Ricerc@Sapienza

This paper presents an improved reversed nested Miller compensation technique exploiting a single additional feed-forward stage to obtain double pole-zero cancellation and ideally single-pole behavior, in a three-stage Miller amplifier. The approach allows designing a three-stage operational transconductance amplifier (OTA) with one dominant pole and two (ideally) mutually cancelling pole-zero doublets. We demonstrate the robustness of the proposed cancellation technique, showing that it is not significantly influenced by process and temperature variations.

Acoustic communications in underwater environment are considerably influenced by the physical characteristics of the medium. This is even more true in the polar regions where the presence of icebergs and icy water layers represent an additional dependence to the signal propagation. Considering a MIMO scenario, we investigate how the channels spatial correlation is conditioned in the case of both frozen and fluid water surface. More, we evaluate the impact of the medium changes on the signal delay spread.