  The anomalous X-ray pulsar XTE J1810$-$197 was the first magnetar found to
emit pulsed radio emission. After spending almost a decade in a quiescent,
radio-silent state, the magnetar was reported to have undergone a radio
outburst in December, 2018. We observed radio pulsations from XTE J1810$-$197
during this early phase of its radio revival using the Ultra-Wideband Low
receiver system of the Parkes radio telescope, obtaining wideband (704 MHz to
4032 MHz) polarization pulse profiles, single pulses and flux density
measurements. Dramatic changes in polarization and rapid variations of the
position angle of linear polarization across the main pulse and in time have
been observed. The pulse profile exhibits similar structures throughout our
three observations (over a week time scale), displaying a small amount of
profile evolution in terms of polarization and pulse width across the wideband.
We measured a flat radio spectrum across the band with a positive spectral
index, in addition to small levels of flux and spectral index variability
across our observing span. The observed wideband polarization properties are
significantly different compared to those taken after the 2003 outburst, and
therefore provide new information about the origin of radio emission.
