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Anechoic Chambers

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Fernando Silveira – One of the best experts on this subject based on the ideXlab platform.

  • antenna characterization without using Anechoic Chambers or tem cells
    Proceedings of the 10th Latin America Networking Conference on, 2018
    Co-Authors: Benigno Rodriguez, Juan Pablo Gonzalez, Leonardo Steinfeld, Javier Schandy, Fernando Silveira

    Abstract:

    One of the accustomed procedures to characterize an antenna is evaluating the radiation pattern in an Anechoic chamber or at least in a TEM cell. Besides avoiding the reflections, these devices allow a very precise measure of the radiation pattern by isolating the external interference. In this paper an alternative to characterize antennas without using Anechoic Chambers or TEM cells is discussed. An example of measures obtained by using this method is shared to show the potential of this technique. Additionally the measures are compared with the simulations results obtained with the simulation tool Computer Simulation Technology (CST).

  • LANC – Antenna Characterization without Using Anechoic Chambers or TEM Cells
    Proceedings of the 10th Latin America Networking Conference on ZZZ – LANC '18, 2018
    Co-Authors: Benigno Rodriguez, Juan Pablo Gonzalez, Leonardo Steinfeld, Javier Schandy, Fernando Silveira

    Abstract:

    One of the accustomed procedures to characterize an antenna is evaluating the radiation pattern in an Anechoic chamber or at least in a TEM cell. Besides avoiding the reflections, these devices allow a very precise measure of the radiation pattern by isolating the external interference. In this paper an alternative to characterize antennas without using Anechoic Chambers or TEM cells is discussed. An example of measures obtained by using this method is shared to show the potential of this technique. Additionally the measures are compared with the simulations results obtained with the simulation tool Computer Simulation Technology (CST).

Kenneth A. Cunefare – One of the best experts on this subject based on the ideXlab platform.

  • Qualification of Anechoic Chambers: 70 years on and we are still trying to get it right.
    Journal of the Acoustical Society of America, 2009
    Co-Authors: Kenneth A. Cunefare

    Abstract:

    There are now three equally “acceptable” techniques in common use for qualification of Anechoic and hemi‐Anechoic Chambers. The historical approach for modeling the inverse square law decay uses the measured sound pressure level at a given reference position from the source and applies the inverse square law therefrom to compute “theoretical” levels at other distances. A second approach, explicitly embodied in ISO 3745:2003 Annex A, seeks to estimate a source strength and source center offset location that yields a theoretical decay that matches the observed decay in a least‐squares sense. This method is motivated by the concern that the true acoustic center of a sound source may not coincide with a visually identifiable point on or near the source. More recently, a third method has come into use which determines an apparent source strength that maximizes the qualified span of a traverse. Nonetheless, the 3745 standard does not constrain the analysis routine, such that one can fully conform to the standar…

  • on the qualification of Anechoic Chambers issues related to signals and bandwidth
    Journal of the Acoustical Society of America, 2006
    Co-Authors: Kenneth A. Cunefare, Jeff Badertscher, Volker Wittstock

    Abstract:

    The qualification of Anechoic and hemiAnechoic Chambers requires selection of signal type and acquisition bandwidth to be used. This work demonstrates that, while a broadband random source may be used, the signal at points removed from the source are not composed of random combinations of direct and reflected waves, except in the limit of infinite bandwidth. It is shown that chamber qualification may be represented as finding the ratio of two transfer functions, where one includes the reflected waves, and the other is the free-field transfer function between the source and receiver. Consideration of this approach leads to a generic representation for the deviation from free-field performance where bandwidth is demonstrated to suppress the dominant modulation contributions of reflections. It is demonstrated that pure-tone qualifications will always exhibit a higher deviation from free-field performance than a broadband qualification. Finally, it is shown that the use of an incoherent source model in method-of-images simulations for the broadband performance of Anechoic Chambers is fundamentally flawed.

  • A test system for free-field qualification of Anechoic Chambers
    Sound and Vibration, 2003
    Co-Authors: Van Biesel, Kenneth A. Cunefare

    Abstract:

    Qualification of Anechoic and hemi-Anechoic Chambers is intended to demonstrate that a chamber adequately supports free-field conditions for a given test sample. However, the common practice of measuring widely spaced points along a traverse line is an inadequate measure of inverse square law performance, particularly for frequencies at and above 1000 Hz. On the other hand, continuous traverses yield a more complete picture of the capabilities and limitations of an Anechoic space. A new qualification measurement system has been developed at Georgia Tech to allow for easily repeatable, automated continuous traverse measurements. The highly portable system makes use of Labview and MATLAB tools to perform, control and analyze a complete traverse test, giving real-time access to the data and immediate processing and analysis of the results. This article will describe the new system, present data taken for an Anechoic chamber and demonstrate the benefits of this system over current methods.

Benigno Rodriguez – One of the best experts on this subject based on the ideXlab platform.

  • antenna characterization without using Anechoic Chambers or tem cells
    Proceedings of the 10th Latin America Networking Conference on, 2018
    Co-Authors: Benigno Rodriguez, Juan Pablo Gonzalez, Leonardo Steinfeld, Javier Schandy, Fernando Silveira

    Abstract:

    One of the accustomed procedures to characterize an antenna is evaluating the radiation pattern in an Anechoic chamber or at least in a TEM cell. Besides avoiding the reflections, these devices allow a very precise measure of the radiation pattern by isolating the external interference. In this paper an alternative to characterize antennas without using Anechoic Chambers or TEM cells is discussed. An example of measures obtained by using this method is shared to show the potential of this technique. Additionally the measures are compared with the simulations results obtained with the simulation tool Computer Simulation Technology (CST).

  • LANC – Antenna Characterization without Using Anechoic Chambers or TEM Cells
    Proceedings of the 10th Latin America Networking Conference on ZZZ – LANC '18, 2018
    Co-Authors: Benigno Rodriguez, Juan Pablo Gonzalez, Leonardo Steinfeld, Javier Schandy, Fernando Silveira

    Abstract:

    One of the accustomed procedures to characterize an antenna is evaluating the radiation pattern in an Anechoic chamber or at least in a TEM cell. Besides avoiding the reflections, these devices allow a very precise measure of the radiation pattern by isolating the external interference. In this paper an alternative to characterize antennas without using Anechoic Chambers or TEM cells is discussed. An example of measures obtained by using this method is shared to show the potential of this technique. Additionally the measures are compared with the simulations results obtained with the simulation tool Computer Simulation Technology (CST).