Discretized Aperture Integration, Surface Integration Analysis of AirborneRadomes

Full-wave electromagnetic methods are becoming increasingly more viable for the design and analysis of airborne radomes; however, there still exist many applications that require the speed associated with high frequency approximation methods. Presented here are accuracy improvements to the aperture integration surface integration (AiSi) method by incorporating both aperture and radome discretization into smaller groups in advance of the propagation routines, herein referred to as discretized radome discretized aperture integration surface integration (DrDaiSi). Dyadic Green’s functions are utilized to determine exact field vectors from source current vectors. The capabilities of DrDaiSi are welltested for typical airborne radomes, and a case study is presented which includes a 2:1 fineness ratio tangent ogive radome with dielectric constant of 7 and a metallic tip. The benefits of the DrDaiSi algorithm over a nondiscretized AiSi method for predicting radome loss, boresight error, and radiation pattern degradation are demonstrated. Results are compared to a full-wave solution of the antenna and radome problem that was solved in CST to represent “truth.” Transmission loss agreement is achieved to within 0.4 dB or better, and boresight error agreement is achieved to within 0.2 deg. or better in both elevation and azimuth scan planes for a severely detuned radome.