This study deals with the co-sintering of copper oxide added ANT with alumina tapes and silver ink. AgNb1/2Ta1/2O3 (refered ANT 22) was synthesized using niobium oxide with fine and large grain size to examine the effect of the granulometry on the tape casting. The resulting multilayers were co-fired between 850 and 900°C. Phase identification was investigated by XRD. Energy Dispersive Spectroscopy was performed to study the interdiffusion between the layers. Permittivity and dielectric losses were measured at 50 kHz for both tape cast samples and bullk material. No interdiffusion was observed between ANT/silver and ANT/alumina and this is a very promising result for LTCC applications.