Design Of FPGA-based Phased Array Control System For Wireless Power Trasnsmission

With the development of the Internet of Things and intelligent home devices,distributed low-power sensors are increasingly widely used in daily life and production.However,overly dispersed sensors,whether powered by batteries or cables,face problems such as environmental pollution,labor costs,and resource waste.The wireless energy transmission technology without cables provides feasibility for solving the above problems.Among various wireless energy transfer technologies,microwave wireless energy transfer technology has the advantage of long transmission distance and is more suitable for supplying power to distributed low-power devices.However,due to the relatively scattered distribution of such devices,if you want to supply power to devices in different directions and distances,you need more transmitting units in different directions,resulting in low efficiency and high cost.The phased array technology can better solve this problem by using the steering ability of the antenna array to the composite beam to power different equipment.This article studies and designs a phase control system for phased array RF wireless energy transmission,and proposes a phased array RF wireless energy transmission scheme based on FPGA controlled digital phase shifter.Utilize 2.4GHz radio frequency electromagnetic waves as an energy source.A digital phase shifter is designed,and by taking advantage of FPGA’s multi-channel parallel operation,the phase shift code of each antenna array element in the antenna array can be calculated simultaneously,thus greatly improving the response speed of the system.Aiming at the phase shifter widely used in phased array antenna array,this dissertation designs a low cost and stable structure 4-bit digital microwave phase shifter,which adopts the RF switch line structure,and can effectively reduce the use cost in large-scale antenna array.The designed phase shifter is controlled by a 4-bit signal and can output 16 different phase offsets.The loss is controlled within 5d B,and the phase deviation of the single-phase is less than 3 °,which can meet the requirements of this system.We have completed the construction and testing experiments of the RF wireless energy transmission system,and after testing,we can receive a signal of-5d Bm at a distance of 4.8meters.In addition,the phased array function of the system was tested,and after beam steering,it can receive-5d Bm of energy at a distance of 3 meters in a lateral direction of 30 degrees.