Telecommunications chassis having a repeater card
View Patent ↗A chassis and associated telecommunication circuit card are disclosed. The chassis has heat dissipation and flame containment features while accommodating a high density of the circuitry cards. Embodiments include an inner housing with a double-layer middle floor dividing the chassis into top and bottom chambers. Each layer has partially aligned slots, and an air gap is provided between the two layers. Embodiments also include a double-layer mesh cover with an air gap existing between the two mesh layers. Projections and grooves are provided on the inner surfaces of the inner housing to receive circuit cards having a guide on one edge and a fin on another. The circuit card includes conductor structures such as multiple board layers with paired and segregated conductors. The circuit card also includes some components positioned to cooperate with the ventilation features of the chassis and includes some components chosen for low-power consumption or reduced flammability.
1. A repeater card, comprising:
a printed circuit board having a ground layer and a power layer separated by a dielectric with the ground layer having a chassis ground plane, a logic ground plane, and a first channel ground plane, and with the power layer having a logic power plane and a first channel power plane, wherein the logic ground plane substantially overlaps with the logic power plane and the first channel ground plane substantially overlaps with the first channel power plane;
a DC-DC converter mounted to the printed circuit board and electrically linked to the logic ground plane, the logic power plane, the first channel ground plane, the first channel power plane, and the chassis ground plane;
a transceiver mounted to the printed circuit board and electrically linked to the DC-DC converter through the logic ground plane, the logic power plane, the first channel ground plane, and the first channel power plane; and
a first amplifier mounted to the printed circuit board and electrically linked to the transceiver, the first amplifier also being electrically linked to the DC-DC converter through the first channel ground plane and the first channel power plane; and
further comprising a second amplifier mounted to the printed circuit board and electrically linked to the transceiver, and wherein the ground layer also has a second channel ground plane and the power layer has a second channel power plane, wherein the second channel ground plane substantially overlaps with the second channel power plane and wherein the transceiver, the second amplifier, and the DC-DC converter are electrically linked to the second channel ground plane and the second channel power plane.
2. The repeater card of claim 1 , wherein the chassis ground plane is disposed on a periphery of the printed circuit board surrounding the logic ground plane and the first channel ground plane.
3. The repeater card of claim 1 , wherein the printed circuit board has a component layer and wherein the DC-DC converter, the transceiver, and the first amplifier are attached to the component layer, the repeater card further comprising an input isolation transformer mounted to the component layer and electrically linked to the first amplifier with the first amplifier being positioned between the isolation transformer and the transceiver, and the repeater card further comprising an output isolation transformer mounted to the component layer and electrically linked to the transceiver with the distance between the output isolation transformer and the transceiver being less than one and one-third inches.
4. The repeater card of claim 1 , wherein the transceiver has a combination of connections to the logic power plane and the logic ground plane with the combination controlling an output signal level and an output signal shape of the transceiver.
5. The repeater card of claim 1 , further comprising:
a first diode electrically connected between a tip output of the transceiver and the first channel power plane;
a second diode electrically connected between a ring output of the transceiver and the first channel ground plane;
a third diode electrically connected between the tip output of the transceiver and the first channel ground plane; and
a fourth diode electrically connected between the ring output of the transceiver and the first channel power plane, wherein the first, second, third, and fourth diodes are positioned over the overlapping first channel power plane and first channel ground plane.
6. The repeater card of claim 2 , further comprising:
a fin disposed on a first edge of the periphery of the printed circuit board; and
a guide disposed on a second edge of the periphery of the printed circuit board opposite the first edge.
7. The repeater card of claim 5 , further comprising a transient suppressor electrically linked to the logic power plane, the logic ground plane, the first channel power plane, the first channel ground plane, and the chassis ground plane.
8. The repeater card of claim 6 , further comprising a faceplate disposed on a third edge of the periphery of the printed circuit board with the faceplate being electrically connected to the chassis ground plane.