Low loss high-speed interconnects
An electronic device and associated methods are disclosed. In one example, the electronic device can include an assembly having asymmetrically situated conductors. In selected examples, the assembly includes a ground plane, a central shield portion, a first side shield portion on a first side, a second side shield portion on a second side, a first conductor asymmetrically situated between the central shield portion and the first side shield portion, a second conductor asymmetrically situated between the central shield portion and the second side shield portion, and dielectric within the assembly.
1. An assembly, comprising:
a ground plane on a bottom surface;
a top surface opposite the bottom surface;
a central shield portion extending between the bottom surface and the top surface, the central shield portion comprising:
one or more central reference layers parallel the ground plane; and
one or more a via vertically coupling together the one or more central reference layers;
a first side shield portion on a first side of the assembly, spaced apart from the central shield portion by a first gap, the first side shield portion comprising:
one or more first side reference layers parallel the ground plane; and
one or more via vertically coupling together the one or more first side reference layers;
a second side shield portion on a second side of the assembly, spaced apart from the central shield portion by a second gap, the second side shield portion comprising:
one or more second side reference layers parallel the ground plane; and
one or more via vertically coupling together the one or more second side reference layers;
a first conductor situated laterally asymmetric in the first gap;
a second conductor situated laterally asymmetric in the second gap, wherein first conductor and the second conductor carry complementary electrical signals; and
dielectric interspersed in and around the central shield portion, the first side shield portion, and the second side portion, the dielectric extending from the top surface to the bottom surface.
2. The assembly of claim 1 , further comprising a solder resist layer on the top surface.
3. The assembly of claim 1 , wherein the one or more first side reference layers and the one or more second side reference layers reside in one or more reference planes.
4. The assembly of claim 1 , wherein each of the one or more first side reference layers, each of the one or more second side reference layers, and each of the one or more central reference layers comprises a reference voltage.
5. The assembly of claim 4 , wherein the reference voltage comprises a ground voltage (Vss) or a power supply voltage (Vcc).
6. The assembly of claim 1 , wherein the electrical signals comprise a differential bus with a transmission data rate of greater than 10 GHz.
7. The assembly of claim 1 , further comprising a second ground plane on the top surface.
8. The assembly of claim 1 , wherein the one or more first side reference layers comprises top, middle, and bottom first side references layers, and wherein the one or more second side reference layers comprises top, middle, and bottom side reference layers.
9. The assembly of claim 8 , wherein the top first side reference layer, the bottom first side reference layer, the top second side reference layer, and the bottom second side reference layer, are each of an approximately equal primary width, and wherein the middle first side reference layer and the middle second side reference layer are of an approximately equal secondary width, wherein the primary width is greater than the secondary width.
10. The assembly of claim 9 , wherein the one or more first side reference layers and the one or more second side reference layers comprise a concave shape around the first and second cond rectors.
11. The assembly of claim 9 , wherein the ratio of the distance from the first conductor to the top first side reference layer of the first side shield portion compared to a parallel distance from the first conductor to the middle first side reference layer of the first side shield portion is about 1:1.2 to about 1:2.
12. The assembly of claim 1 , wherein the impedance comprises above about 90.0 Ω.
13. The assembly of claim 1 , wherein the insertion loss at about 28 GHz comprises less than about 0.09 dB/mm.
14. The assembly of claim 1 , wherein the insertion loss at about 56 GHz comprises less than about 0.15 dB/mm.
15. An electronic device, comprising:
an assembly comprising:
a ground plane;
a shield comprising:
a central portion;
a first side portion; and
a second side portion, the central portion situated between the first side portion and the second side portion;
a differential pair comprising first and second conductors, the first conductor situated laterally asymmetric between the central portion and the first side portion, the second conductor situated laterally asymmetric between the central portion and the second side portion;
a signal transmitter;
a signal receiver, the assembly for connecting the signal transmitter to the signal receiver, and conveying a signal from the signal transmitter to the signal receiver.
16. The device of claim 15 , wherein the assembly comprises a microstrip configuration.
17. The device of claim 15 , wherein the assembly comprises a stripline configuration.
18. An assembly, comprising:
a ground plane on a bottom surface;
a top surface opposite the bottom surface;
a central shield portion extending between the bottom surface and the top surface, the central shield portion comprising:
one or more central reference layers parallel the ground plane; and
one or more a via vertically coupling together the one or more central reference layers;
a first side shield portion on a first side of the assembly, spaced apart from the central shield portion by a first gap, the first side shield portion comprising:
one or more first side reference layers parallel the ground plane; and
one or more via vertically coupling together the one or more first side reference layers;
a second side shield portion on a second side of the assembly, spaced apart from the central shield portion by a second gap, the second side shield portion comprising:
one or more second side reference layers parallel the ground plane; and
one or more via vertically coupling together the one or more second side reference layers;
a first conductor situated laterally asymmetric in the first gap;
a second conductor situated laterally asymmetric in the second gap wherein the ratio of the distance from the first conductor to the central shield portion compared to the distance from the first conductor to the first side shield portion is about 1:1.5 to about 1:10; and
dielectric interspersed in and around the central shield portion, the first side shield portion, and the second side portion, the dielectric extending from the top surface to the bottom surface.
19. The assembly of claim 18 , wherein the ratio of the distance from the first conductor to the central shield portion compared to the distance from the first conductor to the first side shield portion is about equal to the ratio of the distance from the second conductor to the central shield portion compared to the distance from the second conductor to the second side shield portion.