Английски език
This research looks at various bubble sizes in one particular magnetic RAM (MAGRAM) type, from grazing incidence (0??) to 45?? and at a frequency range from 2-18 GHz, TE polarization. The results from the absolute RCS measurement of the various sized RAM bubbles are discussed in terms of a frequency dependent increase in RCS. In the frequency band of interest, 2 --18GHz, a RAM bubble increases the RCS at all angles, from grazing incidence (0??) to 45??. From 10 -18GHz the RAM bubble does not cause an increase in RCS. In general the highest RCS is at 2GHz and tapers down as frequency increases. At near grazing angles the RCS increase due to the bubbles is 10-15dB. At the higher angles, the RCS increase due to the bubbles is 10-20dB. The RCS increase is relative to the noise plus clutter measurement of the range. The range of absolute RCS values for the various bubble sizes can range from --55 dBsm to --25 dBsm. The results of these experiments are captured in a statistical model which provides an estimate of the bubble's dependence on frequency, angle, and size.
