Design and Development of Flexible PDMS Antenna for UWB-WBAN Applications

Wireless Personal Communications - This paper presents the design and development of a flexible Ultra Wide Band (UWB) antenna using polydimethylsiloxane as a substrate. Copper foil having a...     

Metasurface based pattern reconfigurable antenna for 2.45 GHz ISM band applications

In this article, a Z‐shaped antenna is designed for 2.45 GHz ISM band applications. The proposed antenna is surrounded by metasurface‐based unit cells. The unit cells are designed to reflect for the proposed frequency. Each of this unit cells are activated with the help of a diode. Unit cell is considered active by switching on the diode of respective unit cell. According to the activation of unit cell the pattern of the antenna will be reconfigured. The 2.45 GHz ISM band pattern reconfigurable microstrip antenna is presented. The radiation pattern of the antenna can be steered toward a desired direction by activating appropriate metasurface unit cell, minimizing the interference and optimizing medium usage. The proposed antenna performance is presented with the help of reflection coefficient and the pattern steerable capability by activating metasurface unit cells. The proposed antenna is having azimuth‐pattern reconfigurable capability around 360°.     

Specific absorption rate reduction using metasurface unit cell for flexible polydimethylsiloxane antenna for 2.4 GHz wearable applications

This article presents the design of a polydimethylsiloxane based flexible antenna for body worn applications. In order to reduce the specific absorption rate (SAR) metasurface (MS) based unit cell is proposed. Copper foil of thickness 3 mil considered for conducting layers. The proposed antenna is designed with leaf structure and covers the WLAN ISM band 2.4 GHz without metasurface (NMS) and with metasurface (WMS) unit cell. The MS unit cell at the backside of the antenna does not cover the entire antenna but only a portion of it where the backward energy is highly concentrated. This yields better result in reducing the SAR with a very compact sized MS unit cell. This MS structure improves the gain of an antenna and also reduces the SAR, by directing the radiating energy in opposite direction from the human user. The proposed antenna NMS has a simulated SAR value of 2.53 W/kg at 2.4 GHz over volume of 1 g of tissue, whereas WMS it is reduced to 1.53 W/kg. The comparative analysis of the proposed antenna presented with the help of performance matrices like reflection coefficient, SAR, gain, and radiation patterns.     

Step impedance resonator‐based tunable perfect metamaterial absorber with polarization insensitivity for solar cell applications

In this work, a step impedance resonator (SIR)‐based structure is proposed to develop a compact tunable metamaterial (MTM)‐based perfect absorber for solar cell applications. This MTM absorber is able to improve the absorption over a wide range of visible frequency range from 550 to 650 THz. The absorption is high around the frequency 600 THz. The proposed model is designed based on SIR technique to achieve miniaturization. The parametric study of overall size of the proposed MTM absorber analyzed over the frequency range 430‐750 THz. The thickness of dielectric spacer, and top most layer (MTM Structure) illustrates the tunable characteristics of the proposed model. A complete comparative analysis of proposed model with different dielectric spacers like AlGaAs, InAs, GaAs, and AlAs are presented with the help of absorption (S₁₁) and transmission (S₁₂). The proposed model is suitable for high efficiency solar cell energy harvesting applications.