Depolarization Mitigation using Frequency Offset in the Dual-Polarized X-Band for EESS

Dual-polarization frequency reuse technique has been actively adopted in space-to-earth links for earth exploration satellite service (EESS) to meet growing demands on high rate data transmission over the restrictedly allocated bandwidth in X-band. However, the performance of the dual-polarization system is affected by depolarization due to tropospheric propagation impairments such as rain drops and ice particles. In this paper, we investigate the offset scheme as an approach to mitigate the depolarization that always exists inherently in the dual-polarized satellite system. We present numerical formulas to estimate the depolarization effects as a function of the offset frequency, using theoretically derived CPA and XPD, in dual-polarized X-band down link channels for EESS. In addition, we present an example of link budget evaluated by using the calculated parameters.