[en] High-quality Tl₂Ba₂CaCu₂O₈ films for microwave filter application are prepared on both sides of 2 inch lanthanum aluminate substrates as well as on double-sided CeO₂ coated r-cut sapphire substrates. The films have thicknesses as high as 1 μm in the case of lanthanum aluminate substrates. On CeO₂ buffered sapphire substrates it is possible to prepare crack-free superconducting films as thick as 400 nm. For both substrate materials we reach high critical current densities of J_c>2x10⁶ A cm^-2 at 77 K. The microwave surface resistances R_s were measured to fall short of 100 μΩ at 5.6 GHz and 77 K in the low-field case, comparable to the best films made of YBa₂Cu₃O_7-x material. The films were able to tolerate high microwave power levels corresponding to magnetic field amplitudes of B_RF>2 mT. The critical temperature exceeds 102 K. This excellent performance is maintained even after several thermal cycles. The films were used to produce four-pole band-pass filters for the C-band which were operated without any detectable loss in their transfer characteristics up to temperatures of about 85 K. This is the first time that large area (2 inch) double-sided Tl₂Ba₂CaCu₂O₈ films have been prepared on sapphire with excellent critical current density in conjunction with low surface resistance. (author)