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This letter expands the treatments of wideband noise analysis of antenna arrays by including bandwidth effects on beam-equivalent receiver noise temperature, (Formula presented.), and the active reflection coefficient, (Formula presented.). The particular focus of the letter is on receiver noise decorrelation in wideband systems having noise bandwidth (Formula presented.) 1 Hz. The new analysis and simulations show increase in (Formula presented.) and the departure of (Formula presented.) from that obtained using contemporary analyses for (Formula presented.) 1 Hz. Although the paper also shows that for many applications over moderate bandwidths and close connection between the receiver and array the influence of (Formula presented.) on (Formula presented.) is not significant, the simulations of a 71-element array demonstrate that the noise decorrelation due to wide (Formula presented.) can result in tens of percent (as much as 45.5% in simulations described in this letter) increase in (Formula presented.) above the low-noise amplifier minimum noise temperature, which should be taken into account at the design stage of ultra-wide band systems, such as those under investigation by, for example, the Defense Advanced Research Project Agency (DARPA) in its wideband adaptive RF protection (WARP) program and ultra-sensitive active electronically scanned array (AESA) radars for tracking stealth objects.