Bin-Jie Hu

A Novel Broadband UHF RFID Tag Antenna Mountable on Metallic Surface

A novel broadband UHF RFID tag antenna mountable on metallic surface is presented. The structures of T-matching network and double symmetrical radiating patches shorted to ground plane are employed. The proposed antenna has a half power bandwidth of 11.4% when placed in free air and covers two major segments of the UHF RFID band when mounted on metallic surface. The proposed antenna also has good radiation characteristics and cross-polarization performances in both conditions. The results show that the proposed antenna can work not only in free air but also on metallic surface for UHF RFID band.

Analysis of Indoor Positioning Approaches Based on Active RFID

RFID technology is gaining much attention for indoor localization because of its advantages such as non-contact and non-line-of-sight nature. In this paper, we study two typical approaches using active RFID for indoor location sensing: LANDMARC and VIRE, and point out that the latter approach with a fixed threshold of Received Signal Strength Indication (RSSI) difference which determines the elimination of unlikely positions does not work well in complicated indoor environments with severe radio signal multi-path. Analysis of two important factors in VIRE directs us some improvements for adaptation to enhance the accuracy of indoor localization.

A Data Fusion Algorithm in Leach Protocol Using Gauss Membership Function

a new data fusion algorithm based on improved leach protocol and gauss membership function of fuzzy theory in wireless sensor networks is presented. The improved leach protocol is utilized second-level cluster head to transmit fused data which can reduce energy consumption and prolong the network life cycle. The proposed fusion algorithm with the gauss distribution characteristic chart and the gauss membership function can improve the data precision and measurement stability.

Compact Circularly Polarized Square Microstrip Fractal Antenna with Symmetrical T-Slits

Based on the narrow-slit fractal method, a novel compact square microstrip fractal antenna with symmetrical T-slits to achieve circular polarization (CP) operation is proposed. By introducing two pairs of symmetrical T-slits, high cross-polarization is effectively suppressed. In addition, a patch size reduction as large as ~34.3% for the proposed antenna, compared to the conventional regular-size CP antenna without the symmetrical slits, has been obtained.

Adaptive Fusion Method of Multi-Focused Image Based on Wavelet Transform

An adaptive fusion method of multi-focused image based on wavelet transform is presented. The match degree of source image is considered as an adaptive threshold to decide whether maximum selection or weighted average to be used for new wavelet coefficients of sub-images. Experiments show that the proposed method will obtain more information content and higher clarity after wavelet inverse transform than traditional methods.

A Social-Aware Routing Protocol for Two Different Scenarios in Vehicular Ad-Hoc Network

Vehicular Ad-hoc Network (VANET) has recently attracted wide public attention. A key challenge is to design suitable routing protocols for VANET. In order to get high packet delivery ratio and low end-to-end delay, this paper proposes a social-aware routing protocol based on the “store-carry-forward” strategy, called Tie and Duration Based Routing Protocol (TDRP). To select the best relay node, TDRP takes two social metrics into consideration: community and centrality. We adopt a distributed K-Clique community detection to divide vehicles into different communities, and calculate global and local centralities of vehicles by making full use of strong and weak ties, as well as the duration of historical connections. The ONE simulator is used to evaluate the performance of TDRP and Bubble Rap, a typical social-aware routing protocol. Experimental results show that TDRP outperforms Bubble Rap in both city and highway scenarios in terms of packet delivery ratio and end-to-end delay.

A Compact Tri-Frequency Patch Antenna with Planar Left-Handed Materials

A novel compact tri-frequency patch antenna filled with modified planar left-handed (LH) materials is presented. The modified LH structures enhance the LH nature and develop lower LH operating frequency, which enables size reduction and large frequency ratio. The length of LH structures with four unit cells is λ0 / 31.25. Large scale of frequency ratio can be arbitrarily chosen by adjusting the sizes of patch and LH materials.

Novel Circularly Polarized Square Microstrip Antenna with L-Slits

A novel microstrip antenna with four L-slits for achieving circular polarization (CP) operation is proposed. By introducing two pairs of the centrosymmetric L-slits, the high cross-polar level is effectively suppressed. The characteristics of the input impedance, axial ratio, and radiation patterns are simulated. The results show that the good CP performance of the proposed antenna can be obtained.