scholarly journals ELECTRO-MECHANICAL IMPEDANCE BASED SHM OF THICK STRUCTURES IN BROAD-BAND FREQUENCY SPECTRUM

2020 ◽  
Author(s):  
Mesut TEKKALMAZ
Keyword(s):  
Frequency Spectrum ◽  
Broad Band ◽  
Mechanical Impedance ◽  
Band Frequency

Design of a high-gain dual-band antipodal Vivaldi antenna array for 5G communications

2021 ◽  
pp. 1-9
Author(s):  
Sumit Kumar ◽  
Amruta S. Dixit
Keyword(s):  
Frequency Spectrum ◽  
Impedance Matching ◽  
High Gain ◽  
Dual Band ◽  
Dual Frequency ◽  
Band Frequency ◽  
Dielectric Lens ◽  
Bottom Side ◽  
Simulation Results ◽  
Vivaldi Antenna

Abstract This paper presents a dual-band 1 × 4 antipodal Vivaldi antenna (AVA) array with high gain to operate over a dual-frequency band that covers the 5G frequency spectrum. The gain is enhanced by employing a dielectric lens (DL). The AVA array consists of four radiating patch elements, corrugations, DL, and array feeding network on the top side. The bottom side contains four radiating patches which are the mirror images of top radiating patches. The designed AVA contains 1 × 4 array antenna elements with a DL that is operating in the ranges of 24.59–24.98 and 27.06–29 GHz. The dimensions of the designed antenna are 97.2 mm × 71.2 mm × 0.8 mm. For the improvement in gain and impedance matching at the dual-band frequency, corrugation and feeding network techniques are used. The gain obtained is about 8–12 dBi. AVA array is tested after fabrication and the measured results are reliable with the simulation results.

Distributed broad-band frequency translator and its use in a 1-3-GHz coherent reflectometer

1998 ◽  
Vol 46 (12) ◽  
pp. 2244-2250 ◽  
Author(s):  
P. Akkaraekthalin ◽  
S. Kee ◽  
D.W. Van Der Weide
Keyword(s):  
Broad Band ◽  
Band Frequency

Broad-band frequency references in the near-infrared: Accurate dual comb spectroscopy of methane and acetylene

2013 ◽  
Vol 118 ◽  
pp. 26-39 ◽  
Author(s):  
A.M. Zolot ◽  
F.R. Giorgetta ◽  
E. Baumann ◽  
W.C. Swann ◽  
I. Coddington ◽  
...  
Keyword(s):  
Near Infrared ◽  
Broad Band ◽  
Band Frequency

scholarly journals Frequency multiplication by collective nano-scale spin wave dynamics

2021 ◽  
Author(s):  
Georg Woltersdorf ◽  
Rouven Dreyer ◽  
Niklas Liebing ◽  
Chris Körner ◽  
Martin Wagener
Keyword(s):  
Broad Band ◽  
Ferromagnetic Layer ◽  
Low Frequency ◽  
Ferromagnetic Material ◽  
Frequency Multiplier ◽  
Frequency Multiplication ◽  
Band Frequency ◽  
Promising Alternative ◽  
Dynamic Phase ◽  
Non Linear

Abstract Frequency multiplication is a process where harmonic multiples of the input frequency are generated. It is usually achieved in non-linear electronic circuits or transmission lines. Such elements enable the up-conversion of electronic signals to GHz frequencies and are essential for frequency synthesizers and communication devices. Circuits based on the propagation and interaction of spin waves are a promising alternative to conventional electronics. Unfortunately, these systems usually require direct driving in the GHz range as magnonic frequency up-conversion is restricted to a few harmonics only. Here we show that the ferromagnetic material itself can act as a six octave spanning frequency multiplier. By studying low frequency magnetic excitations in a continuous ferromagnetic layer we show that the non-linearity of magnetization dynamics combined with disorder in the ferromagnet leads to the emergence of a dynamic phase generating high harmonics. The demonstrated broad band frequency multiplication opens exciting perspectives for magnonic and spintronic applications since the frequency is up-converted from MHz into GHz frequencies within the magnetic medium itself. Due to the ease at which magnetic media can be structured and modified spatially (and reversibly) we anticipate that a tailored non-linear dynamic phase can be engineered e.g. to stabilize magnetic solitons.

scholarly journals Early Result for Microtremor Characteristic Observation in Merapi and Merbabu

2021 ◽  
Vol 873 (1) ◽  
pp. 012077
Author(s):  
E. Fernanda ◽  
A. Bilqis ◽  
L. Julio ◽  
K. Nursal ◽  
Y. H. Christ ◽  
...  
Keyword(s):  
Frequency Spectrum ◽  
Broad Band ◽  
Vertical Component ◽  
Low Frequency ◽  
Eurasian Plate ◽  
Merapi Volcano ◽  
Hydrocarbon Reservoir ◽  
Central Java ◽  
Recording Station ◽  
Passive Seismic

Abstract The arc magmatism and volcanic activity in Java are dominated by the subducting plate of Indo-Australian into the Eurasian plate. Merapi volcano is located in Central Java and known as one of the most active volcanoes in the world. Several studies have tried to estimate the magma reservoir zone in Mt. Merapi and suggested multiple layers of reservoirs with the shallow one at 1-2 km and a deeper at 6 -9 km or 15 km. The Low-Frequency Passive Seismic is one method to analyze the frequency spectrum below the recording station. Previous related studies show a promising a relation between hydrocarbon reservoir and higher amplitude at vertical component at a frequency between 0.1 – 6 Hz. An observation at the volcano sites have also been reported to display a different spectrum amplitude at the vertical component. This study exploited the same method in LFPS to analyze the frequency spectrum at Mt. Merapi and Mt. Merbabu. We use seismic data from the DOMERAPI temporary seismic network installed in the neighborhood of Merapi and Merbabu volcano. We analyze 53 broad-band seismometers data from October 2013 to mid-April 2015. We also add several stations from MERAMEX network instruments to compare spectrum analysis outside the Merapi and Merbabu volcano. We also removed some tele-seismic and regional events from the data to better analyze the LFPS signal. We have seen a higher amplitude in vertical component near Mt. Merapi and will proceed to analyze all stations.

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