WO2012169370A1

WO2012169370A1 - Antenna device, and electronic device

Info

Publication number: WO2012169370A1
Application number: PCT/JP2012/063437
Authority: WO
Inventors: 尾仲健吾; 田中宏弥; 櫛比裕一
Original assignee: 株式会社村田製作所
Priority date: 2011-06-06
Filing date: 2012-05-25
Publication date: 2012-12-13
Also published as: JPWO2012169370A1; CN103548039B; CN103548039A; JP5700122B2

Abstract

In the present invention, ground conductors (11, 11F) are formed on a first surface of a substrate (10), and a ground conductor (12) is formed on a second surface of the substrate (10). A ground conductor non-forming region (8) is provided along a first side (S1), which is a part of the outer edge of the ground conductor (11). A series circuit is connected to both ends of the ground conductor non-forming region (8) in a direction along the first side (S1), the series circuit contains emission electrodes (13, 14), capacitance elements (C1, C2), and the ground conductor (11F). As an example, the emission electrodes (13) are emission electrodes for a 5 GHz band, and the emission electrodes (14) are emission electrodes for a 2.4 GHz band. The capacitance element (C1) creates a gap capacitance between the emission electrode (13) and the emission electrode (13), and the capacitance element (C2) creates a gap capacitance between the emission electrode (14) and the emission electrode (14).

Description

ANTENNA DEVICE AND ELECTRONIC DEVICE

The present invention relates to an antenna device and an electronic device including the antenna device, and more particularly to an antenna device and an electronic device used for wireless communication in a plurality of frequency bands.

Patent Document 1 discloses an antenna device in which two radiating electrodes are formed on a base and one feeding line is branched into two to feed each radiating element in order to increase the bandwidth or frequency bands. Is disclosed.

In addition, it is a rectangular parallelepiped chip antenna, two radiation electrodes are evenly provided on the top surface with a gap between them, the two radiation electrodes are connected to the ground conductor, and the feed electrode is electromagnetically coupled to one radiation electrode An antenna device configured as described above is disclosed in Patent Document 2.

Japanese Patent Laid-Open No. 11-4113 International Publication No. 2006/000631 Pamphlet

The antenna device of Patent Document 1 can operate in a plurality of frequency bands, but when the resonance frequencies of the two radiating elements are close, in the frequency band where the two frequency bands overlap, the two radiating elements become a continuous line. Resonant operation at 1/2 wavelength. Therefore, the antenna operation is completed at 1/2 wavelength, the equivalent antenna volume is reduced, and the antenna performance (particularly radiation efficiency) is deteriorated. In addition, since design and directivity control including the current flowing in the ground conductor are not considered, for example, it is easily affected by hand fog and noise when applied to a mobile phone.

The antenna device of Patent Document 2 operates in a single frequency band and does not support a plurality of frequency bands.

Therefore, an object of the present invention is to provide an antenna device that has high radiation efficiency and operates in a plurality of frequency bands, and an electronic device including the antenna device.

(1) An antenna device of the present invention includes a substrate on which a ground conductor is formed,
A ground conductor non-formation region provided along a part of the outer edge of the ground conductor;
A plurality of capacitance elements, a plurality of radiation electrodes, and a single or a plurality of capacitance elements, which are connected to both ends of the ground conductor non-formation region along the outer edge of the ground conductor and are disposed so as to straddle the ground conductor non-formation region A series circuit including a ground conductor of
A transmission line branched to a feeder line having a first end connected to the feeder circuit and a second end connected to the plurality of radiation electrodes;
Two radiation electrodes are connected to the ground conductor in the ground conductor non-forming region, and the capacitance element is connected between the radiation electrode and the radiation electrode,
The point branched to the feed line is inside the two outer points of the connection points of the feed lines to the plurality of radiation electrodes.

(2) Of the plurality of radiation electrodes, the region (antenna occupied volume) from each radiation electrode to the inner peripheral edge of the ground conductor non-formation region and the capacitance element is configured to be smaller as the radiation frequency is higher. It is preferable.

(3) Of the plurality of radiation electrodes, the radiation electrode having a higher operating frequency is preferably disposed closer to the branch point of the transmission line.

(4) An electronic device of the present invention includes a metal cavity partially formed with an insulator or dielectric slot, and an antenna device is disposed at a position for exciting the slot inside the metal cavity.
The antenna device is
A substrate on which a ground conductor is formed;
A ground conductor non-formation region provided along a part of the outer edge of the ground conductor;
A plurality of capacitance elements, a plurality of radiation electrodes, and a single or a plurality of capacitance elements, which are connected to both ends of the ground conductor non-formation region along the outer edge of the ground conductor and are disposed so as to straddle the ground conductor non-formation region A series circuit including a ground conductor of
A transmission line branched to a feeder line having a first end connected to the feeder circuit and a second end connected to the plurality of radiation electrodes;
Two radiation electrodes are connected to the ground conductor in the ground conductor non-forming region, and the capacitance element is connected between the radiation electrode and the radiation electrode,
The point branched to the feed line is inside the two outer points of the connection points of the feed lines to the plurality of radiation electrodes.

(5) The slot is preferably filled with a dielectric having a dielectric constant higher than that of air.

According to the present invention, an antenna device having high radiation efficiency and operating in a plurality of frequency bands and an electronic device including the antenna device can be obtained.

FIG. 1A is a plan view of the antenna device 101 according to the first embodiment. FIG. 1B is a rear view thereof. FIG. 2 is an equivalent circuit diagram of the antenna device 101. 3A and 3B are configuration diagrams of the two antenna devices when the antenna device 101 shown in FIG. 1 is separated into two antenna devices for a single frequency band. FIG. 4 is a diagram showing the frequency characteristics of the return loss (S11) of the antenna device 101 and the antenna device for a single frequency band as viewed from the power feeding circuit. FIG. 5 is a diagram showing the directivity of the antenna device 101 and the antenna device for a single frequency band. FIG. 6 is a plan view of the antenna device 102 according to the second embodiment. FIG. 7 is a diagram illustrating the frequency characteristics of the return loss (S11) of the antenna device 102 and the antenna device for a single frequency band as viewed from the power feeding circuit. FIG. 8 is a plan view of the antenna device 103 according to the third embodiment. FIG. 9 is a diagram showing an example of the antenna occupied volume near the three radiation electrodes. FIG. 10 is a plan view of a circuit board including the antenna device 104 of the fourth embodiment. FIG. 11 is an external perspective view of an electronic apparatus 201 according to the fifth embodiment. FIG. 12 is a plan view of the antenna device 106 according to the sixth embodiment. 13A and 13B are diagrams showing the current intensity distribution of the antenna device 106. FIG. FIG. 13A shows a state at 1.575 GHz, and FIG. 13B shows a state at 1.6 GHz. FIG. 14A is a diagram showing the frequency characteristics of the return loss (S11) seen from the power feeding circuit of the antenna device 106, and FIG. 14B is a Smith chart showing the impedance seen from the power feeding circuit over a predetermined frequency range. FIG. FIG. 15 is a diagram showing the efficiency of the antenna device 106. FIG. 16 is a diagram showing the directivity of the antenna device 106.

<< First Embodiment >>
The antenna device of the first embodiment will be described with reference to the drawings. FIG. 1A is a plan view of the antenna device 101 according to the first embodiment. FIG. 1B is a rear view thereof.
The antenna device 101 includes a substrate 10. The

ground conductors

11 and 11F are formed on the first surface of the substrate 10, and the ground conductor 12 is formed on the second surface. The

ground conductors

11, 11F and 12 are connected via a plurality of via conductors (through holes).

As shown in FIG. 1A, the ground conductor 11 on the first surface has a rectangular shape, and has a first side S1 having a long side and a second side S2 facing the first side S1. A ground conductor non-formation region 8 is provided along the first side S1 of the ground conductor 11 at other positions (center position) excluding both ends of the first side S1. The ground conductor non-forming region 8 has an inner side S3 parallel to the first side S1.

As shown in FIG. 1B, the ground conductor 12 on the second surface is formed at a position facing the

ground conductors

11 and 11F on the first surface. Accordingly, the ground conductor non-forming region 9 is also formed at a position facing the ground conductor non-forming region 8 on the first surface. However, a ground conductor is formed at a position opposite to

power supply lines

16A and 16B described later.

A series circuit including the radiation electrode 13 and the capacitance element C1 is connected between the first end in the direction along the first side S1 of the ground conductor non-forming region 8 and the ground conductor 11F. A series circuit including the radiation electrode 14 and the capacitance element C2 is connected between the second end of the ground conductor non-forming region 8 and the ground conductor 11F. That is, the two series circuits are arranged so as to straddle the ground conductor non-forming region 8 with the ground conductor 11F as a stepping stone. Here, the radiation electrode 13 is, for example, a radiation electrode for 5 GHz band, and the radiation electrode 14 is, for example, a radiation electrode for 2.4 GHz band. The capacitance element C1 constitutes a gap capacity between the radiation electrode 13 and the radiation electrode 13, and the capacitance element C2 constitutes a gap capacity between the radiation electrode 14 and the radiation electrode 14.

The substrate 10 is formed with a transmission line 16 branched into

power supply lines

16A and 16B having a first end connected to the power supply circuit and a second end connected to the

radiation electrodes

13 and 14. The feed line 16A is connected between the capacitance element C1 of the radiation electrode 13 and the ground conductor 11F, and the feed line 16B is connected between the capacitance element C2 of the radiation electrode 14 and the ground conductor 11F.

The transmission line 16 and the ground conductor 11 constitute a coplanar line. A microstrip line is configured by a part of the

feeder lines

16A and 16B and the ground conductor on the second surface (back surface) of the substrate 10.

The branch point BP is inside the connection point of the

feeder lines

16A and 16B to the

radiation electrodes

13 and 14. Preferably, the branch point BP is at or near the center of the formation region of the

radiation electrodes

13 and 14 in the ground conductor non-formation region 8. The

feeder lines

16A and 16B are both connected to a position near the ground conductor 11F. With this configuration, the distance from the feeding circuit to the feeding point to the radiation electrode can be shortened, and transmission loss can be suppressed.

In FIG. 1, the first end of the transmission line 16 is simply represented by a circular terminal. A power feeding circuit is connected to this terminal.

FIG. 2 is an equivalent circuit diagram of the antenna device 101. In the antenna device 101, a series circuit including the radiation electrode 13 is connected between the first end of the ground conductor non-forming region 8 and the ground conductor 11F, and the second end of the ground conductor non-forming region 8 and the ground conductor 11F are connected. A series circuit including the radiating electrode 14 is connected between the radiating electrode 13 and the radiating electrode 13 (position near the first end of the ground conductor 11F) and the radiating electrode 14 (position near the second end of the ground conductor 11F). This is a circuit configured as described above.

When the signal fed to the

radiation electrodes

13 and 14 is a 5 GHz band signal, the radiation electrode 13 resonates. That is, the radiation electrode 13 functions as a radiation electrode in the 5 GHz band. When the signal fed to the

radiation electrodes

13 and 14 is a 2.4 GHz band signal, the radiation electrode 14 resonates. That is, the radiation electrode 14 acts as a radiation electrode in the 2.4 GHz band. In either case, a current similar to that of a dipole antenna (like a dipole antenna) is induced in the

ground conductors

11 and 12. The arrow in FIG. 2 represents the current. A similar current flows through the ground conductor 12 on the second surface connected to the first surface by the via conductor.

Thus, current flows in the same phase to the radiation electrodes for each frequency band so as to exceed the ground conductor 11F.

FIG. 3 is a configuration diagram of the two antenna devices when the antenna device 101 shown in FIG. 1 is separated into two antenna devices for a single frequency band. 3A shows an antenna device for the 5 GHz band, and FIG. 3B shows an antenna device for the 2.4 GHz band. The antenna device 101 according to the first embodiment of the present invention shown in FIG. 1 is equivalently equivalent to an integrated antenna for a 5 GHz band and an antenna for a 2.4 GHz band.

FIG. 4 is a diagram showing the frequency characteristics of the return loss (S11) of the antenna device 101 and the antenna device for the single frequency band as viewed from the power feeding circuit. 4, (1) is the characteristic of the antenna for 5 GHz band shown in FIG. 3 (A), (2) is the characteristic of the antenna for 2.4 GHz band shown in FIG. 3 (B), and (3) is FIG. This is the characteristic of the antenna device 101 of the first embodiment shown in FIG.

Here, the dimensions of each part are as follows.
Substrate 10 size: 41 mm × 10 mm × 1.2 mm
Size of ground

conductor non-formation regions

8 and 9 Region for 5 GHz band: 3.75 mm × 4.5 mm
2.4 GHz band area: 6.75 mm x 4.5 mm
As is apparent from FIG. 4, matching is achieved in both the 5 GHz band and the 2.4 GHz band. It can be seen that a bandwidth equal to or greater than that of a single frequency antenna is obtained.

FIG. 5 is a diagram showing the directivity of the antenna device 101 and the antenna device for the single frequency band. The direction of FIG. 5 corresponds to the direction of FIG. FIG. 5A shows the characteristics at 5 GHz, and FIG. 5B shows the characteristics at 2.4 GHz. In either case, the directivity of the antenna device 101 and the directivity of the single-frequency antenna device are almost the same, and are overlapped in FIGS. 5 (A) and 5 (B). Thus, it can be seen that the same characteristics as those of the single-frequency antenna are obtained with respect to directivity.

As shown in FIG. 2, the current flows in the same phase to the radiation electrode for each frequency band so as to exceed the ground conductor 11F, so that in any frequency band, the 0 ° direction (the ground conductor of the ground conductor 11 is not formed). Strong directivity is shown in the side where the region 8 is formed (the direction of the first side S1).

In addition, since the occupied space of the antenna (the side of the ground conductor non-formation region and the region up to the capacitance element) is not reduced by providing a plurality of radiation electrodes, the radiation efficiency of the antenna is the same as that of a single frequency antenna. It can be seen that the characteristics can be obtained.

As described above, according to the present invention, since a plurality of antennas operating at different frequencies do not interfere with each other and operate almost independently, antenna performance such as return loss characteristics, directivity, and radiation efficiency can be achieved in a single frequency band. It is equivalent to an antenna device.

<< Second Embodiment >>
In the second embodiment, examples of antenna devices for 2.4 GHz band and GPS (1.5 GHz) are shown.
FIG. 6 is a plan view of the antenna device 102 according to the second embodiment. The antenna device 102 includes a substrate 10, a ground conductor 11 is formed on the first surface of the substrate 10, and a ground conductor is formed on the second surface. A series circuit including

radiation electrodes

14 and 15, capacitance elements C2 and C3, and a ground conductor 11F is connected to both ends of the ground conductor non-formation region 8 in the direction along the first side S1. That is, the series circuit is arranged so as to straddle the ground conductor non-forming region 8. Here, the radiation electrode 14 is a radiation electrode for 2.4 GHz band, and the radiation electrode 15 is a radiation electrode for GPS (1.5 GHz band). The capacitance element C2 constitutes a gap capacitance between the radiation electrode 14 and the radiation electrode 14, and the capacitance element C3 constitutes a gap capacitance between the radiation electrode 15 and the radiation electrode 15.

Since the sizes of the

radiation electrodes

14 and 15 are determined according to the frequency band, they are different from the

radiation electrodes

13 and 14 shown in FIG. 1A, but the overall basic configuration is the first embodiment. This is the same as the antenna device shown in FIG.

FIG. 7 is a diagram showing the frequency characteristics of the return loss (S11) of the antenna device 102 and the antenna device for the single frequency band as viewed from the power feeding circuit. 7, (1) is the characteristics of the 2.4 GHz band antenna shown in FIG. 6, (2) is the characteristics of the GPS (1.5 GHz band) antenna, and (3) is the second characteristic shown in FIG. It is the characteristic of the antenna apparatus 102 of embodiment.

Here, the dimensions of each part are as follows.
Substrate 10 size: 41 mm × 10 mm × 1.2 mm
Size of the ground conductor non-forming area 2.4 GHz band area: 6.75 mm × 4.5 mm
Area for 1.5 GHz band: 9.00 mm × 4.5 mm
As is clear from FIG. 7, the return loss is small in both the 2.4 GHz band and the 1.5 GHz band. It can be seen that an equivalent bandwidth is obtained even when compared with a single-frequency antenna.

<< Third Embodiment >>
In the third embodiment, an example of an antenna device that can be used in three bands for 5 GHz band, 2.4 GHz band, and GPS (1.5 GHz) is shown.
FIG. 8 is a plan view of the antenna device 103 according to the third embodiment. The antenna device 103 includes a substrate 10, a ground conductor 11 is formed on the first surface of the substrate 10, and a ground conductor is formed on the second surface. A series circuit including the

radiation electrodes

13, 14, 15 and the capacitance elements C1, C2, C3 and the ground conductors 11F1, 11F2 is connected to both ends in the direction along the first side S1 of the ground conductor non-formation region 8. . That is, the series circuit is arranged so as to straddle the ground conductor non-forming region 8. Here, the radiation electrode 13 is a radiation electrode for 5 GHz band, the radiation electrode 14 is a radiation electrode for 2.4 GHz band, and the radiation electrode 15 is a radiation electrode for GPS (1.5 GHz band). The capacitance element C1 constitutes a gap capacitance between the radiation electrode 13 and the radiation electrode 13, the capacitance element C2 constitutes a gap capacitance between the radiation electrode 14 and the radiation electrode 14, and the capacitance element C3 corresponds to the radiation electrode 15. A gap capacitance with the radiation electrode 15 is formed.

The branch point BP of the transmission line 16 is inside the two outer points (connection points of the feed lines 16B, 16C) among the connection points of the

feed lines

16A, 16B, 16C to the

radiation electrodes

13, 14, 15. Further, the branch point BP is at or near the center of the formation area of the

radiation electrodes

13, 14, 15 in the ground conductor non-formation area 8.

The size of the

radiation electrodes

13, 14, 15 is determined according to the frequency band. The substrate 10 is formed with a transmission line 16 that is branched into

power supply lines

16A, 16B, and 16C having a first end connected to the power supply circuit and a second end connected to the

radiation electrodes

13, 14, and 15. The transmission line 16 and the ground conductor 11 constitute a coplanar line. In addition, a microstrip line is configured by the

power supply lines

16A, 16B, and 16C and the ground conductor on the second surface (back surface) of the substrate 10.

FIG. 9 is a diagram showing an example of the antenna occupied volume near the three radiation electrodes. 9A shows a 5 GHz antenna occupied volume OV1 due to the radiation electrode 13, FIG. 9B shows a 2.4 GHz antenna occupied volume OV2 due to the radiation electrode 14, and FIG. Each represents an antenna occupied volume OV3 of .5 GHz. These antenna-occupied volumes are regions from the

radiation electrodes

13, 14, 15 to the inner side S3 of the ground conductor non-formation region 8 and the capacitance element.

Thus, the antenna occupation volume is formed smaller as the radiation electrode has a higher operating frequency. As a result, a plurality of antennas can be efficiently incorporated within a limited substrate area without waste. Therefore, the antenna device can be downsized.

In addition, for an antenna unit that operates at a low frequency (the portion of the antenna-occupied volume), the antenna unit that operates at a high frequency can only be seen as a notch in a relatively small ground conductor. In other words, it is a notch in the ground conductor that has no effect at low frequencies. Therefore, the antenna unit that operates at a low frequency is hardly affected by the antenna unit that operates at a high frequency. Conversely, for an antenna unit that operates at a high frequency, the antenna unit that operates at a low frequency appears to have a low impedance because the capacitance (gap capacitance) of the capacitance element is sufficiently large. In other words, it acts as an equivalent ground conductor. In particular, since the capacity of the capacitance element is set larger as the antenna unit that operates at a lower frequency in order to suppress the increase in size, this effect (appears to be equivalently low impedance) becomes remarkable.
Further, of the

radiation electrodes

13, 14, and 15, the radiation electrode having a higher operating frequency is disposed closer to the branch point BP of the feeder line. In the example shown in FIG. 8, the radiation electrode 13 for 5 GHz is arranged at the position closest to the branch point BP, the radiation electrode 14 for 2.4 GHz band is arranged at the next distant position, and at the most distant position. A radiation electrode 15 for 1.5 GHz band is disposed. As the frequency is higher, transmission loss is more likely to occur, and the characteristic impedance is likely to vary depending on the length of the transmission line. Therefore, the higher the frequency of the radiation electrode is, the closer to the branch point BP of the feeder line, the more suitable impedance matching and the lower the loss.

<< Fourth Embodiment >>
FIG. 10 is a plan view of a circuit board including the antenna device 104 of the fourth embodiment. This circuit board is obtained by mounting various conductor patterns and various elements on a parent substrate 40. The ground conductor 11 of the antenna device 104 has a first side S1 and a second side S2 facing the first side S1. The ground conductor 11 is formed along a part of the outer edge of the parent substrate 40. A main ground conductor 41 is formed on the parent substrate 40, and a ground conductor isolation region 42 is provided between the main ground conductor 41 and the ground conductor 11. A part of the ground conductor 11 is connected to the main ground conductor 41 via the ground connection portion CS.

The configuration of the antenna device 104 is the same as that shown in FIG. 8 in the third embodiment. A high frequency module 34 which is a power feeding circuit for the antenna device is mounted on the parent substrate 40. The high-frequency module 34 and the antenna device 104 are connected by a feeder line 16. The feeder line 16 and the

ground conductors

11 and 41 constitute a coplanar line.

According to the fourth embodiment, since the ground conductor 11 is separated from the main ground conductor 41 of the parent substrate 40 except for the ground conductor of the transmission line portion, the influence of noise generated in the parent substrate 40 is reduced. Therefore, the versatility as an antenna device of the type incorporated in the parent substrate is also high.

In each of the embodiments described above, the example in which the inner side S3 of the ground conductor non-forming region 8 is parallel to the first side S1 is shown. However, the relationship between the sides S1 and S3 is accurate. It does not need to be parallel and may be substantially parallel. In order to solve the problems of the present invention, a series circuit including a plurality of capacitance elements, a plurality of radiation electrodes, and a single or a plurality of ground conductors can be arranged in the ground conductor non-forming region 8, and dipoles are connected to the

ground conductors

11 and 12. Any structure that induces a current similar to that of an antenna (like a dipole antenna) may be used.

<< Fifth Embodiment >>
FIG. 11 is an external perspective view of an electronic apparatus 201 according to the fifth embodiment. The electronic apparatus 201 includes an antenna device 103 together with a substrate on which various circuits are configured inside a metal casing 50. A slot 51 that is excited by the antenna device 103 is provided in a part of the housing 50. In the slot 51, an opening formed over the upper and lower surfaces and side surfaces of the housing 50 is filled with resin. The antenna device 103 inside the housing is arranged at a position where the ground conductor non-forming portion of the antenna device 103 faces the outside of the housing 50 through the slot 51.

Since the direction in which each radiation electrode of the antenna device 103 extends is the gap direction of the slot 51, the electric field generated by the current flowing through the radiation electrode is applied in the gap width direction of the slot 51, and the slot 51 is excited. As a result, even if the gap of the slot 51 is smaller than the overall size of the housing 50, the slot 51 can radiate efficiently. The gap and length of the slot 51 may be determined so that the slot 51 acts as a slot antenna with good radiation efficiency.

The resin filled in the slot is an insulator. However, if the dielectric has a dielectric constant higher than that of air (relative permittivity of 1 or more), the wavelength is shortened, so that the radio wave can be efficiently transmitted even in a smaller slot. Can radiate.

<< Sixth Embodiment >>
FIG. 12 is a plan view of the antenna device 106 according to the sixth embodiment. Unlike the antenna device shown in FIG. 1 in the first embodiment, this example is an example of an antenna device used for two relatively close frequencies. The basic configuration is the same as that shown in FIG. 1, but the dimensions of the

radiation electrodes

13 and 14 differ depending on the applied frequency. Further, the capacitances of the capacitance elements C1 and C2 are determined as necessary. More specifically, the radiation electrode 13 and the capacitance element C1 are used for GLONASS (Global Navigation Satellite System) signal reception, and the radiation electrode 13 and the capacitance element C1 are used for GPS (Global positioning system) signal reception.

13A and 13B are diagrams showing the current intensity distribution of the antenna device 106. FIG. FIG. 13A shows a state at 1.575 GHz, and FIG. 13B shows a state at 1.6 GHz. The higher the current intensity, the higher the concentration. It can be seen that at 1.575 GHz, the inner periphery of the radiation electrode 14 and the ground conductor non-forming region on the radiation electrode 14 side contributes to radiation. In addition, at 1.6 GHz, it can be seen that the radiation electrode 13, the inner periphery of the ground conductor non-forming region on the radiation electrode 13 side, and the radiation electrode 14 contribute to radiation.

FIG. 14A is a diagram showing the frequency characteristics of the return loss (S11) seen from the power feeding circuit of the antenna device 106, and FIG. 14B is a Smith chart showing the impedance seen from the power feeding circuit over a predetermined frequency range. FIG. In FIG. 14B, the mark M01 indicates the impedance at 1.575 GHz, the mark M02 indicates 1.597 GHz, and the mark M03 indicates the impedance at 1.606 GHz.

As is clear from FIGS. 14A and 14B, it can be seen that there is a match between the GPS75 frequency of about 1.575 GHz and the GLONASS frequency of about 1.602 GHz.

FIG. 15 is a diagram showing the efficiency of the antenna device 106. In FIG. 15, curve R is the radiation efficiency and curve T is the total antenna efficiency. As is clear from this figure, an efficiency of 3.0-3.0 dB or higher is obtained in the band including 1.58 GHz to 1.6 GHz band.

FIG. 16 is a diagram showing the directivity of the antenna device 106. In FIG. 16, A is the directivity at 1.575 GHz and B is the directivity at 1.6 GHz. In this way, it is directed in all directions at any frequency, and a higher gain can be obtained particularly in the y-axis direction (the direction in which the

radiation electrodes

13 and 14 shown in FIG. 12 extend).

In each of the embodiments described above, an example of an antenna device provided with a rectangular ground conductor non-formation region is shown, but the shape of the ground conductor non-formation region is not limited to a rectangle. That is, the ground conductor non-forming region may be provided along a part of the outer edge of the ground conductor, and the shape of the side (S2) facing the outer edge of the ground conductor is arbitrary. For example, a semicircular shape or a step shape may be used.

BP ... branching points C1, C2, C3 ... capacitance element CS ... ground connection portions OV1 to OV3 ... antenna occupied volume S1 ... first side S2 ...

second side

8, 9 ... ground conductor non-forming region 10 ... substrate 11, DESCRIPTION OF SYMBOLS 12 ... Ground conductor 11F, 11F1, 11F2 ...

Ground conductors

13, 14, 15 ... Radiation electrode 16 ...

Transmission line

16A, 16B, 16C ... Feed line 34 ... High frequency module 40 ... Main board 41 ... Main ground conductor 42 ... Ground conductor isolation | separation Area 50 ... Metal casing 51 ... Slots 101 to 104, 106 ... Antenna device 201 ... Electronic equipment

Claims

A substrate on which a ground conductor is formed;
A ground conductor non-formation region provided along a part of the outer edge of the ground conductor;
A plurality of capacitance elements, a plurality of radiation electrodes, and a single or a plurality of capacitance elements, which are connected to both ends of the ground conductor non-formation region along the outer edge of the ground conductor and are disposed so as to straddle the ground conductor non-formation region A series circuit including a ground conductor of
A transmission line branched to a feeder line having a first end connected to the feeder circuit and a second end connected to the plurality of radiation electrodes;
Two radiation electrodes are connected to the ground conductor in the ground conductor non-forming region, and the capacitance element is connected between the radiation electrode and the radiation electrode,
The antenna device according to claim 1, wherein a point branched to the feed line is located inside two outer points of connection points of the feed lines to the plurality of radiation electrodes.
2. The antenna device according to claim 1, wherein among the plurality of radiation electrodes, a region from each radiation electrode to an inner peripheral edge of the ground conductor non-formation region and a capacitance element is smaller as the radiation electrode has a higher operating frequency. .
The antenna device according to claim 1 or 2, wherein a radiation electrode having a higher operating frequency among the plurality of radiation electrodes is disposed closer to a branch point of the transmission line.
A metal cavity partially formed with an insulator or dielectric slot;
An antenna device is disposed at a position for exciting the slot inside the metal cavity,
The antenna device is
A substrate on which a ground conductor is formed;
A ground conductor non-formation region provided along a part of the outer edge of the ground conductor;
A plurality of capacitance elements, a plurality of radiation electrodes, and a single or a plurality of capacitance elements, which are connected to both ends of the ground conductor non-formation region along the outer edge of the ground conductor and are disposed so as to straddle the ground conductor non-formation region A series circuit including a ground conductor of
A transmission line branched to a feeder line having a first end connected to the feeder circuit and a second end connected to the plurality of radiation electrodes;
Two radiation electrodes are connected to the ground conductor in the ground conductor non-forming region, and the capacitance element is connected between the radiation electrode and the radiation electrode,
The electronic device according to claim 1, wherein a point branched to the power supply line is located on an inner side of two outer points of connection points of the power supply lines to the plurality of radiation electrodes.
The electronic device according to claim 4, wherein the slot is filled with a dielectric having a dielectric constant higher than that of air.