Novel UWB slotted I-shaped flexible microstrip patch antenna design for satellite reconnaissance, amateur radio, future soil moisture and sea surface salinity missions

In this paper, a flexible I shaped stacked novel ultra wideband (UWB) antenna with defected and reduced ground resonant at 1.26 GHz with an impedance bandwidth of 1.278 GHz (1.0596 GHz to 2.3374 GHz) has been proposed which can be suitably employed for satellite reconnaissance, amateur radio, future soil moisture and sea surface salinity mission applications. The material employed for substrate is flexible FR4 having dielectric constant of 4.4 and copper has been used for radiating patch, ground and feed line. The antenna is resonant at 1.26 GHz with return loss of -43.72 dB. The proposed antenna has a gain of 3.00 dB and directivity of 2.815 dBi at resonant frequency of 1.26 GHz. The antenna has been designed and simulated using CST Microwave Studio 2014. The performance of the antenna has been analyzed in terms of return loss (dB), directivity (dBi), gain (dB), smith chart and VSWR. The antenna has impedance of 50 ohms which makes it suitable to be fed by SMA connector of 50 ohms for maximum power transfer from SMA connector to the patch for radiations. The quarter wave transformer has been employed in order to match the antenna impedance with the port impedance. The antenna has been stacked by placing the flexible FR4 substrate of thickness 8mm over the feed line to enhance the impedance bandwidth of antenna by 2 percent. The proposed antenna has been practically fabricated and tested using E5071C Network analyzer and anechoic chamber. It has been observed that the practical antenna performance results closely match with the CST simulated antenna results. The proposed antenna can be suitably employed for Global Positioning System (GPS) applications (L1|1.57 GHz, L2|1.22 GHz, L3|1.38 GHz, L4|1.37 GHz, L5|1.17 GHz), life detection radar systems (1.26 GHz), soil moisture content missions, (1.26 GHz and 1.41 GHz), sea surface salinity missions (1.26 GHz and 1.41 GHz) and amateur radio (1.24 GHz-1.3 GHz, 1.26 GHz-1.27 GHz) applications.