Simplistic field distribution estimation of a scattered field measurement room

Abstract

Some investigations of the properties in a scattered field measurement environment have been performed using reference half wave dipoles at 900 MHz. The analysis is based on the assumption that the electromagnetic (EM) field distributions at the antennas could be modelled as uniform in azimuth with vertical Gaussian distributions with zero mean. The results indicate that the scattered field measurement environment, including the method to average over both transmit and receive positions/angles, will give the same measured results as an environment with uniform field distributions in azimuth and Gaussian elevation distribution at both transmit and receive antennas and for both polarizations. The result of the analysis is that the estimated standard deviation of the vertical field distributions (VP and HP) is less than 25 degrees. Also the cross polarization power ratios at the receiver antenna for vertical, horizontal or 60/spl deg/ tilted dipole transmit antennas are estimated to >8 dB, <-8.5 dB and -2 to -3 dB respectively. These results have been partly validated by 3D measurements performed by CPK, Aalborg University. The analysis also includes a phantom that has a mean path gain of about -6.4 dB for a vertical transmit dipole and about -5.8 dB for a horizontal transmit dipole. The cross polarization properties of the phantom seem to be different with the vertical transmit dipole and the horizontal transmit dipole.