Research On The Marine Small-scale Receiving Antenna Technology

The maritime radio navigation system which works in the MW and SW bandsis based on the spread spectrum system. It can be widely applied in the military andcivil field. It has the advantages of wide coverage, accurate location, good securityand reliable. However, with the development of radio navigation techniques, therequirement of integration by the system is improved. Due to longer wave length,the receiving antennas of the system are too large and difficult for installation andmaintenance.So, it is a valuable theme to develop high performance antenna work inMW omni and SW from the band can adapt to the development of offshore radionavigation system.So a new miniaturization antenna called Angle reflect antenna based on fractaland Hilbert design method is put forward in this paper. According to the request ofthe maritime radio navigation system, a63cm height omni antenna which works in8.8MHz frequency is designed.To solve the problem of the two thread and complex electromagneticenvironment at the crossing point, normal numerical analysis method is used in thispaper. The mathematical model of Hilbert fractal curve antenna is established：Analysis Hilbert fractal antenna of electromagnetic characteristics is based on themathematical model of the antenna. The influence of various technical indicators ofantenna by the size, fractal dimension, fine structure is summarized. Correctness ofthe theoretical analysis is proved by simulation. The material of medium backboard,thickness, location of feeding point. Angle reflector antenna based on the Hilbertfractal-a new implementation of antenna miniaturization is proposed. It can makeup the problem of Hilbert fractal antenna, such as low gain and hard to apply. Themathematical model of antenna is established. Then a designing method of angelreflector antenna which based on Hilbert fractal is presented.According to the requests of system,180degree angel of angle reflectorantenna based on the Hilbert fractal curve is chosen as the system antenna. Thephysical size of0.6330.3180.0015m3antenna is designed as the example. Themeasurement of simulation and actual are almost the same. It shows that the antennadeveloped in this paper can work in MW and SW with8.8MHz center frequency.The antenna proposed in this paper has3.65dB gain at the center frequency, higherthan8%of relative bandwidth with16.7%height of the original system antenna.