IEEE Std 1302:2008 pdf free download

IEEE Std 1302:2008 pdf free download.IEEE Guide for the Electromagnetic Characterization of Conductive Gaskets in the Frequency Range of DC to 18 GHz.
The effects of the aperture used for measurements can also overshadow the attenuation provided by the gasket alone. Because of the many factors that can affect measurement results, data taken under different test conditions can be markedly diflrent. Further, test resuhs are hard to relate to the gasket’s intrinsic transfer impedance.
The standardized aperture transmission techniques measure the signal coupled through the gasketed aperture at specific antenna orientations and look angles. As previously noted, however, the signal coupled through the gasket is strongly influenced by the measurement antenna locations relative to thc aperture and by the surrounding enclosures. To fully characterize the coupling through the gasket, the illuminating antenna should be mused about so as to expose the seam to various incident field conditions. Since each possible antenna pairing involves a measurement of the coupling with and without a gasket present. the effort to perform the evaluation is high.
The effects of enclosure and fixture resonances musi be recognized, Fixture resonances currently limit the transfer impedance technique to below about 2000 MHz. The chambers used with the radiated techniques arc resonant cavities. Once their longest dimension (typically the distance between diagonally opposite corners) reaches one-half wavelength, resonant modes exist from that frequency upward. Some of these resonances can be very sharp. Consequently, very small changes in antenna position inside the chamber can produce very large changes in the measured signal level. In addition, the size of the aperture influences the attenuation of the field coupled through it. If the aperture is significantly less than one wavelength, the attenuation through it is very high and is inversely proportional to frequency. This attenuation limits the lowest frequencies that can be effectively measured and can restrict the types of gaskets that can be accurately esalurted.
Chamber resonances and aperture dynamic range requirements tend to restrict radiated tests to above about 200 Mhz for the size chambers and apertures typically used in the measurement of gaskets. New techniques taking into account these effects by the characterization of the Q.factors of the chambers have been developed by Holloway et al. IBI 3J.
Between about 200 MHz and 2000 MHz. the potential for direct comparison beween the standardized techniques exists. However, both below and above these overlap regions, direct comparison is ditlicull, For example. below the overlap region, the transfer impcdance technique provides information on the plane wave and magnetic field behavior of the gasket, whereas the radiated techniques largely provide information on electric and magnetic field behavior. Abuse the overlap region, the transfer impedance tixnire exhibits strong resonances that make comparison of its results with the plane-wave data of the radiated techniques difficult.