art. No. 6863032, 232–234, 2014.23. Ibrahim, I. M., T. A. Rahman, M. I. Sabran, and M. F. Jamlos, “Bandwidth enhancement throughslot design on RLSA performance,” IEEE TENSYMP 2014 — 2014 IEEE Region 10 Symposium,Art. No. 6863031, 228–231, 2014.24. Ibrahim, I. M., T. A. Rahman, S. Z. Iliya, and M. I. Sabran, “Aperture slot size effect to wideband open air gap radial-line slot array performance,” Microwave and Optical Technology Letters,Vol. 56, No. 12, 2974–2978, 2014.

A Design of Compact Radial Line Slot Array (RLSA) Antennas

for Wi-Fi Market Needs

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A Design of Compact Radial Line Slot Array (RLSA) Antennas for Wi-Fi Market Needs

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