Slot Tapered Vivaldi Antenna with Corrugated Edges

Transcription

1 , pp Slot Tapered Vivaldi Antenna with Corrugated Edges Dr. K. Srinivasa Naik 1, D. Madhusudan 1 and Dr. S. Aruna 2 1,2 Department of ECE 1 Vignan s Institute of Information Technology, Visakhapatnam, Andhra Pradesh nivas @gmail.com 2 Assistant Professor, AU College of Engineering, Visakhapatnam, Andhra Pradesh aruna @gmail.com Abstract. This paper consist a style of Vivaldi antenna by variable the structural parameters properly to balance pattern, come loss performance by minimizing size. The Linear Tapered Slot Vivaldi Antenna has been changed by adding appropriate size corrugations on its edges to regulate the complicated mutual coupling at high scan angles. The Vivaldi antenna is built exploitation substrate of relative permittivity 3.27 and height mm. The antenna is intended at frequency of 12GHz with dimensions of 41.97mm 72.92mm mm. The simulation result showed that the projected antenna provides waveband from 3.1 GHz to 20 GHz at loss -10dB and HPBW varies around close to 900. The antenna includes a smaller size, with improved HPBW and it will meet the necessities of UWB system Keywords: Ultra-wideband (UWB), Half power beam width (HPBW), corrugations and return loss. 1 Introduction In modern communication system, ultra-wideband antenna have to make happy (by meeting a need or reaching a goal) the different needed things, such as sending more information, transmitting and receiving quality of the information. There are many other kinds of ultra-wideband antenna available such as Bow tie, Helical, Spiral, Logoccasional, Horn and Biconical. Vivaldi antenna is selected because of its superior broad band (features/ qualities/ traits), good impedance matching to the feed line, good energy and easy manufacturing process [3-4]. Vivaldi antenna is a kind of travelling wave and non-period antenna with UWB property, which can be made of microstrip so that it is widely used in many applications and as phased rows [1]. Vivaldi structure is proposed by Gibson in 1979 [2]. Vivaldi antenna maintains symmetrical E plane, and H plane patterns and the planar structure is also symmetrical. The UWB antenna must maintain not only wide impedance radio frequency but also wide immediate radio frequency. For ultra-wideband signal, the US Federal Communications Commission (FCC) defined frequency band as 3.1 to 10.6 GHz over which maximum power is radiated. The performance with a rippled surface vivaldi antenna will play an important role for the UWB Communication system. Vivaldi antenna with (a rippled surface structures are being developed for radar and communication systems [5]. Maksimovitch et al, ISSN: ASTL Copyright 2017 SERSC

2 introduced corrugations in vivaldi antenna with increased antenna radio frequency. The radiation characteristics have been improved by the use of a comb structure etched along the antenna edges combined with resistive films [6]. In the present paper, Vivaldi antenna is designed for reduced size and increase in impedance radio frequency. A linear slot with thinner at the end (tapered) antenna is designed for a frequency band 3.1 to 20 GHz. 2 Design of Tapered Slot Vivaldi Antenna 2.1 Tapered Slot Antenna Design Tapered slot Vivaldi antenna is a kind of antenna that receives signals from one direction. It's basically a flared slot line, created on a single metallization layer and supported by a dielectric. The shape of the Vivaldi antenna used in the present paper has linear tapered slot which impacts the frequency range of the antenna. The opening of the taper is for high frequency matching and wide end of taper is for lower frequency matching. The design of tapered slot Vivaldi antenna is a trade-off between the antenna size and its radio frequency. Slot line starts to radiate significantly under the condition of s w = λ 0 2 Where, sw is width of the slot. In practical conditions, the antenna does not radiate at a single point for a given frequency, but from a small section along the line of the flare. The taper profile is the combination of three linear lines, one linear region for high frequency and others are for low frequency. Linear tapered slot antennas (LTSAs) are the best agreement between beam width and side lobe level. If the number of linear lines increases slowly the linear tapered slot becomes a exponential. At the same time, beam of the radiation pattern becomes narrow. Different tapered slots types are exist. The most common types are linear tapered (LTSA), exponentially tapered (VTSA) and constant width (CWSA). The beam widths of CWSAs are typically the smallest, followed by LTSAs and then VTSAs. Most TSA elements produce symmetric radiation patterns in the E and H planes. In this paper, corrugation is introduced at the sting of the projected antenna. By corrugating the sting of the projected antenna it's potential to suppress surface current on the longitudinal direction and resonant frequency is reduced. Within the array the corrugations scale back the coupling between 2 antennas [7]. (1) Copyright 2017 SERSC 143

3 Fig. 1. Structure of linear Vivaldi antenna 2.2 Feeding Circuit of Vivaldi Antenna A simple line feeding port is employed for Vivaldi antenna and at the tip of the feed a radial stub is employed, that is useful for resistivity matching. The tapered slot Vivaldi antenna is worked up via the microstrip to fit line transition. The transition construction exploits broadband options of a microstrip radial stub used as a virtual broadband short. The microstrip is just about shunted to the second half of the slot line metallization whereas the primary half is a ground metallization for the microstrip line, it's necessary to rework the resistivity of the input feeding microstrip line (50Ω) to the input resistivity (100Ω) of the transition [8-10]. The tapered slot Vivaldi antenna with feeding circuits is shown in Fig. 2. Fig. 2. Feed structure of proposed antenna 144 Copyright 2017 SERSC

4 Table 1. Dimension of the Linear Vivaldi Antenna Width, W Length, L l1 l2 l3 Cavity diameter, r G W50 W100 Radius of the microstrip stub, Rstub 72.92mm 41.97mm 3mm 16mm 27mm 2.9mm 1.5mm mm mm 3.5mm 3 Results and Analysis Linear Tapered Slot Vivaldi antenna designed in the present paper is shown in Fig. 1. The parameters of the Vivaldi antenna are given in Table I. It has mm thickness copper fins on the both sides of a Roger TTM3. The total length is 72.92mm by assuming a lower cut-off frequency at 3GHz. The width is 41.97mm which is sufficiently wide to reduce the reflection. The Tapered slot Vivaldi antenna designed with substrates of Roger TMM3 (ε r =3.27, h= mm, tan(δ) = 0) is simulated with HFSS 15. Simulated results leads to Fig. 3 shows that this tapered slot Vivaldi antenna presents sensible UWB characteristics in terms of resistivity information measure, come loss is below -10 sound unit between three.1 GHz and twenty GHz. VSWR represents of the antenna s fitness; thus, it's vital that the VSWR be below a pair of across the complete UWB spectrum ( GHz). The simulated result presented in Fig 3 clearly shows that the VSWR curve for this antenna is less than 2 over the frequency range of 3.1GHz 20 GHz. Fig. 3. Return loss of the linear Vivaldi Antenna (in db). Copyright 2017 SERSC 145

5 Fig. 4. Simulated VSWR of Vivaldi Antenna. Fig. 5 shows the value of real and imaginary impedance between 3.1 to 20 GHz for the Vivaldi antenna. The figure shows a good matching of the antennas to the feed line and proposed antenna have the values of impedance real part near 50 ohm and value of imaginary part near zero ohm. Fig. 5. Impedance plot for the Vivaldi antenna The E-plane and H-plane radiation patterns for the frequencies of 10 and 12 GHz are shown in Fig. 5. The x-y plane is the E-plane while the x-z plane is the H-plane. The HPBW is almost in between 90 0 to at 10 GHz, 12 GHz. The designed antennas can be used in the entire UWB frequency band with a fractional bandwidth of 146% from 3.1 up to 20 GHz. It exhibits a voltage standing wave of less than 2.0 in a frequency range from 3.1 to 20 GHz. 146 Copyright 2017 SERSC

6 Fig. 5(a). Radiation Pattern at 12 GHz (phi=00) Fig. 5(b). E-field at 12 GHz (phi=0 0 and phi=90 0 ) Fig. 5(c). Radiation Pattern at 10 GHz (phi=00) Copyright 2017 SERSC 147

7 Fig. 5(d). E-field at 10 GHz (phi=0 0 and phi=90 0 ) 3 Conclusion In this paper, the impact of the antenna exploitation furrowed structure on the taperedslot antenna characteristics has been studied. And conjointly reduced size is intended that has sensible resistivity information measure of a linear tapered slot antenna. The aspect lobes of the pattern also are improved. The antenna has sensible beam dimension for array scanning and improved come loss. The projected antenna is often simply integrated with a tabular circuit. References 1. Farzaneh Taringou, David Dousset, Jens Bornemann and Ke Wu, Broadband CPW Feed for Millimeter-Wave SIW-Based Antipodal Linearly Tapered Slot Antennas, IEEE Transactions on Antennas and Propagation, vol. 61, no. 4, pp , April J. H. Shafieha, J. Noorinia, and Ch. Ghobadi, "Probing the Feed Line Parameters in Vivaldi Notch Antennas", Progress In Electromagnetics Research B, Vol. 1, pp , Joon Shin and Daniel H. Schaubert, A Parameter Study of Stripline-Fed Vivaldi Notch- Antenna Arrays, IEEE Transactions on Antennas and Propagation, vol. 47, NO. 5, pp , May P. J. Gibson, The vivaldi aerial, Proceedings of the 9th European Microwave Conference, pp , W. C. K. F. Lee, Advances in microstrip and printed antennas, J. Wiley & sons, pp , Maksimovitch Ye. S., Mikhnev V. A., and Vainikainen P., Radiation properties of ultrawideband printed-board antennas: simulations and experimental verification, Ultrawideband and Ultra short Impulse Signals, Sevastopol, Ukraine, pp , September, Copyright 2017 SERSC

8 7. Yongwei Zhang, K. Brown, Bunny Ear Combline Antennas for Compact WideBand Dual Polarized Aperture Array, IEEE Transactions on Antennas and Propagation, vol. 59, no. 8, pp , august J. B. Knorr, Slot-Line Transitions, IEEE Transactions on Microwave Theory and Techniques, pp , May B. Schuppert, Microstrip / Slotline Transitions: Modeling and Experimental Investigation, IEEE Transactions on Microwave Theory and Techniques, vol. 36, no. 08, pp , Aug Robert A. Scholtz, David M. Pozar, Won Namgoong, Ultra-Wideband Radio, EURASIP Journal on Applied Signal Processing 2005:3, pp , 12 May Daniel Valderas, Juan Ignacio Sancho, David Puente, Ultra-wideband Antennas: Design and Applications, Imperial college press, C. A. Balanis, Antenna Theory Analysis and Design, 2ed edition. J. Wiley & Sons, Z. N. C. a. M. Y. W. Chia, Broadband Planar Antennas: Design and Applications, John Wiley & Sons, Ltd, pp , J. N. M. M. P. Černý, Optimization of Tapered Slot Vivaldi Antenna for UWB Application, Faculty of Electrical Engineering, Copyright 2017 SERSC 149