Design and Implementation of Dual Frequency Microstrip Patch Antenna with Koch Fractal Geometry using co-axial Feeding Technique

Transcription

1 Design an Implementation of Dual Frequency Microstrip Patch Antenna with Koch Fractal Geometry using co-axial Feeing Technique Mr.V.V.Khairnar Prof.Mrs.K.R.Khanagle Prof.Mrs.Abhilasha Mishra the multiban characteristic of fractal shape, the goal of this esign is set to a ual-frequency antenna for operation in ISM ban. The propose esign proceure tries to fin the best geometry from too many possible combinations which satisfy the esire performance of antenna. Simulation is carrie out by using HFSS simulator software to characterize the performance of esignate antenna. Abstract:-In this paper a simple ual-frequency Microstrip patch antenna base on the first iteration of Koch fractal configuration using co-axial feeing technique is presente. Complex structure of fractal shape is buil up through replication of a base shape. The purpose of this research is to explore new fractal element antenna through simulation an fabrication proceure. The Inustry, Scientific an Meical (ISM) Ban, unlicense with the range GHz is use as the operation ban. The maximum banwith can be obtaine by ajusting the probe fee position. The antenna parameters are investigate an optimization is performe by varying the fee position. The various parameters of equilateral triangular Microstrip patch antenna (ETMA) & first iteration of Koch fractal are measure on vector network analyzer. At the en simulate & fabricate results of both the antennas are compare. Simulation of antenna is Simulation is carrie out by using HFSS simulator software to characterize the performance of esignate antenna. The fabricate antennas are teste on Agilent GHz vector network analyzer. Microstrip patch antennas are wiely implemente in many applications in wireless communication ue to their attractive features. Therefore they are extremely compatible for embee antennas in hanhel wireless evices. Some of their principal avantages are light weight, low volume, low fabrication cost, easy to mount, low profile, conformal, linear an circular polarization possible, easy to implement by position of fee. Although rectangular an circular geometries are most commonly use, other geometries having greater size reuction fin wie applications in wireless communication systems, where the prime concern is compactness. The triangular patch antenna & Koch fractal configuration is chosen because it has the avantage of occupying less metalize area on substrate than other existing configurations [-]. Keywors: ETMA, RL, VSWR. I. INTRODUCTION With the avance of wireless communication systems an increasing of its applications, multiban antennas with ifferent shapes an esign become a great eman an esirable for many of uses such as personal communication systems, small satellite communication terminals an other applications involve wireless communication. This situation results in ifferent shapes an types of antenna which were esigne to achieve ifferent variations in antenna characteristics []. There are primarily two active areas of research in fractal antenna engineering. These inclue the stuy of fractal shape antenna elements an the use of fractals in the esign of antenna arrays []. II. RESEARCH METHOD.. Design of a Single Element Equilateral Triangular Patch Micro strip Antenna The fractal geometries are featuring two expecte common properties which are self-similarity an space filling properties. Both of these properties turn out to be a reason why fractals come out as an attractive way in esigning antenna. Self-similarity properties interprete as antenna which hols the uplication of itself at several scales an operation in similar way at several wavelengths. This property allows the wier ban an reveals the multiban frequencies operation. The other one is space filling properties interprete as reuction in antenna size which allows the antenna to be fabricate smaller than elementary shape an attains the small surrouning space []. A probe-fee single patch ETMA is esigne, simulate & fabricate for resonant frequency. GHz on a infinite groun plane. The probe fee technique has been use, since; the fee can be place at any place on the patch to match with its input impeance (usually 0 ohm). The equilateral triangular patch has a sie length S an printe on a substrate of thickness h with relative ielectric constant r.the substrate material is FR glass epoxy with ielectric constant. & substrate thickness is.6mm.the resonant frequency of ETMA with sie length S is given as [6-0], In this paper, esign, simulation & fabricate results of a simple microstrip patch antenna base on first iteration of Koch shape is presente. Emphasizing on

2 increases. Let be the area at iteration,then the area of the next iteration can be compute as [].For this esign of Koch fractal sie length is mm, the area of equilateral triangle & Koch fractal (first iteration) is 00mm & 87. mm respectively. () For above resonant frequency calculations of ETMA fringing fiels are consiere. Where the effective sie length, is effective ielectric constant & c is velocity of light.m & n inicates transmission line moes. The following equation gives the formula for calculation of effective length & effective ielectric constant of ETMA, by consiering fringing fiels. () Where is the sie length of initial triangle that has an area of, () () () h= height of a ielectric substrate. r=ielectric constant. Table shows the calculations of effective sie length & ielectric constant for given a sie length. For sie length of 7.7mm, resonant frequency is. GHz, but uring simulation on HFSS esire results are obtaine at sie length of 7mm. Fig. :Koch geometry in its ifferent iteration stages, (a) Basic geometry, (b) First iteration, (c) Secon iteration () Thir iteration Table.Effective length & ielectric constant calculation Sr No Sie Length (mm) Effectiv e sie length Effectiv e ielectri c constant III. RESULTS AND ANALYSIS.. Equilateral Triangular Microstrip Patch Antenna (ETMA) Resonant Frequency (GHz) Figure shows the fabricate gol plate ETMA, mounte on FR glass epoxy substrate. The antenna is teste on Agilent 87ET vector network analyzer moel, whose frequency range is from 00 KHz to GHz as shown in figure Design of a First Iteration of Koch Fractal Koch fractal geometry is one of the well known fractal shapes. The first iteration of Koch fractal is obtaine by replacing the sies of an equilateral triangle by a Koch curve []. Generation of the fractal, namely the three steps of conventional Koch iterations, is shown in Fig.. In each new iteration the area of the geometry Fig.: Fabricate ETMA

3 Figure gives the current istribution of ETMA.The re color in current istribution inicates that raiation is taking place from vertex of an ETMA. Table gives the comparative analysis of simulate & fabricate results of ETMA. Return loss obtaine uring simulation is B, while fabricate return loss is -.0 B. Fig.: Testing of ETMA on VNA Figure shows the simulate return loss of ETMA at. GHz, which is 9.0 B. Fig. : Return Loss of -9.0 B at.ghz. Table gives return loss of ETMA for ifferent feeing locations. The table shows that for feeing location (6, 8., 0) we are getting maximum return loss. If feeing point is varie above & below this point then return loss ecreases. Fig. : Current Distribution (E fiel) Table.Comparative analysis of ETMA Table.Return loss for ifferent feeing locations Sr No. Feeing Location ( in mm) Return Loss ( in B) Antenna f RL VSWR BW Impeance Simulate. GHz B.0 7. MHz.7Ω Fabricate. GHz -.0 B MHz.70Ω

4 Return Loss Ansoft Corporation.. First Iteration of Koch Fractal HFSSDesign 0.00 Figure 6 shows simulate Koch fractal (first iteration) in HFSS, figure 7 shows testing of fabricate Koch fractal on VNA mm B(St(coax_pin_T,coax_pin_T)) m6 m Name X Y m m m m m m m Curve Info m B(St(coax_pin_T,coax_pin_T)) Setup : Sweep Freq [GHz] Figure 8.Return loss of Koch fractal (First iteration) Fig. 6: Simulate Koch fractal (First iteration) Figure 9.Current Distribution (E Fiel) Table gives the comparative analysis of simulate & fabricate results of first iterate Koch fractal antenna. During simulation two resonant frequencies are obtaine at. GHz &.8 GHz. Fabricate Koch fractal antenna gives 80MHz banwith. Fig. 7: Testing of Koch fractal on VNA Table. Comparative analysis of Koch fractal (First Iteration) Figure 8 gives return loss of first iteration of Koch fractal at. GHz &.8 GHz. Figure 9 gives current istribution of Koch fractal. Re color in current istribution inicates that raiation is taking place from two ifferent vertices of Koch fractal. Antenna Simulate Fabricate f (GHz ) RL (B) VSWR BW (MHz) Impeanc e Ω Ω Ω IV. CONCLUSION In conclusion, esign simulate & fabricate results of probe fee single element equilateral triangular microstrip antenna & first iteration of koch fractal with goo matching, input an raiation characteristics with varying fee position is presente. The antenna was esigne to have a goo return loss an raiation pattern at. GHz, so that the antenna can be use for

5 ISM ban applications. The results of Koch fractal antenna shows that as the number iteration increases, the antenna becomes multiban, with ifferent resonant frequencies. Both the fabricate antennas are gol plate, mounte on FR glass epoxy substrate, teste on VNA. At the en simulate & fabricate results of ETMA & Koch fractal are compare. Also effect of feeing location on gain of antenna is iscusse. In future the number of iteration of Koch fractal antenna can be increase to obtain ifferent resonant frequencies, as per requirement. REFERENCES []. R Garg, P. Bhatia,I.J. Bahl, Microstrip Antenna,Design Hanbook, Artech House, 000. [] D. H. Werner an S. Ganguly, An overview of fractal antenna engineering research, IEEE Antennas Propag., vol., No., pp. 8 7, 00. [] T. Ohira, "Blin aaptive beamforming electronically steerable parasitic array raiator antenna base on maximum moment criterion," IEEE AP-S International Symp., vol., pp.6-6, June 00. [] Antennas an Propagation Symp., vol. 0, May 98. Y. Yusuf an X. Gong, "Beam-steerable patch antenna array using parasitic coupling an reactive loaing," IEEE AP-S International Symp., pp , [] C. A. Balanis, Antenna Theory - Analysis an Design r eition, Wiley, 006. [6] Kumar, G an Ray, K.P; Broaban Microstrip Antenna, Artech House, 00. [7] Dahele, J. S., an K. F. Lee, On the Resonant Frequencies of the Triangular Patch Antenna, IEEE Trans Antennas Propagation, Vol. AP-, January 987, pp [8] R. Garg an S. A. Long, An improve formula for the resonant frequency of triangular microstrip patch antenna, IEEE Trans. Antennas Propagat,vol. AP-6, p.70, Apr [9] K. Guney. Resonant Frequency of a triangular Microstr Antenna. Microwaveopt.Technol.Lett. Vol6. No9.99. PP -7. [0] X. Gang, On the resonant frequencies of microstrip antennas, IEEE Trans Antennas Propagation, pp. 7, Feb [] C. Borja an J. Romeu, on the Behaviour of Koch Islan Fractal Bounary Microstrip patch Antenna, IEEE Trans. on Antennas an Propag. vol., No.6. June 00. AUTHOR S PROFILE Mr.V.V.Khairnar ME (Communication) MIT Aurangaba Vikaskhairnar9@gmail.com Prof.Mrs.K.R.Khanagle Assistant Professor MIT Engg.,Aurangaba Prof.Mrs.Abhilasha Mishra Assistant Professor MIT Engg.,Aurangaba