A Compact CP Star-Shaped Rectenna for WLAN

A novel compact circularly polarized (CP) rectenna is proposed for powering battery less devices operating at 5.8 GHz. The antenna has compact dimensions of 32mm × 32mm × 0.787mm. The simulation results reveal that the antenna provides a CP bandwidth of 343.75 MHz (5.7457-6.0895 GHz) and has an overlapping bandwidth, which is also the impedance bandwidth of 100 MHz (5.75-5.85 GHz). The CP is obtained by incorporating three slits strategically placed along the diagonal. Further, rectification is performed with a single stage voltage doubler circuit for suppression of losses incurred while using multistage rectifier circuit. Thus a compact design with high RF-DC conversion efficiency of 73.8% is achieved at 5.8 GHz. Finally, the proposed compact design offers an output DC voltage of 3.76 V for a 3kΩ load with an input RF power of 28 dBm. The proposed design is suitable for WLAN applications (5.795-5.815 GHz).