PERFORMANCE ANALYSIS OF MICROSTRIP ANTENNAS FOR DIFFERENT MATERIALS

Abstract

The Micro-strip antennas are widely used due to its compactness, simple manufacturing process, budget friendly and versatility. Here, carbon, abundant and easily available element is utilized in the process for the design and fabrication of antenna patch. Seeds of lapsi (Choerospondias axillaris), the indigenous plant of Nepal is used to extract carbon. The seeds are powered and activated chemically. The presence of carbon is verified using XRD technique. Resistance of dry powdered activated carbon is in the range Mega-ohm (MΩ) but after the coating of the paste of activated carbon in a polycarbonate substrate and acted by a laser of light-scribe drive various light and dark patterns were. The darker patches were found to be conducting and lighter patches were found to be non-conducting. After the activation by laser in activated carbon in a polycarbonate substrate resistance hugely dropped from Mega ohm (MΩ) to the range of Kilo-ohm (KΩ). For simulation part, High Frequency Structural Simulator (HFSS) software was used. First the basic rectangular antenna is designed and its properties were studied. Fractal swastika shape slot was later introduced in the design. The performance of antenna is optimized using the genetic algorithm. The optimized copper patch antenna with copper as ground in a polycarbonate substrate with no slot resonates at a frequency of 13.80 GHz with VSWR 1.34 and S11 parameter as -22.24 dB. On changing the patch as graphite in firstly mentioned identical conditions, antenna resonates at dual frequency of 15.40 GHz and 17.40 GHz with S11 parameters of -22.04 dB and -20.97 dB resp., VSWR of 1.17 and 1.19 resp. After the introduction of slot in copper patch antenna, multiple resonating frequencies were obtained as 9.0000, 13.8000, 15.0000, 17.4000 and 18.20000 GHz. In Graphite patch antenna also, there were multiple resonating frequencies. In comparison to cooper patch, graphite patch antennas showed better performance. After the introduction of swastika slot also, polycarbonate substrate has shown better performance for copper-copper patch-ground as antenna whereas properties were comparable in polycarbonate and corning glass substrate for graphite-copper as patch-ground antenna.