Phase-Matched WDM RF over Fiber multi-link system

RFOptic’s phase-matched WDM RF over Fiber (RFoF) multi-link systems represent an innovation in high-frequency signal transmission. Our phase match technology is available for all RFoF product lines and covers frequencies from 1MHz to 67GHz. In certain applications, particularly airborne and maritime, maintaining precise phase alignment over long distances is essential. Excellent phase match results for systems including 6 RFoF links were demonstrated proving reliable performance over wide temperature and frequency ranges. These solutions were deployed in military compatible enclosures and are reproducible due to the development of suitable production support tools and procedures. These RFoF systems find many applications in Direction Finding (DF) radar and EW systems as well as in other applications which are based on interferometry and phased arrays. Integrated remote and local management solutions enhance usability and maintenance efficiency.

When are RF over Fiber phase matched links superior to coax?

Phase-Matched WDM RF over Fiber multi-link system was rewritten
Header was rewritten to “When are RF over Fiber phase matched links superior to coax?”
RFoF phase matched solutions offer exceptionally wideband, low-loss performance and a lightweight solution that is stable over temperature, immune to electromagnetic interference (EMI) and is insensitive to bending. These are far superior to the low bandwidth, high loss and weight of phase matched coaxial cables. In many high frequency or long distance applications RFoF is an enabling technology for applications otherwise impossible using coax cables. RFOptic’s phase match multi-link technology facilitates phase matching across kilometers, enabling reliable source triangulation and analysis. In other applications including airborne deployments, RFoF phase matched solutions offer substantial reduced weight, immunity to RFI and overall lower power consumption since high power RF amplifiers must be used to drive coaxial cables to maintain SNR.

Key characteristics

The RFOptic WDM RFoF system is engineered for high performance, featuring phase match of ±10° up to 18GHz and similarly up to 40GHz. It may be configured with low-noise pre-amplifiers. The multi-link system maintains gain matching of ±1dB and operates over a temperature range of 40°C to +70°C. Its low noise figure allows for optimal performance in low signal scenarios. The system supports remote management via Ethernet webserver or local management through a USB connection with a free app. It can be deployed in indoor, outdoor and custom military enclosures.

Main Applications

RFOptic’s WDM RFoF phase match multi-link RFoF system targets the radar and EW markets. It is an ideal solution for remoting DF antennas and various phased array antennas. It is also useful to deliver signals to MIMO arrays to allow spatial management of radiated power for communication. These solutions are available across an extensive frequency range, supporting signals from 1MHz to 67GHz. Wide bandwidth solutions are useful for applications in radar systems and electronic warfare.

System Configuration (Example)

The phase match system is designed for precise signal triangulation and source localization using multiple RF over Fiber (RFoF) links. Typically, these links connect a quadrant array of antennas to a processing unit which uses the received phase of an incoming signal, slightly different for each of the antennas, to identify the direction of that signal. Such surveillance systems operate continuously and in all weather conditions and therefore the RFoF subsystem must function reliably under the same conditions. The antenna array is typically mounted on a fixed tower along with several support antennas that are used to calibrate the DF system and to illuminate the target in case of an active, radar type system. To add elevation detection to the system, an additional quadrant antenna array is placed above or below the first.

The system is provided with one terminal, installed near the antenna tower, housed in an outdoor enclosure. That terminal features multiplexed RFoF transmitters that convert RF signals into optical signals for fiber transmission. The second terminal includes several receivers which are installed in a 19” rack mounted indoor enclosure. The RFoF converter converts the optical signals into the separate RF signals which are routed to the DF system processor. The system achieves better than ±10° of phase match accuracy over frequency, temperature and across multiple RFoF links, crucial for precise localization. The system supports a wide frequency range to accommodate various RF applications. Its robust outdoor enclosure is built for durability in extreme conditions, ensuring reliable operation. Fiber optic connections reduce signal loss and enhance bandwidth, making the system a powerful solution for accurate direction-finding systems.

Monitoring & Control

RFOptic’s multi-link products can be configured to include remote Management and Control (M&C) options for effective monitoring over IP, supporting protocols like HTML, REST, and SNMP V2c. The M&C interface enables independent management of RFoF modules, providing user-friendly monitoring, event log, alerts and control. Additional options include logical channels which use the same or separate fiber strand as well as Ethernet over fiber link(s) as may be needed by the application.

Monitoring & Control

RFOptic’s multilink products include remote Management and Control (M&C) options for effective monitoring via IP. Supporting protocols like HTML, REST, and SNMP V2c, the M&C interface enables independent management of RFoF modules, providing user-friendly accessibility.

Conclusion

The phase matched multi-link system is very effective antenna remoting solution for direction finder applications. It showcases significant benefits in RFoF high-frequency signal transmission with stable and reliable phase match under adverse environmental conditions. The system is easy to deploy in ground, airborne and maritime environments. By utilizing RF over Fiber (RFoF) technology, the system offers reliable transport of multiple RF channels, maintaining high levels of phase coherence across extended distances. The use of WDM multiplexing enables the simultaneous transmission of several channels while preserving signal integrity. With robust outdoor enclosures designed for harsh environmental conditions, this system meets the required reliable communication in critical applications.