An antenna device disclosed herein is integrated with an earphone for generating sound from an ear receiver, and connected to a wireless equipment through a connector to transmit an audio signal applied from the wireless equipment to the connector through a plurality of earphone signal lines. An antenna element lies between the ear receiver and an intermediate position of an earphone signal line for transmitting the audio signal from the connector to the ear receiver. A branch is disposed at the intermediate position for preventing a high frequency signal on each of the plurality of earphone signal lines from passing therethrough, and for passing the audio signal therethrough to extract a signal received by the antenna element. A coaxial line transmits the signal received by the antenna element and extracted by the branch to the connector through a core line possessed thereby.
1. An antenna device integrated with an earphone for generating sound from an ear receiver, said antenna device connected to a wireless equipment through a connector to transmit an audio signal, applied from said wireless equipment to said connector, through an earphone signal line, said antenna device comprising:
an antenna element lying between said ear receiver and an intermediate position of an earphone signal line for transmitting the audio signal from said connector to said ear receiver, said antenna element being a shield line of a first coaxial cable that has said earphone signal line as a core line;
a connection unit disposed at said intermediate position and including a connection line that is connected to said shield line of said first coaxial cable and extracting a signal received by said antenna element; and
a second coaxial line for transmitting the signal received by said antenna element and extracted by said connection unit to said connector through a core line of said second coaxial line.
2. The antenna device according to claim 1 , wherein:
said earphone is a stereo type one which includes a pair of left and right earphone signal lines extending forward from said connection unit and a pair of left and right ear receivers, and said antenna element is formed between said connection unit and both of said ear receivers.
3. The antenna device according to claim 1 , wherein:
said earphone is a stereo type one which includes a pair of left and right earphone signal lines extending forward from said connection unit and a pair of left and right ear receivers, and said antenna element is formed between both of said ear receivers between which lies said connection unit.
4. The antenna device according to claim 1 , wherein said connection unit includes a matching circuit for achieving impedance matching between said antenna element and said second coaxial line with a predetermined lumped constant.
5. The antenna device according to claim 1 , further comprising a stub circuit for achieving impedance matching between said antenna element and said second coaxial line with a predetermined distributed constant.
6. The antenna device according to claim 1 , further comprising a matching adjuster for achieving impedance matching halfway on said second coaxial line.
7. The antenna device according to claim 1 , wherein said earphone signal line and said second coaxial line are covered with an individual sheath between said connector and said connection unit.
8. An antenna integrated with an earphone, comprising:
an earphone having an audio line and a ground line;
a branch spaced from said earphone and having a high frequency separator connected to said audio line and said ground line;
a connector having connections for an antenna terminal, an antenna ground, an earphone terminal, and an earphone ground; and
a cable connecting said connector to said branch,
said cable comprising (a) a coaxial line with a shield connected to said antenna ground and a core connected to said antenna terminal and to said audio line in said branch between said high frequency separator and said earphone, and (b) a signal line pair separate from said coaxial line and having a first line connected to said earphone terminal and to said audio line through said high frequency separator and a second line connected to said earphone ground and to said ground line through said high frequency separator,
wherein said audio line is an antenna.
9. The antenna integrated with an earphone of claim 8 , further comprising a second earphone terminal in said connector, a third line in said signal line pair that is connected to said second earphone terminal, and a second earphone,
said second earphone having a second audio line and a second ground line, said core being connected to said second audio line in said branch between said high frequency separator and said second earphone, said second ground line being connected to said ground line in said branch, and said second audio line being connected to said third line through said high frequency separator,
wherein said second audio line is also an antenna.