Motorola SG 2000 operation manual DS SG2 DRT 2X/A Digital Return Transmitter, DS-SG2-DRT-2X/A

5 - 2 2 O p e r a t i o n

DS - SG2 - DRT - 2X/A Digital Return Transmitter

The DS-SG2-DRT-2X/A is an SG2 return transmitter that digitizes two independent analog

5 MHz-42 MHz return-path signals to produce two 1.25 Gbps data streams. These two data streams are then multiplexed to create a 2.5 Gbps data stream. This data stream is then routed to a digital laser for transmission to a corresponding digital return receiver.

The transmitter can be configured with a digital laser wavelength that is applicable to the required link length. An APC system regulates the optical output power from the laser. Two user-accessible input level-control adjustments enable you to independently adjust the transmitter input levels + 2 to

−13 dB from an input level of 15 dBmV. All transmitter status-monitor information is available at the digital return receiver.

To facilitate easy upgrades, the DS-SG2-DRT-2X/A fits the same footprint and has the same set-up levels as the analog return transmitters.

Figure 5-23 illustrates a block diagram of the DS-SG2-DRT-2X/A:

Figure 5-23

DS-SG2-DRT-2X/A

Return

band RF 5-42 MHz

	Anti-	RF	A/D
	aliasing
		XFMR	converter	Serial bit	Digital
	LPF
CATV				stream	lightwave to
				@2.5 Gbps	SG2 output
gain block

Transmit

signal

XOprocessing Serializer logic

Return

band RFOptical transmitter module 5-42 MHz

	Anti-	RF	A/D
	aliasing
		XFMR	converter
	LPF
				XO
CATV
gain block

Figure 5-24 illustrates the DS-SG2-DRT-2X/A and attached cable:

Figure 5-24

DS-SG2-DRT-2X/A

RF INPUT B

	Digital Transmitter
STATUS DS-SG2-DRT-2X/A		INPUT
	1310 DFB	B

Test	Test
Point	Point
A	B

You can gain access to test point A through the transmitter test cable MCX-F (DS-SG2-DRT-TC, P/N 476803-001).

SG 2000 Installation and O peration Manual