scholarly journals Minimum Group Velocity, Maximum Amplitude and Quarter Wave-length Law.

1957 ◽  
Vol 5 (1) ◽  
pp. 43-50 ◽  
Author(s):  
KYOZI TAZIME
Keyword(s):  
Group Velocity ◽  
Wave Length ◽  
Maximum Amplitude ◽  
Minimum Group ◽  
Quarter Wave

Dispersive properties of a fluid layer overlying a semi-infinite elastic solid*

1954 ◽  
Vol 44 (3) ◽  
pp. 493-512
Author(s):  
Ivan Tolstoy
Keyword(s):  
Elastic Body ◽  
Group Velocity ◽  
Normal Mode ◽  
Fundamental Mode ◽  
Fluid Layer ◽  
Elastic Solid ◽  
Numerical Results ◽  
Stoneley Wave ◽  
Wave Velocities ◽  
Minimum Group

Abstract The dispersive properties of waves propagating in a system consisting of a fluid layer overlying a semi-infinite elastic body are investigated by means of new formulas for the group velocity. The distribution of stationary values of the group velocity is examined in the light of these formulas and of numerical results. Also it is shown that the minimum group velocity of the fundamental mode may belong either to the normal-mode branch or to the Stoneley-wave branch, depending on the contrast in wave velocities between the two media.

An LTCC Based Filter and Front End Module using Heterogeneous Dielectrics

2006 ◽  
Vol 3 (3) ◽  
pp. 129-135 ◽  
Author(s):  
Jun Chul Kim ◽  
Dongsu Kim ◽  
Hyun Min Cho ◽  
Jong Chul Park ◽  
Nam Kee Kang
Keyword(s):  
Power Amplifier ◽  
Bandpass Filter ◽  
Wave Length ◽  
Signal Delay ◽  
Ceramic Substrates ◽  
Front End ◽  
Quarter Wave ◽  
Front End Module ◽  
Signal Delay Time ◽  
Shunt Capacitor

This paper presents a multi-layered bandpass filter (BPF) and a power amplifier module (PAM) integrated with a SAW duplexer based on heterogeneous ceramic substrates. The heterogeneous substrates are composed of two different ceramic layers with εr = 7.4 and 17.5 in order to take advantage of their own properties. In the PAM substrate, a DC blocking capacitor and a shunt capacitor for an output matching network of a power amplifier are embedded with a material of εr = 17.5 to reduce occupied areas of the capacitors. On the other hand, a quarter-wave-length stripline and RF chokes are realized with a material of εr = 7.4 to reduce signal delay time. In the multi-layered BPF, a coupled stripline and a high shunt capacitor are embedded with materials of εr = 7.4 and 17.5, respectively, resulting in improved spurious characteristics.

A High Power, GaN, Quarter-Wave Length Switch for X-Band Applications

2018 ◽  
Author(s):  
Onur Memioglu ◽  
Duygu Isinsu Turan ◽  
Fatih Kocer ◽  
Ozlem Aydin Civi
Keyword(s):  
High Power ◽  
Wave Length ◽  
X Band ◽  
Quarter Wave

Non-quarter-wave-length matching transformer

2014 ◽  
Vol 57 (7) ◽  
pp. 328-330
Author(s):  
V. Bieliavtsev ◽  
V. Pryimak ◽  
A. Markus
Keyword(s):  
Wave Length ◽  
Quarter Wave ◽  
Matching Transformer

scholarly journals Doubling of Group Velocity near the Coast due to Storm Surge, Tides or Tsunami: An Analytical Study

2021 ◽  
Vol 9 (VI) ◽  
pp. 567-574
Author(s):  
Ramkrishna Datta
Keyword(s):  
Group Velocity ◽  
Storm Surge ◽  
Wave Velocity ◽  
Deep Sea ◽  
Analytical Study ◽  
Perturbation Technique ◽  
Wave Length ◽  
Coastal Region ◽  
Slight Variation ◽  
Harmonic Waves

Tsunami may cause due to storm surge, earthquake at coastal region or at under the sea (obviously Hypocenter of earthquake must be within the earth’s crust or below). Each cases a wave packet which develops a set of simple harmonic motion of different wave lengths. These simple harmonic waves have been analyzed analytically. The velocity of propagation of waves depends upon the wave lengths. So the waves of nearly equal wave lengths can be considered as a group. This group of waves will propagate with nearly equal velocity which is known as group velocity. On considering two consecutive simple harmonic waves of same amplitude, we can find two equations describing simple harmonic motions having slightly different wave lengths and time periods. The combination of these two said SHM’s we can find another resultant SHM with different amplitude than of the previous two SHM’s. This new SHM has a slight variation in wave length and time period than that of that of the said earlier two SHM’s. Then using the perturbation technique on this resultant equation of SHM, we can find a new wave velocity (group velocity) in differential notation of wave velocity. This differential notation of wave velocity has been eliminated from the relation between the wave velocity on the surface of water and the depth of the sea. Then we get a relation between group velocity and wave velocity depending with depth of the sea. The application of boundary conditions on depth of deep sea and that of at the sea shore, we can find the group velocity at each region respectively. It is seen from the analysis that the group velocity at the sea shore is as much as double that of at the deep sea. Several recent cases of tsunamis or storm surges have been studied and it is found that the results depicted the same implementation through devastation that established by analytical study.

scholarly journals Study on Rail Short-Wave Irregularity of Speed Increased Tracks

2020 ◽  
Author(s):  
Jian Fang ◽  
Xiaoyan Lei ◽  
Songliang Lian ◽  
Wenwen Zheng
Keyword(s):  
Statistical Analysis ◽  
Field Test ◽  
Wave Length ◽  
Maximum Amplitude ◽  
Short Wave ◽  
Surface Irregularities ◽  
Standard Values ◽  
Test Points

The data obtained from a field test of irregularity of rail surface in Hu-Kun line, a CWR track, is processed by statistical analysis of maximum amplitude and one-third octave analysis. The result shows that the regularities of rail surface in joint areas of CWR track are worse in common. In general, the amplitudes of rail surface irregularities can get beyond 0.5mm/m, which exceed standard values in every wave length ranges, and the maximum of them can reach 15dB. The conditions of rail surface regularities in non-joint areas are better, and the rail surface irregularities from most of the test points are lower than 0.15mm/m, which do not exceed standard values.

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