Computer-aided analysis for tangent Ogive airborne radome using physical optics method

Airborne radar antennas are usually enclosed in dielectric radomes for protection from a variety of environmental and aerodynamic effects. However, the presence of the radome will affect the radiation performance of the enclosed antenna significantly, due to interactions between the antenna and radome. The ever-increasing demands on the performance of airborne antennas place comparable demands on the design of the enclosing radome to ensure minimal degradation of the antenna radiation pattern. The geometry of the radome being largely determined by aerodynamic consideration, often leads to severe degradation of the electrical performance of the enclosed antenna. For airborne radomes, to withstand the aerodynamic drag, the shape is chosen to be tangent Ogive. The physical optics method using the appropriate ray paths are implemented to analyze the performance of the monopulse slotted array antenna enclosed by the tangent Ogive shaped radome. The developed software will take antenna slot co-ordinates and the excitations, and radome geometry & material properties as input. The output of the software is the antenna radiation pattern with and without the radome. It also gives the boresight error with respect to scan angle. It compares the two to give the distribution in beam width, side lobe level etc., due to the enclosing radome.