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Coupling Loss (coupling + loss)

Distribution by Scientific Domains

Engineering	40%

Selected Abstracts

A variable step-size control of adaptation for acoustic echo cancellation filters

EUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, Issue 2 2002
Vojko Pahor
This paper presents a low-complexity variable step-size control for acoustic echo cancellation filters. The proposed control method is based on two supplementary adaptive filters with low memory length. The first supplementary filter is used to control the double-talk situations while the second supplementary filter is employed to detect variations of the echo-path impulse response. The variable step-size here derived is independent from die echo coupling loss and from the reverberation time and thus it is suitable for both hands-free and handset terminals. [source]

Light propagation in multi-step index optical fibres

LASER & PHOTONICS REVIEWS, Issue 3 2008
J. Zubia
Abstract This paper reviews the theoretical analysis of light propagation we have carried out on multimode multi-step index (MSI) optical fibres. Starting from the Eikonal equation, we derive the analytical expressions that allow calculating the ray trajectories inside these fibres. We also analyse the effects of leaky rays on the transmission properties of MSI fibres. For this purpose, a single analytical expression for the evaluation of the ray power transmission coefficient is calculated. Afterwards, we investigate the effects of extrinsic and intrinsic coupling losses on the performance of MSI fibres, providing analytical expressions to calculate the coupling loss and, also, determining the most critical parameters. Finally, we carry out a comprehensive numerical analysis of the fibre bandwidth under different source configurations. [source]

Fully embedded lumped LC-quadrature hybrid coupler into organic packaging substrate for power sampling

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 3 2009
Yi Jae Lee
Abstract In this article, fully embedded lumped LC-quadrature hybrid coupler are designed, fabricated, and characterized into multilayered organic packaging substrate. This embedded device comprised high Q MIM capacitors and circular spiral stacked inductors. For realizing fully embedded high Q capacitor, barium titanate (BaTiO3) composite high dielectric film was utilized. The measured return loss and isolation were better than 25 dB. Measured insertion loss was about 0.38,0.42 dB at the frequencies ranged from 824 to 894 MHz. The coupler exhibited a coupling loss of 23.3,24 dB. The phase error between through and coupling ports was 1.2°,2.4°. It has a size of 2.8 mm ×2.95 mm ×0.77 mm (height), which is the smallest one in the couplers developed onto the packaging substrate. The measured performance characteristics were also well matched with the 3D EM simulated ones. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 845,848, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24173 [source]

Process Chain for Tailoring the Refractive Index of Thermoplastic Optical Materials using Ceramic Nanoparticles

ADVANCED ENGINEERING MATERIALS, Issue 6 2005
E. Ritzhaupt-Kleissl
Interconnections between active optical devices like laser diodes and polymer optical fibres are a crucial factor of optical damping due to coupling losses at the interfaces. Tailoring the refractive index of thermoplastic polymers can diminish these damping losses. The use of modified thermoplastics in an injection moulding process allows a high throughput and therefore a cost effective method for manufacturing passive optical parts with improved properties. [source]