RF-over-Fiber
ViaLite is a technology for converting RF signals into optical signals for transmission over optical fibers. A typical system will consist of three main elements: an optical transmitter, a fiber optic cable and an optical receiver (to convert back to RF).
The system is defined in terms of normal RF parameters, i.e. gain, noise figure, linearity etc., and can be treated as an RF black box by a systems designer.
ViaLite systems use intensity modulation, which is amplitude modulation in the optical domain. The RF signal applied by the user to the optical transmitter directly modulates the intensity of a light source (e.g. a laser diode). There is no frequency conversion or analog-to-digital conversion involved. This technique results in the widest possible frequency response and highest possible dynamic range. At the optical receiver, the intensity modulated light is converted back into an RF signal using a high frequency photodiode.
Intensity modulation places very demanding requirements on all components in the optical path - particularly the laser diode. In ViaLite products, these components have been designed for optimum efficiency, noise and linearity performance.
So what is fiber optic technology?
Optical fiber is small in size, flexible, very low loss and a well established technology. It offers a number of inherent advantages over the use of coaxial cables or free-space transmission, including:
- very low loss (less than 0.5dB signal loss per km!)
- non-conductive medium, resulting in electrical isolation for safety and interference
- immunity to electrical interference
- easy deployment due to small size and flexibility of the rugged cable.
ViaLite fiber optic systems offer unbeatable advantages for the transmission of analog, RF and digital data signals over optical fiber, and are used for the replacement of conventional coaxial cable in many different applications.
The wide dynamic range and broadband nature of ViaLite technology supports the transmission of data of any modulation type with minimal degradation.
A diverse range of applications is catered for by ViaLite products optimised for specific applications including: teleports, satellite ground stations, satellite downlinks, VSAT, interfacility linking, cellular networks, antenna remoting, TV broadcast and GPS timing signal distribution.
Typical Applications
- Antenna remoting
- Satcom ground stations
- GPS timing distribution
- Tetra radio networking
- Communication links from DC-4GHz
- Military communications
- Broadcast VHF/UHF links
Key Benefits
- Maximum signal integrity
- Off-the-shelf delivery
- Future proof
- Safety and EMC advantages
- Rapid deployment
- Low loss RF transmission
- Well established technology
- Transparent to data format
- Non-conductive medium
- Industry-standard installation techniques