Elements and technical features » History » Version 26

HAENNIG, Gerald, 12/15/2015 10:21 AM

1 23 GOMEZ, Ramon
{{toc}}
2 24 GOMEZ, Ramon
3 5 GOMEZ, Ramon
h1. 2.1 Elements 
4 1 GOMEZ, Ramon
5 21 HAENNIG, Gerald
h2. 2.1.1 Optical link : Radio Frequency Over Fiber
6 12 HAENNIG, Gerald
7 13 HAENNIG, Gerald
p=. !{width:700px}bloc_diagram.png!
8 14 HAENNIG, Gerald
Figure 1. Optical Link (source Miteq).
9 12 HAENNIG, Gerald
10 12 HAENNIG, Gerald
11 10 HAENNIG, Gerald
On optical link consists of :
12 17 HAENNIG, Gerald
* an optical transmitter ; it modulates input Radio Frequency (RF) signal onto the optical wavelength intensity. 
13 11 HAENNIG, Gerald
Optical intensity is varied either directly by varying Laser Diode current or indirectly through a Mach-Zehnder Modulator modulating a constant laser source.
14 10 HAENNIG, Gerald
* fiber optic : in general, monomode fiber optic is used to avoid dispersion especially for long link. Morever, wavelengths around 1300 nm are used as dispersion is minimum in this region.
15 10 HAENNIG, Gerald
* an optical receiver : it is based on a photodectector. It detects RF modulation on the optical wavelength and outputs the RF signal.
16 1 GOMEZ, Ramon
17 15 HAENNIG, Gerald
Such an optical link is referred to as Radio Over Fiber (RoF), as well.
18 14 HAENNIG, Gerald
19 10 HAENNIG, Gerald
The main parameters for an optical link are gain, bandwidth, Noise Figure (NF) and Spurious Free Dynamic Range (SFDR).   
20 1 GOMEZ, Ramon
21 1 GOMEZ, Ramon
MITEQ, Fiber optic products : https://www.miteq.com/docs/MITEQ_FiberOptic_c40.pdf
22 14 HAENNIG, Gerald
23 14 HAENNIG, Gerald
Main applications are 
24 22 GOMEZ, Ramon
* Antenna remoting : 
25 16 HAENNIG, Gerald
for satellite broadcast TV, signal is received on the antenna on the roof but actually demodulated in the tuner in the living room.
26 18 HAENNIG, Gerald
for teleports, Radio-frequency signal transport through optical fibres from Antenna to the main building (containing Modulator/Demodulator, Network Equipments).
27 22 GOMEZ, Ramon
* Signal distribution : 
28 16 HAENNIG, Gerald
for phased array radar application, it could be used to distribute the Local Oscillator to the different array elements.
29 16 HAENNIG, Gerald
for cable television (CATV : Community Antenna TeleVision) : to distribute the TV channels to the homes.
30 19 HAENNIG, Gerald
31 26 HAENNIG, Gerald
h2. 2.1.2 Antenna remoting : IF transport from Antenna Low Noise Block to Tuner/Demodulator for Satellite Broadcast TV
32 9 HAENNIG, Gerald
33 3 GOMEZ, Ramon
Earth stations are based on an indoor/outdoor unit architecture. In our system we will count on: 
34 1 GOMEZ, Ramon
35 8 GOMEZ, Ramon
* Outdoor: L-band reception antenna, the coaxial cable relying the antenna and the modulator transmitter (allows to convert from L-band to optic frequencies) and the 30m of Monomode FO. 
36 3 GOMEZ, Ramon
* Indoor: consists of the receiver L-band/optic demodulator and the coaxial cable to rely the demodulator with the TV. 
37 1 GOMEZ, Ramon
38 6 GOMEZ, Ramon
!schema.jpg!