Compact HMSIW based Centre-Fed Series Antenna Array for ISM Band Energy Harvesting

The global move towards wireless access point densification has alluded towards the possibility of harvesting the unused ambient RF energy, especially in the 2.4GHz and 5.8GHz unlicensed ISM bands, in order to power useful electronic devices. This is done by collecting the ambient RF energy present in the environment growing more and more as a result of the rapid growth in the wireless communication business and transforming that collected energy into electrical power. This paper focus on realization of a compact, dual band, linearly polarized HMSIW antenna and two- and four- element centre-fed series array antenna designed based on HMSIW technique used as a receiving antenna in the RF energy harvesting system. The HMSIW is formed by bisecting the SIW along the quasi-magnetic wall when operating at TE101 and TE201 modes with the similar magnetic field strength observed at both the resonance modes. The feeding position and edge to edge spacing between the elements of the array antenna for HMSIW is chosen such that the proper impedance matching is achieved. Moreover a truncation is made in HMSIW to suppress the unwanted bands at the TE201 mode. The antenna’s performance is analysed based on comparing the simulated and measured return loss, VSWR, gain, axial ratio and radiation pattern which matches well for both the frequencies of interest (2.45GHz and 5.8GHz) can be used in a RF energy harvesting (RF-EH) system.