Patent ID: 7791533

Claim:
A positioning device comprising: an RF signal receiver circuit section that receives a signal that contains a positioning signal transmitted from a positioning satellite, extracts a signal including a frequency band of the positioning signal from the received signal by causing the received signal to pass through a filter section that has a variable passband, the variable passband including at least the frequency band of the positioning signal, and outputs the extracted signal; a passband change section that changes the passband of the filter section based on a signal strength of the signal output from the RF signal receiver circuit section; a positioning section that locates a present position based on the signal output from the RF signal receiver circuit section; and an accuracy-sensitivity storage section that stores a relationship between positioning accuracy and reception sensitivity with respect to the passband of the filter section and the signal strength of the signal output from the RF signal receiver circuit section, the passband change section including an optimum condition-satisfying band search section that searches for a passband of the filter section based on data stored in the accuracy-sensitivity storage section, the positioning accuracy and the reception sensitivity satisfying a specific optimum condition with respect to the signal strength of the signal output from the RF signal receiver circuit section in the searched passband, the passband change section changing the passband of the filter section to the searched passband.