Propagation of transients in waveguides

Karbowiak, A.E.

doi:10.1049/pi-c.1957.0040

Cited by 31 publications

(21 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The spatial refocusing process works only with broadband pulses, with a large number of eigenmodes in the bandwidth of the transmitted pulse. Here, the averaging process that gives a good estimate of the spatial correlation function is not obtained by summing over different realizations of the waveguide, but a sum over "pseudo-realizations" which correspond to the different modes in the same waveguide [158][159][160][161][162]. The signal-to-noise level should increase as the square-root of the number of modes in the width of the transmitted pulse.…”

Section: Research Methodology 31 the Fundamental Physical Mechanism mentioning

confidence: 99%

Time-Reversal for UWB Communications Systems

Qiu¹

2005

View full text Add to dashboard Cite

Public Reporting Burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comment regarding this burden estimate or any other aspect of this collection of information, including suggesstions for reducing this burden, to Washington

show abstract

Section: Research Methodology 31 the Fundamental Physical Mechanism mentioning

confidence: 99%

Time-Reversal for UWB Communications Systems

Qiu¹

2005

View full text Add to dashboard Cite

show abstract

“…The signal-carrying mode will be assumed TE with a cutoff frequency , a wave reactance and a propagation constant . The transfer function in (1) is readily shown to be given by (11) shown at the bottom at the next page (see e.g., [16]), where and (12) The corresponding phase and attenuation constants are then given by (13-a) and (13-b) shown at the bottom of page 963. It is a straightforward academic exercise to find analytic expressions for the characteristic transmission parameters we introduced (or revisited) in (5), (8), and (10).…”

Section: Transmission Over Evanescent Modesmentioning

confidence: 99%

“…Transient analysis of evanescent waveguides is well established in the open literature (e.g., [11]- [13]) and will not be treated here. It is the goal of this contribution to quantitatively and comprehensively investigate the pulse deformation accompanying steady-state evanescent transmissions and the related transmission velocities.…”

Section: Introductionmentioning

confidence: 99%

Steady-state analysis of signal transmission in evanescent channels

Omar

Kamel²

2003

IEEE Trans. Antennas Propagat.

View full text Add to dashboard Cite

Transfer functions of evanescent transmission channels are investigated in details. Based on a Taylor expansion of the corresponding phase and attenuation constants, different characteristic transmission parameters are introduced (or revisited). The steady-state propagation of a carrier signal modulated by a narrowband base-band Gaussian pulse in evanescent waveguide sections is then studied. It is shown that temporal pulse compression as well as carrier frequency drift are usually accompanying such transmissions. It is also shown that under steady-state conditions, conventionally defined transmission velocities are not necessarily restricted to be less than or equal (speed of light in free space) as long as they are not related to direct measurements. Only the power coupling accompanying a measurement is responsible for limiting the transmission velocity of the measured physical quantity below or equal .

show abstract

“…The present results considerably supplement the amount of available data that may be used to either unravel or check the systematic trends in the free-ion and CF parameters across the lanthanide series derived from the spectra for various Ln 2+ ions in several matrices. [15,18] Overall, the combined spectroscopic data enable the investigation of the predictive power of such considerations for the description of spectra for any ion, based on the sets of parameters obtained for another ion in the same matrix. Further studies of the trends in question are in progress.…”

mentioning

confidence: 99%

Optical Absorption Spectra of Divalent Neodymium (Nd²⁺) in Bromide and Iodide Hosts

Karbowiak

Rudowicz

2018

Eur J Inorg Chem

View full text Add to dashboard Cite

The electronic spectra for Nd2+ ions in bromide and iodide hosts are reported for the first time. These spectra, together with the recently obtained spectra for the chloride matrix, constitute a substantial series of Nd2+ spectra in crystals. Importantly, these crystals differ in the factors important for the physical properties of the divalent lanthanide Ln2+ ions; that is, the ligand's chemical character and the symmetry of the crystal field. The available experimental data allow systematic investigations of the impact of these factors on the electronic spectra, and thus, spectroscopic properties of Nd2+ ions. These investigations are the main aim of this study. The results indicate that due to the increasing covalence of the Nd2+ environment in the Cl–Br–I series, the energy of the first f–d transition shifts into the infrared region, from 6121 cm–1 for SrCl2/Nd2+ to ca. 5260 cm–1 for SrI2/Nd2+, whereas the strength of the crystal field decreases along this series. Calculations using the parametric Hamiltonian and superposition model are carried out to quantitatively interpret the measured spectra. The simulated spectra exhibit good agreement with the experimental spectra. Using the proposed approach, a meaningful interpretation and assignment of the bands observed in the spectra has been achieved.

show abstract

Propagation of transients in waveguides

Cited by 31 publications

References 1 publication

Time-Reversal for UWB Communications Systems

Time-Reversal for UWB Communications Systems

Steady-state analysis of signal transmission in evanescent channels

Optical Absorption Spectra of Divalent Neodymium (Nd²⁺) in Bromide and Iodide Hosts

Contact Info

Product

Resources

About

Propagation of transients in waveguides

Cited by 31 publications

References 1 publication

Time-Reversal for UWB Communications Systems

Time-Reversal for UWB Communications Systems

Steady-state analysis of signal transmission in evanescent channels

Optical Absorption Spectra of Divalent Neodymium (Nd2+) in Bromide and Iodide Hosts

Contact Info

Product

Resources

About

Optical Absorption Spectra of Divalent Neodymium (Nd²⁺) in Bromide and Iodide Hosts