An actuating assembly for tuning a circuit and a process for forming a carrier substrate containing a membrane, a conductive layer, and piezoelectric actuators are disclosed. The actuating assembly comprises a membrane overlying a circuit to be tuned, a conductive element connected with the membrane, and a piezoelectric arrangement. Changes in shape of the piezoelectric arrangement allow a deflection of the membrane and a corresponding controllable upward or downward movement of the conductive element. In the process, a membrane and a piezoelectric structure are formed on a substrate.