High-Efficiency Rectifier for Wireless Energy Harvesting Based on Double Branch Structure

A rectifier circuit for wireless energy harvesting(WEH) with a wide input power range is proposed in this paper. We build up accurate models of the diodes to improve the accuracy of the design of the rectifier. Due to the nonlinear characteristics of the diodes, a new band-stop structure is introduced to reduce the imaginary part impedance and suppress harmonics. A novel structure with double branches and an optimized λ/4 microstrip line is proposed to realize the power division ratio adjustment by the input power automatically. The proposed two branches can satisfy the two cases with input power of-20 dBm to 0 dBm and 0 dBm to 15 dBm, respectively. Here, dBm = 10 log(P mW), and P represents power. An impedance compression network(ICN) is correspondingly designed to maintain the input impedance stability over the wide input power range. A rectifier that works at 2.45 GHz is implemented. The measured results show that the highest efficiency can reach 51.5% at the output power of 0 dBm and higher than 40% at the input power of-5 dBm to 12 dBm.

Numerical simulation of shock wave interaction with a deformable particle based on the pseudo arc-length method

In this paper, we combine the pseudo arc-length numerical method with the mathematical model of multiphase compressible flow for simulating the shock wave interaction with a deformable particle. Firstly, an arc-length parameter is introduced to weaken the discontinuous singularity of governing equations, and an efficient pseudo arc-length numerical method of multiphase compressible flow is proposed. Then the accuracy and adaptive moving mesh property of this algorithm are tested. Finally, the multiphase pseudo arc-length numerical method is applied to the problem of interaction between shock wave and the deformable particle. Through the flow flied change and data analysis of key points, it can be found the complex wave structures are presented after the interactions between the planar incident shock wave and the metal particle, and all these wave interactions lead to the movement and deformation of metal particle, and then the deformed particle will affect the transmitted shock wave back. According to the discussion, the deformation of particle and shock wave propagation in the particle are determined by the shock wave impedance of each medium and shock speed, so the interaction between shock wave and the deformable particle can be studied on the basis of physical properties of explosive mediums.