Final rept. Mar-Nov 84,
NORTHEASTERN UNIV BOSTON MA
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In a previous project, a class of RF intrusion sensor systems was analyzed and numerical results were obtained for various intrusion situations. The system consisted of a ported coaxial cable laid circularly around an area to be protected and an antenna near the center of the circle. The presence of an intruder electromagnetic scatterer near the cable perturbs the field and thereby changes the signal at the antenna. The analysis was based on the plane-wave spectral representation of fields and the assumed scatterer was a uniform spheroid with constitutive parameters designed to simulate those of a human frame. Emphasis was on polarization effects. Although the previous analysis constituted an attempt to model this system quite accurately, the price for this accuracy was extremely large computer time. In order to reduce computer time, approximations were made along the way that reduced the overall accuracy. The present report discusses a follow-on to the above mentioned project whose objective was to produce a simpler, less computer-time-intensive model and associated software that can be readily used to study the effects of parameter changes on system performance. Steps were taken toward that objective, as follows 1 The software was thoroughly checked and redesigned for greater efficiency when that step was warranted. 2 The model for the cable-generated fields was simplified. 3 While many of the features of the plane-wave spectral representation of fields were retained, that approach was compromised by approximating the cable-generated fields, within the scatterer volume, as those of a single plane wave propagating in the direction of power flow of the true cable generated fields.
- Electrical and Electronic Equipment
- Active and Passive Radar Detection and Equipment
- Radiofrequency Wave Propagation