JP4413161B2 - ANTENNA DEVICE AND COMMUNICATION DEVICE PROVIDED WITH THIS ANTENNA DEVICE - Google Patents

Description

  The present invention relates to an antenna device that can be used in a wide band, and more particularly, to an antenna device used in a small communication device such as a mobile phone or a PDA (Personal Digital Assistant). The present invention also relates to a communication device including the antenna device that can be used in a wide band.

In recent years, miniaturization of various electronic devices has progressed, and multi-functionalization of portable electronic devices such as mobile phones and PDAs has progressed. In the case where such a small electronic device is used as a communication device, the antenna installed for transmitting and receiving a radio signal is also required to be downsized. As a miniaturized antenna device, a chip antenna configured by winding a copper wire around a dielectric material or depositing a copper foil is provided (see Patent Document 1). This chip antenna can be directly mounted on a substrate on which other circuit elements are installed by processing the rectangular parallelepiped shape and providing electrodes.
Japanese Patent Laid-Open No. 10-313208

  Since such a chip antenna is small, a sufficient effective area as an antenna cannot be obtained, and many chip antennas have a narrow frequency bandwidth. Therefore, when used in a frequency band in which the wavelength is as short as several centimeters and the frequency is several GHz, as in wireless LAN and CS broadcasting, even with this miniaturized chip antenna, the performance degradation is not big. However, when used in a frequency band where the wavelength is as long as several tens of centimeters and the frequency is several hundreds of MHz as in terrestrial digital broadcasting, it is necessary to wire a copper wire with an antenna length of several tens of centimeters. There is. Therefore, when used in such a low frequency band, performance degradation such as a decrease in the reception frequency band cannot be avoided.

  Furthermore, terrestrial digital broadcasting has a wide reception frequency band of 470 MHz to 710 MHz, and in order to make all of this reception frequency band a usable frequency band, a chip antenna is enlarged or a rod antenna that expands and contracts is sufficient. It was necessary to make the shape capable of acquiring a valid antenna effective area. For this reason, a communication device equipped with an antenna configured in this way is prevented from being reduced in size, and the design is limited by the antenna shape.

  In view of such a problem, an object of the present invention is to provide an antenna device using a chip antenna that can have a wide use frequency band, and a communication device including the antenna device.

In order to achieve the above object, an antenna device according to the present invention is an antenna device including a chip antenna as an antenna element. The antenna device includes a plurality of the chip antennas, and a feeding point that is connected to the chip antenna and feeds the chip antenna. A plurality of the chip antennas and a copper wire pattern for electrically connecting the feeding points, wherein a part of the copper wire pattern has a meander shape, and a first switch connected in parallel with the meander shape portion arrangement and, together with the receivable frequency band VSWR of a plurality of said chip antenna is 3 or less do not overlap different do Ri and respectively, voltage standing wave ratio of the antenna device when switching between the first switch Each of the receivable frequency bands having a value of 3 or less overlaps with each other close to each other .

  In such an antenna device, the meander-shaped portion of the copper wire pattern may be provided in the copper wire pattern disposed between a connection node connecting the chip antennas and the feeding point. The meander-shaped portion of the copper wire pattern may be provided in the copper wire pattern that connects the chip antennas, and at this time, further provided in the copper wire pattern that connects the chip antennas. The meander-shaped portion thus formed may be divided for each chip antenna.

  In addition, a second switch that selects an electrical connection with the feeding point may be provided for each chip antenna. At this time, the second switch may be connected to the chip antenna via a meander-shaped portion of the copper wire pattern, and the second switch is connected in parallel to the meander-shaped portion of the copper wire pattern. The chip antenna may be connected to each of the chip antennas by being installed on the route.

  In these antenna devices, the receivable frequency band in which the voltage standing wave ratio of the antenna device when the first switch is turned on is 3 or less, and the voltage of the antenna device when the first switch is turned off. The receivable frequency bands having a standing wave ratio of 3 or less may be close to each other and overlap each other. In addition, it is assumed that the receivable frequency bands in which the voltage standing wave ratio of the antenna device is 3 or less when the chip antenna connected to the feeding point is switched by the second switch overlap each other in the vicinity. It doesn't matter.

  Furthermore, the chip antenna may be installed so as to be parallel to the longitudinal direction, perpendicular to the longitudinal direction, or aligned with the longitudinal direction.

  According to another aspect of the present invention, there is provided a communication apparatus including: an antenna that receives a radio signal; and a tuner that modulates the radio signal received by the antenna. To do. Such a communication device may be a mobile phone device or a PDA. Further, this communication device may include the above-described antenna device as an antenna for receiving terrestrial digital broadcasting.

According to the present invention, by making a part of the copper wire pattern into a meander shape, the device can be miniaturized and adjusted according to the frequency characteristics of the chip antenna. In addition, the receivable frequency band in which the voltage standing wave ratio of the chip antenna is 3 or less is different, and reception is possible in which the voltage standing wave ratio of the antenna device is 3 or less when the first switch is switched. Since each of the frequency bands overlaps with each other close to each other, an antenna device that can receive signals over a wide frequency band can be configured, and the size of the device can be reduced. Furthermore, in a communication device including such an antenna device, the installed antenna can be reduced in size, so that the communication device can be reduced in size. Further, this antenna device can receive a radio signal in a wide frequency band.

<First Embodiment>
A first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram illustrating a schematic configuration of the antenna device of the present embodiment. FIG. 2 is a graph showing the relationship of VSWR (Voltage Standing Wave Ratio) with respect to frequency by the antenna apparatus of the present embodiment.

  The antenna device shown in FIG. 1 includes two chip antennas 1a and 1b having different usable frequency bands that can be received with a VSWR of 3 (value of VSWR when power efficiency is 50%) or less, and a rear stage on the substrate. And a copper wire pattern 3 that connects one end of each of the chip antennas 1a and 1b and the feed point 2 to each other. That is, the chip antennas 1 a and 1 b are connected in parallel to the feeding point 2 through the copper wire pattern 3.

  Then, as shown in FIG. 2, the use frequency band Fa of the chip antenna 1a is assumed to be lower than the use frequency band Fb of the chip antenna 1b. At this time, the lower frequency fbmin (frequency at which VSWR = 3) is the lowest frequency in the used frequency band Fb is higher than the upper frequency famax (frequency at which VSWR = 3) is the highest frequency in the used frequency band Fa. The frequency is set to be slightly lower so that the used frequency bands Fa and Fb are slightly overlapped.

  According to the antenna device configured as described above, as shown in FIG. 2, the use frequency bands (frequency bands where the power efficiency is 50% or more) in which the VSWR of each of the chip antennas 1a and 1b is 3 or less hardly overlap. Therefore, it is possible to prevent the chip antennas 1a and 1b from interfering with each other to deteriorate the performance. Therefore, the frequency band F1 including the used frequency bands Fa and Fb of the chip antennas 1a and 1b can be used as a usable frequency band that can be received by the antenna apparatus having the configuration shown in FIG. That is, when the size of the use frequency bands Fa and Fb is F, respectively, and the lower frequency fbmin of the use frequency band Fb is lower than the upper frequency famax of the use frequency band Fa by the frequency f, The size of the use frequency band F1 of the antenna device having the configuration 1 is 2 × F−f.

  Therefore, for example, when the rectangular parallelepiped chip antennas 1a and 1b having a size of about 3 mm × 3 mm × 20 mm are used in the reception frequency band 240 MHz (= 710 MHz-470 MHz), the use frequency band is about 70 MHz. Then, assuming that the usage frequency bands of the chip antennas 1a and 1b are overlapped by about 10 MHz, the usage frequency band of the antenna device shown in FIG. 1 is 130 MHz (= 70 MHz + 70 MHz−10 MHz), and the chip antennas 1a and 1b are Compared to when used alone, the frequency band in which reception is possible can be expanded.

  In the antenna device configured by the connection relationship as shown in FIG. 1, the chip antennas 1a and 1b may be arranged so that their longitudinal directions are parallel as shown in FIG. Thus, by arranging the chip antennas 1a and 1b so as to be parallel to the longitudinal direction, the area occupied by the substrate on which the chip antennas 1a and 1b are installed can be reduced.

  Further, as shown in FIG. 4, the chip antennas 1a and 1b may be arranged so that their longitudinal directions are vertical. By doing in this way, interference of the magnetic flux of each of the chip antennas 1a and 1b can be reduced as compared with the arrangement example of FIG. Further, as shown in FIG. 5, the chip antennas 1a and 1b may be arranged so that their longitudinal directions are on one straight line. By doing so, the physical positions of the chip antennas 1a and 1b are further distant from each other than the arrangement example of FIG. 4, and the interference of the magnetic fluxes can be further reduced. According to the arrangement examples shown in FIGS. 4 and 5, by reducing the interference between the magnetic fluxes, the influence on the power efficiency of each of the chip antennas 1a and 1b can be reduced, and the power efficiency of the antenna device of FIG. Can be maintained in a wide frequency band.

<Second Embodiment>
A second embodiment of the present invention will be described with reference to the drawings. FIG. 6 is a diagram illustrating a schematic configuration of the antenna device according to the present embodiment. Portions used for the same purpose as the antenna device of FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted. .

  The antenna device shown in FIG. 6 differs from the antenna device of FIG. 1 in that instead of the copper wire pattern 3, the copper wire pattern 3a connecting between one ends of the chip antennas 1a and 1b, and both ends of the copper wire pattern 3a. And a copper wire pattern 3b having a meander shape (zigzag shape) while connecting between one point and the feeding point 2.

  With this configuration, the pattern length of the copper wire pattern 3b can be adjusted according to the frequency characteristics of the chip antennas 1a and 1b. That is, by using the meander shape to increase the pattern length of the copper wire pattern 3b, it is possible to adjust the use frequency band of the antenna device to be lowered as a whole. Also, by making the copper wire pattern 3b into a meander shape, the installation area can be reduced compared with the case where the copper wire pattern 3b is made linear, which is effective in the layout of the board design, and the antenna device is downsized. can do.

  In the present embodiment as well, the frequency characteristics of the chip antennas 1a and 1b are assumed to have a relationship as shown in FIG. 2, as in the first embodiment. Therefore, for example, assuming that the frequency bands used for the chip antennas 1a and 1b are about 70 MHz and the frequency bands used for the chip antennas 1a and 1b are about 10 MHz, the antenna device shown in FIG. The frequency band is 130 MHz (= 70 MHz + 70 MHz−10 MHz).

<Third Embodiment>
A third embodiment of the present invention will be described with reference to the drawings. FIG. 7 is a diagram illustrating a schematic configuration of the antenna device according to the present embodiment. Portions used for the same purpose as those of the antenna device of FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted. . FIG. 8 is a graph showing the relationship of VSWR with respect to frequency by the antenna apparatus of this embodiment.

  The antenna device shown in FIG. 7 is different from the antenna device shown in FIG. 1 in that, instead of the copper wire pattern 3, the copper wire patterns 3x and 3y that are connected to one end of each of the chip antennas 1a and 1b and have a meander shape, and copper A contact a is connected to the other end of the line pattern 3x and a contact b is connected to the other end of the copper wire pattern 3y so that the electrical connection between one of the contacts a and b and the remaining contact c is switched. The switch SW1, and the copper wire pattern 3z that connects the contact c of the switch SW1 and the feeding point 2 are provided.

  With this configuration, when the contacts a and c of the switch SW1 are connected, the electrical connection between the chip antenna 1b and the feeding point 2 is interrupted by the switch SW1, and thus the antenna device of FIG. It works as an antenna device using only the chip antenna 1a. When the contacts b and c of the switch SW1 are connected, the electrical connection between the chip antenna 1a and the feeding point 2 is interrupted by the switch SW1, so that the antenna device of FIG. Works as a device. Thus, since the chip antennas 1a and 1b are completely separated by switching the contact of the switch SW1, there is no mutual interference and the antenna characteristics can be improved.

  Further, in the antenna apparatus of FIG. 7, the relationship between the use frequency bands Fa and Fb of the chip antennas 1a and 1b is the frequency band in which the use frequency band Fa is higher than the use frequency band Fb, as in the first embodiment. The use frequency bands Fa and Fb are set so as to slightly overlap each other. That is, when the contacts a and c of the switch SW1 are connected, reception is possible in the lower use frequency band Fa shown by the solid line in FIG. 8, and when the contacts b and c of the switch SW1 are connected. , Reception is possible in the higher use frequency band Fb indicated by the dotted line in FIG. Therefore, by switching the contacts a and b of the switch SW1, as a result, as shown in FIG. 8, the frequency band F1 obtained by combining the used frequency bands Fa and Fb becomes the used frequency band of the antenna device of FIG.

<Fourth Embodiment>
A fourth embodiment of the present invention will be described with reference to the drawings. FIG. 9 is a diagram illustrating a schematic configuration of the antenna device according to the present embodiment. The parts used for the same purpose as those of the antenna device of FIG. 6 are denoted by the same reference numerals, and detailed description thereof is omitted. . FIG. 10 is a graph showing the relationship of VSWR with respect to frequency by the antenna device of this embodiment.

  The antenna device shown in FIG. 9 has a configuration in which a switch SW2 connected to both ends of the copper wire pattern 3b and arranged in parallel with the copper wire pattern 3b is added to the configuration of the antenna device of FIG. According to the antenna device configured as described above, when the switch SW2 is turned OFF (in a state where the switch SW2 is opened in high frequency), only the meander-shaped copper wire pattern 3b is connected between the copper wire pattern 3a and the feeding point 2. When the switch SW2 is turned ON (high-frequency short-circuited state), a copper wire pattern in which the straight copper wire pattern and the meander-shaped copper wire pattern 3b in the switch SW2 are connected in parallel, It will be in the state connected between the copper wire pattern 3a and the feed point 2. FIG.

  Further, the frequency characteristics of the chip antennas 1a and 1b are different from the frequency characteristics in the first and second embodiments so that the use frequency band Fa of the chip antenna 1a and the use frequency band Fb of the chip antenna 1b do not overlap. It is formed. That is, when the use frequency band Fa is lower than the use frequency band Fb, the lower frequency fbmin (frequency at which VSWR = 3), which is the lowest frequency in the use frequency band Fb, is the highest in the use frequency band Fa. The frequency is higher than the upper frequency famax (frequency at which VSWR = 3). Note that the frequency bands Fa and Fb used for the chip antennas 1a and 1b depend on the frequency characteristics when the switch SW2 represented by the solid W-shaped curve in FIG. 10 is turned off.

  At this time, when the switch SW2 is turned ON, a copper wire pattern in which the straight copper wire pattern and the meander-shaped copper wire pattern 3b in the switch SW2 are connected in parallel is formed, and the switch SW2 is turned OFF. Compared to the case where only the meander-shaped copper wire pattern 3b is used, the copper wire pattern is substantially shortened. Therefore, in the antenna device of FIG. 9, when the frequency characteristic when the switch SW2 is turned on is represented by the dotted W-shaped curve of FIG. 10, the use frequency band is when the switch SW2 is turned off. It becomes higher compared to the frequency band used. That is, the use frequency bands Fa and Fb by the chip antennas 1a and 1b when the switch SW2 is turned off become the use frequency bands Fc and Fd moved to the higher frequency side.

  At this time, the upper side frequency famax of the used frequency band Fa by the chip antenna 1a when the switch SW2 is turned off is the lower frequency in the used frequency band Fc by the chip antenna 1a when the switch SW2 is turned on. It is higher than fcmin, and the lower frequency fbmin of the frequency band Fb used by the chip antenna 1b when the switch SW2 is turned off is the highest frequency in the frequency band Fc used by the chip antenna 1a when the switch SW2 is turned on. Is lower than the upper frequency fcmax. Further, the lower upper side frequency fbmax in the use frequency band Fb by the chip antenna 1b when the switch SW2 is turned off is the lower frequency in the use frequency band Fd by the chip antenna 1b when the switch SW2 is turned on. It is higher than the frequency fdmin.

  That is, the frequency band Fc used by the chip antenna 1a when the switch SW2 is turned on slightly overlaps the frequency bands Fa and Fb used by the chip antennas 1a and 1b when the switch SW2 is turned OFF. Then, the frequency band Fb used by the chip antenna 1b when the switch SW2 is turned off slightly overlaps the frequency bands Fc and Fd used by the chip antennas 1a and 1b when the switch SW2 is turned on.

  The frequency characteristics of the chip antennas 1a and 1b are set and the pattern length of the meander-shaped copper wire pattern 3b is set so that the frequency characteristics as shown in FIG. 10 can be obtained. By doing so, as shown in FIG. 10, in the frequency characteristic when the switch SW2 is turned on, the frequency band when the switch SW2 is turned off is set to the frequency band where the VSWR is 3 or more and the frequency band when the switch SW2 is turned off. Fb can be arranged, and the frequency band Fc used when the switch SW2 is turned on is arranged in a frequency band where the frequency characteristic when the switch SW2 is turned off and the VSWR is 3 or more cannot be received. be able to.

  Therefore, the frequency band that can be received by the antenna device can be switched by switching the switch SW2 ON / OFF, and the frequency band F2 that combines the use frequency bands Fa to Fd is set as the use frequency band of the antenna device of FIG. The antenna device (see FIGS. 1, 6, and 7) in the first to third embodiments can be set to approximately twice the use frequency band. That is, as in the first embodiment, for example, the use frequency bands of the chip antennas 1a and 1b are about 70 MHz, and the use frequency bands obtained by switching the switch SW2 ON / OFF overlap each other by about 10 MHz. Assuming that the antenna device shown in FIG. 9 has a frequency band of 250 MHz (= 70 MHz × 4-10 MHz × 3).

<Fifth Embodiment>
A fifth embodiment of the present invention will be described with reference to the drawings. FIG. 11 is a diagram illustrating a schematic configuration of the antenna device according to the present embodiment. Portions used for the same purpose as those of the antenna device of FIG. 7 are denoted by the same reference numerals, and detailed description thereof is omitted. .

  The antenna device shown in FIG. 11 is different from the antenna device shown in FIG. 7 in that the switch SW3 has both ends connected to both ends of the copper wire pattern 3x, and the switch SW4 has both ends connected to both ends of the copper wire pattern 3y. , And the switch SW1 is omitted, and the copper wire patterns 3x to 3z are connected.

  According to the antenna device configured as described above, when the switch SW3 is turned OFF (in a state where the switch SW3 is opened in high frequency), the meander-shaped copper wire pattern 3x is connected to the feeding point 2 via the copper wire pattern 3z. When the switch SW3 is turned on (high frequency short-circuited), the copper wire pattern in which the linear copper wire pattern and the meander-shaped copper wire pattern 3x in the switch SW3 are connected in parallel is a copper wire. It will be in the state connected with the feed point 2 via the pattern 3z. Similarly, when the switch SW4 is turned off (in a state where it is opened in terms of high frequency), the meander-shaped copper wire pattern 3y is connected to the feeding point 2 via the copper wire pattern 3z, and the switch SW4 is turned on. (A short-circuit state in terms of high frequency), a copper wire pattern in which a straight copper wire pattern and a meander-shaped copper wire pattern 3y in the switch SW3 are connected in parallel is a feeding point via the copper wire pattern 3z. 2 is connected.

  Accordingly, when both the switches SW3 and SW4 are turned OFF, the meander-shaped copper wire patterns 3x and 3y are connected to the feeding point 2 via the copper wire pattern 3z, and the antenna device (see FIG. 9), the switch SW2 is turned off. Further, when both the switches SW3 and SW4 are turned ON, a copper wire pattern in which the meander-shaped copper wire patterns 3x and 3y are respectively connected in parallel with the switches SW3 and SW4 is formed, and power is supplied through the copper wire pattern 3z. Since the state is connected to the point 2, the state is the same as the state in which the switch SW2 is turned on in the antenna device of the fourth embodiment.

  At this time, similarly to the fourth embodiment, the frequency characteristics of the chip antennas 1a and 1b are set so that the frequency bands used by the chip antennas 1a and 1b do not overlap. And the meander-shaped copper wire so that the relationship of the used frequency band when the switches SW3 and SW4 are both switched OFF / ON becomes a W-shaped curve by a solid line and a W-shaped curve by a dotted line in FIG. The pattern lengths of the patterns 3x and 3y are set. By setting in this way, the antenna device according to the present embodiment is the same as the antenna device according to the fourth embodiment, as in the first to third embodiments (see FIGS. 1, 6, and 7). Can be approximately twice the frequency band used.

<Sixth Embodiment>
A sixth embodiment of the present invention will be described with reference to the drawings. FIG. 12 is a diagram illustrating a schematic configuration of the antenna device according to the present embodiment. Portions used for the same purpose as those of the antenna device of FIG. 7 are denoted by the same reference numerals, and detailed description thereof is omitted. . FIG. 13 is a graph showing the relationship of VSWR with respect to frequency by the antenna device of this embodiment.

  The antenna device shown in FIG. 12 has a configuration in which a copper wire pattern 3w having a meander shape and being connected between one end of each of the chip antennas 1a and 1b is added to the configuration of the antenna device of FIG. The That is, the copper wire patterns 3x and 3y and the switch SW1 connected in series and the copper wire pattern 3w are connected in parallel. The relationship between the frequency bands used by the chip antennas 1a and 1b is the same as in the fourth and fifth embodiments. The frequency band used by the chip antenna 1a is lower than the frequency band used by the chip antenna 1b. Set so that the bands do not overlap.

  When configured in this way, when the contacts a and c of the switch SW1 are connected, the chip antenna 1a is connected to the feeding point 2 via the copper wire pattern 3x, and the chip antenna 1b is connected to the copper wire patterns 3w and 3x. It will be connected to the feeding point 2 via Therefore, the route by the copper wire pattern from the chip antenna 1a to the feeding point 2 is shortened, and the route by the copper wire pattern from the chip antenna 1b to the feeding point 2 is lengthened. For this reason, the frequency characteristic of the chip antenna 1b is lower than the original frequency band of use, and the frequency characteristics are such that the frequency bands of use of the chip antennas 1a and 1b overlap each other like a W-shaped curve indicated by the dotted line in FIG. It becomes. That is, when the contacts a and c of the switch SW1 are connected, the frequency band receivable by the antenna device of FIG. 12 is the frequency band Fx in FIG.

  When the contacts b and c of the switch SW1 are connected, the chip antenna 1b is connected to the feeding point 2 via the copper wire pattern 3y, and the chip antenna 1a is connected to the feeding point 2 via the copper wire patterns 3w and 3y. Will be connected. Therefore, the route by the copper wire pattern from the chip antenna 1a to the feeding point 2 becomes longer, and the route by the copper wire pattern from the chip antenna 1b to the feeding point 2 becomes shorter. Therefore, the use frequency band of the chip antenna 1a is lower than the original use frequency band, and the chip antenna 1a is compared with the use frequency band of the chip antennas 1a and 1b as shown by the W-shaped curve shown by the solid line in FIG. , 1b becomes a frequency characteristic in which the used frequency band is further away. That is, when the contacts b and c of the switch SW1 are connected, the frequency bands receivable by the antenna device of FIG. 12 become the use frequency bands Fy and Fz of the chip antennas 1a and 1b in FIG.

  At this time, the lower frequency fxmin, which is the lowest frequency of the receivable frequency band Fx when the contacts a and c of the switch SW1 are connected, and the chip when the contacts b and c of the switch SW1 are connected, respectively. It becomes lower than the upper frequency fymax which is the highest frequency in the use frequency band Fy by the antennas 1a and 1b. Further, when the contacts a and c of the switch SW1 are connected, the upper frequency fxmax, which is the highest frequency in the receivable frequency band Fx, is the chip antenna 1a and 1b when the contacts b and c of the switch SW1 are connected. It becomes higher than the upper frequency fzmin, which is the lowest frequency in the used frequency band Fz.

  The frequency characteristics of the chip antennas 1a and 1b are set and the pattern length of the meander-shaped copper wire pattern 3w is set so that the frequency characteristics as shown in FIG. 13 can be obtained. By doing so, as shown in FIG. 13, the contacts a and c of the switch SW1 are placed in a frequency band when the contacts b and c of the switch SW1 are connected and the frequency characteristics when the VSWR is 3 or more cannot be received. The frequency band Fx used when the switch SW1 is connected can be arranged, and the frequency characteristic when the contacts a and c of the switch SW1 are connected is set to a frequency band where the VSWR is 3 or more and the unreceivable frequency band. Use frequency bands Fy and Fz when the contacts b and c are connected can be arranged.

  Therefore, by switching the contact connection of the switch SW1, the receivable frequency band of the antenna device can be switched, and the frequency band F3 combining the use frequency bands Fx to Fz is set as the use frequency band of the antenna device of FIG. The operating frequency band of the antenna device (see FIGS. 1, 6, and 7) in the first to third embodiments can be approximately doubled.

  Note that the switches SW1 to SW4 used in the antenna devices in the third to sixth embodiments may be configured by diodes. At this time, PIN diodes are used as the diodes constituting the switches SW1 to SW4, so that the capacity during reverse bias can be reduced. Further, by using SPDT (Single Pole Double Throw) as the switches SW1 to SW4, since the forward resistance value is small, the efficiency deterioration of the antenna device may be reduced.

  As in the first embodiment, the positional relationship between the chip antennas 1a and 1b constituting the antenna device in the second to sixth embodiments may be the positional relationship shown in FIGS. In addition, although the antenna device in the first to sixth embodiments is configured by two chip antennas 1a and 1b, it is configured by three or more chip antennas, and each chip antenna is connected. The relationship may be the connection relationship described in the first to sixth embodiments.

  Furthermore, an antenna device that combines the configurations of the antenna devices of the first to sixth embodiments may be used. As a first example of this combined configuration, FIG. 14 shows a configuration in which the configurations of the fourth and fifth embodiments (see FIGS. 9 and 11) are combined. The antenna device shown in FIG. 14 is connected between the connection node to which the copper wire patterns 3x and 3y and the switches SW3 and SW4 are connected and the feeding point 2 so that the copper wire pattern 3b and the switch SW2 are in parallel. The By doing so, a plurality of receivable frequency bands can be combined in the antenna device by a combination of ON / OFF of the switches SW2 to SW4.

  As a second example of the combined configuration, FIG. 15 shows a configuration in which the configurations of the third and fifth embodiments (see FIGS. 7 and 11) are combined. In the antenna device shown in FIG. 15, the switch SW3 and the copper wire pattern 3x are connected to the contact a of the switch SW1 in which the copper wire pattern 3z is connected to the contact c, and the switch SW4 and the copper wire pattern are connected to the contact b of the switch SW1. 3y is connected. By doing so, a plurality of receivable frequency bands can be combined in the antenna device by a combination of switching of the contact of the switch SW1 and ON / OFF of the switches SW3 and SW4.

  As a third example of the combined configuration, FIG. 16 shows a configuration in which the configurations of the fourth and sixth embodiments (see FIGS. 9 and 12) are combined. In the antenna device shown in FIG. 16, the copper wire pattern 3b and the switch SW2 are connected in parallel between the contact c of the switch SW1 and the feeding point 2. By doing so, a plurality of receivable frequency bands can be combined in the antenna device by a combination of switching of the contact of the switch SW1 and ON / OFF of the switch SW2.

<An example of a communication device provided with an antenna device>
One configuration example of a communication device including the antenna device according to the first to sixth embodiments or the antenna device combining the configurations of the first to sixth embodiments as in the configuration examples of FIGS. 14 to 16. Is shown in FIG. In this configuration example, a mobile phone device capable of receiving terrestrial digital broadcast will be described as an example of the communication device in FIG. 17. However, the present invention is not limited to such a mobile phone device. It may be a small communication device that receives a broadband wireless signal such as a possible PDA.

  The mobile phone device shown in FIG. 17 includes a mobile phone antenna 101 that transmits / receives a mobile phone radio signal to / from a base station, a communication unit 102 that performs modulation / demodulation processing of the mobile phone radio signal, and an input call. A microphone 103 that converts audio into an audio signal, a video data output processing unit 104 that decodes video data obtained by demodulation, an audio data output processing unit 105 that decodes audio data obtained by demodulation The display unit 106 reproduces and displays the video based on the video data obtained by decoding by the video data output processing unit 104, and reproduces and outputs the audio based on the audio data obtained by decoding by the audio data output processing unit 105. A speaker 107, an input operation unit 108 for inputting various instructions by being operated by a user, and a digital for receiving a broadcast signal by terrestrial digital broadcasting A transmission / reception antenna 109; a tuner 110 that demodulates a broadcast signal received by the digital broadcast reception antenna 109; a ringer 111 that rings when a radio signal indicating an incoming call from the base station is received by the mobile phone antenna 101; And a system control unit 112 that performs the control operation of the entire portable telephone device.

  In the communication apparatus having such a configuration, when a mobile phone radio signal transmitted from a base station is received by the mobile phone antenna 101, the communication unit 102 demodulates the signal and then the system control unit 112 decodes it. At this time, in the case of a radio signal indicating an incoming call from the other party, the ringer 111 rings to notify the user that the incoming call has been received. Thereafter, when a call is instructed by operating the input operation unit 108, the radio signal from the base station is demodulated by the communication unit 102, and then the voice data is confirmed by the system control unit 112. When this audio data is given to the audio data output processing unit 105, the audio is reproduced and output from the speaker 107. Also, when the call voice input from the microphone 103 is converted into a voice signal, given to the system control unit 112 and encoded, it is modulated by the communication unit 102 and then transmitted from the mobile phone antenna 101 to the base station. Is done.

  Further, when an operation for transmitting data such as an e-mail is performed by the input operation unit 108, the transmission data input by operating the input operation unit 108 is modulated by the communication unit 102, and then the mobile phone Is transmitted from the antenna 101 to the base station. Further, when a radio signal including data such as mail is transmitted from the base station and received by the mobile phone antenna 101, the radio signal is demodulated by the communication unit 102 and given to the system control unit 112. Then, the image data output by the video data output processing unit 104 is decoded by the video data output processing unit 104, and the characters, images, and video obtained by the system control unit 112 are reproduced and displayed on the display unit 106. The audio data obtained by the unit 112 is decoded by the audio data output processing unit 105, and the audio is reproduced and output from the speaker 107.

  Further, since the channel selection operation by the tuner unit 110 is controlled by the system control unit 112 so that the broadcast signal of the channel designated by the input operation unit 108 is received, the broadcast signal by the terrestrial digital broadcast is received for digital broadcast reception. When received by the antenna 109, a broadcast signal of a channel instructed to be selected is selected by the tuner unit 110, and the selected broadcast signal is modulated. When the modulated transport stream (TS) is supplied to the system control unit 112, video data and audio data are extracted and supplied to the video data output processing unit 104 and the audio data output processing unit 105, respectively. And decrypted. Accordingly, the selected broadcast video is reproduced and displayed on the display unit 106, and the selected broadcast sound is reproduced and output from the speaker 107.

  In the communication apparatus configured as described above, as the digital broadcast receiving antenna 109, the antenna apparatus according to the first to sixth embodiments described above, or the first to sixth examples such as the configuration examples of FIGS. An antenna device that combines the configurations of the embodiments is used. By configuring the digital broadcast receiving antenna 109 as described above, the digital broadcast receiving antenna 109 can be reduced in size, and terrestrial digital broadcast having a wide frequency band can be received.

  Since the present invention has a wide use frequency band, the present invention can be applied to a small communication device such as a mobile phone device or a PDA that receives a radio signal using a wide frequency band such as terrestrial digital broadcasting.

These are figures which show schematic structure of the antenna device of 1st Embodiment. These are the graphs which show the relationship of VSWR with respect to the frequency by the antenna apparatus of FIG. These are figures which show an example of the relationship of the installation position of the chip antenna in an antenna device. These are figures which show another example of the relationship of the installation position of the chip antenna in an antenna device. These are figures which show another example of the relationship of the installation position of the chip antenna in an antenna device. These are figures which show schematic structure of the antenna device of 2nd Embodiment. These are figures which show schematic structure of the antenna device of 3rd Embodiment. These are the graphs which show the relationship of VSWR with respect to the frequency by the antenna apparatus of FIG. These are figures which show schematic structure of the antenna device of 4th Embodiment. These are graphs which show the relationship of VSWR with respect to the frequency by the antenna apparatus of FIG. These are figures which show schematic structure of the antenna device of 5th Embodiment. These are figures which show schematic structure of the antenna device of 6th Embodiment. These are graphs which show the relationship of VSWR with respect to the frequency by the antenna apparatus of FIG. These are figures which show schematic structure of the antenna device which combined the structure of 4th and 5th embodiment. These are figures which show schematic structure of the antenna apparatus which combined the structure of 3rd and 5th Embodiment. These are figures which show schematic structure of the antenna device which combined the structure of 4th and 6th embodiment. These are block diagrams which show the structural example of the communication apparatus provided with the antenna apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a, 1b Chip antenna 2 Feeding point 3, 3a, 3b, 3x-3w Copper wire pattern SW1-SW4 Switch 101 Cell-phone antenna 102 Communication part 103 Microphone 104 Image | video data output processing part 105 Audio | voice data output processing part 106 Display part 107 Speaker 108 Input operation unit 109 Digital broadcast receiving antenna 110 Tuner unit 111 Ringer 112 System control unit

Claims (13)

In an antenna device provided with a chip antenna as an antenna element,
With a plurality of the chip antennas,
A feeding point connected to the chip antenna and feeding the chip antenna;
A plurality of the chip antennas and a copper wire pattern for electrically connecting the feeding points,
A part of the copper wire pattern has a meander shape, and a first switch connected in parallel with the meander shape portion is disposed,
Receivable frequency bands in which the voltage standing wave ratio of the plurality of chip antennas is 3 or less are different and do not overlap each other,
Receivable frequency bands in which the voltage standing wave ratio of the antenna device when the first switch is switched are 3 or less overlap each other in close proximity to each other. 2. The antenna device according to claim 1, wherein a meander-shaped portion of the copper wire pattern is provided in the copper wire pattern disposed between a connection node connecting the chip antennas and the feeding point. 3. . The antenna device according to claim 1, wherein a meander-shaped portion of the copper wire pattern is provided in the copper wire pattern that connects the chip antennas. 4. The antenna device according to claim 3, wherein a meander-shaped portion provided in the copper wire pattern for connecting the chip antennas is divided for each chip antenna. The antenna device according to any one of claims 1 to 4, further comprising a second switch that selects an electrical connection with the feeding point for each of the chip antennas. 6. The antenna device according to claim 5, wherein the second switch is connected to the chip antenna through a meander-shaped portion of the copper wire pattern. The second switch is installed on a path connected in parallel with the meander-shaped portion of the copper wire pattern to be one of the first switches, thereby connecting to each of the chip antennas. The antenna device according to claim 5. The receivable frequency band where the voltage standing wave ratio of the antenna device when the first switch is turned on is 3 or less, and the voltage standing wave ratio of the antenna device when the first switch is turned off is 3. The antenna device according to any one of claims 1 to 6, wherein the following receivable frequency bands overlap in the vicinity of each other. Receivable frequency bands in which the voltage standing wave ratio of the antenna device is 3 or less when the chip antenna connected to the feeding point is switched by the second switch overlap in close proximity to each other. The antenna device according to claim 7. The antenna device according to claim 1, wherein the chip antenna is installed so as to be parallel to a longitudinal direction thereof. The antenna device according to claim 1, wherein the chip antenna is installed so as to be perpendicular to a longitudinal direction thereof. The antenna device according to claim 1, wherein the chip antenna is installed so as to be in a straight line in a longitudinal direction thereof. In a communication apparatus comprising an antenna that receives a radio signal and a tuner that modulates the radio signal received by the antenna,
A communication device comprising the antenna device according to any one of claims 1 to 12 as the antenna.

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