Design and Analysis of Triple band Rectangular Microstrip Patch Antenna Array JAGTAR SINGH SIVIA*, MANDEEP SINGH*, SUNITA RANI*, TARA SINGH KAMAL** *ECE Department Yadawindra College of Engineering Punjabi University Guru Kashi Campus Talwandi Sabo,Punjab, INDIA **Radiant Institute of Engineering and Technology Abohar, Punjab, INDIA jagtarsivian@yahoo.com,mswalia23@gmail.com,ersunitagoyal@rediffmail.com , tsk1005@gmail.com Abstract: - It has been observed in the recent year that development in communication system required a light weight, high gain, high directivity, high efficiency antenna with minimum return losses and with minimum cost that should work at a number of frequency in the frequency band. The objective of this paper is to design a 4x1 rectangular patch microstrip antenna array for X- band application (8 GHz - 12 GHz). The proposed 4x1 rectangular microstrip patch antenna array works on three frequencies 8.86 GHz, 9.16 GHz and 11.07 GHz. Roger/RT Duroid substrate material with dielectric constant 2.2 has been used to design the proposed antenna. The purposed antenna array has high gain of order 10.766dB at resonant frequency 9.142 GHz and directivity of order 13.11dB at resonant frequency 8.8163GHz. Method of moments based IE3D software has been used to compute the different parameters such as return losses, directivity, gain, radiation pattern of the purposed antenna array. Key-Words: - 4X1 rectangular microstrip patch antenna array, X-band, Return loss, Gain. 1 Introduction As Microstrip antennas are attractive due to their light weight, conformability and low cost so a number of patch antenna has been designed for the number of application such as in military, biomedical, aerospace, communication and radar system. The patch can take any shape however circular and rectangular configurations are the most commonly used configurations. These patch antennas are used as simple and for the widest and most demanding applications. Dual characteristics, circular polarizations, dual frequency operation, frequency agility, broad band width, feed line flexibility and beam scanning can be easily obtained from these patch antennas [2]. In this paper a 4x1 rectangular patch microstrip antenna array with inset line fed has been modeled, designed and simulated by using IE3D software. The analysis of microstrip patch antenna for X-band application is done using transmission line model in between 2GHz to 4GHz frequency and the designing has been done using IE3D software for a better understanding of the design parameters of an antenna and their effect on the directivity, bandwidth, and return loss and gain patterns. A rectangular microstrip antenna consists of rectangular conducting patch of width (W) and length (h) on a ground plane separated by dielectric substrate which one is Roger/RT duroid substrate material. Low dielectric constant substrates are generally preferred for maximum radiation, so Roger RT duriod with the dielectric constant 2.2 is used as substrate for the design of proposed antenna [3].D.R. Minervino et.al., 2013 designed and compare the performance of microstrip rectangular patch antenna array such as 2x1, 1x2, 4x1, 2x2, 2x4 and 4x2 for aerospace application (2GHz- 4GHz) using HFSS commercial software and concluded that using same number of elements the array designed in manner 2x1 had lower value of return loss than 1x2 but gain of 1x2 antenna array is slightly more than 2x1 and similarly 2x2, 2x4 has lower value of of return losses and higher value of gain (dB) as compare to 4x1 and 2x2 respectively[11]. G. Guru Prasad et.al.2012 designed and analyze the 8x1 rectangular patch microstrip antenna linear array using co axial probe feed method and simulation has been obtained by using IE3D software at 430 MHz frequency for atmospheric wind profile radar application and note down that by using this 1x8 antenna array obtain 17.82 dB gain. M. Gadag 2012 designed microstrip Rectangular patch antenna for RFID application at 2.4 GHz frequency and achieve minimum Return loss using Quarter wave Line feed as compare to strip line and inset line feed [6]. Lai et al. (2005) designed a 6x6 circular patch microstrip array Advances in Circuits, Systems, Signal Processing and Telecommunications ISBN: 978-1-61804-271-2 97