Abstract: Research has proved that the distribution and shape characteristics of sensor apertures for an airborne antenna play a critical role in the low observable （LO） effect of a stealth airplane. The characteristic signals of an airborne radio frequency (RF) aperture system (including its radar cross section (RCS) and electromagnetic radiation) need to be effectively controlled in order to achieve a high level of stealth efficiency of the whole plane by means of optimizing its contour, structure, and materials. So far antenna dispersion characteristics have not been perfectly appraised, and an effort has to be made to search methods/measures for reducing antenna RCS. This article addresses comprehensively the LO design characteristics of the airborne RF aperture systems for F/A-22 and F-35 (and other advanced aircraft), and puts forward the LO requirements for the airborne RF aperture system from the point of view of general LO configuration. A conceptual solution is proposed, in which the number of antenna apertures is minimized, both the dimensions and characteriatic signals of the apertures are reduced, and low probability of intercept (LPI) techniques are adopted, in accordance with specific application requirements.

Key words: advanced aircraft, stealth technology, antenna, radio frequency, aperture system, radar cross section, low probability of intercept, low observable