Abstract: A branching filter, which is operatively connected between an antenna and a communication device which utilizes different frequency bands, suppresses a mutual interference between signals transmitted to and from the communication device. An antenna circuit, which is operatively connected between the antenna, or a branching filter, and the communication device, converts an impedance with respect to a signal in a frequency band having a lower frequency, and reduces loss resulting from a capacitive antenna impedance.

Abstract: An antenna element including a loading coil is telescopically extendable and retractable from within a housing tube. A characteristic impedance of a transmission line from a lower end part of the antenna element to a cable is equal to one of a cable. A part of the loading coil is reinforced. A branching filter, which is operatively connected between the antenna and a communication device using a different frequency band, suppresses a mutual interference between signals for the communication device. An antenna circuit, which is operatively connected between the antenna or a branching filter and the communication device, converts an impedance of a lower part in a frequency band, and reduces a loss due to a capacitive antenna impedance.