Emerging Technologies

Linearization of PA

The challenge of multi-carrier communication systems lies in the requirement for strict linearity specifications over a wide bandwidth, often several octaves. The challenge of such a system on board military vessels is to maintain high performance in an extremely complex RF environment.

The use of Digital Signal Processing allows the simultaneous implementation of a pre-distortion system and a feed-forward system, together ideal candidates for a composite system, incorporating both techniques through two independent control loops.

The original contribution of Spectral Research rests in addressing the Navy’s goal of suppressing unwanted spectral components at the output of a power amplifier (PA), whether their origin is within the PA or in the problematic RF environment where the PA is operating. Only a feed-forward cancellation system will be able to solve the problem, and only the combination of the feed-forward system with a pre-distortion system will allow the extreme levels of distortion suppression required by the Navy’s communication systems on board their vessels.