• Table of contents
• 2.3 Main Parameters
  • 2.3.1 Optical link
  • 2.3.2 Coaxial cable
  • 2.4 References

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

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

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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

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

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

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

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