The design and analysis on the small-scale antenna of spread frequency radio lifesaving system

Radio lifesaving system which is based the spread frequency system works at the MW & SW band, uses the ground wave to orientation with the characteristics of high orientation precision, short responding time and large working bound. However, as the large signal wavelength of the band, the receiver usually adopts a large whip antenna as the signal receiving equipment, which is so large that to become a technical difficulty of equipment miniaturization. To solving this problem, this paper proposes a new-designed angle reflector antenna based on the Hilbert fractal curve as the system antenna which is simulated based on the finite-difference time-domain method (FDTD). Shown as the simulation result, the antenna with the size of 30 mm × 30 mm can work in the band of 1.5~10 MHz has the characteristics of high gain, low VSWR, and omni-direction, meets the system requirements.