Radio Frequency (RF) System Performance and Electromagnetic Interference (EMI) in Dynamic Environments Navy SBIR FY2010.3 Sol No.: Navy SBIR FY2010.3 Topic No.: N103-202 Topic Title: Radio Frequency (RF) System Performance and Electromagnetic Interference (EMI) in Dynamic Environments Proposal No.: N103-202-0007 Firm: Delcross Technologies, LLC 3015 Village Office Place Champaign, Illinois 61822 Contact: Robert Kipp Phone: (312) 873-1101 Web Site: www.delcross.com Abstract: Modern military and commercial aircraft include numerous RF systems and associated antennas. The designed freestanding performance of antennas is typically degraded by their platform installation. Also, the cositing of many RF systems in a small region creates enormous opportunity for inter-system EMI via antenna coupling that can significantly harm receiver performance. As challenging as these problem are to address in integrating antennas into platforms, they are compounded by dynamic factors such as rotating props and rotors, gimbaled and electronically steered antennas, and dynamic EM environments. For example, spinning rotors introduce Doppler spectra in signals that play a complex role during receiver demodulation. This proposal focuses on such dynamic effects. We propose to develop tools based on existing high-fidelity simulation technologies for installed antenna performance and system-level interference assessment that incorporate the effects of the identified dynamic elements. Phase I will focus on development of relevant algorithms and analysis frameworks, including proof-of-concept simulations. In Phase II, we will develop a prototype end-user tool suite, including GUIs emphasizing 2-D/3-D visualization of the problem setup, dynamic conditions, and presentation of dynamic simulation results. Some attention will be devoted toward developing dynamic performance metrics that deliver actionable design and analysis information for engineers. Benefits: The principal benefit of the proposed development is that it will result in more successful integration of increasingly complex and numerous RF systems into military and commercial platforms in terms of both stand-alone antenna/system performance and inter-system EMC. It will allow problems with candidate antenna placements to be more reliably identified at an early stage, reducing engineering time and material costs for rework and test measurements. Currently, there are several commercially available tools for high-fidelity simulation of antennas installed on realistic platforms, and some of these are in use at NAVAIR. An important limitation of all these tools is that they only handle static conditions. While it is possible to use them for dynamic scenarios, it is a difficult and error-prone undertaking even for experienced engineers, involving the creation of specialized scripts and batch jobs to sequence through "snapshots" of whatever dynamic condition is to be assessed. After the generation of raw data, post-processing programs must be developed to turn the raw snapshot data into useful information. For example, in the case of modeling rotor-blade modulation, this would involve the generating many CAD model instances to capture the rotor rotation, computing the installed pattern or antenna-to-antenna coupling for each blade position, and then post-processing the results with FFTs to generate Doppler spectra. The proposed solution would automate this process so that the problem could be set-up, executed, and post-processed entirely in the same GUI. In the case of modeling system-level EMI, the process would be further streamlined by automatically passing relevant data to the coupling-channel while providing a simulation framework for handling such dynamically augmented data. There are at least three important areas of commercial application of the proposed capability. First, commercial aircraft face many of the same RF system integration problems as military aircraft, including the identified issues introduced by dynamic conditions. Second, the proposed capability would be directly relevant to automotive safety systems, which frequently rely on onboard radars operating in dynamic traffic environments that generate intense and rapidly changing electromagnetic scattering conditions. Finally, with the explosion of wireless technology and applications, the intersection of wireless with complex motion is increasingly common, and we judge there will be many opportunities to apply the proposed dynamic modeling technology in this area as well to address specialized problems. Return