International Journal on Recent and Innovation Trends in Computing and Communication ISSN: 2321-8169 Volume: 10 Issue: 9 DOI: https://doi.org/10.17762/ijritcc.v10i9.5747 Article Received: 02 July 2022 Revised: 09 August 2022 Accepted: 18 August 2022 Publication: 30 September 2022 ___________________________________________________________________________________________________________________ 1 IJRITCC | September 2022, Available @ http://www.ijritcc.org Conformal Printed Log Periodic Microstrip Antenna Array for Triple Band Applications Swetha Velicheti, Prudhivi Mallikarjuna Rao Department of ECE, Andhra University, Visakhapatnam, India Email: swethaphd7@gmail.com Abstract In this paper, a conformal Printed Log periodic microstrip antenna (LPMA) is proposed for sub-6 GHz (triple band) applications. This antenna consists of twelve rectangular patch elements along with microstrip feed line and those are fabricated on a polyimide substrate with dielectric constant value of 3.3. The adaptability of the antenna is shown by bending the LPMA horizontally and vertically across the angle of 30 0 , 45 0 and 60 0. The execution of the antenna is analysed in terms of its return loss, Gain, H-E plane patterns and efficiency. The designed antenna is capable of operating with the resonant frequencies 2.4 GHz, 4 GHz and 5.9 GHz with the gain of 8.2, 8.9&7.5 dBi respectively, providing voltage standing wave ratio (VSWR) < 2. Using CST software the designed antenna designed, simulated and the estimated results are in great concurrence with the simulation results. Keywords: LPMA, conformal, triple band 1. Introduction Planar LPDA antennas [1-7, 20] have been broadly utilized for wide range of wireless applications because of its wide data transmission, high increase and planar profile. It was initially proposed by Dwight E-Isbell and Raymond Du Hamel in 1957 [8] and then developed by Carrel in 1961[9]. Using frequency independent antenna principles, the log- periodic microstrip antenna can be scaled from period-to- period, so that its exhibition is corresponding to the logarithm of frequency [10, 11]. However, planar antennas are frequently not functional for joining onto bended surfaces. In order to overcome this, a conformal [12] or non planar antennas [13] are introduced. To design conformal structures there are various flexible substrates have been investigated [14-17]. However, it can be challenging to design and implement the antenna on very thin substrate. Bandwidth enhancement is mainly depending on substrate thickness [18]. Data transfer capacity is conversely corresponding to the substrate thickness. In addition, a near adaptability examination is useful for analyst working in this space [19]. In this paper, we have investigated the electromagnetic characteristics of the designed antenna which is designed on very thin polyimide substrate having the thickness of 0.1mm. As a result, it is possible to estimate radiation patterns and similar impedance qualities with LPDA under the specified bending configurations. Furthermore, the antenna is meant to be more flexible by using a microstrip feed. 2. Log periodic microstrip antenna design The log periodic microstrip antenna is designed using flexible substrate i.e. (Polyimide) with dielectric constant value of 3.3 is shown in figure 1. The LPMA consist of 12 elements on each side of the antenna. Initially the scaling and spacing factors τ = 0.92, α=0.17 are chosen to achieve the gain of 7.8 dB [9, 10]. After that other design parameters of log periodic antenna are computed, where the length of the longest dipole value is 45mm. In order to achieve the compactness, it is optimized and the optimized length is 24mm. Further the remaining lengths are calculated using design equations [9, 10], the resulting lengths are shown in figure 1. The widths and spacing between the elements are chosen as uniform, those are width=1mm and spacing =5mm. Therefore the total dimension of the antenna is 50x40x0.1mm 3 . All these dipoles of the antenna are fed by an identical microstrip lines on the two sides of the substrate having a width of 2 mm. Figure.1 Schematic View of the Proposed Log periodic microstrip antenna top and bottom surfaces. 3. Designed antenna Bending analysis The designed antenna is horizontally and vertically bended across the angle of 30 0 , 45 0 and 60 0 . The electromagnetic performance of the designed antenna is analyased in value of S11, Gain, efficiencies and radiation patterns. The figure 2 and 3 states the bending analysis of proposed antenna.