  In this paper we investigate the possibility of modeling a single antenna
alone and in close proximity to a physical object by means of discrete point
source scatterers. The scatter point model allows joint modeling of a physical
antenna and the human body as a single extended object with direction dependent
scattering coefficients for the scatter points. We introduce the term extended
antenna describing antenna and human body together. To investigate the
identifiability of the model parameters we make use of ultrawideband channel
measurements and accurate ground truth position and orientation measurements
obtained with an optical tracking system. By comparing measurements of the
antenna attached directly to the user with measurements for the antenna without
the user nearby, we show the shadowing and scattering effects of the human body
and the antenna.
