A qualitative study of current trends in microwave wireless power transmission including current advancements and challenges

Wireless power transmission (WPT) has become an emerging topic for the researchers in the past decade because saving wires helps to avoid I
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R loss, leads to the improvement of safer transmission and is more convenient. Wireless transmission, at present, has been achieved using different approaches with the major ones including the Near field techniques comprising of Inductive coupling and Electromagnetic radiation and the Far field techniques consisting of Microwave wireless power transmission and Laser power transmission. This paper presents an exhaustive study based on the scopes of improvement of the efficiency of Microwave wireless power transmission. The paper focuses on four major parts of the microwave WPT system to enhance the efficiency where the first one being selecting the optimum input waveform to obtain maximum efficiency in RF-DC conversion at the rectenna end, second one is a thorough study on the channel efficiency. Thirdly a non uniform antenna array was designed, which produced higher gain and more stability of the reflection coefficient than the conventional uniform arrays currently being used. Lastly, improving the rectifier circuit by selecting the best possible diode in a Class F single-shunt rectifier for optimum RF-DC conversion was analyzed thoroughly.