Moon-Kyun Oh

UHF RFID Reader Antenna With a Wide Beamwidth and High Return Loss

A compact circularly polarized antenna with a wide beamwidth and high return loss (RL) is presented. The antenna consists of four U-shaped metal strips sequentially rotated and fed with a 90 ° phase difference feed network located beneath the ground plane. The antenna is designed to operate at around 915 MHz for UHF radio frequency identification applications, and the experimental results show that it has a wide beamwidth of over 114 ° and high RL of over 34 dB in the 902-928 MHz range.

Antenna with wide beamwidth and high return loss for UHF RFID reader

A circularly polarized antenna with a wide beamwidth and high return loss is presented. The antenna consists of four U-shaped metal strips sequentially rotated and fed with a 90° phase difference. The antenna is designed for UHF RFID applications, and the experimental results show that it has a wide beamwidth of over 114° at 915 MHz and high return loss of over 34 dB in the 902-928 MHz range.

Virtual source-based minimum interference path multicast routing with differentiated qos guarantees in the next generation optical internet

WDM networks using wavelength routing are considered to be potential candidates for the next generation backbone networks. One of the critical issues of the future network is a provision of proper QoS guarantees for a wide variety of multimedia multicast service. This paper concerns with the problem of optical multicast routing with QoS guarantees in WDM networks. Using Virtual Source (VS) nodes, we proposes a new MCRWA method for a multicast session, combining the VS-based tree method with Multi-Wavelength Minimum Interference Path Routing (MW-MIPR). This paper also proposes a QoS MCRWA method in combination with QoS constraints and a recovery strategy based on the differentiated QoS service model to provide QoS guarantee for a wide variety of multicast application in the next generation optical networks.