Investigation on Effect from variational Electromagnetic Parameters of absorbing patch for RCS of Almond model

Abstract

The RCS of the almond model which was affected by the change from electromagnetic parameters (ε and $\mu)$ of the absorbing patch was researched, and the moment method was utilized. The $\varepsilon$ andμ of the absorbing patch can be measured and the values were assumed to vary with equal difference in the interval of 5%~30%, the measured values of $\varepsilon$ and $\mu$ worked as variable which were used to calculate the RCS of the almond model with the different $\varepsilon$ and $\mu$ of the patch. Here, two almond model RCS were obtained, one is circumferential RCS which generated by the gradient of $\varepsilon$ and $\mu$ of absorbing patch, and the other Radar Cross-Section (RCS) generated by the known electromagnetic parameter measurements. Comparing the two RCS mentioned above, the calculated results show that for the HH polarization, the undulation values of the almond model RCS vary within 0.4dB when the real part of $\varepsilon$ and $\mu$ of the absorbing patch vary within 5%-30% at 10GHz, and for the VV polarization, the undulation values changes within 2.5 dB, Moreover, the polar differences of both polarizations decrease with the increase of the real part of the $\varepsilon$ and $\mu$, in both polarization modes, the polar RCS is sensitive to the variation of $\varepsilon$ and $\mu$, and the VV polarization is much more sensitive than the HH polarization.