Patent ID: 7907095
Filing Date: 2011-03-15
Classification: H01Q,H04R

Abstract:
1. An antenna device for receiving a broadcast wave in each of a first frequency band and a second frequency band, said antenna device comprising: a relay circuit, and a base end of an antenna element cable connected to a device; wherein said relay circuit connects a core line of a coaxial line to a ground line, and sets an outer covering conductor of said coaxial line in a non-connected state, and an antenna switching circuit performs switching to make the core line of said coaxial line transmit a high-frequency signal in an operation mode in which reception is performed in the first required frequency band, whereby an earphone cable and the core line of said coaxial line are used as an aerial and operate as a sleeve antenna structure, and said antenna switching circuit performs switching to make the outer covering conductor of said coaxial line transmit a high-frequency signal in an operation mode in which reception is performed in the second required frequency band, whereby the outer covering conductor of said coaxial line is used as an aerial and operates as a monopole antenna structure.