  This paper presents a general technique for the joint Direction-of-Arrival
(DoA) and Time-of-Arrival (ToA) estimation in multipath environments. The
proposed ultra-wideband technique is based on phase-mode expansions and the use
of nearly frequency-invariant elliptical arrays. New possibilities open with
the present approach, as not only elliptical, but also circular and linear
(highly flattened) arrays can be considered with the same implementation.
Systematic selection/rejection of signals-of-interest/signals-not-of-interest
in smart wireless environments is possible, unlike with previous approaches
based on circular arrays. Concentric elliptical arrays of many sizes and
eccentricities can be jointly considered, with the subsequent improvement that
entails in DoA and ToA detection. This leads to the realization of
pseudo-random array patterns; namely, quasi-arbitrary geometries created from
the superposition of multiple elliptical arrays. Some simulation and
experimental tests (measurements in an anechoic chamber) are carried out for
several frequency bands to check the correct performance of the method. The
method is proven to give accurate estimations in all tested scenarios, and to
be robust against noise and position uncertainty in sensor placement.
