ON-VEHICLE SATELLITE TRACKING DEVICE AND ON-VEHICLE SATELLITE RECEIVING SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide an on-vehicle satellite tracking device with a satellite antenna capable of automatically tracking an artificial satellite conducting digital broadcast (or communication). ;SOLUTION: In this on-vehicle satellite receiving system, when tracking control is carried out to automatically direct the plane antenna 20 toward the artificial satellite 2, the kind (BS or CS) of the satellite 2 to be tracked is determined to tune in for a beacon signal of a fixed frequency sent from the satellite 2 together with a radio wave of broadcast, and the direction of the antenna 20 is controlled so as to maximize the level of the signal. To tune in for the beacon signal, the oscillation frequency of a local oscillation circuit 56 is controlled by using a highly accurate reference frequency CO generated by a TCXO (temperature-compensated crystal oscillator) 50 and a local oscillation signal from the oscillation circuit 56 is mixed with a received signal and passed through a crystal filter 54. As a result, even if the broadcast signal is digital, the antenna 20 can automatically track the satellite.;COPYRIGHT: (C)2001,JPO