Progress In Electromagnetics Research
ISSN: 1070-4698, E-ISSN: 1559-8985
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By R. U. Nair, S. Vandana, S. Sandhya, and R. M. Jha

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Nosecone radomes of hypersonic flight vehicles show degradation of electromagnetic (EM) performance characteristics due to variations in the dielectric parameters (dielectric constant and electric loss tangent) of the radome wall resulting from heating due to extreme aerodynamic drag. It is indicated that the EM performance predictions based on conventional monolithic half-wave wall based on average dielectric parameters corresponding to temperature ranges in hypersonic conditions may not be accurate. This necessitates the radome wall under hypersonic conditions to be modeled as an inhomogeneous dielectric structure for accurate EM performance predictions. In the present work, the hypersonic radome is considered as an inhomogeneous dielectric radome such that the cross-section of the radome wall in each EM window region is considered as an inhomogeneous planar layer (IPL) model with stacked layers of varying dielectric parameters. The material considered is RBSN Ceralloy 147-010F (an alloy of silicon nitride), which has excellent thermal shock resistance, dielectric and mechanical properties required for hypersonic radome applications. The EM modeling of a section of the radome wall in hypersonic conditions (i.e. IPL structure) is based on Equivalent Transmission Line Method. A comparative study of basic EM performance parameters of the radome wall (power transmission, power reflection, and insertion phase delay) for both the IPL model and conventional monolithic half-wave model are carried out over a range of incidence angles corresponding to the antenna scan ranges in each EM window region of the radome. Further the study is extended to compute the EM performance parameters of an actual tangent ogive nosecone radome (made of RBSN Ceralloy 147-010F) enclosing an X-band slotted waveguide planar array antenna, in a hypersonic environment. The antenna-radome interaction studies are based on 3-D Ray tracing in conjunction with Aperture Integration Method. It is observed that the EM performance analysis based on conventional monolithic radome wall design cannot accurately predict the radome performance parameters in actual operating conditions during hypersonic flight operations. The current work establishes the efficacy of Inhomogeneous Dielectric Radome model for better EM performance predictions of streamlined airborne radomes in hypersonic environments.

R. U. Nair, S. Vandana, S. Sandhya, and R. M. Jha, "Temperature-Dependent Electromagnetic Performance Predictions of a Hypersonic Streamlined Radome," Progress In Electromagnetics Research, Vol. 154, 65-78, 2015.

1. Poisl, W. H., C. Solecki, and J. M. Wahl, "Mission challenges spur next generation missile radome materials innovations," Raytheon Technology Today, No. 2, 64-65, May 2012.

2. Chen, F., Q. Shen, and L. Zhang, "Electromagnetic optimal design and preparation of broadband ceramic radome material with graded porous structure," Progress In Electromagnetics Research, Vol. 105, 445-461, 2010.

3. Zhou, L., Y. Pei, R. Zhang, and D. Fang, "Optimal design for high-temperature broadband radome wall with symmetrical graded porous structure," Progress In Electromagnetics Research, Vol. 127, 1-14, 2012.

4. Nair, R. U. and R. M. Jha, "Electromagnetic design and performance analysis of airborne radomes: Trends and perspectives," IEEE Antennas and Propagation Magazine, Vol. 56, 276-298, August 2014.

5. Kilcoyne, N. R., "A two-dimensional ray-tracing method for the calculation of radome boresight error and antenna pattern distortion,", Technical Report: 2767-2, Electro Science Laboratory, Department of Electrical Engineering, The Ohio State University, Columbus, Ohio, USA, October 1969.

6. Weckesser, L. B., R. K. Frazer, D. J. Yost, B. E. Kuehne, G. P. Tricoles, R. Hayward, and E. L. Rope, "Aerodynamic heating effects on radome boresight errors," Proceeding of 14th Symposium on Electromagnetic Windows, 45-51, Atlanta, June 1978.

7. Pendergrass, N. S., "Radome analysis,", Technical Report: SD83-BMDSCOM-2682, Department of the Army, Ballistic Missile Defence Command, Systems Technology Project Office, Huntsville, Alabama, USA, October 1983.

8. Rope, E. L. and G. Tricoles, "Feasibility of electromagnetic tests of radomes heated by hot gases," Proceeding of IEEE Antennas and Propagation Society International Symposium, Vol. 2, 879-880, June 1986.

9. Parul, R. U. Nair and R. M. Jha, "Temperature dependent EM performance predictions of dielectric slab based on inhomogeneous planar layer model," Proceeding of IEEE International Symposium on Antennas and Propagation, 1-2, Chicago, USA, July 2012.

10. Nair, R. U., S. Sandhya, and R. M. Jha, "EM performance analysis of a hypersonic radome," Proceeding of International Symposium on Antennas and Propagation (APSYM), 343-346, Cochin University of Science and Technology, Kochi, December 17-19, 2014.

11. Mangles, J., B. Mikijelji, and B. Lockhart, "Ceramic radomes for tactical missile systems,", www.ceradyne-thermo.com.

12. Nair, R. U. and R. M. Jha, "Electromagnetic performance analysis of a novel monolithic radome for airborne applications," IEEE Transactions on Antennas and Propagation, Vol. 57, No. 11, 3664-3668, November 2009.

13. Kozakoff, D. J., Analysis of Radome Enclosed Antennas, Artech House, Norwood, USA, 2010.

14. Siwiak, K., A. Hessel, and L. R. Lewis, "Boresight errors induced by missile radomes," IEEE Transactions on Antennas and Propagation, Vol. 27, No. 6, 832-841, November 1979.

15. Burks, D. G., E. R. Graf, and M. D. Fahey, "A high-frequency analysis of radome-induced radar pointing error," IEEE Transactions on Antennas and Propagation, Vol. 30, No. 5, 947-955, September 1982.

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