IJSRD || National Conference on Advances in Computing and Communications || October 2016 ©IJSRD 2016 Published by IJSRD 17 Design of Hybrid Triangular Gap-Coupled Rectangular Microstrip Antenna for Multiband Operations Rajeshwari Biradar 1 Dr. S. N. Mulgi 2 1 Research Scholar 2 Professor 1,2 Department of Applied Electronics (P. G. Studies & Research) 1,2 Gulbarga University, Gulbarga, Karnataka, India Abstract— In this paper a design of hybrid triangular gap-coupled rectangular microstrip antenna for multiband operation is presented. The proposed antenna is printed on the glass epoxy substrate material of dielectric constant εr = 4.2 with thickness 1.6 mm. This antenna consists of a hybrid triangular radiating patch which is placed above the conventional rectangular microstrip antenna (CRMSA) with gap of 2 mm. The antenna is excited through a simple microstripline feed. Proposed antenna is operates between the frequencies from 2.80 GHz to 11.85 which gives a six operating bands with reasonable impedance bandwidth. A maximum gain of 3.4 dB is observed in its operating bands and gives a broadside linearly polarized radiation characteristics. The measured and simulated results of the antennas are in good agreement with each other. The design concepts of the proposed antennas are given and results are presented and discussed. This antenna may find application in wireless communication such as WLAN, IEEE 802.11a, C- and X-band and satellite communication. Key words: Microstrip Antenna, Triangular, Gap-Coupled, Multiband I. INTRODUCTION In present era the microstrip antennas (MSAs) have reached very significant place in modern wireless communication systems due to their inherent features such as, planar structure, light weight, low profile, easy of fabrication, compatibility and integration with MMICS, ruggedness, low cost etc. [1].The MSA designers strived hard to put forth many methods and techniques such as embedded slots of different geometries like H-shape, U-shape, square ring, triangular, bow-tie, circular ring narrow slot, square etc. on the radiating patch [2-7]. These methods are quite effective at the cost constraints to design such antennas. Also, the other methods such as gap-coupling, using parasitic element etc. are proposed in the literature for the multiband operation and enhancement of gain of MSA [8].In view of this simple technique has been used to get multiband operations by using the gap-coupling technique. This technique also enhances the gain when compared to the gain of the CMSA designed for the same resonant frequency. II. DESIGN OF THE ANTENNA Figure 1 shows the top view geometry of CRMSA. This antenna is designed for the resonant frequency of 3 GHz using the design equations available in the literature for the design of CRMSA [9]. The CRMSA consist of substrate of area X × Y. The rectangular radiating patch of length L and width W is excited through a simple 50Ω microstripline feed of length Lf and Wf using quarter wave impedance matching transformer of length Ltr and Wtr. The proposed antennas are sketched using computer software AutoCAD and are fabricated on commonly available low cost glass epoxy substrate material of dielectric constant εr= 4.2 with thickness h = 1.6 mm. Fig. 1: Top view geometry of CRMSA