A New Broadband Question Mark Circularly Polarized Rectenna

In this paper, a new type of compact broadband question mark rectenna has been designed. The rectenna is formed by receiving antenna and rectifier circuit. The receiving antenna consists of three parts: ?-shaped (question-mark) patch, a rectangular ground etched a fan-shaped slot, and a dielectric substrate. By etching a fan-shaped slot on the ground plate, the available bandwidth of the antenna is expanded. The rectifier circuit consists of capacitors, the diode of HSMS2862 and resistor. Both of the antenna and the rectifier circuit are printed on a dielectric substrate with a dielectric constant of 4.4. The realized rectenna has a dimension of 28 mm × 26 mm × 1.6 mm. The result shows that the impedance and AR bandwidth are 60.79% (3.95 - 7.4 GHz) and 34.67% (4.65 - 6.6 GHz), respectively, and the highest efficiency is 45%.