N092-134 TITLE: Modeling Electromagnetic Performance of Large, High Power Phased Arrays

TECHNOLOGY AREAS: Information Systems, Sensors, Electronics

ACQUISITION PROGRAM: CGX Program, PMS 502

OBJECTIVE: Develop an innovative approach that provides rigorous analysis capabilities for predicting radiated emissions from large, high power phased array antenna systems.

DESCRIPTION: Future naval surface combatants will make extensive use of phased array antennas comprised of tens of thousands of elements operating across the electromagnetic spectrum (e.g. 1-20GHz) and potentially at high power levels (e.g. several megawatts). The combination of these antennas� size, frequencies, and power of operation will require the use of modeling approximations beyond that available with current tools and methods. The Validated Integrated Physics-based Electromagnetic Radiation (VIPER) and Computational Research and Engineering Acquisition Tools and Environments (CREATE) toolsets are examples of current efforts to address this gap in modeling capability. VIPER�s approach may not be efficient enough to model the large future arrays described above. VIPER does not allow the modeler to accurately characterize performance parameters important to ship integration studies for arrays of this size, including array to array electromagnetic interference (EMI) and the performance impact of mounting such antennas on the ship�s superstructure. CREATE is a design tool development effort of larger scope into which successful technologies resulting from this topic might be integrated. Current electromagnetic algorithms for array modeling can only process several thousand elements at a time without the use of a supercomputer.

This topic seeks to develop an advanced innovative approach that provides rigorous analysis capabilities for predicting radiated emissions from large, high power phased array antenna systems. A key challenge is going to be achieving the computational efficiencies that will provide element-to-element coupling within the array and fidelity of up to tens of thousands of elements (horn, slotted waveguide, patch, dipole, monopole, etc.) across the entire face of the array operating across a wide span of frequencies. The approach proposed must employ a first-order, full-wave method to generate electric and magnetic field maps on surfaces in the near field of the array (distances less than several wavelengths). The approach must allow for these field maps to be exported to serve as input parameters to other codes. The theoretical approach must accurately calculate the edge effects of the large but finite array, including surface waves launched on the structure adjacent to the array. The approach will model arrays of uniform, non-uniform and conformal spacing and must allow for beam steering through modeling of phase and time shifts. The approach should also allow for a set of phase perturbations to be specified in addition to the linear set required for beam steering. The approach should also allow users to specify a set of transmit phase steering vectors to be used in creating the array�s current distribution. The software must allow the user to specify a phase or time shift for each element of the array and must also allow calculate constituent shifts for each element based upon beam steering input given by the user. Proposed approaches must have a user-friendly graphical user interface and must be capable of importing structure geometry from IGES and STEP formats for use in analyses.

Representative and relational data will be provided for this project. All information provided and generated as a result of this effort will be unclassified.

PHASE I: Demonstrate the feasibility of an innovative, approach for predicting radiated emissions from large, high power phased array antenna systems. Establish performance goals of the approach and software tool. Provide a Phase II development approach and schedule that contains discrete milestones for product development.

PHASE II: Develop, demonstrate and fabricate a prototype as identified in Phase I. In a laboratory environment, demonstrate that the prototype meets the performance goals established in Phase I. Perform documented, detailed verification and validation studies to assess the accuracy, speed, and repeatability of predicted electromagnetic behavior Develop a cost benefit analysis and a Phase III installation, testing, and validation plan.

PHASE III: Working with government and industry, prepare user-friendly packages for use by analysts in military, government, and civilian work environments. Continue to conduct validation testing as appropriate.

PRIVATE SECTOR COMMERCIAL POTENTIAL/DUAL-USE APPLICATIONS: Any sector requiring analysis of large, high power phased array antenna systems will benefit from this effort. Potential users of this technology could include defense contractors, universities, and government agencies employing large phased arrays and private research laboratories.

REFERENCES:
1) Volakis, John C. "Phased Arrays". Antenna Engineering Handbook, 4th ed. Pp. 20-1 � 20-40. McGraw Hill Publishing, 2007.

2) Post, D. E. et al. "A New DoD Initiative: the Computational Research and Engineering Acquisition Tools and Environments (CREATE) Program". Journal of Physics: Conference Series 125, 2008.

3) Ho, T. Q. et al. "CFDTD Solution for Large Waveguide Slot Arrays". IEEE/ACES International Conference, 3-7 April 2005. Pp. 261-264.

KEYWORDS: electromagnetic; radar; phased array; modeling and simulation;CREATE; VIPER

** TOPIC AUTHOR (TPOC) **

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