| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method and system for the data transmission between a mobile module and a fixed module that is most suitable for an automatic door of a vehicle or the like, in which the opening/closing of the door or the like is simply and surely controlled. SOLUTION: This system has a mobile module 10 such as a key module and a fixed module 20 such as a door module. The modules 10, 20 are of configuration similar to those having oscillators S1 , S2 , antennas A1 , A2 , superheterodyne receiver components V1 , V2 , L1 , V2 , VD2 , V2 and processing meansμP1 ,μP2 such as microprocessors. Furthermore, the fixed module 20 has mobile detectors A2 , M2 , DV, SD of the Doppler system to detect the movement (approaching) of the mobile module 10. Both the oscillators S1 , S2 are operated at e.g. 24 GHz band having an intermediate frequency difference of 59 MHz.</p> |
