2.3 Main Parameters

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

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 kilometres.
  • Optical Receiver ORX1900 from the manufacturer lynx-technik : it detects optical wavelength intensity modulation and outputs the RF modulating signal.

2.3.1.1 OTX1910 Optical Transmitter

OTX1910 Optical Transmitter
Figure 1. OTX1910 Optical Transmitter (source : lynx-technik website)

Optical transmitter OTX1910 min typ max Unit comments
Supply 9 12 14 V
Current consumption - - 450 mA
RF Input Connector 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 LC/PC single mode
Optical signal wavelength - 1310 - nm
Optical power level - 1 - dBm

2.3.1.2 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

2.3.1.3 ORX1900 Optical Receiver

ORX1900 Optical Receiver
Figure 2. 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 LC/PC single mode
Optical input signal wavelength range 1270 1310 1610 nm
Optical input signal level range -6 - 4 dBm
RF Output Connector 75 Ohm F-type
RF Input Frequency 700 - 2300 MHz

2.3.1.4 Overall Optical link with fiber length of 1 m

Lynx-technik technical provided us more technical specifications about the optical link. However, they did not 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

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
RF Loss @ 20°C - 0.9 - 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.

2.4 References

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