Scattering of electromagnetic radiation for a perfect electric conducting cylinder by using multiple angles of polarization

Radar is a device which detects distant or non visible objects by means of reflected radio waves. The quality of the reflected signal depends on the shape and orientation of the target with respect to the type of polarization used. Most of the antennas currently used on radar systems employ one type of polarization at a time for target detection. This paper describes the importance of employing polarizations of multiple angles on targets, approximately at the same instant of time. To implement this idea a generalized set of equations have been derived which represent the backscatter generated by a cylindrical object. Using different angles in these equations would give the backscatters of different polarizations employed on the same target, at small time intervals. The logic behind this is that there would be at least one angle that would have the maximum signal strength in the backscatter. The backscatter for this angle would satisfy the best quality criterion as compared with the rest of the polarization angles.

I. INTRODUCTION

Materials contain charged particles, and when these materials are subjected to electromagnetic fields, their charged particles interact with the electromagnetic field, producing currents and modifying the electromagnetic wave propagation in those media compared to that in free space [2]. This has been the operational point for all electromagnetic wave based systems and radar is one of them. Polarization is an underlying concept, in all of the electromagnetics oriented applications, that explains the different ways in which electromagnetic waves can be made to interact with materials. Polarization forms one of the base points for radar system applications. The emphasis of this paper has being laid on deriving a set of equations using linear polarization that would characterize the case for the simultaneous use of different angles of polarizations rather than just horizontal and vertical. To implement this, polarizations of all possible angles are being tested on the target because maximum signal strength occurs only when there is a proper alignment between the transmitter and the target. For the analysis, a stationary cylindrical target has being considered. The reason for this consideration was that most of the real world objects tend to be cylindrical; therefore, the consideration for using a cylindrical test target would yield to more realistic results. A generalized set of equations describing the electromagnetic parameters for a cylindrical target are derived, these equations can be used to derive the parameters for every possible angle. Moreover, dual polarization radars that are being currently used require two antennas for simultaneous transmission of polarizations, whereas, the application of this concept practically can be achieved by a single antenna system using short time gaps between each transmission.