JP4087394B2 - Linear antenna and antenna system - Google Patents

Description

The present invention relates to a linear antenna and an antenna system for receiving a VHF band and UHF charged wave of television broadcasting.

(Background Technology 1)
There is a headphone used as an FM antenna (see, for example, Patent Document 1). In the headphones disclosed in Patent Document 1, one end of an audio signal supply cord is connected to a plug, and an acoustic unit is connected to the other end of the cord. A high frequency choke coil is provided in the middle of the cord, the length of the cord between the plug and the high frequency choke coil is set to a quarter wavelength of the FM frequency, and the cord between the plug and the high frequency choke coil is used as an FM antenna. . Thereby, the cord for supplying the audio signal of the headphones is also shared as the FM antenna.

(Background Technology 2)
There is a headphone with a built-in antenna having a wireless signal reception function (see, for example, Patent Document 2). The antenna-embedded headphone of Patent Document 2 has a structure in which a connection plug, a cord, and a band portion to be worn on the user's head are connected. The cord has a built-in acoustic cord and three coaxial cables dedicated to the antenna. The band portion incorporates an antenna composed of the central conductors of the above-described three coaxial cables. The center conductors of these three coaxial cables are each N times (1/2 or 1/4) of the wavelength of the center frequency of the L-VHF band, H-VHF band, and UHF band of the television. It is the length, and the reception sensitivity is the highest for each center frequency. Thereby, the L-VHF band, the H-VHF band, and the UHF band of the television can be received.
JP-A-9-331209 (page 3, FIG. 1) JP 2003-274477 A (pages 3 to 5, FIG. 1, FIG. 2, FIG. 5)

The headphones disclosed in the related art 1 have a problem that only the FM frequency band can be received.
The headphone with a built-in antenna disclosed in the related art 2 has a problem that transmission loss in the UHF band is particularly large because the distance between the connection plug and the band portion is long. In addition, there is a problem in that interference occurs because the antenna formed of the central conductors of the three coaxial cables is built in the band portion without a gap.
The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a linear antenna that can obtain a good antenna gain in the VHF band and the UHF band.

In order to achieve the above object, a linear antenna according to the present invention is for an earphone in which a coaxial cable composed of a signal line and a ground line is connected to an RF plug of a connector and is provided at a predetermined distance or more away from the coaxial cable. An audio line is connected to an audio plug of the connector, and is a linear antenna corresponding to a first frequency and a second frequency higher than the first frequency, and the middle of the ground line from the connector side The first inductor and the second inductor are divided in this order, and the first inductor and the second inductor that cut off the second frequency are connected to each other, and the first inductor between the two inductors is connected. said first capacitor for blocking a third frequency lower than the frequency arranged, the first and second inductors, the capacitors and the coaxial cable between the signal line and the point near The entire Le a first antenna element corresponding to the length of one of the integral multiple of nearly a quarter of the wavelength of said first frequency, said signal and said capacitor from said between the inductor and the point near the ground line A second antenna element corresponding to an integral multiple of a quarter of the wavelength of the second frequency from the connector to the RF plug, and from the connector to the first inductor The distance to the neighboring point side is a value shorter than about one eighth of the wavelength of the second frequency .

  According to the present invention, a good antenna gain in the VHF band and the UHF band can be obtained. Further, it can be a linear antenna shared with earphones or the like.

  Embodiments of the present invention will be described below with reference to the drawings.

The first embodiment relates to an earphone antenna in which a coaxial cable is added for the purpose of antenna and is integrated with an audio signal line for the earphone at a predetermined distance or more.
FIG. 1 is a circuit diagram of an earphone antenna (linear antenna) according to a first embodiment of the present invention. The earphone antenna 101 includes an earphone jack 6 (connector) having plugs 1 to 5, a coaxial cable 18, an audio signal line 19, a left acoustic unit 20, a right acoustic unit 21, and the like. The earphone jack 6 is for connection with a portable terminal. The plugs 1 and 2 are RF plugs for supplying a television broadcast radio signal received by the earphone antenna 101 to the mobile terminal. The plugs 3 to 5 are audio plugs for supplying audio signals from the mobile terminal to the acoustic units 20 and 21 of the earphone antenna 101. Of the three audio signal lines 19, the middle line is a common return line.

  The signal line 16 of the coaxial cable 18 is connected to the plug 1. The ground wire 17 side of the coaxial cable 18 is divided in series by the first inductor 10 and the second inductor 14 and connected to the plug 2. A first ground line 13 is defined between the first inductor 10 and the second inductor 14. The first inductor 10 and the second inductor 14 serve to prevent the ground line 17 side from functioning as a ground line for direct current and low frequencies, and from becoming a ground line as a frequency band for television broadcasting. It is.

  The first inductor 10 and the first ground line 13 are connected to the signal line 16 via the capacitor 9 from the branch point 11 near the connection point. The capacitor 9 is for cutting direct current or low frequency generated in the coaxial cable 18. In this configuration, the UHF element 8 is formed from the plug 1 through the capacitor 9 to the front of the second inductor 14 including the first ground line 13, and the length of the UHF element 8 is set to the frequency of the UHF band of television broadcasting. It functions as a UHF antenna with wavelengths of approximately λ / 2, λ / 4, 3λ / 4, etc. The entire coaxial cable 18 functions as the VHF element 15 with a length of approximately λ / 2, λ / 4, 3λ / 4, etc. of the wavelength of the VHF band of television broadcasting.

  The distance 7 from the vicinity of the connection point between the first inductor 10 and the first ground line 13 to the earphone jack 6 will be described later (FIGS. 7 to 9). The interval 12 between the coaxial cable 18 and the audio signal line 19 will be described later (FIGS. 7 to 9). The coaxial cable 18 and the audio signal line 19 are held together, and the entire earphone antenna 101 serves as both an antenna and an earphone.

  FIG. 2 is a diagram illustrating an arrangement example of the earphone antenna according to the first embodiment of the present invention. This represents how the components of the circuit diagram of FIG. 1 are arranged, and the same components as those in FIG. The earphone antenna 102 is an example in which the first inductor 10 and the capacitor 9 are arranged inside the earphone jack 6 and the relay board 22 for arranging the second inductor 14 is provided. A distance 7 from the vicinity of the connection point between the first inductor 10 and the first ground line 13 to the earphone jack 6 corresponds to zero. Thereby, when the distance 7 = zero, the relay board 22 can be used alone.

  FIG. 3 is a diagram illustrating another arrangement example of the earphone antenna according to the first embodiment of the present invention. The earphone antenna 103 is a case where the distance 7 from the vicinity of the connection point between the first inductor 10 and the first ground line 13 to the earphone jack 6 has a value L. This is an example in which a relay substrate 23 for arranging the first inductor 10 and the capacitor 9 is provided. By providing the relay board 22 and the relay board 23, components can be arranged.

  FIG. 4 is a circuit diagram of a relevant portion of the mobile terminal to which the earphone antenna of FIGS. 1 to 3 according to the first embodiment of the present invention is connected. The relevant part of the portable terminal 201 includes an earphone jack 86 having plugs 81 to 85, a radio wave receiver 87, an audio output unit 88, and the like. The earphone jack 6 of the earphone antenna and the earphone jack 86 of the portable terminal 201 are connected. A radio signal from the earphone antenna is received by the radio wave receiver 87. The audio signal from the audio output unit 88 drives the acoustic units 20 and 21 via the audio signal line 19 of the earphone antenna.

FIGS. 5 and 6 are diagrams for explaining other arrangement examples of the earphone antenna and the portable terminal according to the first embodiment of the present invention. In this example, some parts of the earphone antenna are distributed and arranged in the portable terminal.
FIG. 5 is a circuit diagram of the earphone antenna. The same parts as those in FIG. Earphone antenna 104 has a structure obtained by removing first inductor 10 and capacitor 9 from earphone antenna 101 (FIG. 1). The removed first inductor 10 and capacitor 9 are arranged on the mobile terminal side.
FIG. 6 is a connection diagram of relevant portions of the mobile terminal to which the earphone antenna 104 (FIG. 5) is connected. The same components as those of the portable terminal 201 (FIG. 4) will be described with the same numbers. The first inductor 10 and the capacitor 9 removed by the earphone antenna 104 (FIG. 5) are connected between the plugs 81 and 82 of the portable terminal 202 and the radio wave receiver 87.
The distance (not shown) from the vicinity of the connection point between the first inductor 10 and the first ground wire 13 to the earphone jack 6 corresponds to zero. Thus, when there is room on the mobile terminal side, the structure of the earphone antenna can be simplified by arranging components on the mobile terminal.

  FIG. 7 is a graph of experimental data of the earphone antenna according to Example 1 of the present invention. Representing the reception performance of the earphone antenna 101 (FIG. 1), the horizontal axis is FM (76-90 MHz), TV 1ch-12ch (VHF90-220MHz), TV 13ch-62ch (UHF470-770MHz) as frequency channels. The vertical axis indicates the reception level [dBm] in each frequency channel. The dotted line in the graph represents the reception performance in a state where the UHF element 8 of the earphone antenna 101 is not present, that is, in a state where the capacitor 9 is deleted, the first inductor 10 is short-circuited, and the second inductor 14 is short-circuited.

  The solid line in the graph represents the reception performance in the state where the UHF element 8 is provided as in the earphone antenna 101. By providing the UHF element 8, the reception performance in the UHF band is improved compared to the dotted line in the graph. In the state where the UHF element 8 is present, the distance 12 between the coaxial cable 18 and another line (audio signal line 19) and the distance from the vicinity of the connection point between the first inductor 10 and the first ground line 13 to the earphone jack 6 Data is taken by changing 7 and will be described below.

  FIG. 8 is a diagram quantifying experimental data of the earphone antenna according to the first embodiment of the present invention. The average value of the reception level of each channel in the UHF band (13 ch to 62 ch) is calculated for the experimental data graph (FIG. 7). When the UHF element 8 is present (reference numeral 302), when the distance 12 between the coaxial cable 18 and another line (audio signal line 19) is used as a parameter, it is changed to “contact”, “4 mm”, “8 mm”. Reception performance data. Strictly speaking, the interval 12 is an interval between the three wires of the audio signal line 19 and the wire closest to the ground wire 17 of the coaxial cable 18. These are compared with the state without the UHF element 8 (reference numeral 301). As another condition, the length of the UHF element 8 is approximately the wavelength / 4 of the UHF band frequency. The distance 7 from the vicinity of the connection point between the first inductor 10 and the first ground line 13 to the earphone jack 6 is 0 cm.

  Reference numeral 303 indicates the absolute value [dBm] of the reception level, and reference numeral 304 indicates the difference with reference to a state where no UHF element 8 is provided (0 dB). As shown in the column 304, when the interval 12 is in the “close contact” state, the effect is only about “1.5 dB” compared to the state without the UHF element 8. When the interval 12 is “4 mm”, an effect of “4.8 dB” appears, and when the interval 12 is “8 mm”, an effect of “6.6 dB” appears. Thus, the UHF band reception performance is improved by disposing the UHF element 8 with the distance 12 between the coaxial cable 18 and another line (audio signal line 19) separated by several mm or more.

  FIG. 9 is a diagram quantifying other experimental data of the earphone antenna according to the first embodiment of the present invention. The average value of the reception level of each channel in the UHF band (13 ch to 62 ch) is calculated for the experimental data graph (FIG. 7). In the state where the UHF element 8 is present (reference numeral 402), the distance 7 from the vicinity of the connection point between the first inductor 10 and the first ground line 13 to the earphone jack 6 is used as a parameter, “0 cm”, “4 cm”, “8 cm”. It is the reception performance data when changed. These are compared with the state without the UHF element 8 (reference numeral 401). As another condition, the length of the UHF element 8 is approximately one quarter of the wavelength of the UHF band frequency. Further, the interval 12 between the coaxial cable 18 and another line (audio signal line 19) is sufficiently separated.

  Reference numeral 403 indicates the absolute value [dBm] of the reception level, and reference numeral 404 indicates the difference with reference to a state where the UHF element 8 is not present (0 dB). As shown in the reference numeral 404 column, when the distance 7 is “8 cm”, there is no effect at “−2.2 dB” compared to the state without the UHF element 8. When the distance 7 is “0 cm”, the effect of “3.0 dB” appears, and when the distance 7 is “4 cm”, the effect of “1.1 dB” appears. The wavelength of the UHF band frequency of 470 to 770 MHz is 64 cm to 39 cm, and the distance 7 = 4 cm corresponds to approximately one eighth or less of the shortest wavelength. As described above, the UHF band reception performance is improved by arranging the UHF element 8 in the vicinity of the earphone jack 6 so that the distance 7 is approximately one-eighth or less of the UHF band wavelength.

  According to the first embodiment of the present invention, the antenna of the coaxial cable is integrated with the audio signal line for the earphone that is originally connected to the portable terminal and separated by a predetermined distance or more, so that it can be shared as the earphone antenna. Can do. Moreover, the antenna of a coaxial cable can respond | correspond to both UHF and VHF.

Instead of the earphone audio signal line, a remote control cord or charging cable that is originally connected to a mobile terminal is used, and the linear antenna is integrated with the coaxial cable separated by a predetermined distance or more. May be.
Moreover, the linear antenna which integrated the antenna of the coaxial cable in the strap for hanging a portable terminal may be sufficient.
Further, it may be a linear antenna having only a coaxial cable without being integrated with another cord or the like.

The second embodiment relates to an earphone antenna in which a coaxial cable functions as a VHF antenna, a part of an audio signal line for earphone functions as a UHF antenna, and these are integrated.
FIG. 10 is a circuit diagram of the earphone antenna according to the second embodiment of the present invention. The same components as those in FIG. 1 (Example 1) are denoted by the same reference numerals. The earphone antenna 105 includes an earphone jack 6 having plugs 1 to 5, a coaxial cable 18, an audio signal line 19, a left acoustic unit 20, a right acoustic unit 21, and the like. The earphone jack 6 is for connection with a portable terminal. The plugs 1 and 2 are RF plugs for supplying a television broadcast radio signal received by the earphone antenna 105 to a portable terminal. The plugs 3 to 5 are audio plugs for supplying audio signals from the mobile terminal to the acoustic units 20 and 21 of the earphone antenna 101.

  The signal line 16 of the coaxial cable 18 is connected to the plug 1. The ground wire 17 side of the coaxial cable 18 is connected to the plug 2. The audio signal line 19 is connected from the plugs 3, 4, 5 through the separating inductor 32, the first inductor 33, and the inductor 34. The common return line of the audio signal line 19 is divided in series by the first inductor 33 and the second inductor 37, and the first audio signal line 36 is defined between the first inductor 33 and the second inductor 37. The first inductor 33 and the second inductor 37 are for passing a low-frequency audio signal and blocking the frequency band of television broadcasting.

  The capacitor 31 branches from the vicinity of the connection point between the first inductor 33 and the first audio signal line 36 and connects the capacitor 31 to the signal line 16. The capacitor 31 is used for cutting direct current or low frequency. In this configuration, the UHF element 38 extends from the plug 1 through the capacitor 31 to the front of the second inductor 37 including the first audio signal line 36, and the length of the UHF element 38 is the frequency of the UHF band of television broadcasting. Function as a UHF antenna at approximately λ / 2, λ / 4, 3λ / 4, and the like. The entire coaxial cable 18 functions as the VHF element 15 with a length of approximately λ / 2, λ / 4, 3λ / 4, etc. of the wavelength of the VHF band of television broadcasting.

As for the distance 7 from the vicinity of the connection point between the first inductor 33 and the first audio signal line 36 to the earphone jack 6 and the distance 12 between the coaxial cable 18 and the audio signal line 19, the earphone of the first embodiment is used in terms of high frequency. This is the same as the experimental data of the antenna (FIGS. 7 to 9), and the description is omitted.
The coaxial cable 18 and the audio signal line 19 are held together, and the entire earphone antenna 105 serves as both an antenna and an earphone.
The relevant part of the mobile terminal to which the earphone antenna 105 is connected is the same as that of the mobile terminal 201 (FIG. 4), and the description thereof is omitted.

FIGS. 11 and 12 are diagrams for explaining other arrangement examples of the earphone antenna and the portable terminal according to the second embodiment of the present invention. In this example, parts of the earphone antenna are partly distributed in the portable terminal.
FIG. 11 is a circuit diagram of the earphone antenna. The same components as those of the earphone antenna 105 (FIG. 10) will be described with the same numbers. The earphone antenna 106 has a structure obtained by removing the inductor 32, the first inductor 33, the inductor 34, and the capacitor 31 from the earphone antenna 105. The removed inductor 32, first inductor 33, inductor 34, and capacitor 31 are arranged on the mobile terminal side.
FIG. 12 is a connection diagram of relevant portions of the mobile terminal to which the earphone antenna 106 (FIG. 11) is connected. The same components as those of the portable terminal 201 (FIG. 4) will be described with the same numbers. The inductor 32, the first inductor 33, and the inductor 34 that are removed by the earphone antenna 106 are connected between the plugs 83, 84, and 85 of the portable terminal 203 and the audio output unit 88. In addition, the capacitor 31 branches from the vicinity of the connection point between the plug 84 and the first inductor 33 to connect the capacitor 31 to the signal line of the plug 81.
The distance (not shown) from the vicinity of the connection point between the first inductor 33 and the first audio signal line 36 to the earphone jack 6 corresponds to zero. Thus, when there is room on the mobile terminal side, the structure of the earphone antenna can be simplified by arranging components on the mobile terminal.

According to the second embodiment of the present invention, a part of the earphone audio signal line that is originally connected to the mobile terminal and used can function as a UHF antenna. In addition, a coaxial cable installed at a predetermined distance or more from the audio signal line can function as a VHF antenna. And it can share as an earphone antenna by integrating a voice signal line and a coaxial cable.
Instead of the earphone audio signal line, a remote control cord or charging cable that is originally connected to a mobile terminal is used, and the linear antenna is integrated with the coaxial cable separated by a predetermined distance or more. May be.

Example 3 relates to an earphone antenna in which an audio signal line for an earphone is a VHF element and a UHF element branched from the middle is provided.
FIG. 13 is a circuit diagram of an earphone antenna according to a third embodiment of the present invention. The same components as those in FIG. 1 (Embodiment 1) and FIG. 10 (Embodiment 2) are denoted by the same reference numerals. The earphone antenna 107 includes an earphone jack 6 having a plug 1 and plugs 3 to 5, an audio signal line 19, a left acoustic unit 20, a right acoustic unit 21, a UHF element 41, and the like. The earphone jack 6 is for connection with a portable terminal. The plug 1 is an RF plug for supplying a television broadcast radio signal received by the earphone antenna 107 to a portable terminal. The plugs 3 to 5 are audio plugs for supplying audio signals from the mobile terminal to the acoustic units 20 and 21 of the earphone antenna 107.

  The audio signal line 19 is connected from the plugs 3, 4, 5 through the separating inductor 32, the first inductor 33, and the inductor 34. The common return line of the audio signal line 19 is divided in series by the first inductor 33, and the first audio signal line 42 is formed between the first inductor 33 and the acoustic units 20 and 21. The first inductor 33 is for passing a low-frequency audio signal and blocking a television broadcast frequency band.

  The UHF element 41 is provided by branching directly from the vicinity of the connection point between the first inductor 33 and the first audio signal line 42. In this configuration, the length of the line including the UHF element 41 from the plug 1 via the branch point 35 is set to about λ / 2, λ / 4, 3λ / 4, etc. of the wavelength of the UHF band of the television broadcast. It functions as a UHF antenna. Also, the first audio signal line 42 functions as the VHF element 43 with a length of about λ / 2, λ / 4, 3λ / 4, etc. of the wavelength of the VHF band frequency of television broadcasting.

Regarding the distance 7 from the vicinity of the connection point between the first inductor 33 and the first audio signal line 42 to the earphone jack 6 and the distance 12 between the UHF element 41 and the audio signal line 19, the earphone of the first embodiment is used in terms of high frequency. This is the same as the experimental data of the antenna (FIGS. 7 to 9), and the description is omitted.
The UHF element 41 and the audio signal line 19 are held together, and the entire earphone antenna 107 serves as both an antenna and an earphone.

FIG. 14 is another circuit diagram of the earphone antenna according to the third embodiment of the present invention. The same elements as those of the earphone antenna 107 (FIG. 13) will be described with the same numbers. In the earphone antenna 108, the capacitor 31 is provided between the branch point 35 and the UHF element 41 to form a separation circuit 44. Capacitor 31 blocks DC and low frequency audio frequencies.
FIG. 15 is another circuit diagram of the earphone antenna according to the third embodiment of the present invention. The same components as those of the earphone antenna 108 (FIG. 14) will be described with the same numbers. In the earphone antenna 109, the capacitor 31 is provided between the branch point 35 and the UHF element 41, and the second inductor 45 between the branch point 35 and the first audio signal line 42 is provided as the separation circuit 46. The second inductor 45 prevents the UHF band but allows the VHF band to pass.
13 to 15, the distance 32 is set to zero, and the inductor 32, the first inductor 33, the inductor 34, the branch point 35, the capacitor 31, the second inductor 45, and the like are arranged inside the earphone jack 6. It may be. In this case, the UHF element 41 has a structure that is directly pulled out from the inside of the earphone jack 6.

  FIG. 16 is a circuit diagram of a relevant portion of the mobile terminal to which the earphone antenna of FIGS. 13 to 15 according to the third embodiment of the present invention is connected. The relevant part of the portable terminal 204 includes a plug 81, an earphone jack 86 having plugs 83 to 85, a radio wave receiver 87, an audio output unit 88, and the like. The earphone jack 6 of the earphone antenna and the earphone jack 86 of the portable terminal 204 are connected. A radio signal from the earphone antenna is received by the radio wave receiver 87. The audio signal from the audio output unit 88 drives the acoustic units 20 and 21 via the audio signal line 19 of the earphone antenna.

FIG. 17 is another circuit diagram of a relevant portion of the mobile terminal according to the third embodiment of the present invention. Although not shown, the earphone antenna connected to the portable terminal 205 has a structure in which the inductor 32, the first inductor 33, and the inductor 34 of the earphone antenna of FIGS. Then, the deleted inductor 32, first inductor 33, and inductor 34 are arranged in the portable terminal 205.
Furthermore, the capacitor 31 and the second inductor 45 may be deleted from the earphone antenna, and they may be arranged in the mobile terminal.

According to the third embodiment of the present invention, an audio signal line for an earphone that is originally connected to a mobile terminal and used can function as a VHF antenna. Further, a UHF element branched from the audio signal line can be provided to function as a UHF antenna. And it can share as an earphone antenna by integrating a voice signal line and a coaxial cable.
It is a linear antenna that uses a remote control cord or charging cable that is originally connected to a mobile terminal, instead of the earphone audio signal line, and is integrated with the UHF element separated by a predetermined distance or more. May be.

Example 4 relates to an earphone antenna in which a coaxial cable is used as a VHF element and a UHF element branched from the middle is provided. The audio signal line is irrelevant in terms of antenna function, and the coaxial cable and the audio signal line are integrated in mounting.
FIG. 18 is a circuit diagram of an earphone antenna according to a fourth embodiment of the present invention. The same components as those in FIG. 1 (Example 1) are denoted by the same reference numerals. The earphone antenna 110 includes an earphone jack 6 having a plug 1 and plugs 3 to 5, a coaxial cable 18, an audio signal line 19, a left acoustic unit 20, a right acoustic unit 21, a UHF element 41, and the like. The earphone jack 6 is for connection with a portable terminal. The plugs 1 and 2 are RF plugs for supplying a television broadcast radio signal received by the earphone antenna 110 to the portable terminal. The plugs 3 to 5 are audio plugs for supplying audio signals from the mobile terminal to the acoustic units 20 and 21 of the earphone antenna 110.

  A UHF element 52 that branches directly from a branch point 51 in the middle of the signal line 16 of the coaxial cable 18 is provided. In this configuration, the length of the line including the UHF element 52 from the plug 1 via the branch point 51 is set to approximately λ / 2, λ / 4, 3λ / 4, etc. of the wavelength of the UHF band of the television broadcast. It functions as a UHF antenna. Further, the coaxial cable 18 functions as the VHF element 15 with a length of approximately λ / 2, λ / 4, 3λ / 4, etc. of the wavelength of the VHF band of television broadcasting.

Regarding the distance 7 from the vicinity of the branch point 51 to the earphone jack 6 and the distance 12 between the UHF element 52 and the signal line 16, the experimental data (FIGS. 7 to 9) of the earphone antenna of Example 1 is used in terms of high frequency. This is the same and will not be described.
The UHF element 52, the coaxial cable 18, and the audio signal line 19 are held together, and the entire earphone antenna 110 serves as both an antenna and an earphone.

FIG. 19 is another circuit diagram of the earphone antenna according to the fourth embodiment of the present invention. The same elements as those of the earphone antenna 110 (FIG. 18) are described with the same numbers. In the earphone antenna 111, a capacitor 53 is provided between the branch point 51 and the UHF element 52 to form a separation circuit 54. Capacitor 53 blocks DC and low frequency audio frequencies.
FIG. 20 is another circuit diagram of the earphone antenna according to the fourth embodiment of the present invention. The same components as those of the earphone antenna 111 (FIG. 19) will be described with the same numbers. In the earphone antenna 112, a capacitor 53 is provided between the branch point 51 and the UHF element 52, and an inductor 55 is provided between the branch point 51 and the signal line 16 to form a separation circuit 56. The inductor 55 prevents the UHF band but allows the VHF band to pass.
18 to 20, the capacitor 53 and the inductor 55 may be disposed inside the earphone jack 6 with the distance 7 = 0. In that case, the UHF element 52 has a structure that is directly pulled out from the inside of the earphone jack 6.

According to the fourth embodiment of the present invention, the coaxial cable can function as a VHF antenna. Further, a UHF element branched from the signal line of the coaxial cable can be provided to function as a UHF antenna. And it can share as an earphone antenna by integrating a voice signal line and a coaxial cable.
Instead of the audio signal line for the earphone, a linear antenna that integrates the coaxial cable with a remote control cord or a charging cable that is originally connected to the portable terminal and may be used.

Example 5 relates to a mounting structure for a mobile terminal and an earphone antenna.
FIG. 21 is an external view of a mobile terminal equipped with the earphone antenna according to the fifth embodiment of the present invention. The portable terminal 206 is the portable terminal described in the first to fourth embodiments, and includes a display unit 89 and a key 90 on the front. In addition, an earphone jack 86 is provided on a side surface or the like. The earphone antenna 113 is the earphone antenna described in the first to fourth embodiments, and includes the earphone jack 6, the UHF element 61, the acoustic unit 20, the acoustic unit 21, and the like. The UHF element 61 may be any UHF element described in the first to fourth embodiments.

  When the earphone jack 6 is attached to the earphone jack 86, the UHF element 61 has a structure that does not hang down and is fixed in a direction away from the portable terminal 206. In FIG. 21, the UHF element 61 portion extends in the 1 o'clock direction of the timepiece when viewed from the front. This direction should just be a direction which does not approach the portable terminal 206 main body like 12 o'clock to 4 o'clock direction of a timepiece. The code portions from the UHF element 61 to the acoustic units 20 and 21 are in a free state.

  According to the fifth embodiment of the present invention, even if the cord portion of the earphone antenna moves freely, the UHF element 61 portion does not approach the mobile terminal 206 main body, and the frequency is high and the influence is exerted from other portions. It is possible to stably receive easily received radio waves in the UHF band.

1 is a circuit diagram of an earphone antenna according to Embodiment 1 of the present invention. The figure explaining the example of arrangement | positioning of the earphone antenna which concerns on Example 1 of this invention. FIG. 6 is a diagram illustrating another arrangement example of the earphone antenna according to the first embodiment of the invention. The circuit diagram of the relevant part of the portable terminal to which the earphone antenna of FIGS. 1-3 which concerns on Example 1 of this invention is connected. The figure explaining the other example of arrangement | positioning of the earphone antenna which concerns on Example 1 of this invention, and a portable terminal. The figure explaining the other example of arrangement | positioning of the earphone antenna which concerns on Example 1 of this invention, and a portable terminal. The graph of the experimental data of the earphone antenna which concerns on Example 1 of this invention. The figure which digitized the experimental data of the earphone antenna which concerns on Example 1 of this invention. The figure which digitized other experimental data of the earphone antenna which concerns on Example 1 of this invention. The circuit diagram of the earphone antenna which concerns on Example 2 of this invention. The figure explaining the other example of arrangement | positioning of the earphone antenna which concerns on Example 2 of this invention, and a portable terminal. The figure explaining the other example of arrangement | positioning of the earphone antenna which concerns on Example 2 of this invention, and a portable terminal. The circuit diagram of the earphone antenna which concerns on Example 3 of this invention. FIG. 10 is another circuit diagram of the earphone antenna according to the third embodiment of the present invention. FIG. 10 is another circuit diagram of the earphone antenna according to the third embodiment of the present invention. The circuit diagram of the relevant part of the portable terminal to which the earphone antenna of FIGS. 13-15 which concerns on Example 3 of this invention is connected. The other circuit diagram of the relevant part of the portable terminal which concerns on Example 3 of this invention. The circuit diagram of the earphone antenna which concerns on Example 4 of this invention. The other circuit diagram of the earphone antenna which concerns on Example 4 of this invention. The other circuit diagram of the earphone antenna which concerns on Example 4 of this invention. The external view of the portable terminal carrying the earphone antenna which concerns on Example 5 of this invention.

Explanation of symbols

1 to 5 Plug 6 Earphone jack 7 Distance 8 UHF element 9 Capacitor 10 First inductor 11 Branch point 12 Spacing 13 First ground wire 14 Second inductor 15 VHF element 16 Signal line 17 Ground line 18 Coaxial cable 19 Audio signal line 20 , 21 Acoustic unit 22 Relay board 23 Relay board 31 Capacitor 32 Inductor 33 First inductor 34 Inductor 35 Branch point 36 First audio signal line 37 Second inductor 38 UHF element 41 UHF element 42 First audio signal line 43 VHF element 44 Separation Circuit 45 Second inductor 46 Separation circuit 51 Branch point 52 UHF element 53 Capacitor 54 Separation circuit 55 Inductor 56 Separation circuit 61 UHF elements 81 to 85 Plug 86 Earphone jack 87 Radio wave reception section 88 Audio output section 89 Display 90 Key 101-113 Earphone antenna 201-206 Portable terminal

Claims (5)

A coaxial cable composed of a signal line and a ground line is connected to the RF plug of the connector, and an audio line for an earphone provided in parallel with the coaxial cable at a predetermined distance or more is connected to the audio plug of the connector. And a linear antenna corresponding to a second frequency higher than the first frequency ,
The middle of the ground line is divided at the first place and the second place in the order from the connector side, and the divided places are connected by the first and second inductors that cut off the second frequency. , a capacitor for blocking a third frequency lower than the first frequency between said signal line and near point of the first inductor between the inductor are arranged,
The first and second inductors, the capacitor, and the entire coaxial cable serve as a first antenna element corresponding to a length that is an integral multiple of approximately a quarter of the wavelength of the first frequency ;
Corresponding to an integral multiple of a quarter of the wavelength of the second frequency between the two inductors of the ground line and from the neighboring point to the RF plug via the capacitor and the signal line a second antenna element that was,
The linear antenna according to claim 1, wherein a distance from the connector to the neighboring point side of the first inductor is a value shorter than approximately one eighth of the wavelength of the second frequency . A coaxial cable composed of a signal line and a ground line is connected to the RF plug of the connector, and an audio line for an earphone provided in parallel with the coaxial cable at a predetermined distance or more is connected to the audio plug of the connector. And a linear antenna corresponding to a second frequency higher than the first frequency ,
The signal line and the ground line as a first antenna element corresponding to a length that is an integral multiple of about a quarter of the wavelength of the first frequency;
The middle of the audio line is divided at the first place and the second place in the order from the connector side, and the divided places are connected by the first and second inductors that cut off the second frequency, respectively. , a capacitor for blocking a third frequency lower than the first frequency between said signal line and near point of the first inductor between the inductor are arranged,
Corresponding to an integral multiple of a quarter of the wavelength of the second frequency between the two inductors of the audio line and from the neighboring point to the RF plug via the capacitor and the signal line a second antenna element that was,
The linear antenna according to claim 1, wherein a distance from the connector to the neighboring point side of the first inductor is a value shorter than approximately one eighth of the wavelength of the second frequency . An antenna system having a mobile terminal and a linear antenna connected to the mobile terminal, corresponding to a first frequency and a second frequency higher than the first frequency,
The linear antenna is
A signal line of the coaxial cable is connected to a first plug of the first connector, and a ground line of the coaxial cable is connected to a second plug of the first connector;
An audio line for an earphone provided side by side with the coaxial cable at least a predetermined distance is connected to the audio plug of the first connector;
It is divided at a point in the middle of the ground line, and the divided point is connected by a second inductor that cuts off the second frequency,
The portable terminal is
A second connector coupled to the first connector and a radio wave receiver;
A first plug of the second connector and a first receiving unit of the radio wave receiving unit; a second plug of the second connector and a second receiving unit of the radio wave receiving unit; Is connected by a first inductor that cuts off the second frequency, and a third frequency that is lower than the first frequency is between the first and second plugs of the second connector. Connect with a capacitor that cuts off
The second inductor and the entire coaxial cable as a first antenna element corresponding to an integral multiple of a quarter of the wavelength of the first frequency;
The second connector of the first connector, the second connector of the second connector of the portable terminal, and the capacitor from the connection portion of the second inductor of the ground line of the linear antenna to the capacitor An antenna system characterized in that the first antenna unit of the radio wave receiver is a second antenna element corresponding to a length that is an integral multiple of approximately a quarter of the wavelength of the second frequency. A first coaxial cable having a connector, a first signal line and a first ground line, a relay unit, a second coaxial cable having a second signal line and a second ground line are provided. A linear antenna connected in order and corresponding to a first frequency and a second frequency higher than the first frequency,
The connector is
One end is connected to the first plug, a signal line connecting portion that connects the first plug and one end of the first signal line, a second plug, and the second plug. A first inductor that cuts off the second frequency, a ground line connection that connects the other end of the first inductor and one end of the first ground line, the ground line connection and the signal A capacitor connected between line connections and blocking a third frequency lower than the first frequency;
The relay unit is
A first connecting portion for connecting the other end of the first signal line and one end of the second signal line, a second inductor for blocking the second frequency, and the first ground line. A second connecting portion connecting the end and one end of the second inductor, and a third connecting portion connecting one end of the second ground wire and the other end of the second inductor,
The first antenna element corresponding to the first frequency is from the plurality of plugs of the connector to the second coaxial cable through the first coaxial cable and the relay portion.
From the first plug of the connector to the first ground line between the other end of the first inductor and one end of the second inductor via the capacitor, a second frequency corresponding to the second frequency As an antenna element,
By incorporating the capacitor and the first inductor in the connector, the distance between the connector and the ground line connection portion is set to a value shorter than approximately one eighth of the wavelength of the second frequency. Linear antenna. A second coaxial cable having a connector, a first coaxial cable having a first signal line and a first ground line, a first relay section, a second signal line and a second ground line And the third coaxial cable having the second relay unit, the third signal line, and the third ground line are connected in this order, and the first frequency and the first frequency higher than the first frequency are connected. A linear antenna corresponding to a frequency of 2,
The connector has a first plug to which one end of the first signal line is connected, and a second plug to which one end of the first ground line is connected,
The first relay unit is
A first connecting portion that connects the other end of the first signal line and one end of the second signal line, a first inductor that cuts off the second frequency, and the first ground line. A second connecting portion connecting the end and one end of the first inductor, a third connecting portion connecting one end of the second ground wire and the other end of the first inductor, and the third connecting portion A capacitor connected between the first connection portions and blocking a third frequency lower than the first frequency;
The second relay unit is
A fourth connecting portion that connects the other end of the second signal line and one end of the third signal line, a second inductor that cuts off the second frequency, and the second ground line. A fifth connecting portion connecting the end and one end of the second inductor, and a sixth connecting portion connecting one end of the third grounding wire and the other end of the second inductor,
Corresponding to the first frequency from the plurality of plugs of the connector to including the third coaxial cable through the first coaxial cable, the first relay section, the second coaxial cable, and the second relay section The first antenna element,
From the first plug of the connector through the first signal line, the first connection portion, and the capacitor until the second ground line between the other end of the first inductor and one end of the second inductor is included. Is a second antenna element corresponding to the second frequency,
A linear antenna characterized in that a distance between the connector and the third connecting portion is set to a value shorter than about one eighth of the wavelength of the second frequency.

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