Design And Implementation Of A Novel Top Edge Detection Algorithm-Based Smart Security System

In this research work, the author designed the peripheral interfacing modules such as ultrasonic sensor circuitry, moveable sensor plates by stepper motor circuitry, and image capture controlling circuit using Microcontroller (AVR ATmega8535), to develop the Smart Security System (SSS)

An IoT based Self Quarantine System with RFID Tracking

An Internet of Things (IoT)-based self quarantine system with Radio Frequency Identification (RFID) and Global Positioning System (GPS) tracking is proposed to monitor the health conditions of the Covid 19 patients and track their real time location via mobile application. There are biomedical sensors used to measure health conditions such as temperature, pulse oximetry, and heart rate monitor sensors. In addition, the RFID readers are used to detect patients that intend to leave the quarantine area, and the GPS modules are used to track their actual geometrical location so that further action can be taken by the authorities. The real time data is automatically pushed to the cloud server for the authorities to remotely view the patient’s health condition and location on the Google map using smart devices. Finally, a hardware prototype and a mobile application have been successfully developed in this project to display all measured data on a liquid crystal display (LCD) screen, as well as on a smart phone

Design of RF to DC Rectifier using Steep Slope Tunnel FET Device for RF Powered Systems

Radio Frequency (RF) harvesting is a process of converting the available ambient RF sources in to Dc electricity which can able to power up the ultra low power wireless sensor networks, charging systems, RFID applications and bio-implantable devices.There is a significant challenge in the design of rectifier part in the RF harvesting system, to improve the output dc power with Power Conversion Efficiency (PCE). The main objective of this study is to choose a suitable device and structure of the RF-DC rectifier circuit in the harvesting system which operates in high frequencies. The rectifying device such as schottky diode and diode connected MOSFET, used in the RF rectifiers are suffered with bad threshold voltage levels which makes a large increase in the channel resistance Ron , reduces the on-drive current and increase in the voltage drop which leads on to high resistive power loss, low power conversion efficiency and acquire very low dc output voltage. To overcome the above issues, a GaN/InN steep slope tunnel FET device is proposed for an efficient structure design . The designed tunnel fet rectifier is thoroughly investigated with different design parameters such as number of stages input dbm, width of TFET, capacitor values and DC current of known load values. The simulation of the circuit shows that it can able to generate a power conversion efficiency of 26.8% for a minimum RF input of -15 dBm at 900 MHz operating frequencies, providing the output dc voltage of 2 V, 4 μA with a load resistive of 500 KΩ

Schottky behavior of reduced graphene oxide at various operating temperatures

Demand of portability has been a growing trend due to the thirst of catching up with the latest evolution of technology. This scenario has urged power supply designers to develop devices that are relatively smaller, faster and having a higher percentage of efficiency. In contrast, smaller devices tend to experience overwhelming heat dissipation which can be hazardous to the devices. A Schottky diode is a semiconductor diode which has a relatively low forward voltage drop and fast switching action. Despite having low voltage drop, Schottky devices are extremely sensitive to elevated temperature owing to high leakage at reverse bias region. The leakages are due to low energy barrier which is susceptible to thermal runaway when a nominal amount of heat is applied. This paper presents the study of Schottky behaviour of reduced graphene oxide (RGO) at various operating temperature. RGO has superior electronic and thermal properties as well as high carrier mobility. Graphene was obtained by chemical exfoliation of graphene oxide, which is a reduction method. Through spray-coating, the RGO is deposited onto a trench-structured Schottky base to form a Schottky diode. Electrical characterization has been carried out at different range of temperature; ranging from 25 °C to 125 °C. Result shows that overall, the device has the same range voltage drop around 1 V in all five different temperatures and is also considered to have a significantly low leakage current. Furthermore it also shows a unique current-voltage (I-V) pattern in which the impedance tangent increases from 25 °C to 50 °C but as the temperature gets higher, the impedance approaches the characteristics of a room temperature