Bistatic Radar Cross Section : NASA Almond
Benchmark
CST MICROWAVE STUDIO® (CST MWS) offers the facility to calculate the boradband RCS of arbitrary objects. The TimeDomain Solver in CST WMS can deliver the RCS results at arbitrary frequencies defined by the user - a tremendous
advantage for RCS simulations. The ability of the time-domain solver to handle electrically large structures is also a major
feature. The maximum dimension of the structure is about 10 wavelengths.
The geometry of the Almond is given in figure 1 with a plane wave excitation applied. The angle of incidence of the plane
wave, the polarisation of the field vector can be fully parameterised. The Almond is approximately 9.936 inches long and is
defined as a Perfect Electrical Conductor (PEC). The dimensions of the Almond are given in equation form in References 1
and 2. These equations were used to create the geometry in CST MWS.
Figure 1: Almond Geometry with applied plane wave excitation
Figure 2 shows the comparsion between measured and simulated vertical component of RCS at 7 GHz.
Figure 2: Horizontal polarisation component of RCS against azimuth at 7 GHz
Bistatic Radar Cross Section : NASA Almond Benchmark
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Figure 3 shows the comparsion between measured and simulated horizontal component of RCS at 7 GHz.
Figure 3: Vertical polarisation component of RCS against azimuth for excitation at 7 GHz
In a similar manner, the results for the vertical component of RCS at 1.19 GHz are shown in figure 4.
Figure 4: Vertical polarisation component of RCS at 1.9 GHz
Bistatic Radar Cross Section : NASA Almond Benchmark
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Figure 5: Supperimposed E-Field Plane distributions at 9.92 GHz
Figures 5 and 6 show various field quatntites that can be extracted at any desired frequency from a single simulation run. In
Figure 5, the electric fields on two orthogonal planes are superimposed. The surface current density is plotted in figure 6.
Figure 6: Surface Current distribution at 9.92 GHz
This article demonstrates the application of CST MWS to the broadband extraction of Radar Cross Section for electrically large
structures. Just a single run is necessary for high resolution RCS data.
Bistatic Radar Cross Section : NASA Almond Benchmark
© 2017 CST AG - http://www.cst.com
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References
1. A. K. Dominek, H. Shamanski, R. Wood, and R. Barger, "A
Usehl Test Body," in Proceedings Antenna Measurement Techniques
Association, September 24, 1986.
1. A. K. Dominek and H. T. Shamanski, "The Almond Test
Body," Report 721929-9, The Ohio State University Electro-
Science Laboratory, Department of Electrical Engineering, prepared
under Grant Number NSG1613, NASA Langley Research
Center, March 1990
Bistatic Radar Cross Section : NASA Almond Benchmark
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