Product Description

1. Product Summary
Optical transmitter is the most important equipment to construct the CATV HFC network. It mainly used for the long distance optical fiber transmission of TV image signal, digital television signal, telephone voice signal and data (or compressed data) signal. This product does use the high-performance DFB laser as the optical source. The RF drive part adopts RF power digital automatic processing technology and advanced RF pre-distortion circuit, and built-in microcomputer automatic monitoring system, to ensure the excellent performance indicators.

2. Performance characteristics

Adopt high-performance coaxial/butterfly DFB laser, narrow spectral lines, good linearity and high output power.
The RF drive part adopts the RF power digital automatic processing technology. Automatic processing the drive level power according to the RF input signal level and the number of channels (15-84 channels), make the CSO, CTB and C/N index always at the optimal value to ensure the overall performance.
Advanced multi-frequency RF pre-distortion technology, combined with the GaAs device, effectively improve the CATV system most important CTB and CSO index, C/N index also gets the maximum upgrade.
Adopt advanced 32 bit processor; coordinate with perfect automatic monitoring system circuit. It can timely and accurately monitor working status of the laser to ensure a stable optical output power and effectively extend the working life of the laser.
Built-in blue screen 160×32 dot matrix LCD monitor on the front panel, accurately showing all working status parameters.
19″1U standard rack mount, equipped standard IEEE802.3 10Base-T Ethernet interface and RS232 interface, can expediently realize network management monitoring.
Fully support <GB/T 20030-2005 HFC Network device management system specification>.

3. Technology Parameters
3.1 Link test conditions
Special instructions: The performance parameters of this manual according to the measuring method of GY/T 143-2000 <Specifications and methods of measurement on AM optical transmitter and receiver used in CATV systems>, and tested under the specified test conditions.
Test condition: With standard optical fiber and standard optical receiver composed the test link. Set 84 PAL-D analog TV channel signal at 750MHz frequency range under the specified link loss. When the optical input power of optical receiver is -1dBm, measure the C/CTB, C/CSO and C/N.

3.2 Technique Parameters Table

Item

Unit

Technique parameters

Optical output power

mW

4

6

8

10

12

14

16

18

20

22

24

26

28

30

Optical link loss

dB

7

9

10

11

11.8

12.5

13

13.6

14

14.4

14.8

15.1

15.5

15.8

Optical wavelength

nm

1310±20

Laser type

DFB laser

Optical modulation mode

Direct optical intensity modulation

Optical connector type

FC/APC or SC/APC

Frequency range

MHz

47-750/862/1003

RF input level

dBuV

72-88

Flatness in band

dB

±0.75

RF input impedance

Ω

75

Input return loss

dB

≥ 16(47-550MHz); ≥ 14(550-750/862/1003MHz)

C/CSO

dB

≥ 60

C/CTB

dB

≥ 65

C/N

dB

≥ 51

AGC control range

dB

±5

MGC control range

dB

0-10

Power supply voltage

V

AC 110V-250V(50Hz)

Consumption

W

30

Operating temperature

ºC

0 -- 45

Storage temperature

ºC

-20 -- +65

Relative humidity

%

Max 95% no condensation

Dimension

mm

483(L)×380(W)×44(H)

3.3 Optical link carrier to noise ratio degradation table

Optical power	Optical link loss (dB)
Optical power	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18
4mW	53.8	52.8	51.8	51	50.1	49.2	48.2
6mW				53.0	52.0	51.0	50.1	49.1	48.1
8mW					52.8	51.9	51.0	50.1	49.2	48.2
10mW						52.9	51.9	51.0	50.1	49.1	48.2
12mW							52.7	51.8	50.8	49.9	49.0	48.0
14mW								52.4	51.5	50.5	49.5	48.6	47.8
16mW									52.0	51.0	50.1	49.1	48.1
18mW									52.5	51.6	50.6	49.7	48.7	47.9
20mW										51.9	51.0	50.0	49.0	48.0
22mW										52.2	51.4	50.4	49.4	48.6	47.8
24mW											51.5	50.3	49.2	48.5	47.7
26mW											51.5	50.2	49.2	48.5	47.6