A novel k-means powered algorithm for an efficient clustering in vehicular ad-hoc networks

Considerable attention has recently been given to the routing issue in vehicular ad-hoc networks (VANET). Indeed, the repetitive communication failures and high velocity of vehicles reduce the efficacy of routing protocols in VANET. The clustering technique is considered an important solution to overcome these difficulties. In this paper, an efficient clustering approach using an adapted k-means algorithm for VANET has been introduced to enhance network stability in a highway environment. Our approach relies on a clustering scheme that accounts for the network characteristics and the number of connected vehicles. The simulation indicates that the proposed approach is more efficient than similar schemes. The results obtained appear an overall increase in constancy, proven by an increase in cluster head lifetime by 66%, and an improvement in robustness clear in the overall reduction of the end-to-end delay by 46% as well as an increase in throughput by 74%

A new structure of a wide band bridge power limiter

In this work, new design and simulation of a microstrip power limiter based on Schottky diode is presented. The proposed circuit is a zero bias power limiter built by associating a transmission line in parallel to a four Schottky rectifier bridge circuit. The first circuit using a single stage rectifier is analyzed and simulated. To improve this single stage, a second and final limiter is designed with two stages rectifier. Simulation results for the final circuit show an ideal limiter behavior and good performance of limiting rate up to 20dB for a threshold input power varying from 5 dBm to 30 dBm. While insertion loss remains low at small signal

A Miniature L-slot Microstrip Printed Antenna for RFID

This work presents a miniature microstrip antenna at 2.45 GHz by using the slots technique. This microstrip antenna is fed by a CPW technique and designed for RFID reader system on FR4 substrate. A size reduction equal to 66.6% has been obtained compared to the conventional rectangular microstrip antenna. The total area of the final circuit is 19x31 mm2. The validated antenna has good matching input impedance with a stable radiation pattern, a loss return of -40 dB, and a gain of 1.78 dBi, a prototype of the proposed antenna has been fabricated and measured

A novel microstrip low pass filter based on ring topology

This paper describes the design of a new configuration of a low pass filter (LPF). This filter structure is based on a ring topology. The proposed LPF is miniature and low cost because it is mounted on FR4 substrate. The validation of this circuit into simulation was based on many optimization methods integrated in ADS "Advanced Design System" and some tuning methods. At the end, the fabrication and the test of the final circuit permits to have a good agreement between simulation and measurement results reaching a low pass behavior. The proposed filter has an area of 25x25 mm2, with a cutoff frequency of 2GHz and good performances in term of insertion losses, which are around -0.127 dB in the whole bandwidth and a high stopband

A New Design of a CPW-Fed Dual-Band Monopole Antenna for RFID Readers

This paper comes with a new dual-band planar monopole antenna fed by Coplanar Waveguide (CPW) line designed for RFID readers and it operates at 2.45 GHz, 5.80 GHz. This antenna is designed with reasonable gain, low profile and low cost production. The designed antenna based on theoretical equations is simulated and validated by using ADS from Agilent technologies and CST Microwave Studio electromagnetic solvers. A parametric study of the proposed antenna has been carried out by optimizing some critical parameters. The antenna has a total area of 35×38 mm2 and mounted on an FR4 substrate with dielectric permittivity constant 4.4 and thickness of 1.6 mm and loss tangent 0.025. The comparison between simulation and measurement results permits to validate the final achieved antenna structure in the desired RFID frequencies bands. Details of the proposed antenna design and both simulated and experimental results are described and discusse

A novel structure of a wideband zero-bias power limiter for ISM band

In this paper, a new broadband microwave microstrip power limiter is designed and realized. The Power Limiter is based on microstrip technology integrating a Zero Bias commercial Schottky diodes HSMS2820.The power limiter is optimized and validated in two steps. The enhanced and achieved circuit is obtained by concatenating two basic structures. The final circuit was validated into simulation by using ADS solver. Finally this circuit was realized and tested. Simulation and measurement results are in a good agreement. The final circuit achieves a limiting rate of 14 dB with a threshold input power level of 0 dBm until a maximum input power level of 30 dBm

A novel configuration of a miniature microstrip low pass filter

In this paper, we will present the design and the fabrication of a new configuration of a microstrip low pass filter. The originality of this work is that the final proposed filter is miniature and presents good performances in term of insertion loss around -0.15dB and it has a wide stopband until 7 GHz. The design of such filter is based on the use of optimization and tuning methods integrated into two electromagnetic solvers ADS and CST-MWS. After the fabrication, the final LPF structure is tested which give a good agreement between simulation results for the both solvers and measurement responses. The proposed filter has a cutoff frequency of 2.33 GHz which makes it suitable for many standards like DCS "Digital communication system", and UMTS "Universal Mobile Telecommunications System" bands. The final circuit presents an area of 20x20mm2

A New Compact CPW-Fed Dual-Band Uniplanar Antenna for RFID Applications

In this paper a new dual-band uniplanar monopole antenna fed by Coplanar Waveguide (CPW) line is proposed for Radio Frequency Identification (RFID) applications. The antenna structure includes a CPW fed line and the dual-band operation is achieved from the G-shaped folded antenna. The antenna parameters have been investigated and optimized by using CST Microwave Studio. To validate the CST Microwave Studio results before the antenna achievement, we have conducted another study by using ADS. The final circuit was achieved, measured and validated. Experimental results show that the proposed antenna with compact size of 30*45 mm2 is simple in design and compact in size. It exhibits broadband impedance matching, consistent omnidirectional radiation patterns and appropriate gain characteristics suitable for the microwave RFID applicartions

A Dual-band Microstrip Slotted Antenna for UHF and Microwave RFID Readers

In this paper a new and simple dual-band microstrip slot antenna design combined with two inverted L-shaped slots integrated in the radiating patch is presented. This antenna is suitable for operating at 915 MHz and 2.45 GHz in order to cover the Radio Frequency Identification (RFID) frequencies bands. By optimizing the structure design, good performances in term of return loss radiation pattern and efficiency are achieved. The simulation results were obtained by using ADS and CST Microwave Studio electromagnetic solvers. The proposed antenna is mounted on an FR4 substrate with dielectric permittivity constant 4.4, thickness of 1.6 mm and loss tangent of 0.025 and a total area of 48×47 mm2. The design methodology used to achieve the dual-band antenna and both experimental, simulated results are presented