scholarly journals Precise-Orientation-Beamforming Scheme for Wireless Communications between Buoys

2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
Zhihui Wu ◽  
Bin Zhang ◽  
Fengzhong Qu ◽  
Ye Cheng ◽  
Zhujun Zhang ◽  
...  
Keyword(s):  
Antenna Array ◽  
Second Step ◽  
Destination Node ◽  
Regular Waves ◽  
Phased Array Antenna ◽  
Whole Process ◽  
Communication Distance ◽  
A New Technique ◽  
Unstable Position ◽  
Beamforming Algorithm

Utilizing wireless sensor network (WSN) to monitor the marine environment is one of the major techniques in oceanographic monitoring, and how to increase the limited communication distance between the buoys in WSN has become a hot research issue. In this paper, a new technique called precise-orientation-beamforming (POB) which uses the beamforming algorithm to increase the communication distance between buoys is presented. As was widely applied in the radar and sonar, the beamforming method was not used to extend the communication distance between buoys so far. The POB method overcomes the unstable position of buoys caused by waves by implementing the orientation filter. The whole process includes two steps: First, the real-time attitude of the antenna array is calculated by the orientation filter. With the known relative direction of the destination node to the antenna array, the second step is to control phased array antenna beamforming parameters, directing the beam at the destination node. The POB scheme has been simulated under the condition of regular waves. The results reveal that POB provides significant power gains and improves the distance between two communicating nodes effectively.

A New Technique for Scan Chain Failure Diagnosis

2002 ◽  
Author(s):  
Ruifeng Guo ◽  
Srikanth Venkataraman
Keyword(s):  
Hold Time ◽  
Failure Diagnosis ◽  
Second Step ◽  
Fault Type ◽  
Transition Faults ◽  
Input Side ◽  
Output Side ◽  
A New Technique ◽  
Scan Chain ◽  
Diagnostic Resolution

Abstract In this paper, we present a scan chain fault diagnosis procedure. The diagnosis for a single scan chain failure is performed in three steps. The first step uses special chain test patterns to determine both the faulty chain and the fault type in the faulty chain. The second step uses a novel procedure to generate special test patterns to identify the suspect scan cell within a range of scan cells. Unlike previously proposed methods that restrict the location of the faulty scan cell only from the scan chain output side, our method restricts the location of the faulty scan cell from both the scan chain output side and the scan chain input side. Hence the number of suspect scan cells is reduced significantly in this step. The final step further improves the diagnostic resolution by ranking the suspect scan cells inside this range. The proposed technique handles both stuck-at and timing failures (transition faults and hold time faults). The experimental results based on simulation and silicon units for several products show the effectiveness of the proposed method.

Research on the Conformal Phased-Array Antenna

2014 ◽  
Vol 685 ◽  
pp. 324-327
Author(s):  
Shuang Zhao ◽  
Yu Bo Yue
Keyword(s):  
Mathematical Model ◽  
Antenna Array ◽  
Phased Array ◽  
Design Method ◽  
Array Antenna ◽  
Phased Array Antenna ◽  
Conformal Antenna ◽  
Conformal Array ◽  
Design Requirements ◽  
The Mathematical Model

The mathematical model of conformal antenna array is the premise and basis of the conformal array antenna signal processing. Based on the analysis of the antenna array, a design method for adjusting the direction of the conformal array antenna is proposed. Through simulation, the pattern of antenna meets the actual needs of the project and it reaches pre design requirements.

Microstrip antenna array with an inclined surface and an increased distance between patches

2021 ◽  
Author(s):  
A.R. Bestugin ◽  
M.B. Ryzhikov ◽  
Yu.A. Novikova ◽  
I.A. Kirshina
Keyword(s):  
Antenna Array ◽  
Mutual Influence ◽  
Weather Radar ◽  
Main Beam ◽  
Weather Radars ◽  
Weather Events ◽  
A New Technique ◽  
The Impact ◽  
Inclined Surface ◽  
Inclined Beam

A new technique for designing a path antenna array with an inclined beam is proposed. It boils down to finding a certain combination of parameters that use the secondary main maxima of the diagram as the main beam and at the same time guarantee the greatest distance between the emitters that does not yet lead to the occurrence of secondary main maxima in the antenna radiation pattern. This simplifies the geometric structure of the antenna, reduces its cost, simplifies the microstrip power system, and reduces the mutual influence of individual elements in the antenna array. To combine the possibility of reducing the radio visibility of the antenna by changing the orientation of the antenna opening while maintaining its emissivity in a given viewing plane, it is possible to implement an antenna with a main beam deviated from the normal. The efficiency of reducing backscattering for the radar range due to the tilt of the antenna outside the operating frequency band of the antenna is investigated. Thus, when mechanically scanning the antenna, due to the fact that the main beam of the antenna array is deviated from the normal, it is possible to achieve a significant reduction in the average backscattering pattern of at least 25 dB. It is known that improving the safety of small aircraft at low altitudes, as well as on take-off and landing sites, is directly related to the introduction of a small weather radar, which warns of the presence of dangerous phenomena along the flight path: thunderstorms, turbulence, and wind. When the onboard radar is operating in thunderstorm or turbulence detection modes, the presence of re-reflections from the Earth's surface can lead to the formation of false areas that are dangerous for flight. You can reduce the likelihood of such false zones by spatial filtering of interference from the ground using antennas with a low level of side lobes in the lower hemisphere. The relevance of the problem of reducing the influence of interference from the ground on the correctness of the wind speed estimation in the weather radar is confirmed by publications. They are focused on filtering interference from the earth's surface in the frequency domain for ground-based weather radars or for airborne radars, but by the main beam of the alignment diagram and the rule of its elevation to avoid touching the ground. The second part of the research is devoted to reducing the influence of re-reflections from the earth on the probability of forming false areas of dangerous weather events in the weather radar. To reduce the impact of interference, it is proposed to install an antenna with an upward tilt.

Technology Research about Beamforming of Multiple-Beam Array Antenna

2014 ◽  
Vol 568-570 ◽  
pp. 1336-1339
Author(s):  
Gao Feng Pan ◽  
Sheng Liang ◽  
Hao Xue ◽  
Guang Ming Xu ◽  
Xing Yuan Xu
Keyword(s):  
Theoretical Basis ◽  
Phased Array ◽  
Array Antenna ◽  
Engineering Practice ◽  
Technology Research ◽  
Phased Array Antenna ◽  
Key Technology ◽  
Beam Array ◽  
Low Sidelobe ◽  
Beamforming Algorithm

Active phased array antenna (APAA) can realize multi-object tracking and the beamforming is the key technology. Multi-area array and the implement method of its beamforming are introduced in this paper. Coordinated transformation formula is offered based on engineering practice and beams are synthesized by beamforming algorithm of low sidelobe. Following simulation shows results about beam coverage, those provide theoretical basis for the further research.

Double incision and snare resection in symptomatic Zenker’s diverticulum: a modification of the stag beetle knife technique

Endoscopy ◽  
2017 ◽  
Vol 50 (02) ◽  
pp. 137-141 ◽  
Author(s):  
Stefan Gölder ◽  
Juliane Brueckner ◽  
Alanna Ebigbo ◽  
Helmut Messmann
Keyword(s):  
Endoscopic Treatment ◽  
Second Step ◽  
Zenker’S Diverticulum ◽  
Treatment Technique ◽  
Oral Nutrition ◽  
Cricopharyngeal Muscle ◽  
Zenker's Diverticulum ◽  
Step Procedure ◽  
A New Technique

Abstract Background and study aim Relief from dysphagia and regurgitation are the main goals of therapy in symptomatic Zenker’s diverticulum. Flexible endoscopic treatment has proved to be an effective and safe method in control of these symptoms. The aim of our study was to further improve the resection of the cricopharyngeal muscle using a new technique, the double incision and snare resection (DISR) procedure, to reduce the recurrence rate. Patients and methods From February 2016 to April 2017, 16 patients were treated with 18 DISR procedures at our institution. The symptoms of the patients were recorded by a seven-item questionnaire prior to treatment, and re-evaluation was scheduled at 1 and 6 months after treatment. Results The median age was 70 years (range 55 – 85), and 10 patients were men (62 %). The median size of the diverticulum was 20 mm (range 5 – 40 mm), and the DISR procedure was performed in 28 minutes (range 20 – 47 minutes), with no major postinterventional complications. All patients re-started oral nutrition on the day after the intervention; a gastric tube was not required. The median follow-up was 3 months (range 1 – 15 months). Two patients received a planned second-step procedure, one because of a very large cricopharyngeal muscle and one because of a cyst inside the Zenker’s bridge. Although one patient suffered from mild recurrence of symptoms, she refused a second treatment. All other patients were free of symptoms after treatment. Conclusions The DISR procedure is a new endoscopic treatment technique that safely and reproducibly offers relief from symptomatic Zenker’s diverticulum.

A novel adaptive beamforming algorithm for antenna array CDMA systems with strong interferers

2002 ◽  
Vol 51 (5) ◽  
pp. 808-816 ◽  
Author(s):  
Seungwon Choi ◽  
Jinho Choi ◽  
Heung-Jae Im ◽  
Byungcho Choi
Keyword(s):  
Antenna Array ◽  
Adaptive Beamforming ◽  
Cdma Systems ◽  
Beamforming Algorithm

Prevention of Black Hole Attacks on Mobile Ad Hoc Networks Through Intrusion Detection Systems

2019 ◽  
Vol 15 (2) ◽  
pp. 73-91
Author(s):  
Hicham Zougagh ◽  
Noureddine Idboufker ◽  
Rida Zoubairi ◽  
Rachid El Ayachi
Keyword(s):  
Routing Protocol ◽  
Ad Hoc Network ◽  
Ad Hoc ◽  
Mobile Ad Hoc Network ◽  
Destination Node ◽  
Intermediate Node ◽  
Detection Systems ◽  
Mobile Ad Hoc ◽  
A New Technique ◽  
Hoc Networks

In a mobile ad hoc network, a source node must rely on intermediate nodes to forward its packets along multi-hop routes to the destination node. The performance of a mobile ad hoc network is closely related to the capability of the implemented routing protocol to adapt itself to unpredictable changes of topology network and link status. One of these routing protocols is optimized link state routing protocol which assumes that all nodes are trusted. However, in a hostile environment, the OLSR is known to be vulnerable to various kinds of malicious attacks. Without having any control on packet forwarding, an intermediate node can behave selfishly or maliciously to drop packets going through it. Therefore, in this article, the authors propose a new technique for the selection of multipoint relays whose aims to provide each node the ability to select alternative paths in order to reach any destination two hops away.

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