Radiated emissions and experimental precautions of equipment with cables in GTEM cells

Any electric or electronic equipment sold within the European Union has to comply with the EC Directive on Electromagnetic Compatibility (EMC). To achieve compliance, the equipment must be tested for radiated/conducted emissions and immunity. A wide range of national and international testing methods and standards are in force such as the IEC 61000-40-20. However, standards in general lack of describing testing methods for equipment with cables. Since most devices and systems contain leads and cables; the current standards cannot be directly employed. In an effort to approach this crucial matter, we present the outcomes of measurements conducted on an EUT (metal box) with different cable bundle configurations, in conjunction with both, the correlation algorithm given in the standards and the repeatability concerns between different GTEM cell

Measurements and modelling of cellular interference in local point-to-multipoint distribution systems

Frequency and polarisation reuse for optimum spectral efficiency in local multipoint distribution system (LMDS) networks generate co- and adjacent-channel inter-and intra-cell interference because of the line-of-sight constraints among transmitting and receiving antennas. Such operational constraints limit the system capacity and affect link performance. Measurements at 40 GHz from a number of possible interference scenarios for two different LMDS reuse cellular plans of dual-frequency and dual-polarisation discriminations are presented. An electromagnetic-stochastic propagation model is employed. The model successfully predicts the interference parameters and takes into account the effects of multiple paths and depolarisation caused by reflection and scatter from building surfaces at millimetre-wave frequencies. The probability density function of the signal-to-interference ratio and the statistical channel parameters, such as the average signal strength and the Rician K-factor, are extracted from the measured data and compared with model predictions