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This article discusses the design analysis of a wideband rectenna (Antenna + Rectifier). It empowers low power devices, battery-less power sensors, and many Internet of Things (IoT) devices. The main focus of this work is divided into two parts. First, to develop the power to operate the wideband frequency of operation without system complexity. To obtain rectifier bandwidth sufficiently, L-section impedance matching with dual Schottky diode HSMS270B is proposed. Second, to improve the rectenna efficiency and output DC power. Wideband rectenna harvests the maximum RF power of 30.590 dBm, 1145.51 mW, 10.703 Volts at 3.2 GHz. The harvested power is easily available to power up the low powered sensor such as gas sensor (500-800 mW), pressure sensor (10-15 mW), and temperature sensor (0.5-5 mW). The peak conversion efficiency of the rectenna is 88.58% at 0 dBm, 34.70% at 10 dBm, and 53.52% at 20 dBm under the load resistance of 100 kΩ. The proposed work shows a 20-25% improvement in conversion efficiency with this approach. For efficient RF energy harvesting applications, the proposed rectenna is capable of covering a wideband application from 1.975 to 4.744 GHz with a single radiation patch. This shows that the novel approach of the considered work and the proposed rectenna has the specialty to capture more energy from a wide area at once.

Abstract-Simulation and experimental measurement of a new design of an oblique incidence and polarization insensitive metamaterial absorber with multiband absorption is presented in this paper. The unit cell of the proposed metamaterial absorber comprises concentric continuous rings of different radii and widths placed in four different quadrants with identical pair of rings placed diagonally opposite, with each ring responsible for high absorption. The calculated dispersion behavior of MM absorber in terms of effective permittivity (ε eff ), effective permeability (μ eff ), and refractive index (η eff ) shows the metamaterial characteristics. The surface current and field distributions in MM absorber are simulated to understand the occurrence of absorption bands. The measured results show the absorption peaks of 99.5%, 99.8%, 99.5% and 99.9% at 7.20 GHz, 9.3 GHz, 12.61 GHz, and 13.07 GHz, respectively. The simulated results are well supported by the experimentally measured performance of the fabricated metamaterial absorber. It offers multiband absorption with bands lying in C-band, X-band and Kuband for mobile communication, satellite communication and radar applications. With merged third and fourth absorption peaks, the proposed metamaterial absorber structure exhibits a broadband absorption.