Motorola SG 2000 ユーザーズマニュアル

5 - 2 0   O p e r a t i o n  

The DS-SG2-DRT/A is an SG2 return transmitter that digitizes a single analog 5 MHz-42 MHz 
return-path signal to produce a 1.6 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 automatic power control (APC) system regulates the optical output power from the 
laser. User-accessible input level-control adjustments enable you to adjust the transmitter 

+

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/A fits the same footprint and has the same set-up 
levels as the analog return transmitters. 

Figure 5-21 illustrates a block diagram of the DS-SG2-DRT/A: 

Serializer

Transmit

signal

processing

logic

A/D

converter

RF

XFMR

XO

Anti-

aliasing

LPF

Return

band RF

5-42 MHz

CATV

gain block

Digital

lightwave to

SG2 output

Optical transmitter module

Serial bit

stream

@1.6 Gbps

Optical

TP

RF TP

XO

 

Figure 5-22 illustrates the DS-SG2-DRT/A and attached cable: 

Test

Point

A

 

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