Efficient Metasurface-Based Wireless Power Transfer System for ISM Band Applications

Abstract

The invention presented here is an innovative for a novel WPT system architecture that achieves excellent transfer power efficiency while being compact. The suggested metasurface has a total volume of 10 x 10 mm. A metasurface with an extensive range of phase shift is designed using of hexagon-shaped unit cell. The presented metasurface for 2.4 GHz ISM band applications has been developed and examined. This metasurface offers the ability to transmit any incoming waves as planar waves. To set up a Wireless Power Transfer (WPT) system, two Triangular Microstrip Antennas (TMSAs) operating at 2.39 GHz and 2.42 GHz are analyzed. Based on scattering responses of 3x3 array metasurface is proposed to increase the Power Transfer Efficiency (PTE) from 18.17% to 22.95%. When the Tx and Rx antennas are separated by more than a certain distance, it offers improved power efficiency. A simple triangular microstrip patch antenna and a hexagon-shaped metasurface are combined to set up a WPT system between transmitter and receiver. WPT efficiency has a maximum achievable level of 76.5%. To assure the transfer power efficiency, the right ratio between the transmitter and receiver's distance and the metasurface's electrical length can be adjusted.

Specification

Description:The desired metasurface design consists of a single, 0.8 mm-thick metallic layer placed on a FR4 dielectric substrate. The octagonal ring-shaped structure, measuring 0.035 mm in height, is described by the radiating patch. This metasurface structure has an overall volume of a = 10 mm, D1 = 8 mm, and D2 = 2 mm, as illustrated in Fig. 1. Fig. 2 provides the metasurface's scattering parameters, comprising the transmission and reflection coefficients. Bandpass response is shown by the reflection characteristics (S11), while bandstop response is shown by the transmission characteristics (S12). The designed structure's transmission coefficient provides a wideband of 1.65 GHz at a 10 dB level, spanning from 1.5 GHz to 3.15 GHz. Figure 3 shows the surface current density at 2.4 GHz for both fields of the proposed metasurface. Demonstrating clearly that the octagonal ring's inner and outer edges have the most resonance. The analysis of the high current distributions indicates that both sides of the octagonal ring configuration are orange in color.
Proposed TMSA Antenna
The designed antenna contains a traingle radiating patch measuring 30 x 40 mm and a dielectric substrate made of materials measuring 50 x 60 mm (same to the metasurface). For perfect matching, the proposed design incorporates a microstrip feedline having a 50Ω impedance. The feed dimensions are 2.9 mm and 13 mm, respectively. Figure 4 displays the suggested TMSA's architectural layout. The antenna's measurements are as follows: A = 34 mm, WS = 50 mm, LS = 60 mm, WF = 2.9 mm, and LF = 13 mm respectively. Over the frequency range of 2GHz to 2.5GHz, it is observed that the metasurface antenna produces return loss better than 10dB. At the resonant frequency of 2.3GHz, the suggested antenna without an metasurface results in a return loss of -24.08dB. Using an patch on the substrate improves the return loss at 2.39 GHz by roughly -26.02dB. Surface wave radiation is seen to be reduced by antenna structures on the substrate; consequently, the return loss decreases to -26.02dB from -24.08dB. Figure 5 displays the suggested antenna's return loss and radiation analysis.

Wireless Power Transfer Analysis

By designing the transmitting and receiving antennas, the WPT configuration of the planned system is examined, as shown in Fig. 6. The two TMSA antennas' initial spacing (D) is 30 mm. Figure 7 displays the variations in both transmission and reflection coefficients as a proportion of frequency. The transfer power throughout the 20 mm to 110 mm distance is shown by the parametric sweeps of the variations in the S21. Nevertheless, because of the dielectric losses in the air across the distance between and the radiating waves from the Tx antenna, the transmission coefficient values is fairly low. At a distance of 30 mm from the origin axis, a 3x3 set of hexagon-shaped metasurface may be found between the Tx and Rx antennas. Fig. 6(ii) depicts the suggested WPT system's simulation configuration. Distance D is used to analyze the overall power transmission distance between the Tx and Rx antennas. The metasurface array between the two antennas is varied to analyze the total transfer power efficiency of the suggested system. Figure 8 illustrates the arrangement that was also completed by comparing it with and without metasurafce analysis. It is evident that the suggested metasurface offers superior transfer efficiency in comparison to without metasurface. , Claims:1) An invention that employs a efficient metasurface-based wireless power transfer system for ism band applications.
2) As claimed in Claim 1, WPT efficiency has a maximum achievable level of 76.5%.
3) As claimed in Claim 1, it supports ISM applications at a frequency of 2.4 GHz.
4) As claimed in Claim 1, metasurface is proposed to increase the Power Transfer Efficiency (PTE) from 18.17% to 22.95%.
5) As claimed in Claim 1, total size just about 10 x 10 mm2.

Documents