Research On Electromagnetic Energy Harvesting Antenna Techniques Based On Holographic Modulated Surfaces

Holographic modulated surface as a kind of artificial electromagnetic surfaces,has the advantages of simple structure,low profile,high gain and easy conformal,which provides a new possibility for precise control of electromagnetic waves.Electromagnetic energy collection is a rising star in the field of energy collection.Because of the space electromagnetic energy is increasing dramatically and its superiority of not affected by time and space,makes it possible to supply power for wireless sensor networks and wireless devices using electromagnetic energy in the near future.Combining Holographic modulated surfaces technology with electromagnetic energy collection is a meaningful work,there is a big space for theoretical research and practical application value.Domestic and foreign scientific research teams studied deeply in the fields of artificial electromagnetic surfaces and rectifying antennas,but the research of combining each other is still in its infancy.Aimming for applying holographic surface antenna into the field of electromagnetic energy collection,this article mainly studied the following research works:1.For the phenomenon of a split in the main lobe direction of traditional center feed holographic surface antenna,change the holographic impedance surface modulated function and the position of feed to eliminate the zero point in the main lobe direction.2.Using the Babinet principle for reference,takes the holographic complementary structure as the ground of holographic surface antenna.For the strong near-filed coupling of holographic surface and its complementary structure,the surface current are guided to flow to the surface edges,a more uniform surface current distribution effectively improve the gain of antenna.3.Based on the idea of holographic modulated surface generating,changing the wave function of target radiation and the position of feed,a double beam and a cone beam holographic surface antenna are designed.By dividing the holographic surface into four quadrants,each quadrant independently radiates one beam,a four beams holographic surface antenna is designed.Applying the holographic surface antenna into electromagnetic energy collection and supplying power for the wireless devices in real life,there are many challenges to be overcomed.Multi-polarization holographic surface receiving antenna and a wideband electromagnetic energy collection system can effectively improve the efficiency of free space electromagnetic energy collection.The design of a high conversion efficiency under a very low input power of rectifier circuit and the efficient power management units are the key to change the scientific research to practical applications.