Angle-dependent reflection, transmission and absorption coefficients measurement using a 2D waveguide

A method to determine the acoustic reflection and absorption coefficients of porous media by using modal dispersion in a waveguide.

The measurement of acoustic material characteristics using a standard impedance tube method is generally limited to the plane wave regime below the tube cut-on frequency. This implies that the size of the tube and, consequently, the size of the material specimen must remain smaller than a half of the wavelength. This paper presents a method that enables the extension of the frequency range beyo...

Absorption / Transmission / Reflection Spectroscopy

Ultraviolet Visible Near-Infra red (UV-Vis-NIR) spectroscopy is useful to characterize the absorption, transmission, and reflectivity of a variety of technologically important materials, such as pigments, coatings, windows, and filters. This more qualitative application usually requires recording at least a portion of the spectrum for characterization of the optical or electronic properties of ...

Transmission, Reflection, and Second-Harmonic Generation in a Nonlinear Waveguide

We present an experimental, analytical and numerical investigation of the passage of electromagnetic signals through a device with voltage-dependent differential capacitance. This dependence gives rise to the device’s nonlinear response, which can then be tuned by an externally applied static electric field. The system is modeled with a wave equation for the current and the charge density with ...

Optimization of Reflection and Transmission Characteristics of a Waveguide Window

Waveguide windows are known to be major components of transmission lines used with highpressure or vacuum applicators, particle accelerators, and microwave plasma devices [1-5]. The function of the window is to provide vacuum/gas isolation of the source from the cavity while transmitting microwaves with minimum attenuation. It essentially consists of a dielectric plate surrounded by a metal fra...

Reflection and absorption coefficients for use in room acoustic simulations