A polarization-reconfigurable filtering antenna system: a visual approach to investigating the bandwidth of transmission lines with non-z0 impedance [education column]

2013 ◽  
Vol 55 (6) ◽  
pp. 197-235 ◽  
Author(s):  
Theng Huat Gan ◽  
Zaifeng Yang ◽  
Eng Leong Tan ◽  
Jun Xian Lim ◽  
Minh Quan Huynh ◽  
...  
Keyword(s):  
Transmission Lines ◽  
Antenna System ◽  
System A ◽  
Visual Approach

scholarly journals Frequency Reconfigurable Antenna using PIN Diodes

2019 ◽  
Vol 9 (1S5) ◽  
pp. 66-70
Keyword(s):  
Antenna System ◽  
Reconfigurable Antenna ◽  
Multiple Frequency ◽  
Pin Diodes ◽  
Wireless Applications ◽  
System A ◽  
Ansoft Hfss ◽  
System Requirements ◽  
Simulation Results ◽  
Frequency Reconfigurable Antenna

With the increase in wireless applications, there is a need for compact antennas that adapt their behavior with changing system requirements or environmental conditions. Here adapt implies the antenna should be able to alter operating frequencies, impedance bandwidths, polarizations, radiation patterns. These all features are provided by the “Reconfigurable antenna”. The important feature of reconfigurable antenna is that, they provide the same throughput as a multi-antenna system. A compact frequency reconfigurable antenna is designed with the aid of Ansoft HFSS that provides multiple frequency bands. This is achieved by using electrical switches such as PIN diodes. Depending on state of switches different operating frequencies are obtained. The switches placed on the antenna elements are powered wirelessly by the antenna itself. The design, geometries and simulation results of a frequency reconfigurable antenna are presented in this report. Further advancements are to be done for this structure to achieve polarization and radiation pattern re-configurability.

scholarly journals Evaluation of Beamforming and Direction Finding for a Phased Array HF Ocean Current Radar

2016 ◽  
Vol 33 (12) ◽  
pp. 2599-2613 ◽  
Author(s):  
Wei Wang ◽  
Eric W. Gill
Keyword(s):  
Radial Velocity ◽  
Phased Array ◽  
Environmental Parameters ◽  
Direction Finding ◽  
Antenna System ◽  
Optimal Choice ◽  
Ocean Current ◽  
Music Algorithm ◽  
Phased Array Antenna ◽  
System A

AbstractThe errors in the current radial velocity measurements are examined using Bartlett beamforming and Multiple Signal Classification (MUSIC) direction-finding algorithms with a linear phased array antenna system. A variety of radar and environmental parameters are examined. Suggestions for the optimal choice of operating parameters are proposed. The MUSIC algorithm has shown promising performance in current measurement when beamforming is used to first establish the maximum current velocity. Comparisons of radar field data and current meter measurements show RMS radial velocity differences in magnitude of 7.44 and 6.64 cm s−1 for the Bartlett beamforming and MUSIC–Bartlett algorithms, respectively. The results indicate that there are advantages to using a MUSIC–Bartlett approach in operational applications.

Timing Acquisition Based on Cooperation Verification of Distributed Receive Antennas in Linear Cell

2013 ◽  
Vol 340 ◽  
pp. 551-556
Author(s):  
Chao Jin Qing ◽  
Jin Cheng Wei ◽  
You Xi Tang ◽  
Jin Lian Liu
Keyword(s):  
Time Delays ◽  
Antenna System ◽  
Distributed Antenna System ◽  
Timing Acquisition ◽  
Verification Method ◽  
Threshold Detection ◽  
System A ◽  
Distributed Antenna ◽  
The Difference ◽  
Linear Cell

To improve the probability of correct acquisition for distributed antenna system, a cooperation verification method of distributed antennas is proposed. In the flat Rayleigh channels of linear cell, the difference of time-delays is firstly exploited to compose a pre-condition for cooperation. Then, the timing acquisition based on threshold detection is performed at each distributed antenna. For eliminating part of acquisition errors, the cooperation verification is introduced into the timing acquisition according to pre-condition. Analysis and simulation results verify the correctness of the proposed method.

A Vector-Sensing Antenna System: A high-frequency, vector-sensing array based on the two-port loop antenna element.

2016 ◽  
Vol 58 (6) ◽  
pp. 57-63 ◽  
Author(s):  
John H. Meloling ◽  
John W. Rockway ◽  
Michael P. Daly ◽  
Aldo R. Monges ◽  
Jeffery C. Allen ◽  
...  
Keyword(s):  
High Frequency ◽  
Antenna System ◽  
Loop Antenna ◽  
Antenna Element ◽  
Frequency Vector ◽  
System A

TDR Analysis on Short Transmission Lines

2014 ◽  
Author(s):  
Nicholas Konkol
Keyword(s):  
Failure Analysis ◽  
Transmission Line ◽  
Transmission Lines ◽  
Time Domain ◽  
System Level ◽  
Electrical Failure ◽  
Advantages And Disadvantages ◽  
System A ◽  
Time Domain Reflectometer ◽  
Line Analysis

Abstract Transmission line analysis is done in electrical failure analysis labs in order to find root causes that result in system level failures. After a fault is narrowed to a particular signal in a system, a Time Domain Reflectometer (TDR) can be used to analyze the physical transmission line associated with the signal. The transmission lines on smartphones often have inaccessible signal vias, few or no ground vias, probe points that are difficult to see, and short transmission lines. One solution that can alleviate these problems is to design a TDR Accessory Card. This paper discusses the processes involved in testing long and short transmission lines, providing the comparison between the expected and actual TDR measurement and the advantages and disadvantages of TDR, explaining four main points for using a TDR Accessory Card and two reasons for not using the TDR Accessory Card.

Integrated Analysis and Optimization of the Large Airborne Radome-Enclosed Antenna System

2020 ◽  
Vol 35 (10) ◽  
pp. 1192-1199
Author(s):  
Chang Zhai ◽  
Xunwang Zhao ◽  
Zhongchao Lin ◽  
Yu Zhang
Keyword(s):  
Domain Decomposition ◽  
Decomposition Method ◽  
Optimization Problems ◽  
Domain Decomposition Method ◽  
Random Access ◽  
Antenna System ◽  
Adaptive Mutation ◽  
Integrated Analysis ◽  
Optimization Strategy ◽  
System A

In order to realize integrally analysis and optimization of the large airborne radome-enclosed antenna system, a novel optimization strategy is proposed based on an overlapping domain decomposition method by using higher-order MoM and out-of-core solver (HO-OC-DDM), and combining with adaptive mutation particle swarm optimization (AMPSO). The introduction of parallel out-of-core solver and DDM can effectively break the random access memory (RAM) limit. This strategy can decompose difficult-to-solve global optimization problems into multi-domain optimization problems by using domain decomposition method. Finally, take airborne Yagi antenna system as an example, the numerical results show that the design of large airborne radome-enclosed antenna system based on the proposed strategy is convenient and effective.

Composite Severity Indices Based Contingency Management of Power System: A Comparative Study

2016 ◽  
Vol 26 ◽  
pp. 132-141 ◽  
Author(s):  
Akanksha Mishra ◽  
Gundavarapu Venkata Nagesh Kumar
Keyword(s):  
Power System ◽  
Transmission Lines ◽  
Contingency Management ◽  
Probabilistic Approach ◽  
Proper Solution ◽  
Contingency Analysis ◽  
System A ◽  
Composite Indices ◽  
Line Overload ◽  
Ranking Technique

Severity assessment of transmission lines is a very important aspect of contingency analysis of a power system. Thereafter, a proper solution needs to be provided to ensure a secured power supply. In this paper, rapid contingency ranking technique (RCRT) has been introduced for the contingency assessment of a power system. Several composite indices have been designed by forming different combinations of line overload indices and voltage stability indices and the results have been compared. Deterministic and probabilistic approach have been used for the placement of IPFC and the results have been compared. While, the probability approach protects the system against most of the contingencies, the deterministic approach protects the system against the severe-most contingency. Thereafter, the IPFC is tuned using the differential evolution method. A multi-objective function has been formulated for tuning the device. The use of IPFC to overcome the post-contingency problems has been reinforced by implementing the proposed strategy on an IEEE 57 bus system.

scholarly journals Investigation of the method of improving the interference protection of axisymmetric antennas in the anterior semispace

2019 ◽  
Vol 27 (1) ◽  
pp. 89-94
Author(s):  
V. I. Magro ◽  
V. M. Morozov
Keyword(s):  
Focal Point ◽  
Antenna System ◽  
Geometric Optics ◽  
System A ◽  
Working Frequency ◽  
Axis Of Symmetry ◽  
The Difference ◽  
Frequency Changes ◽  
Diffraction Effects ◽  
Focusing Properties

The method of improving the interference protection of axisymmetric antennas is considered. An experimental study of the focusing properties of a zonal antenna is carried out in this work. Such a zonal antenna acts as a shading screen and is located in the aperture of an axisymmetric antenna. The combination of a shading screen with an axisymmetric antenna can significantly reduce the level of side lobes in the anterior semi-space, and as a result, significantly improve the immunity of the antenna system. A zonal antenna for 40 GHz frequency is manufactured. The field distribution along the axis of symmetry for different numbers of rings in the antenna is experimentally investigated. The number of rings varied from 1 to 5. The focusing properties of the zonal antenna are studied at the change of operating frequency. The position of the focus is investigated when the working frequency changes in relation to the calculated frequency. It is established that the experimentally found focal point does not coincide with the focal point found by geometric optics. For a zonal antenna with three rings, the difference between the experimentally found focus and the focus found by the law of geometric optics is 0.1%. The distribution of the field in planes perpendicular to the focal line is investigated. It is established that an increase in the number of rings in a zonal antenna to more than five leads to diffraction effects which impair the focusing properties of the zonal antenna. At the same time there is a "deliquescence" of the wave beam in the focus. These studies allow us to determine the boundaries of the working frequency of a complex antenna system.

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