Optical Zonu Satcom RF over Fiber signal transport solutions provide seamless coverage for all antenna systems regardless of operating environment. RF over Fiber provides a simple, cost-effective and reliable RF connection between satellite antenna and modem in those instances where coaxial cable is impractical.

There are many advantages of transporting RF signals over fiber as opposed to coaxial cable. A primary reason for fiber transport is the high RF attenuation of coaxial cabling. For example, at 6 GHz, the RF attenuation of RG-6 is ~30 dB over 100 feet. On the other hand, RF loss through fiber is ~ 0.7 dB/km independent of RF frequency. Optical Zonu fiber links transport from UHF/VHF up to Ka-Band, and above. An additional benefit of transporting RF signals over fiber is security. Optical fiber does not radiate electromagnetic energy; therefore, it is not easily detected.

Typically, the RFoF or analog over fiber Satcom links receive the down-converted satellite signals from a remote Antenna and carry them to other locations which may be 100s of meters to kilometers away. High quality low-loss coax is very bulky and expensive. Coaxial cable often has a large diameter, making it inflexible and difficult to manipulate. There is also a direct electrical connection between the antenna and expensive receiver equipment. This direct electrical connection may conduct destructive electrical surges from environmental sources such as lightning.

Due to low received signal level at the antenna site, it is critical to have a low Noise figure RFoF link, in order to transport such signals without noise contamination. Optical Zonu offers built-in Low Noise Figure amplifiers in the optical transmitter to reduce the optical link NF to as low as 12 dB, improving signal quality substantially for these applications.

Optical fiber operates by transmitting light along a dielectric glass fiber, rather than electrical signals over copper wires. This provides a highly secure, tamper-resistant medium for signal transfer, minimizing security risks and unauthorized signal interception concerns. Light is also unaffected by electro-magnetic interference, allowing signals to be transmitted unaffected through electrically noisy environments.

Optical Zonu offers a wide range of products in a variety of form factors for a variety of applications. Fiber optic Inter-Facility Links (IFL) are capable of providing long or short distance uplink/downlink solutions which may be achieved using cost-effective isolated DFB lasers. Professional and more demanding long distance or multi-carrier CWDM applications may be met using wide dynamic range, cooled or uncooled DFB Lasers – delivering excellent signal quality in a variety of conditions.

Optical Zonu fiber transmitters are available in CWDM and DWDM wavelengths, hence multiple RF signals may be multiplexed onto a single fiber for transport. Optical Zonu subsystem solutions may be monitored and controlled via SNMP v2 and v3. Optical Zonu also provides Ethernet over fiber datalinks for the purpose of data transport, as well as facilitating the monitoring of remote equipment over fiber.

FAQ
 For Satellite Communication Feeder line (RFoF)

What is RF over Fiber (RFoF)? And why 6 GHz is critical?

6 GHz RF over Fiber (RFoF) is a signal transport architecture that carries analog radio frequency signals over fiber optic cable rather than traditional coaxial cable. Instead of converting the signal into digital data packets, RFoF preserves the original analog waveform and transports it optically between the antenna and indoor equipment. This approach combines the performance advantages of fiber optics with the simplicity of analog RF transport.  The 6GHz enables very high instantaneous bandwidth that current digital system can’t duplicate.

How does RFoF work?

In an RFoF system, the analog RF signal is connected directly to an optical transmitter located near the antenna. A high-linearity laser converts the electrical RF signal into corresponding variations in light intensity. The optical signal then travels over single-mode fiber to the receiving equipment, where a photodiode converts the light back into an identical analog RF signal. Because the process is transparent to the communications protocol, the original signal characteristics are preserved throughout the transport path, allowing it to accommodate spread-spectrum and other advanced modulation techniques to remain future-proof.

Where is 6 GHz RFoF commonly used?

6 GHz RFoF is widely used in satellite ground stations, teleports, gateway facilities, defense communications networks, and telecommunications infrastructure. It is valuable in applications where long-distance signal transport, wide bandwidth support, low latency, and high signal fidelity are critical requirements.  It is currently in wide deployment of commercial services worldwide.

Why is fiber optic cable used instead of coaxial cable?

Fiber optic cable offers significantly lower signal loss over long distances than coaxial cable. This allows operators to place antennas much farther from indoor equipment without degrading signal quality. Fiber is also immune to electromagnetic interference, helping protect sensitive satellite and telecommunications signals from external noise sources. You can imagine the benefits this has in any mission critical situation whether commercial or military.

Why is the architecture designed for up to 6 GHz?

The 6 GHz range is a great balance between performance, flexibility, and commercial deployment requirements. Operators can transport much wider bandwidths than traditional L-Band intermediate frequency systems while supporting a broad range of satellite and telecommunications applications. The frequency range also aligns well with C-Band operations, allowing native RF signals to be transported directly over fiber without requiring additional frequency conversion at the antenna.

How does 6 GHz RFoF improve on traditional L-Band architectures?

Traditional satellite ground systems often rely on L-Band intermediate frequencies to minimize signal loss in coaxial cable. With RFoF, the low-loss characteristics of fiber remove many of these constraints. Operators can transport wider sections of spectrum at higher intermediate frequencies, providing greater flexibility for modern high-capacity satellite services while reducing the limitations associated with crowded L-Band infrastructure.

How does RFoF compare with Digital Intermediate Frequency (IF) architectures?

RFoF and Digital IF architectures address similar transport requirements but use different approaches. RFoF maintains the signal in its original analog form, while Digital IF systems convert the RF signal into digital data for transport over IP networks. RFoF is valued for its simplicity, low latency, and ability to handle wide bandwidths without requiring high-speed analog-to-digital conversion. On the other hand, Digital IF systems often provide greater flexibility for routing and distributing signals across standard network infrastructure.

What are the performance advantages of RFoF?

Because RFoF transports the signal as an analog waveform, it avoids the need for high-speed analog-to-digital converters at the antenna. It provides higher instantaneous bandwidth with higher dynamic range while eliminating quantization noise and minimizing processing latency. RFoF systems can also support very wide instantaneous bandwidths, making them well suited for demanding satellite communications and telecommunications applications. However, using RFoF effectively requires specialized design that is not currently produced for mass markets and should not be treated as a commodity purchase.

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