Taikyeong Jeong

RF energy harvesting system and circuits for charging of mobile devices

RF energy harvesting holds a promise able future for generating a small amount of electrical power to drive partial circuits in wirelessly communicating electronics devices. This paper presents the overview and progress achieved in RF energy harvesting field. A modified form of existing CMOS based voltage doubler circuit is presented to achieve 160% increase in output power over traditional circuits at 0 dBm input power. A schottky diode based RF energy harvesting circuit performance is also studied with practical and simulations results.

Viewer Identification and Authentication in IPTV using RFID Technique

This paper presents the application of RFID (radio frequency identification) to identify and authenticate the viewer for personalized and interactive services offered by the IPTV (internet protocol television). Main purpose of the setup is to identify and authenticate the viewer, the person who is watching the TV, for parental control, payment services, consumer feedback and input etc. Using RFID reader with IPTV STB (set-top box) for authentication of viewer and service verification results in identifying viewer, using RFID tag wirelessly and at low cost. With RFID service becoming ubiquitous and its application and connectivity with home automation systems, the proposed system is thought to be widely adaptable. This Interactive identification technique also provides reliable security to protect the viewer contents, media and parental control.

A new approach to thermometer-to-binary encoder of flash ADCs- bubble error detection circuit

In this paper, we propose a new approach to thermometer-to-binary encoder of Flash ADCs. Instead of integrating bubble error correction circuit as previous approaches, proposed approach integrates a bubble error detection circuit. The advantage of this approach is that it can handle all types of bubble error whereas previous approaches often deal with first-order bubble error only. Simulation results show that the bubble error detection circuit consumes very little energy.

Thermometer-to-binary encoder with bubble error correction (BEC) circuit for Flash Analog-to-Digital Converter (FADC)

Thermometer-to-binary (TM2B) encoder is an important component of a Flash Analog-to-Digital Converter (FADC). Bubble error, extremely often, effects the correction of TM2B as well as high speed sampling rate. In this paper, we propose a MUX-based TM2B circuit that can correct bubble errors. Error correction ability of our proposed circuit is compatible with previous methods. The simulation results show that the proposed circuit requires a small number of transistors and consumes low power.

Implementation of low power adder design and analysis based on power reduction technique

This paper presents improved design of low power adder and analysis based on power reduction technique. Using example of adder and multiplier, low leakage power CMOS digital circuit is verified by respective benchmark suite for each example and compared with conventional design of adder and multiplier. Using various supply voltages and fault coverage as parameters, reduction in power was measured. Simulation result and validation by example foresee implementation of proposed design as an essential part of high performance circuit design. The proposed technique offer power reduction up to 20.2% and fault coverage of 99.65%.

Wirelessly charging mobile devices from ambient RF sources

A universal wireless battery charger for portable and mobile devices can use ambient Radio Frequency (RF) or electromagnetic signals as a renewable energy resource, emitted by different sources for communications. In this paper, we designed a RF circuit that enables to charging mobile devices. This will result in continuous charging of device especially in urban areas where the density of RF sources is high.

A Novel Manufacturing Method for Carbon Nanotube/Aramid Fiber Filled Hybrid Multi-component Composites

A novel manufacturing method for hybrid composites filled with carbon nanotubes (CNTs) and aramid fibers is proposed. To disperse the CNTs in the epoxy matrix with the presence of aramid fibers, CNT/polyethyleneoxide (PEO) composites are prepared and utilized because PEO is miscible in the epoxy resin. After thin films are made of the CNT/PEO composite and placed together with the aramid fibers, the epoxy resin is infused to them. The PEO is dissolved in the epoxy and then the CNTs are dispersed in the PEO/epoxy matrix between aramid fibers before the pre-heated matrix is cured. It is found that the PEO is completely miscible with the epoxy resin and CNTs are dispersed well in the space between the aramid fibers.

Image streaming and recognition for vehicle location tracking using mobile devices

The image of a license plate is scanned by the camera attached to a mobile PDA device and the numbers on the plate are detected by the image processing parts in the proposed Mobile system. Then the numbers and the location of a mobile PDA device are encoded and transmitted along with the location information to a remote server through a wireless communication network. Finally, the server decodes the transmitted data as a text format and transmits it to the destination user. Consequently, this paper contributes a case study on the embedded system for designing of intelligent interface between a moving vehicle and a mobile PDA device, using a spatial relative distance scheme. The experimental results show that detection and tracking of a location of moving vehicle can be conducted efficiently with a mobile PDA device in real-time through wireless communication system and Internet.

Energy charging circuits in Bluetooth environment for smart phone

Recent mobile handhelds, e.g., Smart-phone, can be charged wirelessly using the traditional wireless communication technologies. In particular, Bluetooth with a charging circuit enables a short-range wireless charging of a mobile handheld. This paper presents an overview of power charging structures and proposes a new charging circuit based on schottky diode with a real commercial film-type antenna on mobile terminal. Our new circuit improves the charging efficiency approximately by 160%.

A new binary tree algorithm implementation with Huffman decoder on FPGA

Compression is useful technique in digital system, as it reduces the channel bandwidths and storage size. This paper presents new Huffman decoder based on binary tree method for improving usage of memory and speed. It is shown through experiment result related to computational speed that the propose method is superior to other predecessor. The customized Huffman hardware decoder comparison is presented at different speed on various FPGAs.