A reconfigurable multiband rhombic shaped microstrip antenna for wireless smart applications

This article proposes a reconfigurable multiband rhombic shaped microstrip antenna (RMRS-MSA) up to 20 GHz based on wireless smart applications. In this article radio frequency (RF) PIN diodes are loaded with microstrip feed line on radiating patch for frequency switching. It has a rhombic shaped copper loaded radiating patch. This radiating patch has two more connected rhombic patches inside with a 1 mm gap named as radiating patch 1 and radiating patch 2. These rhombic shaped radiating patches are enclosed with a square parasitic patch for achieving directional radiation pattern. A prototype of reconfigurable multiband rhombic shaped reconfigurable MSA is fabricated using a 30 x 30 mm(2)on FR-4 substrate with a dielectric thickness of 1.6 mm. The proposed RMRS-MSA is designed, fabricated, and experimentally validated. The experimental report at center frequency 5.21, 9.41, 10.46, 12.69, 14.39, and 17.09 GHz have reflection coefficients of -16.89, -25.54, -24.86, -28.62, -26.80 and -43.02 dB, respectively, when all diodes are OFF. Similarly, when all diodes are ON, at center frequency 14.57 and 15.18 GHz have reflection coefficients of -26.15 and -28.99 dB, respectively. The measured and simulated results agree well. The proposed antenna is more suitable for C, X, and Ku band-based applications.