Notice of Retraction: The Bounded Phase Property of the Time-Reversal Current Transfer Function for the Locations of Longitudinal Defects in Transmission Lines

2018 ◽  
Vol 60 (6) ◽  
pp. 1987-1992
Author(s):  
Enza Pellegrino ◽  
Antonio Orlandi ◽  
Carlo Olivieri
Keyword(s):  
Transfer Function ◽  
Transmission Lines ◽  
Time Reversal ◽  
Current Transfer ◽  
Phase Property

scholarly journals Theory and Design of a Flexible Two-Stage Wideband Wilkinson Power Divider

Electronics ◽  
2021 ◽  
Vol 10 (17) ◽  
pp. 2168
Author(s):  
Antra Saxena ◽  
Mohammad Hashmi ◽  
Deepayan Banerjee ◽  
Muhammad Akmal Chaudhary
Keyword(s):  
Transfer Function ◽  
Transmission Lines ◽  
Short Circuit ◽  
Wide Band ◽  
Power Divider ◽  
Design Parameters ◽  
Two Stage ◽  
Quarter Wave ◽  
Band Pass ◽  
Wilkinson Power Divider

This article presents the design scheme of a wideband Wilkinson Power Divider (WPD) with two-stage architecture utilizing quarter-wave transmission lines and short-circuit stubs. The bandwidth of the proposed WPD is flexible and can be controlled using the design parameters. The proposed design achieves excellent isolation between output ports in addition good in-band performance. The analysis of the proposed circuit results in a simplified transfer function which is then equated with a standard band-pass transfer function to determine the parameters of transmission lines, stub’s impedances, and the value of the isolation resistors. Furthermore, it is also demonstrated that a simple alteration in the proposed circuit enables the design of a wideband DC isolated WPD that maintains a good in-band and isolation performance. A number of case studies have been included to highlight the flexibility of the proposed design. Two distinct prototypes are developed on different boards to demonstrate the wideband performance of the proposed design. An excellent agreement between the experimental and measured results for both the designs over a wide band including very good isolation between ports validate the proposed design.

A Time Reversal Imaging Method without Relying on Transfer Function for Impact and Damage Monitoring of Composite Structures

2013 ◽  
Vol 330 ◽  
pp. 542-548
Author(s):  
Lei Qiu ◽  
Shen Fang Yuan ◽  
Tian Xiang Huang
Keyword(s):  
Transfer Function ◽  
Time Reversal ◽  
Lamb Wave ◽  
Composite Structures ◽  
Structural Damage ◽  
Composite Panel ◽  
Synthesis Process ◽  
Propagation Mechanism ◽  
Imaging Method ◽  
Phase Synthesis

Composite structures adopted in aerospace structures have attracted much interest to structural health monitoring (SHM) for localization of impact and damage positions due to their poor impact resistance properties. Propagation mechanism and frequency dispersion characteristics of Lamb wave signals on composite structures are more complicated than that on simple aluminum plates. Recently, much attention has been paid to the research of time reversal focusing method because this method shows a promising advantage to give a focusing image of the structural damage, improve the signal-to-noise ratio and compensate the dispersion of Lamb wave signals. In this paper, aiming at developing a practical method for on-line localization of impact and damage on aircraft composite structures which can take advantage of time reversal focusing and does not rely on the transfer function, a new phase synthesis based time reversal focusing method is proposed. Impact and damage images are given out directly through time reversal focusing based on phase synthesis process of the signals. A SHM demonstration system is built on a composite panel of an aircraft wing box with many bolt holes and stiffeners using the phase synthesis based time reversal focusing method. The demonstration results show that this method can estimate the positions of impact and damage efficiently with a low sensitivity of velocity errors.

scholarly journals Assessment of 50%-Propagation-Delay for Cascaded PCB Non-Linear Interconnect Lines for the High-Rate Signal Integrity Analysis

2013 ◽  
Vol 2 (1) ◽  
pp. 1
Author(s):  
T. Eudes ◽  
B. Ravelo ◽  
R. Al-Hayek
Keyword(s):  
Transfer Function ◽  
Transmission Lines ◽  
Time Domain ◽  
High Speed ◽  
Signal Integrity ◽  
Frequency Dispersion ◽  
Propagation Delay ◽  
High Rate ◽  
Propagation Time ◽  
Time Assessment

This paper presents an enlarged study about the 50-% propagation-time assessment of cascaded transmission lines (TLs). First and foremost, the accurate modeling and measurement technique of signal integrity (SI) for high-rate microelectronic interconnection is recalled. This model is based on the reduced transfer function extracted from the electromagnetic (EM) behavior of the interconnect line RLCG-parameters. So, the transfer function established takes into account both the frequency dispersion effects and the different propagation modes. In addition, the transfer function includes also the load and source impedance effects. Then, the SI analysis is proposed for high-speed digital signals through the developed model. To validate the model understudy, a prototype of microstrip interconnection with w = 500 µm and length d = 33 mm was designed, simulated, fabricated and tested. Then, comparisons between the frequency and time domain results from the model and from measurements are performed. As expected, good agreement between the S-parameters form measurements and the model proposed is obtained from DC to 8 GHz. Furthermore, a de-embedding method enabling to cancel out the connectors and the probe effects are also presented. In addition, an innovative time-domain characterization is proposed in order to validate the concept with a 2.38 Gbit/s-input data signal. Afterwards, the 50-% propagation-time assessment problem is clearly exposed. Consequently an extracting theory of this propagation-time with first order RC-circuits is presented. Finally, to show the relevance of this calculation, propagation-time simulations and an application to signal integrity issues are offered.

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