Economical boosted high speed data cable
A high speed video cable carries signals according to the High-Definition Multimedia Interface (HDMI), and includes a raw cable and a boost device. Each of four high speed video signals is carried on the inner conductors of a pair of coaxial lines in the raw cable. Lower speed signals are carried on the galvanically or capacitively coupled shields of a pair of coaxial lines.
1. A cable for carrying a high speed differential digital data signals and one or more auxiliary signals between a source device and a sink device according to a cable specification, the cable comprising:
a raw cable, comprising a split dual shielded cable element, comprising two shielded conductors, each of said two shielded conductors being enclosed in an individual shield, wherein the individual shield of the first shielded conductor electrically couples a first auxiliary signal from the source device to the sink device;
a coupling capacitor capacitively coupling the first individual shield of the split dual shielded cable element to the second individual shield of the split dual shielded cable element; and wherein:
the shielded conductors of the split dual shielded cable element are designated for carrying the high speed differential digital data signal.
2. The cable of claim 1 , wherein capacitance of the coupling capacitor is chosen to be low enough not to cause cross talk between low speed auxiliary signals, but high enough to preserve transmission characteristics of the dual shielded cable element with respect of the high speed differential signal.
3. The cable of claim 1 , further comprising a boost device for boosting the high speed differential digital data signals.
4. The cable of claim 1 , the raw cable further comprising a dual shielded cable element, comprising two shielded conductors and a common shield;
wherein:
the two shielded conductors of the dual shielded cable elements are designated for carrying a respective high speed differential digital data signal; and
the common shield of the shielded conductors is designated for carrying an additional auxiliary signals.
5. The cable of claim 4 , wherein the raw cable comprises only two split dual shielded cable elements, and two dual shielded cable elements, each dual shielded element comprising two shielded conductors and a common shield.
6. The cable of claim 4 , wherein the dual shielded cable element is a dual coaxial element, comprising two coaxial lines whose shields are joined, and said shields of each coaxial line enclosing a respective shielded conductor.
7. The cable of claim 1 , further comprising a first circuit carrier for connecting the raw cable to the source device, and a second circuit carrier for connecting the raw cable to the sink device.
8. The cable of claim 7 , wherein the first circuit carrier comprises:
terminals for connecting the high speed differential digital data signal from the source device to respective shielded conductors of the split dual shielded cable element; and
terminals for connecting respective auxiliary signals from the source device to the individual shields respectively.
9. The cable of claim 7 , wherein the second circuit carrier comprises:
terminals for connecting the high speed differential digital data signals from respective shielded conductors of the split dual shielded cable element to the sink device; and
terminals for connecting respective auxiliary signals from the individual shields to the sink device.
10. The cable of claim 1 , wherein capacitance of the coupling capacitor is about 1 nF.
11. The cable of claim 1 , wherein the cable specification is a High-Definition Multimedia Interface (HDMI) standard.
12. The cable of claim 1 , wherein the individual shields of the split dual shielded cable element are designated for carrying Power and Ground auxiliary signals.
13. The cable of claim 1 , wherein the individual shields of the split dual shielded cable element are designated for carrying a Hot Plug Detect (HPD) auxiliary signal and CEC (Consumer Electronics Control) auxiliary signal.
14. The cable of claim 1 , wherein the cable specification is a DisplayPort standard.
15. The cable of claim 1 , wherein said split dual shielded cable element is a split dual coaxial element, comprising two coaxial lines whose shields are capacitively coupled to one another, and each coaxial line enclosing one shielded conductor.
16. A method for transmitting a high speed differential digital data signal and one or more auxiliary signals between a source device and a sink device according to a cable specification over a cable extending between the source device and the sink device, the method comprising:
carrying the high speed differential digital data signal over the cable in two shielded conductors of a split shielded cable element, each of the two shielded conductors having an individual shield;
capacitively coupling the individual shields of the split dual shielded cable element through a coupling capacitor; and
carrying said one or more auxiliary signals on respective individual shields of the shielded conductors.
17. The method of claim 16 , further comprising carrying yet another auxiliary signal on a common shield of a dual shielded cable element comprising two shielded conductors and the common shield.
18. The method of claim 16 , wherein the carrying is performed according to the cable specification, which is a High Definition Multimedia Interface (HDMI) standard or a DisplayPort standard.