JAE, VOL. 22, NO. 1, 2020 JOURNAL OF APPLIED ELECTROMAGNETISM 9 INVESTIGATION OF EFFECT OF SILVER COATING ON MICROSTRIP ANTENNA ARRAYS K. Prahlada Rao * , R.M. Vani ** , P. V. Hunagund * * Department of PG Studies and Research in Applied Electronics, Gulbarga University Gulbarga, India 585106 pra_kaluri@rediffmail.com ** University Science Instrumentation Centre, Gulbarga University Gulbarga, India 585106 Abstract In this paper the effect of silver coating on the performance of microstrip antenna array is examined. The conventional four element microstrip antenna array is producing narrow bandwidth of 4.89 % and high values of mutual coupling of -16.95, -14.22 and - 17.30 dB respectively. The modified microstrip antenna array is producing enhanced bandwidth of 31.43 % and reduced mutual coupling of -29.45, -32.71 and -29.94 dB respectively. In addition, good amount of reduction in backward power and increase of forward power indicate improved performance of modified microstrip antenna array. The microstrip antenna arrays are designed using Mentor Graphics IE3D software. The thickness of silver deposition is equal to 30 nm. The conventional microstrip antenna array designed at 6 GHz is resonating at 5.53 GHz with a return loss of -21.12 dB. The dielectric substrate used to design and fabricate microstrip antenna arrays is FR-4 glass epoxy. The measured results of the fabricated antenna arrays are obtained using vector network analyzer. 1. INTRODUCTION Microstrip antennas and arrays have created a new dimension in the field of antennas. These antennas are suitable for applications in wireless communications, radar technology, satellite communications etc. These antennas have dielectric substrate placed in between the radiating patch and ground plane. Microstrip antennas are characterized by ease of compatibility with other circuits and devices, ease of fabrication, low cost etc. On the other hand, they possess narrow bandwidth and surface wave excitation in the dielectric substrate. Narrow bandwidth implies less amount of information can be