To meet the need of customers, we have launched our high-frequency Altimeter Optical Delay Line (ALT ODL) to provide a high-performance solution for testing and calibration of radar altimeter systems. The ALT ODL is part of the RFOptic’s family of Optical Delay lines.
RFOptic’s ALT ODL unit is a compact solution, which provides superb signal performance and altitude simulation accuracy with an ultra-silent operation.
The ALT ODL can be configured to emulate a single altitude or up to 4,096 altitude steps.
The Altimeter ODL offers very high accuracy up to 0.3ns for altitude steps under 6ft and > 0.1% above. The maximum altitude can reach 100,000 feet or 30Km in one enclosure.
RFOptic is a leading provider and vendor of RF over Fiber (RFoF) and Optical Delay Line (ODL) solutions as well as embedded RF Optical solutions for OEM customers in the telecommunications, aerospace & defense, broadcasting, and infrastructure industries.
RFOptic is known for its RFoF links, multi-link / multi-channel RFoF systems and subsystems to meet customer requirements, including diverse enclosures (indoor and outdoor), and supporting multiple RFoF links with monitoring and management capabilities. RFOptic’s RF over Fiber solutions offer the best cost performance ratio, featuring noise figure of 5dB and gain link of around 40dB.
The programmable low frequency RF over Fiber units (0.5MHz to 6GHz) are based on direct modulation. The MiniQ High SFDR series indirect modulation product family supports applications from 10MHz to 40GHz with low noise and high spurious-free dynamic range (SFDR). RFOptic’s Optical Delay Line solutions are available as “fixed” ODL with up to 8 predefined time delay values in a single unit, or as “variable” supporting up to 255 delay states. All Optical Delay Lines feature delays of up to 250 μsec (>250 μsec upon request) while maintaining excellent performance. Customers can add RFoF functionality with RFOptic’s compact OEM board for high volume requests. The company’s unique software communicates with our programmable RFoF units, offering you unparalleled flexibility for you RFoF or ODL deployments.
In addition, RFOptic also develops, integrates, and delivers the most cost-effective and state-of-the-art product development of mixed microwave and optical solutions to companies worldwide. The company’s extensive experience and know-how overcomes the technological challenges which customers face, from original concept up to production.
The procedure for customized solution consists of 5 steps from request to implementation:
Getting the requirements from the customer
Building the concept
Defining the specifications and setting the budget
At the request of customers, RFOptic has now launched 12GHz, 18GHz, 20GHz, 30GHz, and 40GHz RF over Fiber links that have an ultra-low spurious level of less than -95dBm. This means that RFOptic’s MiniQ RFoF series provide spurious-free dynamic range (SFDR) better than -112dB/Hz. Spurious RFoF solutions are essential in order to mix non-harmonic spurious signals with the input RF signals at the output of the RFoF link. The spurious signals increase the Probability of False Alarm (PFA) and Minimum Detection Signal level (MDS) for EW and RADAR systems and degrade the Adjacent Channel Power Ratio (ACPR) in communication systems.
On a technical level, achieving extremely low spurious levels is a major challenge, particularly in small and tight RFoF modules where power consumption must be kept as low as possible. Many applications can only be supported by a design that achieves low spurious levels across extremes of the RFoF link bandwidth. Applications such as Optical Delay Lines, used in many RADAR test ranges, require ultra-low spurious to test and optimize extremely sensitive systems.
Thanks to the efforts of RFOptic’s R&D department, the new offering will achieve this critical parameter, which opens the market for RADAR and EW as well as other applications.
In general, a high spurious-free dynamic range (SFDR) is desirable when multiple signals of very different power levels are expected to coexist. A high SFDR RFoF solution simplifies signal conditioning requirements that are required to separate true signals from the unwanted spurious. There are well-known techniques, which are intended to identify the spurious signals and null them including LO dither, adjustable ALC, and power range stepping.
However, these techniques complicate the extraction of the real signals of interest and require extra signal processing, which now can be reduced or re-directed to deal with the real input signals rather than with artifacts of the RFoF link. During antenna, RADAR, or communications system testing, high SFDR is essential due to the typical large signal amplitude ratios between main and side lobes or between close and distant targets. The same applies to DF/ELINT systems, which have to handle strong jammers concurrent with weak signals of interest.
An Optical Delay Line (ODL) is an electric-optic-electric instrument. (in some literature, an optical delay line is also referred to as fiber delay line or a fiber optic delay line), It performs fixed time delay(s), between a few nanoseconds up to several hundred microseconds, for RF signals from 10MHz up to 40GHz and more. There are low-frequency ODL versions ranging from 10MHz to 6GHz. The high-frequency ODLs versions are up to 8GHz, 15GHz, 18GHz, 20GHz, and 40GHz.
On a more technical level, the RF input signal is converted into an optical modulated signal. The optical signal is transmitted into a long single mode fiber, usually at a 1.55 micron wavelength or similar. Passing the fiber, the optical signal is converted back into an electrical RF signal. The electrical control on the ODL elects the optical system automatically, with no need for any tuning by the operator.
Components and Features of Fiber Optic Delay Line
An Optical Delay Lines system (ODL) also incorporates high performance lasers such as DFBs, optical modulators for high operation frequencies, photodiodes, and optionally other components such as optical dispersion compensators, optical switches, optical amplifiers and pre- and post RF amplifiers to provide exceptionally high performance. The ODL optical system supports very high bandwidths of analog signals, high sensitivity with wide dynamic range, for various delays.
Applications and Variable Optical Delay Lines
Variable Optical Delay Lines (also known as Progressive ODLs) are used in a variety of applications including radar range simulation and signal processing. The Progressive ODL has a few delay lines using the same transceiver where the customization is done by RFOptic.
The most common practical approach for a variable delay system is an ODL system configuration which includes cascaded 1:2 and 2:2 optical matrices with several different delay lines in between (replacing the above two optical switch matrix 1:8). This cascaded switch matrix is a Progressive Delay Configuration which is shown below.
Desired Combination of Delay Lines
The desired combination of delay lines is selected to define the required delay. In the diagram below, there are 4 progressive delay lines with cascaded switch matrices. In such a configuration, the user can select any of the 16 combinations of possible delay values (16=24). For example, a delay can be selected which is equivalent to Dtot= D1+D2 +D4, or Dtot= D3+D4 etc.)
Progressive Optical Delay Line configuration consisting of four 2:2 optical switch, providing 16 different delay lengths.
Dispersion Compensation in Optical Delay Lines
Sometimes, dispersion compensation is needed when the signal frequency and the delay line length increase, resulting in the optical signal to be dispersed and weakened significantly. As RFOptic, we solve this problem by incorporating DCM (Dispersion Compensation Module) in our Optical Delay Line (ODL) solutions.
For very long delay lines, RFOptic also uses Optical Amplifiers (EDFAS) which compensate the optical loss. In some cases, also Pre and Post amplifiers are required.
Any changes of the delay lines and the attenuation are made through a user-friendly software interface with easy to use GUI (Graphic User Interface).
Contact Us for More ODL Information
For more information about Optical Delay Lines, contact us.
About RFOptic
RFOptic is a leading provider of RF over Fiber (RFoF) and Optical Delay Line (ODL) solutions. For the last 20 years, its team of industry veterans has been developing, designing and integrating superior quality technology for a wide range of RFoF and ODL solutions. The solutions are deployed at various industries, including broadcasting, aviation, electronic warfare, and defense. RFOptic offers its customers and OEMs various off-the-shelf products, as well as custom-made solutions optimized for a wide range of RFoF products at affordable prices and with a quick turnaround. RFOptic makes it its mission to help its customers to turn innovation into real business by providing them with the highest quality, cutting edge RFoF solutions as well as customized solutions based on individual requests and objectives.
Recently, RFOptic attended the IBC 2017 to meet existing and new customers, strategic partners and distributors. Since we are a leading provider of RF over Fiber & Optical Delay Line solutions, it was a given that we would be attending this world’s leading media, entertainment and technology show.
The IBC 2017, which celebrated its 50th anniversary, was highly successful with a record attendance of over 57,000 visitors. The IBC Exhibition covered fifteen halls across the RAI Exhibition and Convention Centre in Amsterdam and hosted over 1,700 exhibitors spanning the creation, management and delivery of electronic media and entertainment.
At the event, RFOptic had 45 meetings with AV and Satcom integrators as well as wireless cameras and microphones companies who showed an interest in our RFoF and ODL solutions that are already used by Tier 1 and other enterprises active in the broadcast, audio and video sector as well as in the telecom, aerospace, governmental, and research labs industries.
We also met potential distributors and integrators for strategic partnerships and cooperation, and met several of our competitors to discuss mutual interests.
We will be attending the next IBC, so come and meet us again at the IBC 2018 that will take place September 13-17, 2018 in the RAI Exhibition and Convention Centre in Amsterdam.
RFOptic
At the request of customers, RFOptic has now launched 12GHz, 18GHz, 20GHz, 30GHz, and 40GHz 
