# Multifunction RF Systems for Naval Platforms
## 5 MFRF System Resource Management  
As discussed in the previous sections, the design trade-offs that prevent realization of the ideal MFRF system architecture are driven primarily by existing performance limitations and/or costs of hardware technologies related to array radiating elements, ADCs, and RF components such as HPAs, LNAs and circulators. Consequently, the continued advancement of these technologies will be the most significant factor in enabling the optimal design and cost-effective deployment of naval MFRF systems. It will be valuable to maintain a technology watch in these areas with the aim of identifying future MFRF system design concepts that can exploit advances in the underlying hardware technology. The technology watch effort would involve monitoring the available literature to recognize relevant emerging technology trends, and periodically surveying commercial-off-the-shelf products to establish current state-of-the-art.  
A key area of future research in MFRF systems is resource management, a task which is executed by the Resource Allocation Manager (RAM) depicted in the block diagram of Figure 1. In the past, most research in RAM architectures and algorithms as they pertain to RF systems has focused on resource management for phased array radars, since radar comprises a number of functions, and historically was the first and largest application of phased arrays. There has been significant previous  
\begin{table}
\begin{tabular}{c c c c c} \hline
**Device** & **Frequency (GHz)** & **Gain (dB)** & **Output Power (W)** & **PAE (\%)** \\ \hline HPA 1 & 4.5–18 & 19 & 2 (CW and pulsed) & 25–30\% \\ HPA 2 & 5–12 & 20 & 4 (pulsed) & 25–30\% \\ \hline \end{tabular}
\end{table}
Table 4: Specifications for M-AES HPAs.  
work carried out in adaptive radar resource _m_anagement (RRM) [55; 56; 57]. This work provides a solid foundation for investigating RAM implementations for MFRF systems, since many of the techniques studied for RRM are somewhat generic in their application. The challenge in extending this work to MFRF systems lies in the fact that not only must more RF functions be accommodated within the set of shared electronics and AESAs, but some of the additional functions also have priorities as high as or even higher than those of the radar functions. For example, the ES function must always be allocated a portion of system resources to enable continuous monitoring for threat emissions, and the EA function, when active, commands the highest priority due to its critical self-protection role. Consequently, a careful study of resource management techniques for MFRF systems is required to determine the extent to which potentially suboptimal resource allocation to any single RF function during system overload conditions may impact their performance.  
Signal processing for RF functions is another important area of future research. This topic is not discussed here due to space constraints. Instead, the reader may consult references on signal processing for radar [58], ES [59], EA [60], and communications [61]. Based on the above observations, key elements of resource management for MFRF systems are presented below.