In this paper, a novel corrugated structure at the edges of the Vivaldi substrate is presented. Compared with the Vivaldi antenna without corrugated structure, the new structure has a better radiation pattern. While compared with the traditional corrugated structure, the new structure has a better front-to-back ratio (F/B ratio). Properly chosen thickness and dielectric constant of substrate en...

This paper will summarized the different size of opening width and length of the slot flare Vivaldi Antenna. The different size of opening width and length will bring effects on the VSWR and S11. The Vivaldi Antenna is designed to cover from 2 to 18 GHz by using the CST Microwave Studio Software. Then these antennas are constructed using RT/Duroid 5870 which have dielectric constant r 2.33. T...

An optimized 1×8 Vivaldi antenna array designed for the lower-band UWB (2-4 GHz) through-wall imaging systems has been developed. Tapered slot antennas were utilized as the array elements and optimized to have a compact size. A one to eight wideband Wilkinson power divider was designed and fabricated to compose the feed network for Vivaldi antenna array. Measured results of the manufactured Viv...

Many large-scale Internet applications optimize their overlay network to reduce latencies. Embedding coordinate systems like Vivaldi are valuable tools for this new range of applications since they propose light-weight algorithms that permit to estimate the latency between any pair of nodes without having to contact them first. It has been recently demonstrated that coordinate systems in genera...

We describe Vivaldi (VIsualization and VALidation DIsplay; http://pdbe.org/vivaldi), a web-based service for the analysis, visualization, and validation of NMR structures in the Protein Data Bank (PDB). Vivaldi provides access to model coordinates and several types of experimental NMR data using interactive visualization tools, augmented with structural annotations and model-validation informat...

Network Coordinate (NC) system is an efficient and scalable mechanism to estimate the distance between Internet hosts. However, the existence of Triangle Inequality Violation (TIV) decreases the accuracy of NC system. With focus on most widely used NC system, Vivaldi, we propose an effective mechanism of neighbor selection based on TIV Severity Sort to improve Vivaldi performance. By sorting ex...

Ultra Wideband (UWB) has a number of applications that make it attractive for a variety of applications such as microwave imaging, wireless communications, ground penetrating radars, remote sensing and phased arrays. This paper offered the design of a tapered slot Vivaldi antenna for ultra-wideband application using FR4 substrate which has relative permittivity of 4.4. The Vivaldi Antenna is de...

An Ultrawideband (UWB) high gain compact Vivaldi antenna with end fire radiation patterns is presented for radar and microwave imaging applications. The antenna is operating for 2.9GHz to more than 11GHz with -10dB impedance bandwidth and is designed on low cost FR4 substrate of thickness 0.8mm. While designing the proposed antenna, initially a compact exponential tapered slot Vivaldi antenna i...

A Network Coordinate (NC) system is an efficient mechanism to predict Internet distance with scalable measurements. In this paper, we focus on the node churn problem – the continuous process of nodes arrival and departure – in distributed applications. Studies on Vivaldi, a representative distributed NC system, show that under node churn the prediction accuracy of the NC system will be seriousl...

Internet coordinate systems have emerged as an efficient method to estimate the latency between pairs of nodes without any communication between them. They avoid the cost of explicit measurements by placing each node in a finite coordinate space and estimating the latency between two nodes as the distance between their positions in the space. In this paper, we adapt the Vivaldi algorithm to use...