Mobile communication system having multi-band antenna

A mobile communication system having a multi-band antenna, comprising:

• a GPS processing section for receiving a signal of a first frequency band, so as to generate global positioning information;
• a communication signal processing section for receiving signals of a second frequency band and a third frequency band, demodulating the received signals, and signals to be transmitted of the second frequency band and the third frequency band and outputting the modulated signals, the second frequency band being lower than the first frequency band and the third frequency band being higher than the first frequency band;
• a multi-band antenna for receiving and transmitting signals of multiple frequency bands including the first to third frequency bands, the multi-band antenna including a dual-pitch helical antenna which includes first and second helical coil portions connected in series to each other, the first and second helical coil portions having pitches different from each other, so that the first and second helical coil portions have different impedances for the signals of the first to third frequency bands;
• a frequency band separator section connected between the multi-band antenna and the GPS processing section and communication signal processing section, the frequency band separator section supplying the signal of the first frequency band to the GPS processing section while supplying the signals of the second and third frequency bands to the communication signal processing section, the frequency band separator section supplying signals, which are outputted from the GPS processing section and the communication signal processing section, to the multi-band antenna;
• and
• a control section for controlling the GPS processing section and the communication signal processing section.