X band
X band functionality (8 to 12 GHz frequency range) is optimal for minimizing low-altitude propagation effects, narrow beam width for best tracking accuracy, wide frequency bandwidth for effective target discrimination, and the target illumination for SM-2 and Evolved Sea Sparrow Missiles (ESSM). The X-band has, in general, favorable low-altitude propagation characteristics, which readily support the horizon search functionality of the AN/SPY-3. A large operating bandwidth is required to mitigate large propagation variations due to meteorological conditions.