Two high frequency antennas are provided in a multilayer substrate. Each high frequency antenna is configured of a radiation element, a high frequency power supply line, and a high frequency power supply unit. A low frequency antenna is configured of a series radiation element, a low frequency power supply line, and a lower frequency power supply unit. The series radiation element is formed of two radiation elements connected by a radiation element connection line. One end side of the series radiation element is connected to the low frequency power supply unit via the low frequency power supply line. Open stubs to block transmission of a high frequency signal (SH) are connected to the radiation element connection line and the low frequency power supply line. Short stubs to block transmission of a low frequency signal (SL) are connected to the high frequency power supply lines.