Substrate with embedded signal line and ground planes with a slot therein
View Patent ↗A substrate with an HF-compatible line arranged in this substrate will be proposed that is formed similar to a tri-plate strip line in which, however, at least one of the ground planes has a slot that follows the profile of the signal line arranged between two ground planes. With the aid of this slot, the capacitive constant of the line can be lowered and thus the impedance of the line can be increased.
1. A substrate with a line, the substrate comprising:
a plurality of dielectric layers; and
a plurality of metallization planes arranged between the dielectric layers so that the substrate has a multiple layer construction;
wherein the plurality of metallization planes include a line embedded in the substrate, the line including a strip-shaped signal conductor arranged between a first ground plane and a second ground plane and separated from each of the first and second ground planes by at least one of the dielectric layers,
wherein one of the first and second ground planes has a slot therein that follows a profile of the signal conductor,
wherein, in the slotted ground plane, the slot is expanded at one position into a recess, and
wherein a feedthrough extends through the recess and connects the signal conductor electrically to a structure that is arranged at another of the plurality of metallization planes of the substrate.
2. The substrate according to claim 1 , wherein the slot is centered above the signal conductor.
3. The substrate according to claim 1 , wherein the slot follows the signal conductor across a large part of the entire length of the signal conductor.
4. The substrate according to claim 1 , wherein the slot follows the signal conductor across more than 80% of the entire length of the signal conductor.
5. The substrate according to claim 1 , wherein the strip-shaped signal conductor is one of a plurality of signal conductors that are embedded in the substrate.
6. The substrate according to claim 1 , wherein the first ground plane is divided by the slot into sub-areas, wherein all of the sub-areas are connected to the second ground plane by feedthroughs.
7. The substrate according to claim 1 , wherein the substrate comprises an LTCC ceramic.
8. The substrate according to claim 1 , wherein the signal conductor has different distances measured vertical to a substrate plane from the first and second ground planes.
9. The substrate according to claim 1 , wherein a width of the slot equals s and a width of the strip-shaped signal conductor equals d, where: 0.25d<s<5d.
10. The substrate according to claim 1 , wherein the other of the first and second ground planes has a slot therein, and each slot follows a profile of the signal conductor are provided in the first and second ground planes.
11. The substrate according to claim 1 , wherein an impedance of the line is matched to an impedance of 50 Ω.
12. A device comprising:
a substrate according to claim 1 ; and
an electrical component operating at high frequency arranged on the substrate and electrically connected to the line.
13. The substrate according to claim 12 , wherein the electrical component comprises the component operating with acoustic waves.