Disk drive comprising stacked and stepped traces for improved transmission line performance
View Patent ↗A disk drive is disclosed comprising a disk, a head actuated over the disk, a preamp, and an interconnect for coupling the head to the preamp. The interconnect comprises a first transmission line stacked over a second transmission line, and a dielectric between the first transmission line and second transmission line. A shape of the first and second transmission lines varies along a length of the interconnect such that the interconnect comprises an approximation of an inductor/capacitor ladder network.
1. A disk drive comprising:
a disk;
a head actuated over the disk;
a preamp; and
an interconnect comprising a first transmission line stacked over a second transmission line, and a dielectric between the first transmission line and second transmission line, the interconnect for coupling the head to the preamp, wherein a shape of the first and second transmission lines varies along a length of the interconnect such that the interconnect comprises an approximation of an inductor/capacitor ladder network.
2. The disk drive as recited in claim 1 , wherein the shape of the first and second transmission lines comprises a width of the first and second transmission lines.
3. The disk drive as recited in claim 2 , wherein the width of the first transmission line varies symmetrically with the width of the second transmission line.
4. The disk drive as recited in claim 1 , wherein:
the first transmission line comprises a first segment;
the second transmission line comprises a second segment symmetric with the first segment;
the first transmission line comprises a third segment;
the second transmission line comprises a fourth segment symmetric with the third segment;
the first segment forms a first series inductance;
the second segment forms a second series inductance; and
the third and fourth segments form a shunt capacitance.
5. The disk drive as recited in claim 4 , wherein a width of the first and second segments is less than a width of the third and fourth segments.
6. The disk drive as recited in claim 1 , wherein the interconnect comprises a substantially constant group delay over a frequency band of at least one of a read signal and a write signal.
7. The disk drive as recited in claim 6 , wherein the interconnect comprises a substantially constant magnitude response over a frequency band of at least one of a read signal and a write signal.
8. The disk drive as recited in claim 1 , wherein the interconnect comprises a substantially constant magnitude response over a frequency band of at least one of a read signal and a write signal.
9. The disk drive as recited in claim 1 , wherein a shape of the first and second transmission lines varies along a length of the interconnect such that the interconnect comprises an approximation of an inductor/capacitor lattice network.
10. The disk drive as recited in claim 9 , wherein the lattice network flattens a group delay of the interconnect.
11. A suspension for use in a disk drive, the suspension comprising an interconnect comprising a first transmission line stacked over a second transmission line, and a dielectric between the first transmission line and second transmission line, the interconnect for coupling a head to a preamp, wherein a shape of the first and second transmission lines varies along a length of the interconnect such that the interconnect comprises an approximation of an inductor/capacitor ladder network.
12. The suspension as recited in claim 11 , wherein the shape of the first and second transmission lines comprises a width of the first and second transmission lines.
13. The suspension as recited in claim 12 , wherein the width of the first transmission line varies symmetrically with the width of the second transmission line.
14. The suspension as recited in claim 11 , wherein:
the first transmission line comprises a first segment;
the second transmission line comprises a second segment symmetric with the first segment;
the first transmission line comprises a third segment;
the second transmission line comprises a fourth segment symmetric with the third segment;
the first segment forms a first series inductance;
the second segment forms a second series inductance; and
the third and fourth segments form a shunt capacitance.
15. The suspension as recited in claim 14 , wherein a width of the first and second segments is less than a width of the third and fourth segments.
16. The suspension as recited in claim 11 , wherein the interconnect comprises a substantially constant group delay over a frequency band of at least one of a read signal and a write signal.
17. The suspension as recited in claim 16 , wherein the interconnect comprises a substantially constant magnitude response over a frequency band of at least one of a read signal and a write signal.
18. The suspension as recited in claim 11 , wherein the interconnect comprises a substantially constant magnitude response over a frequency band of at least one of a read signal and a write signal.
19. The suspension as recited in claim 11 , wherein a shape of the first and second transmission lines varies along a length of the interconnect such that the interconnect comprises an approximation of an inductor/capacitor lattice network.
20. The suspension as recited in claim 19 , wherein the lattice network flattens a group delay of the interconnect.
21. A disk drive comprising:
a disk;
a head actuated over the disk;
a preamp; and
an interconnect comprising a first transmission line and a second transmission line forming an approximation of at least one inductor/capacitor ladder network and an approximation of at least one inductor/capacitor lattice network,
wherein the interconnect comprises a substantially constant group delay over a frequency band of at least one of a read signal and a write signal.
22. The disk drive as recited in claim 21 , wherein the lattice network flattens a group delay of the interconnect.
23. A suspension for use in a disk drive, the suspension comprising an interconnect comprising a first transmission line and a second transmission line forming an approximation of at least one inductor/capacitor ladder network and an approximation of at least one inductor/capacitor lattice network, wherein the interconnect comprises a substantially constant group delay over a frequency band of at least one of a read signal and a write signal.
24. The suspension as recited in claim 23 , wherein the lattice network flattens a group delay of the interconnect.
25. A disk drive comprising:
a disk;
a head actuated over the disk;
a preamp; and
an interconnect comprising a first transmission line and a second transmission line forming an approximation of at least one inductor/capacitor ladder network and an approximation of at least one inductor/capacitor lattice network,
wherein the lattice network flattens a group delay of the interconnect.
26. A suspension for use in a disk drive, the suspension comprising an interconnect comprising a first transmission line and a second transmission line forming an approximation of at least one inductor/capacitor ladder network and an approximation of at least one inductor/capacitor lattice network, wherein the lattice network flattens a group delay of the interconnect.