Frequency filter and its manufacturing process

Frequency filter according to the previous claim, characterised in that the resonator elements are made from silicon or ceramic.

Frequency filter according to any one of the previous claims, characterised in that it comprises an electromagnetic shielding, the said shielding comprising:

• a first metallisation layer (27, 43, 53) covering the bottom (23) and the walls (22) of the single cavity (21) and the face (80) of the structure containing the single cavity,
• a second metallisation layer (31) closing the single cavity (21) and being in electrical contact with the first metallisation layer (27, 43, 53) and with the resonator elements.

Frequency filter according to the previous claim, characterised in that the second metallisation layer (31) is deposited on a host substrate (32, 61) with low dielectric losses.

Frequency filter according to the previous claim, characterised in that these openings are made at the resonator elements.

Process for manufacturing at least one frequency filter according to the previous claim, characterised in that it also comprises a metallisation step of the back face (80) of the structure, the walls (22) and the bottom (23) of the cavity before the embedment step of the resonator elements (20, 60), and a step to close the cavity (21) using a metallisation layer (31) after the said embedment step.

Process for manufacturing at least one frequency filter according to the previous claim, characterised in that the metallisation layer used to close the cavity comprises at least two openings.

Process for manufacturing a filter according to the previous claim, characterised in that the first substrate (40) is made from a material with low dielectric losses.

Process for manufacturing a filter according to the previous claim, characterised in that the first substrate (40) is made from a material chosen among silicon, quartz or any other similar material.

Process for manufacturing a filter according to the previous claim, characterised in that the mask used has a pattern to obtain a cavity (21) with at least one protuberant part (200) and at least one setback part (300) in at least one wall (22) and/or the bottom (23) of the cavity (21).

Process for manufacturing a filter according to the previous claim, characterised in that it also comprises a step to adjust the height of the said second substrate (50) after the step to supply the second substrate.

Process for manufacturing a filter according to the previous step, characterised in that the manufacture of resonator elements also includes a step to deposit a metallisation layer (53) on the face(s) of the second substrate (50) comprising a layer of dielectric material (52).