A compact rectenna device at low power level

Abstract

This article describes the design and performances of a rectenna that collects low incident power density levels, at a single ISM-band frequency (f0= 2.45GHz). A new rectenna topology consisting only of an antenna, a matching circuit, a Schottky diode, and a DC filter has been modeled using a global simulation. A circular aperture coupled patch antenna is proposed to suppress the first filter in the rectenna device, and in addition, the losses associated with this filter. The harmonics rejection of the antenna is primarily used to reduce the rectenna size. The implementation of the filter in the antenna structure, combined with a reduction of the rectenna size, gives several advantages in several applications where the size and weight are critical criteria. The maximum energy conversion efficiency in this configuration is 34% and is reached for a load of 9.2 kΩ and a RF collected power of SRF = 17 μWZcm2 (≈ -10dBm RF incident upon the diode).