SOURCEFORGE » RALF » 2015 Evaluation and test of an optical / L-band tranceiver

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h1. 2.3 Main Parameters

This part lists the main specifications and highlights the main parameters to compare an optical link with a coaxial cable

h2. 2.3.1 Optical link

The optical link consists of :
* Optical transmitter OTX1910 from the manufacturer lynx-technik : it modulates the intensity of the optical 1320 nm wavelength with the RF input signal ;
* Monomode fiber 9/125 OS2 (to avoid dispersion effect) to optical signal on a distance up to 10 kilometers ;
* Optical Receiver ORX1900 from the manufacturer lynx-technik : it detects optical wavelength intensity modulation and outputs the RF modulating signal.

*Optical transmitter OTX1910*

p=. !{width:700px}OTX1910_Image.png!
Figure 1. OTX1910 Optical Transmitter (source : lynx-technik website)

p=.
|_. Optical transmitter OTX1910 |_. min |_. typ |_. max |_. Unit |_. comments |
|Supply |=. 9 |=. 12 |=. 14 |=. V |=. |
|Current consumption |=. - |=. - |=. 450 |=. mA |=. |
|RF Input Connector |\3=. 75 Ohm F-type |=. |=. |
|RF Return Loss |=. 14 |=. - |=. - |=. dB |=. |
|RF Maximum Input Level |=. - |=. - |=. 15 |=. dBm |=. |
|RF Input Dynamic Range |=. -65 |=. - |=. -10 |=. dBm |=. |
|RF Input Frequency |=. 700 |=. - |=. 2300 |=. MHz |=. |
|Optical Connecctor |\3=. LC/PC single mode |=. |=. |
|Optical signal wavelength |=. - |=. 1310 |=. - |=. nm |=. |
|Optical power level |=. - |=. 1 |=. - |=. dBm |=. |

*Fiber Monomode 9/125 OS2 (G.652.D ITU-T compliant), low dispersion at 1320 nm*

|_. Fiber Optic |_. min |_. typ |_. max |_. Unit |_. comments |
| Optical Loss |=. - |=. 0.3 |=. - |=. dB/km |=. 1320 nm |

*Optical receiver ORX1900*

p=. !{width:700px}ORX1900_Image.png!
Figure 1. ORX1900 Optical Receiver (source : lynx-technik website)

|_. Optical receiver ORX1900 |_. min |_. typ |_. max |_. Unit |_. comments |
|Supply |=. 9 |=. 12 |=. 14 |=. V |=. |
|Current consumption |=. - |=. 240 |=. - |=. mA |=. |
|Optical Input Connector |\3=. LC/PC single mode |=. |=. |
|Optical input signal wavelength range |=. 1270 |=. 1310 |=. 1610 |=. nm |=. |
|Optical input signal level range |=. -6 |=. - |=. 4 |=. dBm |=. |
|RF Output Connector |\3=. 75 Ohm F-type |=. |=. |
|RF Input Frequency |=. 700 |=. - |=. 2300 |=. MHz |=. |

*Overall Optical link with fiber length of 1 m*

Lynx-technik technical provided us more technical specifications about the optical link.

However, they do have any phase noise measurements.

|_. Optical link with fiber length of 1 m |_. min |_. typ |_. max |_. Unit |_. comments |
|Noise Figure |=. - |=. - |=. 31 |=. dB |=. |
|Carrier to Noise Ratio |=. 55 |=. - |=. - |=. dB |=. Pin=-13 dBm, Fiber=1 m |
|SFDR |=. 102 |=. - |=. - |=. dB/Hz2/3 |=. Pin=-13 dBm, IM3=50 dBc|
|IIP3 |=. 12 | - |=. - |=. dBm |=. Pin=-13 dBm, IM3=50 dBc|

h2. 2.3.2 Coaxial cable

*The optical link is a replacement of a coaxial cable EN50117-6 11PATC/PH 1.7/6.9 Class A 3GHz (B93) 17/13 139m.*

|_. COAXIAL CABLE |_. min |_. typ |_. max |_. Unit |_. comments |
|/12. RF Loss @ 20°C |=. - |=. 0.9 |=. - |/12. dB/100m |=. 5 MHz |
| - |=. 2.7 |=. - |=. 50 MHz |
| - |=. 3.8 |=. - |=. 100 MHz |
| - |=. 5.4 |=. - |=. 200 MHz |
| - |=. 7.7 |=. - |=.400 MHz |
| - |=. 11 |=.- |=. 800 MHz |
| - |=. 11.5 |=. - |=. 862 MHz |
| - |=. 12.1 |=. - |=. 950 MHz |
| - |=. 14.6 |=. - |=. 1350 MHz |
| - |=. 16.7 |=. - |=. 1750 MHz |
| - |=. 18.7 |=. - |=. 2150 MHz |
| - |=. 22.3 |=. - |=. 3000 MHz |
| IIP3 |=. 50 |=. - |=. - |=. dBm |=. Estimation |

IIP3 is only an estimation to be compared with optical link : this value is deemed quite conservative due to the fact the cable is a passive component.

h2. 2.4 References

lynx-technik web site : http://www.lynx-technik.com/en/home/
Latest OTX1910 transmitter datasheet : http://media.lynx-technik.de/uploads/tx_lynx/product/pdf/OTX1910-rev3.pdf
Latest ORX1900 receiver datasheet : http://media.lynx-technik.de/uploads/tx_lynx/product/pdf/ORX1900-rev3.pdf