Efficiency and Accuracy of Computer Simulations of the Input Impedance of Wide-Band Antennas

2001 ◽  
Author(s):  
Pekka Eskelinen ◽  
Arvi Serkola ◽  
Timo Pulkkinen
Keyword(s):  
Computer Simulations ◽  
Input Impedance ◽  
Wide Band

Notice of Retraction: Direct Characterization of Grounding System Wide-Band Input Impedance

2018 ◽  
Vol 60 (1) ◽  
pp. 292-293 ◽  
Author(s):  
Babak Honarbakhsh ◽  
Hamidreza Karami ◽  
Keyhan Sheshyekani
Keyword(s):  
Input Impedance ◽  
Wide Band ◽  
Grounding System

A Broadband Impedance-Matching Method for Microstrip Patch Antennas Based on the Bode-Fano Theory

Frequenz ◽  
2018 ◽  
Vol 72 (7-8) ◽  
pp. 373-380
Author(s):  
Christopher M. A. Bonenberger ◽  
Klaus W. Kark
Keyword(s):  
Input Impedance ◽  
Low Cost ◽  
Impedance Matching ◽  
Single Mode ◽  
Wide Band ◽  
Low Complexity ◽  
Microstrip Antennas ◽  
Patch Antennas ◽  
Linearly Polarized ◽  
Matching Techniques

Abstract Considering the narrow bandwidth of microstrip antennas, but also their applicability in upcoming technologies, this paper addresses the problem of wide-band matching, the theoretical bounds on the matching bandwidth and low-cost and low-complexity matching strategies. In this context the Bode-Fano bounds of single mode, linearly polarized aperture-coupled microstrip antennas is evaluated, optimized and compared to the theoretical bounds on matching bandwidth of other common feeding technologies. A detailed study of the input impedance of aperture-coupled patch antennas shows how to widen the Fano bounds. Based on this, a straight-forward and effective method to optimize the Fano bound is given. After optimization of the antennas input impedance, basic matching techniques can be applied, to exploit the enlarged bandwidth potential. As an example a $\lambda/4$-transformer as matching element is proposed. Design equations and simulation and measurement results of X-band prototypes are given as verification.

Design and Simulation of a Wide-Band LPDA

2014 ◽  
Vol 687-691 ◽  
pp. 4024-4028
Author(s):  
Si Hao Wang ◽  
Yong Li ◽  
Shen Ke Zhang
Keyword(s):  
Performance Analysis ◽  
Computer Simulations ◽  
Frequency Band ◽  
Optimization Design ◽  
Low Cost ◽  
Wide Band ◽  
Simulation Software ◽  
Simulation Results ◽  
Design Construction ◽  
A Performance

A reconfigurable wideband Log-Periodic Dipole Array (LPDA) is here in introduced. Built utilizing low cost it can cover frequencies from 0.2GHz to 2GHz, through the discrete adjustment of its elements. The gain of antenna in a given frequency band of operation can also be changed by the reconfiguration of its elements. The design, construction and testing processes are discussed and a performance analysis is made based on computer simulations. In this paper simulation software HFSS is used to get the optimization design of LPDA, and the simulation results are agree with the experimental dates appropriately.

Seven-colour photometry at the Geneva Observatory

1966 ◽  
Vol 24 ◽  
pp. 262-266 ◽  
Author(s):  
M. Golay
Keyword(s):  
Wide Band ◽  
Electric System ◽  
Band Type

During the last 5 years, we have developed a seven-colour photometry at the Geneva Observatory. Our multicolour photo-electric system is of a wide-band type; the bandwidth being about 500Å for four filters. The three others are similar to theUBVsystem. In Table 1 we give the filter combinations used in our photometry (1).

A High Resolution Study of G.P. Zones in Aluminum - 4.2 at % Silver

1982 ◽  
Vol 40 ◽  
pp. 722-723 ◽  
Author(s):  
R. Gronsky
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Computer Simulations ◽  
Structural Characteristics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Resolution Study

The phenomenon of clustering in Al-Ag alloys has been extensively studied since the early work of Guinierl, wherein the pre-precipitation state was characterized as an assembly of spherical, ordered, silver-rich G.P. zones. Subsequent x-ray and TEM investigations yielded results in general agreement with this model. However, serious discrepancies were later revealed by the detailed x-ray diffraction - based computer simulations of Gragg and Cohen, i.e., the silver-rich clusters were instead octahedral in shape and fully disordered, atleast below 170°C. The object of the present investigation is to examine directly the structural characteristics of G.P. zones in Al-Ag by high resolution transmission electron microscopy.

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