Research And Design Of Ultra-wideband Energy Harvesting Antenna

In the radio frequency and antenna field,different receiving antenna is applied to harvest ambient electromagnetic energy for high frequency alternating current.Then,high frequency alternating current is transmitted to rectifier circuit which converts high frequency alternating current to direct current for feeding some low-power devices or components.And,electromagnetic energy harvesting technology has been become a research hotspot because the problem of energy shortage becomes more and more serious.The operating bandwidth,gain and polarization of the antenna directly affects the performance of the electromagnetic energy harvesting system.In this paper,a dual-notched bands ultra-wideband antenna with dual-circular polarization and a half wave rectifier circuit is designed,and an electromagnetic energy harvesting system is built to verify the performance of the electromagnetic energy harvesting system.The main research work is as follows:(1)A dual-notched bands ultra-wideband antenna is designed by cutting orthogonal triangle of rectangle radiation patch,adding the quarter-wavelength impedance matcher and slotting C-shaped slot on radiation patch.The operating bandwidth of dual notched ultra-wideband antenna is 2.8 GHz-3.15 GHz,3.95 GHz-5.5 GHz and 5.75 GHz-13.8GHz,and the dual-notched bands are 3.15 GHz-3.95 GHz and 5.5 GHz-5.75 GHz.The antenna could harvest electromagnetic energy of more frequency band when used in an electromagnetic energy harvesting system.On the other hand,the influence of the global microwave interconnection access signal at 3.5 GHz and the wireless local network signal at 5.5 GHz can be effectively filtered in the ultra-wideband communication system.And the gain of dual-notched bands ultra-wideband antenna is 8 d Bi.(2)Then,the dual-notched ultra-wideband antenna and a metasurface,which is composed of 5×5 wheel-shaped reflected elements,is combined.The linear polarization of dual-notched bands ultra-wideband antenna is converted to dual circular polarizations when dual-notched bands ultra-wideband antenna combines with the metasurface,at 4.3 GHz-5.5 GHz,5.75 GHz-7.9 GHz and 8.1 GHz-12.6 GHz.It improves the electromagnetic energy harvesting performance of antenna,when the gain of antenna is same.However,the operating bandwidth and gain of dual-notched bands ultra-wideband antenna is affected when dual-notched bands ultra-wideband antenna combines with the metasurface.(3)A half wave rectifier circuit is designed using the half wave rectifier principle.The operating band of half wave rectifier circuit is 4.4 GHz-4.8 GHz,6 GHz-6.3 GHz,7.8 GHz-8.1 GHz.The dual-notched bands ultra-wideband antenna,metasurface and half wave rectifier circuit is fabricated and tested.The test results show that the above design is feasible.Finally,the above two antennas and rectifier circuit is connected.The performance of electromagnetic energy harvesting system is tested under different operating frequencies and gains of antenna.