Differential Microstrip Antenna for RF Energy Harvesting

A differential microstrip antenna with improved gain for RF energy harvesting is presented in this paper. The developed antenna can be used in either center grounded or differential configuration. The antenna is designed and fabricated for GSM900 band (890-960 MHz). The antenna has a gain of 8.5 dBi at the center frequency and exhibits VSWR <= 2 for frequencies between 870 MHz to 1.05 GHz. The efficiency of the antenna is 80%. The developed antenna finds its application in energy harvesting, RFID tags and in wireless communication circuits, where differential inputs/outputs are needed. A complete differential RF energy harvesting system with a peak efficiency of 65.3% for a load of 3 k Omega is also developed

<span style="font-size:11.0pt;font-family: "Times New Roman";mso-fareast-font-family:"Times New Roman";mso-bidi-font-family: Mangal;mso-ansi-language:EN-GB;mso-fareast-language:EN-US;mso-bidi-language: HI" lang="EN-GB">Traditional <i style="mso-bidi-font-style:normal">Lepcha</i> craft <i>Sumok-thyaktuk</i> (<i style="mso-bidi-font-style:normal">Lepcha</i> Hat) and its conservation in Dzongu Tribal Reserved Area (DTRA), Sikkim, India</span>

537-541<span style="font-size:11.0pt;font-family: " times="" new="" roman";mso-fareast-font-family:"times="" roman";mso-bidi-font-family:="" mangal;mso-ansi-language:en-gb;mso-fareast-language:en-us;mso-bidi-language:="" hi"="" lang="EN-GB">The Sumok thyaktuk or Lepcha traditional hat is an oldest form of craft, unique and exclusive to the Lepcha tribe living in the Dzongu Tribal Reserve Area (DTRA) of Sikkim. The hat is intricately woven with the Ru or cane (Calamus acanthospathus), Po-young <span style="font-size: 11.0pt;font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" mso-bidi-font-family:mangal;mso-ansi-language:en-in;mso-fareast-language:en-us;="" mso-bidi-language:hi"="">–<span style="font-size:11.0pt; font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" mso-bidi-font-family:mangal;mso-ansi-language:en-gb;mso-fareast-language:en-us;="" mso-bidi-language:hi"="" lang="EN-GB"> local bamboo (Cephalostachyum capitatum). Each part of the hat and its artistic design hold its own traditional meaning and significance. The hat formed the headgear of the royal soldiers later on Sikkim Guard during the regime of Chogyal dynasty in Sikkim. Wearing the head gear in marriage ceremony, worships and other festivals is mandatory in the tribe. With the advent of other modern day<span style="font-size:11.0pt; font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" mso-bidi-font-family:mangal;mso-ansi-language:en-in;mso-fareast-language:en-us;="" mso-bidi-language:hi"="">’<span style="font-size:11.0pt; font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" mso-bidi-font-family:mangal;mso-ansi-language:en-gb;mso-fareast-language:en-us;="" mso-bidi-language:hi"="" lang="EN-GB">s trendy outfits in the locality, these traditional head gear is now facing serious threat and is actually in the verge of extinction. Therefore, the present study is an attempt to study the detail work of art and to document them systematically for the conservation of this dying art.</span

Broadband Bent Triangular Omnidirectional Antenna for RF Energy Harvesting

In this letter, a broadband bent triangular omnidirectional antenna is presented for RF energy harvesting. The antenna has a bandwidth for VSWR <= 2 from 850 MHz to 1.94 GHz. The antenna is designed to receive both horizontal and vertical polarized waves and has a stable radiation pattern over the entire bandwidth. Antenna has also been optimized for energy harvesting application and it is designed for 100 Omega input impedance to provide a passive voltage amplification and impedance matching to the rectifier. A peak efficiency of 60% and 17% is obtained for a load of 500 Omega at 980 and 1800 MHz, respectively. At a cell site while harvesting all bands simultaneously a voltage of 3.76 V for open circuit and 1.38 V across a load of 4.3 k Omega is obtained at a distance of 25 m using an array of two elements of the rectenna