RF transport on optical fiber offers multiple advantages over coax cable. These advantages include wider bandwidths, lower loss, longer distances, EMI immunity and higher reliability, all with smaller size. lower weight, less power consumption, and lower cost. These characteristics have resulted in RF over fiber being the technology of choice in many applications, including antenna remoting, signal processing, electronic warfare (EW), Radar simulations, precise time and frequency distribution, as well as sensors.
The most common application for RF over Fiber is the transport of RF signals between a processing location and one or more antennas. Low optical fiber loss allows for signal transport distances up to 80 km. The use of erbium doped optical amplifiers (EDFAs) can compensate for additional path losses. Systems are available for frequency ranges from below 1kHz to greater than 60 GHz, including L, S, C, X, Ku, Ka, Q, U, and V frequency bands. The capacity of a single optical fiber can be increased using Wavelength Division Multiplexing (WDM), which uses different laser wavelengths to create independent optical transport paths within a single optical fiber. GPS, Radar, broadcasting and satellite communications are all examples of RF over Fiber signal transport applications.
In Electronic Warfare (EW), RF on fiber is valued not only for its improved performance, but for other critically important attributes, such as EMI immunity and SWaP: small Size, low Weight, and low Power. EW applications include signal transport to and from antennae, High-Frequency Direction Finding (HFDF), GPS, SATCOM, Phased Array Radar, Signal Jamming and Signal Processing.
RF over Fiber is often used for distribution of timing signals. Linear Photonics is recognized worldwide for high-performance Time and Frequency Distribution products. Our products include campus-wide point-to-point transfer of low Allan Variance atomic clock signals, point-to-multipoint distribution of ultra-low phase noise LO references, 1 PPS and IRIG timing signals, and GPS antenna remoting. Signals can easily be distributed to multiple locations using passive optical components and EDFAs.
Our On-Time PPS system is unique in that it provides real-time compensation of any changes in the optical fiber path between facilities, compensating for thermal and other path length variations in the optical fiber. This allows for two-way fiber time transfer (TWFTT), synchronously locking the output 1PPS to the input 1PPS within an accuracy of 0.5 sec, for distances up to 25km.
Delay Line Applications
The transmission delay through optical fibers can be precisely controlled by adjusting the length, the transmission wavelength, the type of fiber used, and the temperature of the optical fiber. The precise time delay can be combined with a transmitter and receiver to create an optical delay for use in radar simulation and testing. These delay lines can also be used to implement signal processing.
Linear Photonics uses an extensive set of lasers, modulators, passive components, circuit designs, and packaging techniques that can be used to develop a specific solution. Designs for high reliability, small space, low power, and harsh environments are balanced with the need for low cost, high performance, and time to market. We will work with you to fulfill your custom requirements in a timely and cost-effective way. Linear Photonics offers component, modular and system-level products to fulfill the needs of these and other applications.