Compensation techniques for rain depolarization in satellite communications

Abstract

Compensation techniques for rain depolarization in satellite links are discussed from the viewpoint of system configuration, performance, and technical feasibility. The compensator using two rotatable polarizers has sufficient performance at microwave region. Two types of compensators, as combination of 90° and 180° polarizers and a combination of two 90° polarizers, were developed and tested. Satisfactory results were obtained at 4‐GHz band by using the INTELSAT satellite. The compensation system for an operational use is also presented in this paper.

Mitigation of rain and ice particle cross polarization at RF for dual circularly polarized waves

“…Papers have been published describing various methods of reducing the adverse cross-polarizing effects caused by rain [2], [14], [15]. Some methods achieve this objective by modifying the RF portion at the input of the receiver.…”

“…This will degrade the net G/T of the receiver, but this degradation can be mitigated by amplifying the incoming signals prior to the restoration circuit at RF. A cross polarization cancellation method has been described that utilizes dual cross-coupling circuits between the two "orthogonally" polarized output channels [2], [14], [15].…”

Electromagnetic wave propagation in rain and polarization effects

“…, RF, IF, or baseband stages. Many scientists have proposed various techniques 50 – 62 ) and several experimental investigations have been done. 56 , 57 , 60 , 62 ) In the 4- and 6-GHz bands, differential attenuation is very small compared with the differential phase (see Fig.…”