NAVIGATION DEVICE FOR AUTOMOBILE

摘要

PURPOSE: To provide a navigation system for a vehicle driving on a high way. CONSTITUTION: A questioning apparatus 20 built in a vehicle 16 has an antenna 22 to transmit question signals at a prescribed angle to a high way 10. An answering apparatus 26 installed to receive the question signals comprises a reception antenna to receive the question signals from the questioning apparatus 20 of the vehicle 16 when the vehicle 16 on the high way 10 is within a defined distance range from the answering apparatus 26. The answering apparatus 26 has a modulator to add information of navigation of the vehicle 16 to the received question signals. The answering apparatus 26 is also provided with a reflection transmission type Van Atta array antenna to re-transmit the encoded received question signals as signals of a responding apparatus toward the questioning apparatus 20. The questioning apparatus 20 has a reception antenna to receive the signals of a responding apparatus and a means to decode the encoded information.