Dual band Dual Polarized Rhombic Slot Antenna for ISM Band Applications

This paper aims to present a dual band dual polarized rhombic slot antenna (RSA) for ISM band applications. The proposed antenna of size 60×60×1.6 mm3, consist of a rhombic slot with a pair of L shaped slits etched at two of its opposite arms and a rectangle etched at two of its corners. Two ports are placed perpendicular to each other. Both the ports are excited by a 50-Ω microstrip line due to which the impedance bandwidth (BW) of proposed antenna is enhanced and radiated with horizontal and vertical polarizations. The proposed rhombic slot antenna achieved a dual band 10 dB return loss bandwidth of |S11| 23.4% (1.96-2.48 GHz) and 36.4% (4.09-5.91 GHz) and for |S22| 30% (1.96-2.64 GHz) and 36.5% (4.8-6.95 GHz) respectively. Hence both the ports can operate in 2.45 GHz and 5.8 GHz ISM band applications, with isolation greater than 20 dB in the entire band and achieved a peak realized gain of 3.6 dBi in lower band and 5.6 dBi in higher band. The simulated results of proposed antenna show good radiation characteristics for ISM band applications.