A compact CPW-fed printed UWB antennas

In this work, we present the design and analysis of compact coplanar waveguide-fed ultra wideband rectangular antennas. These proposed antennas exhibit very wide operating bandwidth (return loss ≤ -10dB) which covers 3.2-15 GHz range, which means a relative bandwidth of 126% covering FCC defined UWB band with stable omnidirectional radiation patterns and important gain. The parameters of antennas have been investigated and optimized by using two electromagnetic solvers. A good agreement has been obtained between simulation and measurement results. These antennas are useful for UWB indoor applications, handheld and wireless communication requiring low profile antennas. The antennas achieved are low cost and easy to fabricate and integrate with RF circuit. The simulated and the experimental results are described and discussed

Corner Cut CPW-Fed Printed Antenna for Ultra Wide Band Applications

International audienc

Bio-Guided Targeting for Preservative and Anti-Ageing Cosmetic Ingredient Development

To develop a new antioxidant, antibacterial and natural cosmetic ingredient without cytotoxicity to skin cells, bioactive molecules contained in Kalanchoe pinnata leaf methanolic extract were targeted using semi-preparative HPLC fractionation linked to biological activity tests. Chromatographic effluent was collected at the column outlet into a 96 deep-well microplate, filling successively all the wells. After freeze-drying, the microplate was ready to use for different biological tests such as antimicrobial activity on microorganisms, skin cell viability and antioxidant activity on human keratinocyte cells. The injection of only 2.64 mg of crude extract into the HPLC system reveals a good correlation between the chromatographic peaks and the different biological activities. One fraction is mainly of interest since good antibacterial and antioxidant activities without cytotoxicity are observed. The analysis of this fraction using mass spectrometry allows the identification of glycoside derivatives of quercetin, isorhamnetin and kaempferol. Thus, a correlation between biological activity and the presence of these flavonoids is obtained. This screening method allows a rapid fractionation associated with a biological activity evaluation and a first molecular identification, saving time by limiting sample treatments and solvent consumption