Figure 1

Figure 1 Typical military application.

RF-over-fiber is emerging as a technology that has the potential to revolutionize the way we transmit and receive RF signals. This solution provides benefits in industry applications ranging from telecommunications and defense to broadcasting and research. PPM Systems has developed an RF-over-fiber-enabled electronic support measure (ESM) system and has been instrumental in advancing this technology. Figure 1 shows electronic warfare (EW)-equipped military vehicles.

RF-over-fiber is a communication technology that leverages the properties of optical fibers to transmit RF signals over long distances. The technology relies on converting RF signals into optical signals that are transmitted through optical fibers and then converted back into RF signals at the receiving end. This process offers several advantages over traditional RF transmission methods, making it a preferred choice in numerous applications.

Some of these advantages include:

Low Signal Loss: RF-over-fiber minimizes signal loss, ensuring signal quality over extended distances. This is crucial in applications where signal fidelity is of paramount importance, such as in military communications and satellite links.

Immunity to Electromagnetic Interference: Optical fibers are immune to electromagnetic interference, unlike traditional coaxial cables. This property is especially vital in critical applications like radar systems, where any interference can have dire consequences.

Long-Distance Transmission: Optical fibers can transmit RF signals over much longer distances than traditional copper cables. This extended reach is vital in applications like telecommunication networks and remote sensing.

Security and Signal Integrity: RF-over-fiber provides enhanced security since it is difficult to tap or intercept optical signals. This is crucial in secure communications and military applications.

Reduced Size and Weight: The use of optical fibers can decouple components within RF systems, enabling lightweight more man-portable subsystems suitable for applications like remote sensing equipment.

RF-over-fiber has found its way into a multitude of applications, each benefiting from its unique advantages. In the telecommunications industry, RF-over-fiber is utilized to transmit signals between cell towers, data centers and central offices. The signal characteristics help enable reliable network connectivity. In broadcasting applications, TV and radio broadcasters use RF-over-fiber to transmit high-quality signals from remote locations to broadcasting studios. This technology ensures that the signal remains pristine over long distances, which is critical in delivering high-definition content to viewers.

In the aerospace and defense sector, RF-over-fiber is extensively used in radar systems, EW and secure communications applications. The immunity to electromagnetic interference and long-distance transmission capabilities of the technology are advantageous in these applications. In satellite communications applications, this technology is used to transmit signals from ground stations to satellites in orbit. The low signal loss of RF-over-fiber helps to close the link budget to maintain communication links with the satellite. There are also applications in the instrumentation, oil and gas, along with the transportation and traffic management industries.

PPM Systems is a recognized leader in RF-over-fiber technology and has been at the forefront of innovation in this field. The company has contributed significantly to the development and implementation of RF-over-fiber solutions, continually pushing the boundaries of what this technology can achieve. PPM offers a range of RF-over-fiber products that include transceivers, amplifiers, antennas and signal processing equipment. These products are designed to meet the unique requirements of various applications, ensuring reliable and high performance RF-over-fiber solutions.

Figure 2

Figure 2 Antenna close coupled unit.

Figure 3

Figure 3 Antenna power control unit.

Figure 4

Figure 4 Radio interface unit.

PPM has released an RF-over-fiber ESM system based on its commercial off-the-shelf (COTS) products. Figure 2 shows the antenna close coupled unit (CCU). This unit is typically installed with the power control unit (PCU) shown in Figure 3 and the radio interface unit (RIU) shown in Figure 4.

The antenna CCU receives RF signals and converts them from electrical to optical signals for distribution to the RIU. The antenna mounting of the CCU minimizes signal loss and electromagnetic disturbances to maximize signal fidelity. There are two optical outputs for a low band of 10 MHz to 6 GHz and a high band of 1 to 18 GHz, which are combined into a single fiber-optic cable.

The antenna PCU is typically installed with the antenna CCU. The enclosure provides the power supply and control functionality, converting the main power supply to DC power for the antenna CCU. The PCU also contains a manual switch to bypass the low noise amplifiers in the antenna for sensitivity tuning.

The RIU ties the system together. It has open standards embedded at the core to convert the signal from the optical to the electrical domain, process it and securely distribute any signal anywhere. The RIU operates from 10 MHz to 18 GHz in two bands.

While this product suite is intended for COTS solutions, PPM Systems understands that different industries have specific needs. Custom solutions cater to the unique requirements of customers, guaranteeing that their systems are optimized for maximum efficiency. Through research and development (R&D) activities, PPM Systems continues to invest to stay at the forefront of RF-over-fiber technology. This commitment to innovation ensures that its products are always on the cutting edge.

PPM Systems also offers comprehensive customer support, including system design, commissioning and maintenance. The experts are available to assist customers in achieving the best possible results from these RF-over-fiber solutions. As this technology continues to evolve, it will become a cornerstone in commercial and defense systems. PPM’s commitment to quality, ongoing R&D and customized solutions ensures that the company remains a trusted partner and enabler for businesses and organizations seeking to harness the full potential of RF-over-fiber technology.

PPM Systems
Swindon, U.K.