VARIABLE BEAM ANTENNA DEVICE, MONITORING DEVICE TO BE USED TOGETHER WITH THE ANTENNA DEVICE, AND ACCOUNTING SYSTEM

摘要

PROBLEM TO BE SOLVED: To vary antenna beams in accordance with road width, etc., and to adjust antenna gains in an antenna device that communicates with an on-vehicle device mounted on a vehicle traveling on a road and is used in the case of accounting the vehicle. SOLUTION: The antenna device has an array antenna 13 and generates an amplitude control value and a phase control value by obtaining the amplitude and phase of power to be imparted for every antenna element in accordance with a communication area instruction in a variable beam control circuit 32. An amplitude and phase variable circuit 31 varies the antenna beams by adjusting the amplitude and the phase to be provided by every antenna element based on the amplitude control value and the phase control value. Furthermore, a gain of a variable rain amplifier 26 on the transmitting side is calculated as a gain value on the transmitting side and a gain of a variable gain amplifier 27 on the receiving side is calculated as a gain value of the receiving side according to the communication area instruction in the variable beam control circuit. Each of the variable gain amplifier on the transmitting side and the variable gain amplifier on the receiving side adjusts the antenna gains by adjusting the gains on the transmitting and receiving sides according to the gain values on the transmitting and receiving sides.