  We applied the Koch snowflake fractal antenna in planning calibration of the
Five-hundred-meter Aperture Spherical radio Telescope (FAST), hypothesizing
second-order fractal primary reflectors can optimize the orientated sensitivity
of the telescope. Meanwhile, on the grounds of NASA Science Working Group
Report in 1984, we reexamine the strategy of Search for Extraterrestrial
Intelligence (SETI). A mathematical analysis of the radar equation will be
performed in the first section, aiming to make it convenient to design a
receiver system that can detect activities of an extraterrestrial civilization,
according to the observable region of the narrowband. Taking advantage of the
inherent potential of FAST, we simulate the theoretical detection of a
Kardashev Type I civilization by a snowflake-selected reflecting area.
