  Spintronic THz emitters, consisting of Ta/Co/Pt trilayers patterned into
rectangles of lateral size in the 10 ${\mu}$m range, have been integrated in
planar electromagnetic antennas of various types (dipole, bow-tie, spiral).
Antenna dimensions and shapes have been optimized with the help of
electromagnetic simulations so as to maximize antenna efficiency in both
narrow-band and broad-band geometries at/around 1 THz. The THz emission has
been studied using a pump probe free space electro-optic sampling set up, both
for a single emitter geometry and for arrays of emitters. Results show an
increase of the detected THz signal for all antenna geometries, with
enhancement ratios in the range of three to fifteen depending on antenna type
and frequency range, together with changes of the emission bandwidth consistent
with simulated characteristics.
