  Millimeter wave wireless systems rely heavily on directional communication in
narrow steerable beams. Tools to measure the spatial and temporal nature of the
channel are necessary to evaluate beamforming and related algorithms. This
paper presents a novel 60~GHz phased-array based directional channel sounder
and data analysis procedure that can accurately extract paths and their
transmit and receive directions. The gains along each path can also be measured
for analyzing blocking scenarios. The sounder is validated in an indoor office
environment.
