Design of a Rectenna Array Without a Matching Network

A novel approach to designing rectenna systems by eliminating the use of a matching network between the antenna and the rectifier is presented. The proposed rectenna consists of a wide impedance bandwidth 8 octagon disks placed at two different layers laying on both sides of a single substrate and backed by a ground plane. A Schottky diode is placed at each layer right at the feeding location without matching network, forming an array of two rectennas. The rectified power is smoothed out using a low pass filter composed of two RF choke inductors for each rectenna. By virtue of the wide impedance bandwidth of the antenna, the measurement results of the rectenna yielded a 50% radiation to DC efficiency at the operating frequency of 2.1 GHz. The rectifiers were then connected in series or parallel to study the effect of the connection type on the rectified output power. Wideband load resistance response and configurable amount of output DC currents and voltages can be realized using certain DC power combining methods.