Laminate substrate for a radiofrequency device

A laminate substrate for a radio frequency application comprising, from a first main side to a second main side:

• a first metal layer and a transmission line, a first slot open on one of its sides being formed in the first metal layer, the transmission line being coplanar with the first metal layer and penetrating into the first slot;
• a second metal layer comprising a second, laterally closed slot;
• a third metal layer comprising a third laterally closed slot;
• a fourth metal layer comprising a fourth slot;
• a dielectric layer being arranged between each metal layer;
• the second slot, the third slot, and the fourth slot forming a vertical radio frequency feedthrough in the laminate substrate;
• a frequency matching element arranged in at least one of the second slot, the third slot, or the fourth slot.