Dual-frequency characterization of bending loss in hollow flexible terahertz waveguides

2014 ◽  
Author(s):  
Pallavi Doradla ◽  
Robert H. Giles
Keyword(s):  
Dual Frequency ◽  
Bending Loss ◽  
Terahertz Waveguides

scholarly journals Characterization of bending loss in hollow flexible terahertz waveguides

2012 ◽  
Vol 20 (17) ◽  
pp. 19176 ◽  
Author(s):  
Pallavi Doradla ◽  
Cecil S. Joseph ◽  
Jayant Kumar ◽  
Robert H. Giles
Keyword(s):  
Bending Loss ◽  
Terahertz Waveguides

Bending loss and propagation characterization of hollow pipe polymer terahertz waveguides

2018 ◽  
Vol 60 (12) ◽  
pp. 2862-2869 ◽  
Author(s):  
Nan Wang ◽  
Tianying Chang ◽  
Ye Yang ◽  
Jin Zhang ◽  
Xiaoxuan Zhang ◽  
...  
Keyword(s):  
Bending Loss ◽  
Terahertz Waveguides

scholarly journals Characterization of Carrier Phase-Based Positioning in Real-World Jamming Conditions

2021 ◽  
Vol 13 (14) ◽  
pp. 2680
Author(s):  
Søren Skaarup Larsen ◽  
Anna B. O. Jensen ◽  
Daniel H. Olesen
Keyword(s):  
Real World ◽  
Carrier Phase ◽  
Reference Station ◽  
Baseline Length ◽  
Dual Frequency ◽  
Positioning Accuracy ◽  
The Impact ◽  
Single Versus ◽  
Selection Of

GNSS signals arriving at receivers at the surface of the Earth are weak and easily susceptible to interference and jamming. In this paper, the impact of jamming on the reference station in carrier phase-based relative baseline solutions is examined. Several scenarios are investigated in order to assess the robustness of carrier phase-based positioning towards jamming. Among others, these scenarios include a varying baseline length, the use of single- versus dual-frequency observations, and the inclusion of the Galileo and GLONASS constellations to a GPS only solution. The investigations are based on observations recorded at physical reference stations in the Danish TAPAS network during actual jamming incidents, in order to realistically evaluate the impact of real-world jamming on carrier phase-based positioning accuracy. The analyses performed show that, while there are benefits of using observations from several frequencies and constellations in positioning solutions, special care must be taken in solution processing. The selection of which GNSS constellations and observations to include, as well as when they are included, is essential, as blindly adding more jamming-affected observations may lead to worse positioning accuracy.

Characterization of an Array-Based Dual-Frequency Transducer for Superharmonic Contrast Imaging

2021 ◽  
pp. 1-1
Author(s):  
Jing Yang ◽  
Emmanuel Cherin ◽  
Jianhua Yin ◽  
Isabel G. Newsome ◽  
Thomas M. Kierski ◽  
...  
Keyword(s):  
Dual Frequency ◽  
Contrast Imaging ◽  
Frequency Transducer

Optical and mechanical characterization of ultrananocrystalline diamond films prepared in dual frequency discharges

2010 ◽  
Vol 204 (12-13) ◽  
pp. 1997-2001 ◽  
Author(s):  
Monika Karásková ◽  
Lenka Zajíčková ◽  
Vilma Buršíková ◽  
Daniel Franta ◽  
David Nečas ◽  
...  
Keyword(s):  
Mechanical Characterization ◽  
Diamond Films ◽  
Dual Frequency ◽  
Ultrananocrystalline Diamond

scholarly journals Acoustic characterization of seafloor habitats on the western continental shelf of India

2007 ◽  
Vol 64 (3) ◽  
pp. 551-558 ◽  
Author(s):  
Bishwajit Chakraborty ◽  
Vasudev Mahale ◽  
Gajanan Navelkar ◽  
B. Ramalingeswara Rao ◽  
R. G. Prabhudesai ◽  
...  
Keyword(s):  
Continental Shelf ◽  
Dual Frequency ◽  
Scattering Process ◽  
Backscatter Signal ◽  
Sediment Volume ◽  
Interface Scattering ◽  
Acoustic Characterization ◽  
Power Law Exponent ◽  
Different Grain Size

Abstract Chakraborty, B., Mahale, V., Navelkar, G., Rao, B. R., Prabhudesai, R. G., Ingole, B., and Janakirinam, G. 2007. Acoustic characterization of seafloor habitats on the western continental shelf of India. – ICES Journal of Marine Science, 64: 551–558. This is a study of the interaction effects of the dual-frequency (210 and 33 kHz) backscatter signal with seafloor sediment and benthic biota along a transect in water 27–83 m deep offshore of the Goa region of India's central west coast. Estimation of the power-law exponent using seafloor topographic data provided equivalent values even when using dual high-frequency systems for different grain-size sediments. Backscatter signals corrected from system-related gain, etc., reveal better correlations with sedimentary and benthic parameters than the estimated coherence parameters (using echo peaks). Statistically, correlations are significant for the 210 kHz backscatter signal with sand and calcium carbonate (CaCO3) sediment content. Also, correlations are higher for macrobenthic biomass (wet weight) and population density with a 210 kHz backscatter strength, emphasizing the dominant seawater–seafloor interface scattering process. For 33 kHz backscatter strength, the absence of such correlations indicates a different scattering process, i.e. dominant sediment volume scattering attributable to the comparatively lower signal attenuation. Additionally, to validate the results, the backscatter signals from other locations in the vicinity of this transect were considered.

scholarly journals Vernier spectrometer using counterpropagating soliton microcombs

Science ◽  
2019 ◽  
Vol 363 (6430) ◽  
pp. 965-968 ◽  
Author(s):  
Qi-Fan Yang ◽  
Boqiang Shen ◽  
Heming Wang ◽  
Minh Tran ◽  
Zhewei Zhang ◽  
...  
Keyword(s):  
High Resolution ◽  
Relative Frequency ◽  
Frequency Comb ◽  
Laser Frequency ◽  
Dual Frequency ◽  
Molecular Absorption ◽  
Laser Tuning ◽  
Technical Simplification

Determination of laser frequency with high resolution under continuous and abrupt tuning conditions is important for sensing, spectroscopy, and communications. We show that a single microresonator provides rapid and broadband measurement of optical frequencies with a relative frequency precision comparable to that of conventional dual-frequency comb systems. Dual-locked counterpropagating solitons having slightly different repetition rates were used to implement a vernier spectrometer, which enabled characterization of laser tuning rates as high as 10 terahertz per second, broadly step-tuned lasers, multiline laser spectra, and molecular absorption lines. Besides providing a considerable technical simplification through the dual-locked solitons and enhanced capability for measurement of arbitrarily tuned sources, our results reveal possibilities for chip-scale spectrometers that exceed the performance of tabletop grating and interferometer-based devices.

scholarly journals Simulation and Characterization of a Nonlinear Dual-Frequency Piezoelectric Energy Harvester

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 908 ◽  
Author(s):  
Sofiane Bouhedma ◽  
Yuhang Zheng ◽  
Dennis Hohlfeld
Keyword(s):  
Energy Harvester ◽  
Frequency Tuning ◽  
Dual Frequency ◽  
Piezoelectric Energy ◽  
Frequency Agile ◽  
Classical Vibration ◽  
Multi Mode

In this paper, we present a concept, simulation and characterization results of a dual-frequency piezoelectric energy harvester with magnetic frequency tuning capabilities. We demonstrate that the frequency-agile multi-mode capability enables the device to harvest on a wider range of operating frequencies than classical vibration harvesters.

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