Circular Monopole Time Reversal Mirror for Microwave Wireless Power Transfer Applications

Abstract

This paper presents the design of a circular microstrip patch antenna time reversal mirror (TRM) for microwave wireless power transfer applications. The proposed antenna has 4.9 GHz bandwidth covering the 5.8 GHz WLAN band. Defects were used to improve the bandwidth and return loss of the proposed antenna TRM with enhanced radiation suitable for wireless power transfer for off-body biomedical applications. For the antenna time reversal mirror proposed, the slots act as scatterers enhancing the performance of the antenna time reversal mirror with transforming structures. The proposed antenna is designed on a microwave substrate of relative permittivity of 2.65 having a loss tangent of 0.003. It has a compact size of 30mm by 28mm. A rectangular bracket shaped slot was etched on the circular patch to improve its return loss with a maximum return loss of -55dB, better than -10dB with impedance bandwidth of 3.67-8.57 GHz and improved radiation pattern. Square slots were also etched on the partial ground plane of the proposed antenna.