Abstract: This article presents the electromagnetic scattering of a plane submerged inlet at 15 GHz in Ku wave band. The radar cross section (RCS) characteristics of the submerged inlet at different azimuth, attack angle and terminators have been obtained. The results indicate that: (1) The average RCS of the submerged inlet missile model with a fan terminator at ±60°azimuth has -27.42 dBsm in horizontal polarization, and -28.50 dBsmin vertical polarization, which means that the submerged inlet is a stealth arrangment; (2) The RCS of the submerged inlet is not sensitive to atttack angle. When the attack angle is shifted from -5° to 10°, the variation of the average RCS of the inlet is less than 4 dB; (3) The RCS curve of the finite difference time domain (FDTD) numerical simulation at different aspect angles is basically in accord with the experiment results. The difference of the average RCS at ±60°azimuth between experiment and computation is around 1 dB.

Key words: aerospace propulsion system, submerged inlet, electromagnetic scattering, stealth technique