JP4359921B2 - Multi-frequency surface mount antenna, antenna device using the same, and radio communication device - Google Patents

Description

  The present invention relates to a multi-frequency surface-mounted antenna, an antenna device, and a wireless communication device that are used in a mobile communication device such as a mobile phone and can transmit and receive signals in a plurality of different frequency bands.

  In recent years, such as GSM (Global System for Mobile Communications) and DCS (Digital Cellular System), PDC (Personal Digital Cellular) and PHS (Personal Handyphone System), GPS (Global Positioning System), Bluetooth, etc. In addition, for example, a wireless communication device such as a cellular phone capable of supporting a plurality of applications capable of supporting a plurality of applications is frequently used, and the size of a communication terminal is being reduced in consideration of portability.

  These wireless communication devices are adapted to miniaturization by various surface mount antennas and the like. An example of a conventional surface mount antenna and an antenna device using the same will be described with reference to a perspective view of FIG. 5 (see Patent Document 1) and a development view of FIG. 6 (see Patent Document 2).

  In FIG. 5, reference numeral 51 denotes a surface mount antenna, which is mounted on a mounting substrate 58 to constitute an antenna device. In the surface mount antenna 51 shown in FIG. 5, 55 is a rectangular parallelepiped base, 54 is a feeding electrode terminal, and 52 and 53 are radiation electrodes. In the mounting substrate 58, 57 is a power supply electrode, and 56 is a ground conductor layer.

  In the conventional surface mount antenna 51, the spiral connected to the feeding electrode terminal 54 on the side surface of the base 51 in order to cope with two frequencies by changing the pitch of the radiation electrodes 52, 53, that is, to cope with two different frequencies. In this structure, the pitch of the radiation electrodes 53 is increased, and the pitch of the spiral radiation electrodes 52 connected to the radiation electrodes 53 is increased.

  Then, such a surface mount antenna 51 is mounted on the surface of the mounting substrate 58 by connecting the power supply electrode terminal 54 to the power supply electrode 57, whereby the dual-frequency antenna device 60 is configured.

  Moreover, in FIG. 6 (refer patent document 2), 61 is a surface mount antenna. In the surface mount antenna 61, 64 is a feeding electrode terminal, 62 is a radiation electrode, 63 and 67 are non-feed radiation electrodes, and 68 is a ground electrode.

  In the conventional surface mount antenna 61, the radiation electrode 62 can be adapted to multiple frequencies, that is, to correspond to a plurality of different frequencies by the higher-order mode of the radiation electrode 62, the parasitic radiation electrodes 63 and 67, and the branch electrode. In addition to this, parasitic radiation electrodes 63 and 67 are secured as current paths having different electrical lengths.

In addition, as a multi-frequency compatible antenna, a plurality of frequency bands including other frequency bands different from the predetermined frequency band can be obtained by connecting the ground capacitance of the antenna element to the antenna element for the predetermined frequency band and changing this value. An antenna for a mobile communication terminal that is used in the above is disclosed (for example, see Patent Document 3). According to this, since a switch is not inserted in series in the transmission / reception signal transmission path, the antenna can be adapted to a plurality of frequencies without causing a problem of signal transmission loss.
JP 2002-204120 A JP 2001-298313 A JP 2002-232232 A

  However, in the conventional surface mount antenna 51 as shown in FIG. 5, the operating frequency of the surface mount antenna 51 for each of the lower frequency f1 and the higher frequency f2 of the radio signal used in the communication system. In order to match, it is necessary to adjust the length and pitch (interval) of the spiral radiating electrodes 52 and 53, and there is a problem that the adjustment is very troublesome.

  In addition, when trying to reduce the size of the surface-mounted antenna 51 by increasing the dielectric constant of the base 55, an unexpected unwanted resonance mode occurs between the spiral long radiation electrodes 52 and 53 and the ground conductor 56. In addition, since stable antenna characteristics for two frequencies cannot be obtained, there is a problem that it is difficult to reduce the size.

  Moreover, the antenna element disclosed in Patent Document 1 has a problem that it is difficult to surface-mount on a mounting substrate.

  Further, the surface mount antenna 61 disclosed in Patent Document 2 as shown in FIG. 6 has a structure in which parasitic radiation electrodes 63 and 67 are secured as current paths having different electrical lengths in order to cope with a plurality of frequencies. Therefore, the method of branching the electrodes was used. However, in the case of the surface mount antenna 61, there is a problem that the electrode pattern occupies an area and it is difficult to downsize the entire antenna. In addition, there is a method for miniaturization by changing the electrode pattern to a meander pattern, but the electrode pitch of the too fine meander pattern is reduced, and deterioration of characteristics due to interference between the electrodes is observed.

  Further, in the radiation electrode 62, a technique of partially changing the width of the electrode width is used in order to separately adjust the frequency of the fundamental wave and the frequency of the higher order mode. In the case of the surface mount antenna 61, the frequency of the fundamental wave and the higher-order mode is adjusted by narrowing a part of the electrode pattern. However, when performing further frequency adjustment, the pattern has to be changed, and the frequency adjustment is very difficult. In addition, the frequency adjustment by making the electrode pattern partially thick can be easily imagined, but in the case of an electrode pattern such as the surface mount antenna 61, the current path is changed by trimming the partially thick pattern part. Therefore, it was difficult to finely adjust the frequency.

  The present invention has been devised to solve the above-described problems in the prior art, and the object is to stably obtain good antenna characteristics and to easily adjust the frequency. It is an object of the present invention to provide a surface mount antenna, an antenna device using the surface mount antenna, and a wireless communication device.

The multi-frequency surface-mount antenna of the present invention has a substantially rectangular parallelepiped base made of a dielectric material or a magnetic material, one end connected to a power supply electrode terminal over two or more surfaces of the base, and the other end being an open end. And a radiation electrode formed in a spiral pattern such that the open end is on the inside when viewed in plan, and outside the spiral pattern when the radiation electrode is viewed in plan on at least a part of the radiation electrode a multi-frequency surface mount antenna comprising a secondary radiation electrode formed toward said between sub radiation electrode and said open end, that have a thick the frequency adjusting section width than the open end side is formed It is characterized by this.

  The multi-frequency surface-mount antenna according to the present invention is characterized in that the radiation electrode has a wide direction and a narrow direction in a predetermined direction.

  The surface-mount antenna of the present invention is characterized in that in each of the above-described structures, a through hole and / or a groove is provided in the base.

  Next, the antenna device according to the present invention includes a multi-frequency surface-mounted antenna according to the present invention having the above-described configuration on a mounting substrate on which a feeding electrode and a ground conductor layer disposed on one side of the feeding electrode are formed. One of them is mounted on the other side of the feeding electrode, and the feeding electrode terminal is connected to the feeding electrode.

  Furthermore, the antenna device of the present invention mounts the multi-frequency surface-mounted antenna on the mounting substrate on the other side of the feeding electrode in a direction in which the narrow direction of the radiation electrode faces the ground conductor layer. The electrode terminal is connected to the power supply electrode.

  The wireless communication apparatus of the present invention is characterized in that a transmitting circuit and / or a receiving circuit corresponding to wireless signals in a plurality of frequency bands are connected to any of the antenna apparatuses described above.

  According to the multi-frequency surface-mounted antenna of the present invention, a substantially rectangular parallelepiped base made of a dielectric material or a magnetic material, one end connected to the power supply electrode terminal over two or more surfaces of the base, and the other end open And a radiation electrode formed in a spiral pattern such that the open end is on the inside when viewed in plan, and the outside of the spiral pattern when the radiation electrode is viewed in plan on at least a part of the radiation electrode Since the radiation electrode is formed in a spiral pattern, a long electrode can be formed in a small space, and the antenna can be miniaturized. Further, the radiation electrode formed in a spiral pattern whose open end is inward when viewed in plan, and outside the spiral pattern when the radiation electrode is planarly viewed on at least a part of the radiation electrode Because the sub-radiation electrode exists in a form that is not surrounded by the radiation electrode, the interference between the two can be suppressed, and the deterioration of the antenna characteristics can be kept low. it can. In addition, since there are two or more paths of current flowing through the antenna, a multi-frequency surface mount antenna can be realized.

  Moreover, since the radiation electrode of the spiral pattern has a wide direction and a narrow direction in a predetermined direction, a desired polarized wave can be transmitted and received more strongly depending on the mounting direction of the antenna.

  In addition, since at least a part of the radiation electrode having a spiral pattern is made thick, it is possible to easily adjust the frequency of each of the multiple frequencies by using a frequency adjusting unit for adjusting the frequency by trimming.

  Further, by providing the substrate with through holes and / grooves, the substrate can be reduced in weight while maintaining the antenna characteristics, so that the reliability of mounting strength against impact after mounting can be increased.

  According to the antenna device of the present invention, since the multi-frequency surface-mounted antenna of the present invention is provided, high mounting strength reliability that supports multi-frequency, good antenna characteristics, excellent directivity, and easy frequency adjustment is achieved. Can have.

  In addition, according to the antenna device of the present invention, by mounting the narrow direction of the radiation electrode of the multi-frequency surface-mount antenna in a direction facing the ground conductor layer, the radiation electrode and the ground conductor layer are roughly positioned substantially vertically. Thus, the interference between the two can be kept low, and the deterioration of the antenna characteristics can be kept low.

  And according to the radio communication apparatus of the present invention, the antenna apparatus of the present invention and the transmitter circuit and / or the receiver circuit corresponding to radio signals of a plurality of frequency bands connected to the antenna apparatus are provided. A wireless communication apparatus having good antenna characteristics, excellent directivity, easy frequency adjustment, and high mounting strength reliability.

  As described above, according to the present invention, a multi-frequency surface mount antenna having multi-frequency compatibility, excellent antenna characteristics, excellent directivity, easy frequency adjustment, and high mounting strength reliability, and the same are used. An antenna device and a wireless communication device can be provided.

  Embodiments of a multi-frequency surface-mounted antenna, an antenna device using the same, and a wireless communication device according to the present invention will be described below with reference to the drawings.

  FIG. 1A is a perspective view showing an embodiment of an antenna device in which a multi-frequency surface-mounted antenna of the present invention is mounted on the surface of a mounting board. 1 is a multi-frequency surface-mounting antenna, which is mounted on the mounting board 8. The antenna device is configured by being mounted. FIG. 1B is a development view for viewing the radiation electrode 2 of the multi-frequency surface-mount antenna 1 in the antenna apparatus of FIG.

  A multi-frequency surface-mounted antenna (hereinafter also simply referred to as an antenna) 1 according to the present invention includes a substantially rectangular parallelepiped base 5 made of a dielectric material or a magnetic material, and one end connected to the surface of the base 5 to a feeding electrode terminal 4. The radiation electrode 2 is formed so that the other end is an open end. As shown in FIG. 1B, when the radiation electrode 2 is viewed in plan, the open end 2A is on the inside. The sub-radiation electrode 3 is formed to be formed in a spiral pattern and formed on at least a part of the radiation electrode 2 toward the outside of the spiral pattern.

  Since the radiation electrode 2 is formed in a spiral pattern, the entire radiation electrode 2 becomes compact, and the antenna 1 can be downsized.

  According to such a multi-frequency surface-mounted antenna 1, a ¼ wavelength monopole antenna corresponding to the lowest frequency f1 among the radio signals in the frequency band used in the communication system is formed by the radiation electrode 2 portion. As a result, the antenna 1 corresponding to the frequency f1 can be operated.

  In addition, the radiation electrode 2 can operate as the antenna 1 corresponding to the frequency f2 of the radio signal in the frequency band approximately twice the frequency f1 as a higher-order mode of the frequency f1.

  Further, since the connecting portion of the radiation electrode 2 to the feeding electrode terminal 4 is connected to the sub-radiating electrode 3 and the portion of the sub-radiating electrode 3, a current path different from that of the radiating electrode 2 and a different electrical length portion are obtained. Thus, a quarter-wave monopole antenna corresponding to the frequency f3 of the radio signal in the frequency band is formed, so that the antenna 1 corresponding to the frequency f3 can be operated.

  Therefore, the multi-frequency surface-mounted antenna 1 of the present invention is disposed on the other side of the feeding electrode 7 on the mounting substrate 8 on the surface of which the feeding electrode 7 and the ground conductor layer 6 disposed on one side of the feeding electrode 7 are formed. While being mounted, the antenna device obtained by connecting the feeding electrode terminal 4 to the feeding electrode 7 can cope with multiple frequencies.

  FIG. 2 is a diagram showing the frequency characteristics of reflection loss of the multi-frequency surface-mounted antenna 1 of the present invention. In FIG. 2, the horizontal axis represents frequency, the vertical axis represents VSWR (standing wave ratio), and the characteristic curve represents the frequency characteristic of VSWR. As shown in this figure, the antenna operates as a multi-frequency antenna corresponding to different frequencies f1, f2, and f3.

  Further, according to the multi-frequency surface-mounted antenna 1 of the present invention, the end portion of the radiation electrode 2 connected to the feeding electrode terminal 4 is always present outside the spiral pattern when viewed in plan. Thus, unbalanced power feeding can be performed by surface mounting without using a coaxial cable or the like.

  Further, since the sub-radiation electrode 3 is formed on at least a part of the radiation electrode 2 toward the outside of the spiral pattern when the radiation electrode 2 is viewed in plan view, the sub-radiation electrode 3 is surrounded by the radiation electrode 2. Therefore, the interference between the two can be kept low, and the deterioration of the antenna characteristics can be kept low.

  The length of the sub-radiation electrode 3 is preferably such that it occupies 1/8 or more of the electrical length corresponding to the desired frequency f3. This is because, when the electrical length ratio occupied by the sub-radiation electrode 3 becomes approximately 1/8 or less, the magnetic fields of the frequencies f1 and f2 by the radiation electrode 2 become dominant, the impedance matching is shifted, and the transmission / reception loss of the antenna increases. Because.

  Further, the position where the auxiliary radiation electrode 3 is provided may be at any position as long as the electrical length ratio occupied by the auxiliary radiation electrode 3 is 1/8 or more. Preferably, the closer to the connection with the power supply electrode terminal 4, the better. This is because the electrical length ratio of the sub-radiation electrode 3 portion increases as the connection portion with the power supply electrode terminal 4 is closer.

  Moreover, when providing the sub-radiation electrode 3, it is desirable to set it as three or less. This is because when there are four or more sub-radiating electrodes 3, the pitch between the sub-radiating electrodes 3 and the radiating electrodes 2 is narrowed, and the antenna characteristics are deteriorated due to mutual interference. Further, if the pitch between each sub-radiation electrode 3 and radiation electrode 2 is widened in order to prevent deterioration of the antenna characteristics, the antenna size becomes large and does not conform to the intention of the present invention.

  The radiation electrode 2 preferably has a wide direction and a narrow direction in a predetermined direction.

  As shown in FIG. 1A, the entire radiation electrode 2 has a shape in which the wide direction is formed in the direction of the length a, and the narrow direction is formed in the length b direction.

  The lengths a and b in each direction indicate the maximum length a and the minimum length b among the radiation electrodes 2 formed in a rectangular parallelepiped, and the lengths a and b in each direction of the radiation electrode 2 are a> Therefore, when the multi-frequency surface-mount antenna 1 is used to mount the antenna device, the feed electrode 7 is arranged so that the narrow direction of b faces the ground conductor layer 6 of the mounting substrate 8. In addition, the portion facing the multi-frequency surface-mounted antenna 1 and the grounding conductor layer 6 is reduced by connecting the feeding electrode terminal 4 of the multi-frequency surface-mounting antenna 1 to the feeding electrode 7. 6 interferes with the magnetic field of the antenna 1. Thereby, it is possible to suppress a decrease in antenna characteristics.

  Furthermore, it is preferable that at least a part of the radiation electrode 2 is thicker than the width of other portions.

  As shown in FIG. 1B, by providing a thick portion of the radiating electrode 2 as the frequency adjusting section 9, the quarter-wave monopole antenna formed by the radiating electrode 2 is trimmed. It is possible to adjust the frequency f1 and the frequency f2, which is a higher-order mode of the frequency f1, at different rates. This is because trimming the frequency adjusting unit 9 causes a difference in frequency fluctuation ratio between the frequency f1 and the frequency f2 which is the higher order mode. Thereby, the frequency f1 and the frequency f2 can be adjusted separately.

  Here, the frequency adjusting unit 9 indicates a portion that is thicker than the minimum width in the entire length of the radiation electrode 2.

  The frequency adjusting unit 9 is preferably provided at the peak portion of the current distribution of the higher-order mode of the radiation electrode 2. FIG. 7 shows current distributions of the frequency f1 due to the fundamental wave and the frequency f2 due to the double higher-order mode wave in the radiation electrode 2. FIG. The fundamental wave shows the current distribution of the quarter wavelength antenna. The double higher-order mode wave shows the current distribution of the 1/2 (2 × 1/4) wavelength antenna.

  At the open end 2A of the radiation electrode 2, no current flows and the distribution is zero. Considering a ¼ wavelength antenna with this point as a reference, the current distribution becomes the maximum in the power feeding section.

  On the other hand, the half-wavelength antenna has a current distribution in which the current is the maximum between the open end and the power feeding unit, and 0 does not flow in the power feeding unit. Since the current distribution is different between the two in this way, the frequency adjustment unit 9 is formed at a position where the current distribution is different, that is, a position corresponding to the A portion in the figure, and when this portion is trimmed, the fundamental wave deviates from the peak portion of the current distribution. The frequency fluctuation is small. On the other hand, the higher-order mode wave has a peak portion of the current distribution, and the frequency variation due to trimming is large. From this, it becomes possible to adjust the frequency f1 and the frequency f2 separately.

  The frequency adjusting unit 9 is formed in a shape that is thickened outwardly of the spiral pattern when a part of the spiral pattern of the radiation electrode 2 is viewed in plan, and the current path flows through the shortest part of the radiation electrode 2. The frequency adjusting unit 9 is formed in a form that does not change the current path. Therefore, the trimming by the frequency adjusting unit 9 can finely adjust the frequency by changing only the electric length without changing the current path of the radiation electrode 2.

  Further, in the positional relationship between the sub-radiation electrode 3 and the frequency adjustment unit 9, it is preferable that the frequency adjustment unit 9 is formed on the open end side of the radiation electrode 2 with respect to the sub-radiation electrode 3.

  This is because if the frequency adjusting unit 9 is formed closer to the feeding electrode terminal 4 than the sub-radiating electrode 3, the fluctuation of the frequency f3 due to the trimming of the frequency adjusting unit 9 becomes large. This is because the frequency f3 can be adjusted by the tip of the sub-radiating electrode 3, and it is difficult to adjust the frequency if there are other frequency variation factors.

  For example, the dielectric constant is 9.6, the length perpendicular to the ground conductor layer 6 is 20 mm, the length parallel to the ground conductor layer 6 is 12 mm, and the thickness is 2 mm. The radiation electrode 2 is connected to the terminal 4 and the other end is an open end, and the length of the radiation electrode 2 formed in a substantially spiral pattern with the open end side being the inner periphery is 6 mm. The multi-frequency surface-mounted antenna 1 of the present invention in which a pattern in which the length of the sub-radiation electrode 3 formed toward the outside of the spiral pattern is 8 mm is formed is 40 × 80 mm in size on the surface of the mounting substrate 8. When mounted at a distance of 2 mm from the ground conductor layer 6 to the substrate 5, the radiating electrode 2 portion includes CDMA (frequency band: 824 to 894 MHz) and PCS (frequency band: 1820 to 1990 MHz), and the auxiliary radiating electrode 3. Bluetooth (frequency band in the part : It can be a three-frequency corresponding antenna corresponding to 2400~2500MHz).

  In the multi-frequency surface-mounted antenna 1 of the present invention as described above, the base 5 is made of a cube or a rectangular parallelepiped made of a dielectric or magnetic material, for example, a dielectric material (ratio of alumina) as a main component. It is produced using ceramics obtained by pressure-molding and firing a powder having a dielectric constant εr: 9.6). The base 5 may be a composite material of ceramic and resin as a dielectric, or a magnetic material such as ferrite.

When the substrate 5 is made of a dielectric, the propagation speed of the high-frequency signal propagating through the radiation electrode 2, the sub-radiation electrode 3, and the feeding electrode terminal 4 is slowed down, and the wavelength is shortened. Then, the effective length of the conductor pattern of the radiation electrode 2, the sub radiation electrode 3, and the feeding electrode terminal 4 becomes εr ^1/2 times, and the effective length becomes longer. Therefore, if the pattern lengths of the conductor patterns are the same, the current distribution region increases, so that the amount of radio waves to be radiated can be increased and the gain of the antenna 1 can be improved.

Conversely, if the characteristics are the same as the conventional antenna characteristics, the pattern length of the radiation electrode 2, the sub radiation electrode 3, and the feeding electrode terminal 4 can be 1 / (εr ^1/2 ) The mounting antenna 1 can be downsized.

  When the substrate 5 is made of a dielectric, if εr is lower than 3, it tends to approach the relative permittivity (εr = 1) in the atmosphere, making it difficult to meet the market demand for antenna miniaturization. There is. If εr exceeds 30, the antenna can be reduced in size, but the gain and bandwidth of the antenna are proportional to the antenna size. Therefore, the gain and bandwidth of the antenna 1 become too small and the characteristics as the antenna 1 cannot be achieved. Tend. Therefore, when the substrate 5 is made of a dielectric, it is desirable to use a dielectric material having a relative dielectric constant εr of 3 to 30. Examples of such a dielectric material include ceramic materials such as alumina ceramics and zirconia ceramics, and resin materials such as tetrafluoroethylene and glass epoxy.

  On the other hand, when the substrate 5 is made of a magnetic material, the impedances of the radiation electrode 2, the sub radiation electrode 3, and the feeding electrode terminal 4 are increased, so that the Q of the antenna can be lowered and the bandwidth can be widened.

  When the base 5 is made of a magnetic material, if the relative permeability μr exceeds 8, the bandwidth of the antenna 1 becomes wide, but the gain of the antenna 1 is proportional to the antenna size, so the gain of the antenna 1 becomes small. Therefore, there is a tendency that the characteristics as an antenna are not achieved. Therefore, when the substrate 5 is made of a magnetic material, it is desirable to use a magnetic material having a relative permeability μr of 1 to 8. Examples of such a magnetic material include YIG (yttria, iron, garnet), Ni—Zr compounds, Ni—Co—Fe compounds, and the like.

  The radiation electrode 2, the sub radiation electrode 3, the feeding electrode terminal 4, and the frequency adjusting unit 9 are formed of a metal whose main component is aluminum, copper, nickel, silver, palladium, platinum, gold, or the like. In order to form each pattern with these metals, conductors having a desired pattern shape can be formed by various printing methods, thin film forming methods such as vapor deposition methods and sputtering methods, metal foil bonding methods, and plating methods. A layer may be formed on a predetermined side surface of the substrate 5.

  As the mounting substrate 8, a normal circuit substrate such as glass epoxy or alumina ceramic is used.

  The ground conductor layer 6 and the power supply electrode 7 are formed of a conductor used for a normal circuit board such as copper or silver.

  For mounting the multi-frequency surface-mounted antenna 1 of the present invention on the surface of the mounting substrate 8 and connecting the feeding electrode terminal 4 to the feeding line electrode 7, solder mounting using a reflow furnace or the like can be used.

  The multi-frequency surface-mounted antenna 1 of the present invention has a through-hole penetrating between both end surfaces or both side surfaces or between both main surfaces of the base 5 as shown in FIG. By providing a groove penetrating between or between both side surfaces, the weight can be reduced and the reliability of the mounting strength against an impact after mounting can be improved.

  The antenna device using the multi-frequency surface-mounted antenna 1 as described above is preferably used as a radio communication device, and the radio communication device is a radio signal of a different multi-frequency band connected to the antenna device. And at least one of a transmission circuit and a reception circuit corresponding to the above. In addition, a radio signal processing circuit may be connected to a surface mount antenna, an antenna device, a transmission circuit, or a reception circuit in order to enable radio communication as desired, and various other configurations may be adopted.

  According to such a wireless communication apparatus of the present invention, the multi-frequency surface-mounted antenna 1 of the present invention or the antenna apparatus of the present invention as described above, and transmission corresponding to wireless signals of different multi-frequency bands connected thereto. Since it includes at least one of a circuit and a receiving circuit, a single surface-mounted antenna or antenna device can be used for a multi-frequency wireless communication device that is compatible with different multi-frequency and that is small and highly functional.

  Note that the multi-frequency surface-mounted antenna and antenna device of the present invention are not limited to the above embodiments, and various modifications may be made without departing from the scope of the present invention. For example, the shapes of the radiation electrode 2, the sub radiation electrode 3, and the feeding electrode terminal 4 of the multi-frequency surface-mounted antenna 1 of the present invention are not limited to the rectangular shape as shown in FIG. A meander-shaped radiation electrode 2 ′, sub-radiation electrode 3 ′, and power supply electrode terminal 4 ′ as shown in the plan view may be used. By changing the electrical length in this way, the corresponding frequency can be lowered or reduced in size. This antenna can also be manufactured.

(A) It is a perspective view which shows an example of embodiment of the multifrequency surface mount antenna of this invention, and embodiment of the antenna apparatus of this invention using the same.

(B) It is an expanded view of an example of embodiment of the multifrequency surface mount antenna of this invention.
It is a diagram which shows the example of the frequency characteristic of the reflection loss of the multifrequency surface mount antenna of this invention. It is a perspective view which shows the example of the base | substrate used for the multifrequency surface mount antenna of this invention. It is a top view which shows the example of the shape of the radiation electrode used for the multifrequency surface mount antenna of this invention, a sub radiation electrode, and a feeding electrode terminal. It is a perspective view which shows the example of the conventional surface mount antenna and an antenna apparatus using the same. It is an expanded view which shows the conventional surface mount antenna. It is the electric current distribution of the fundamental wave of a 1 / 4lambda monopole antenna formed with the radiation electrode part of the multifrequency surface mount antenna of this invention, and a high-order mode wave.

Explanation of symbols

1: Surface mount antenna 2: Radiation electrode 3: Sub radiation electrode 4: Feed electrode terminal 5: Base body 6: Ground conductor layer 7: Feed electrode 8: Mounting substrate 9: Frequency adjustment unit

Claims (6)

A substantially rectangular parallelepiped base made of a dielectric material or a magnetic material, one end of which is connected to the power supply electrode terminal over the two or more surfaces of the base, and the other end is an open end. A radiation electrode formed in a spiral pattern such that the radiation electrode is on the inside, and a secondary radiation electrode formed on at least a part of the radiation electrode toward the outside of the spiral pattern when the radiation electrode is viewed in plan view multi-frequency surface mount an antenna, wherein during the secondary radiation electrode and said open end, the multi-frequency surface mount antenna characterized that you have a thick the frequency adjusting section width than the open end side is formed comprising . The multi-frequency surface-mount antenna according to claim 1, wherein the radiation electrode has a wide direction and a narrow direction in a predetermined direction. Multi-frequency surface mount antenna according to claim 1 or 2, characterized in that a through hole and / or grooves in the substrate. The multi-frequency surface-mounted antenna according to any one of claims 1 to 3 is mounted on the other surface of the power supply electrode on a mounting substrate on which a power supply electrode and a ground conductor layer disposed on one side of the power supply electrode are formed. An antenna device, wherein the antenna device is mounted on the side and the power supply electrode terminal is connected to the power supply electrode. 3. The multi-frequency surface-mount antenna according to claim 2, wherein the width direction of the radiation electrode is a ground conductor layer on a mounting substrate on which a power feed electrode and a ground conductor layer disposed on one side of the power feed electrode are formed. The antenna device is mounted on the other side of the feeding electrode in a direction opposite to the feeding electrode, and the feeding electrode terminal is connected to the feeding electrode. Radio communication apparatus characterized by connecting the transmitting circuit and / or receiving circuit corresponding to the radio signal of the plurality of frequency bands to the antenna device according to claim 4 or 5.

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