Optimization of vibration characteristics of a radar antenna structure

Download
2011
Baran, İsmet
Radar antenna structures especially array antennas which are integrated onto structures of aerial vehicles are subject to dynamic structural and aerodynamic loads. Due to occurrences of these dynamic loads there will be certain dynamic deformations which affect the antenna’s performance in an adverse manner. The influence of deformations and vibrations are important on array antenna structures, since they cause a change in orientation of elements of the phased array antenna which affects the gain of the antenna negatively. In this study, vibration characteristics of a particular radar antenna structure are optimized using topology and stiffener design optimization methods such that negative effects of mechanical vibrations on functional performance of radar antenna are minimized. Topology and stiffener design optimization techniques are performed separately by the use of ANSYS Finite Element (FE) software in order to modify the design of the radar antenna structure such that its critical natural frequencies in the range of 0-500 Hz are shifted out of the dominant peak sinusoid frequency range of the air platform. As a result of this, it will be possible to minimize the vibration response of the phased array elements in the frequency range of 0-500 Hz; hence better antenna performance can be achieved. In addition to this, it will also be possible to minimize the broadband random vibration response of base excitation coming from air platform.

Suggestions

Jammer cancelation by using space-time adaptive processing
Uysal, Halil; Severcan, Mete; Department of Electrical and Electronics Engineering (2011)
Space-Time Adaptive Processing (STAP) has been widely used in spaceborne and airborne radar platforms in order to track ground moving targets. Jammer is an hostile electronic countermeasure that is being used to degrade radar detection and tracking performance. STAP adapts radar’s antenna radiating pattern in order to reduce jamming effectiveness. Jamming power that enters the system is decreased with respect to the adapted radiation pattern. In this thesis, a generic STAP radar model is developed and imple...
Radar cross section analysis by shooting and bouncing rays method
Çakır, Mustafa Kağan; Tokdemir, Turgut; Department of Engineering Sciences (2015)
In this study, a MATLAB code incorporating `Shooting and Bouncing Rays (SBR) Method` is developed for calculating Radar Cross Section (RCS) of complex shapes. The code can calculate ray paths, magnetic current sheets, incident and scattered electric fields and RCS in horizontal, vertical and cross polarizations. While reflection effects are calculated by SBR algorithm, diffraction effects due to edges and corners are handled by `Equivalent Edge Currents (EEC’s)`. Wave frequency, aspect angle and number of r...
Spectral and statistical analyses of experimental radar clutter data
Kahyaoğlu, Nazlı Deniz; Yılmaz, Ali Özgür; Department of Electrical and Electronics Engineering (2010)
The performance of radar detection and imaging systems strongly depends on the characteristics of radar clutter. In order to improve the radar signal processing algorithms, successful analysis and modeling of radar clutter are required. For a successful model of radar clutter, both the spectral and statistical characteristics of the clutter should be revealed. Within the scope of this study, an experimental radar data acquisition system is established to analyze radar clutter. The hardware and the data proc...
Parametric estimation of clutter autocorrelation matrix for ground moving target indication
Kalender, Emre; Tanık, Yalçın; Department of Electrical and Electronics Engineering (2013)
In airborne radar systems with Ground Moving Target Indication (GMTI) mode, it is desired to detect the presence of targets in the interference consisting of noise, ground clutter, and jamming signals. These interference components usually mask the target return signal, such that the detection requires suppression of the interference signals. Space-time adaptive processing is a widely used interference suppression technique which uses temporal and spatial information to eliminate the effects of clutter and ...
Height Estimation for Ballistic Platforms using Differential Measurements
Vural, Aydin; Sengul, Orhan; Demir, Şimşek; Hizal, Altunkan (2013-10-01)
Use of radio waves is a very common choice for proximity fuzes. The stand-off distance for fuzes varies between a lower and an upper limit depending on the electromagnetic reflectivity of terrain (target). If the reflectivity of the terrain is comparably higher, the return power at the receiver reaches to the threshold level more quickly and the stand-off distance increases. The work presented here introduces an approach to estimate the height of airborne ballistic platforms more precisely compared with the...
Citation Formats
İ. Baran, “Optimization of vibration characteristics of a radar antenna structure,” M.S. - Master of Science, Middle East Technical University, 2011.