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1)General
The unit applies the imported highly linear DFB laser of low noise, big transmission capability and small nonlinear distortion. It is completed with reliable APC (Automatic Power Control) circuit for light power output and ATC (Automatic Temperature Control) for thermo-electric cooler, MGC (Manual Gain Control) and AGC (Automatic Gain Control) circuit for input radio-frequency current drive. AGC applies the automatic digital processing technology for radio frequency power, by which the driving level power can be automatically processed according to the level of input radio frequency and the channel quantity, and the output level of the optical receiver can keep constant to maintain the CSO, CTB and C/N indexes at the optimum state all the time, thus to ensure the stable operation of the chain indexes and the laser all through its service life.
A GaAs element is adopted as the preamplifier, which not only lowers the input level and adds a radio frequency predistortion circuit, but also enhances the CSO, CTB and C/N indexes. The built-in microprocessor software provides multiple functions including real-time monitoring for the transmitter operating state, digital display, aural-visual alarm and network management. Once an operational parameter of the laser runs out of the preconfigured allowable range, the power supply to the laser will be automatically switched off, and the red indicator will flash for warning. The embedded blue screen LCD on the front panel indicates various tasks of the unit, parameters and fault messages in Chinese distinctly.
The optical transmitter provides standards RS-232 and RS-485 interfaces for network management and remote monitoring.
The optical transmitter applies standard 19” 1U rack, which is provided with high efficient switching power supply for transmitting CATV, telephone, and digital or compressed digital messages.
2). Main Parameters
1. Optical characteristics:
Output light wavelength: 1310±30 nm, single mode
Output light power: ≥2 MW
Type of optical connector: FC/APC (optional)
Light reflection loss: ≥45 dB
2. Radio frequency parameters:
System bandwidth: 45-860 MHz
In-band unflatness: <±0.75dB
Input radio requency level: 72-88dBuV
Input impedance: 75Ω
Reflection loss: ≥16dB, (47~550) MHZ; ≥14dB (550~862) MHZ
3. Chain characteristics:
Carrier-to-noise ratio CNR: ≥51dB, CSO: ≤-60dB, CTB: ≤-65dBc
4. Range of AGC control: ±8dB; Range of MGC control: ±8dB
5. Power supply requirement:
Power supply: ~250~160V/50Hz
Dissipation power: ≤30W
6. Environmental parameters:
Working ambient temperature: 0~45°C
Storage temperature: -20~65°C
Humidity: 5-95%, no condensation
7. Physical parameters:
Outside dimensions: 19″×14.3″×1.8″
Whole-set weight: <3Kg |
1310 nm Optical Transmitter SXT86 (75) III