JP2003332840A - Antenna device and radio equipment the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the interconnection between a plurality of antennas and the radio wave leakage from a transmitting side antenna to a receiving side antenna in an antenna device with the respective antennas arranged on the same ground conductor plate. <P>SOLUTION: In this antenna device wherein a first antenna 13 consisting of an antenna element 14 connected to a first feeding point 11 and a plate-like short-circuit element 15 and a second antenna 16 connected to a second feeding point 12 are installed on the ground conductor plate 10, the plate-like shunt element 15 is installed between the first feeding point 11 and the second feeding point 12 and almost perpendicularly to the ground conductor plate 10, and the second antenna 16 is configured in a profile smaller than the plate-like shunt element 15. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna device used for transmitting, receiving, or transmitting / receiving a plurality of radio waves having different frequencies, and a radio device including the antenna device.

[0002]

2. Description of the Related Art As an antenna for transmitting and receiving radio waves, a helical or monopole antenna for linear polarization whose length is adjusted according to the operating frequency, that is, the frequency or wavelength of the radio wave to be transmitted or received, or a dielectric Conventionally used planar antennas for circularly polarized wave reception, etc., in which a radiation conductor is provided on one surface of the body substrate and a ground conductor is provided on the other surface, and a feeding point for feeding the radiation conductor is provided in the radiation conductor. Has been.

One application of the antenna is a vehicle-mounted antenna. In recent years, automobiles are equipped with television receivers, television receivers, car navigation devices that receive GPS radio waves for navigation, telephones and other communication devices, and the like. These devices transmit and receive radio waves of different frequencies to perform a required operation, and thus basically require individual antennas having different operating frequencies corresponding to the respective transmission and reception frequencies. But,
It is not preferable to separately install a plurality of antennas from the viewpoint of installation space and cost.

Therefore, an antenna device in which a plurality of antennas having different operating frequencies are integrated has been considered. For example, Japanese Patent Application Laid-Open No. 2000-307341 proposes an antenna device in which an inverted F antenna and a microstrip antenna are arranged on one ground conductor plate. Since this antenna device has a plurality of antennas arranged on the same ground conductor plate, the overall size is small, and when it is used as a vehicle-mounted antenna device, it has an advantage that there are few parts protruding outside the vehicle.

When an inverted F antenna and a microstrip antenna are brought close to each other in order to further reduce the size of such an antenna device, mutual coupling of the two antennas occurs, which changes the antenna characteristics and adversely affects communication. The problem occurs. Also, in the situation where one of both antennas is transmitting and the other is receiving, if the transmitting frequency and the receiving frequency are close to each other, the transmitting wave from the transmitting antenna may be received by the receiving antenna. To be In such a case, in the receiver connected to the receiving antenna, the radio wave radiated from the transmitting antenna is received as an unnecessary wave, so that the communication quality deteriorates. Moreover, since the distances between the antennas are close to each other, the intensity of the electric wave leaking from the transmitting antenna to the receiving antenna is very large, which damages the preamplifier inserted in the receiver. There is a risk.

[0006]

As described above, in an antenna device in which a plurality of antennas having different operating frequencies are arranged close to each other, when the antennas are brought close to each other in order to reduce the size, the antenna characteristics change due to mutual coupling between the antennas. There is also a problem that the communication quality is deteriorated due to the leakage of the transmission wave into the receiving antenna, or the wireless device is damaged.

The present invention provides an antenna device which can reduce deterioration of communication quality due to mutual coupling between a plurality of antennas and leakage of radio waves from a transmitting side antenna to a receiving side antenna, and a radio device using the same. The purpose is to

[0008]

In order to solve the above problems, an antenna device according to the present invention is provided with a ground conductor plate, at least one first feeding point installed on the ground conductor plate, and at least one. Two second feeding points, an antenna element connected to the first feeding point, and a vertical position on the grounding conductor plate at a position between the first feeding point and the second feeding point and substantially perpendicular to the grounding conductor plate. At least one first antenna including a plate-shaped shorting element having a portion of a predetermined height for electrically short-circuiting a part of the antenna element, and the second feeding point connected to the ground conductor plate. And a second antenna having a height lower than the height of the plate-shaped short-circuit element installed in.

A radio device according to the present invention is connected to the above antenna device and a first feeding point, and at least one of transmitting and receiving a signal of a first frequency via the first antenna. A first radio circuit and at least one second radio circuit that is connected to the second feeding point and performs at least one of transmission and reception of a signal of the second frequency via the second antenna. To have.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 shows the configuration of an antenna device according to a first embodiment of the present invention. First and second feeding points 11 and 12 are arranged on a ground conductor plate 10 made of a conductive plate such as a metal plate, and further first and second antennas 13 and 16 are arranged close to each other. Has been done. Feeding point 11,
Reference numeral 12 is, for example, a coaxial structure composed of a center conductor and an outer conductor surrounding the center conductor, and the outer conductor is electrically connected to the ground conductor plate 10. The first and second antennas 13 and 16 are connected to the center conductors of the first and second feeding points 11 and 12, respectively.

The first and second antennas 13 and 16 have different operating frequencies, and perform transmission or reception or transmission / reception of radio waves of those frequencies. That is, the first antenna 13 is configured to perform at least one of transmission and reception of radio waves of the first frequency,
The second antenna 16 is configured to perform at least one of transmission and reception of a radio wave having a second frequency higher than the first frequency. Hereinafter, specific configurations of the antennas 13 and 16 will be described.

The first antenna 13 is an inverted F antenna in this example, and is composed of an antenna element 14 which is a linear conductor and a plate-shaped short-circuit element (hereinafter referred to as a short-circuit plate) 15. One end of the antenna element 14 is connected to the first feeding point 11, extends substantially perpendicular to the ground conductor plate 10 from this one end, and then bends so as to be substantially parallel to the ground conductor plate 10. The other end is open.

The short circuit plate 15 is a metal plate having an inverted L-shaped cross section, and one end thereof has a first feeding point 11 and a second feeding point 12.
It is connected to the ground conductor plate 10 at a position between and. And
The short-circuit plate 15 extends substantially perpendicularly to the ground conductor plate 10 with one end connected to the ground conductor plate 10 as a starting point, and then bends so as to be parallel to the ground conductor plate 10, and the other end bends the antenna element 14. Connected to the department. Therefore, the antenna element 14 is electrically short-circuited by the short-circuit plate 15 at a portion substantially perpendicular to the ground conductor plate 10.

As described above, in the first antenna 13, the monopole antenna, which is the linear antenna element 14 whose one end is connected to the first feeding point 11 on the ground conductor plate 10, is connected to the ground conductor plate 10 midway. The height from the ground conductor plate 10 is lowered by bending so as to be substantially parallel to the so-called low profile. Further, since the radiation resistance is reduced in this way, the reduction of the radiation resistance is compensated by connecting the short-circuit plate 15 in the middle of the antenna element 14 in the first antenna 13.

On the other hand, the structure of the second antenna 16 is not particularly limited, but it is, for example, a T-type monopole antenna or a microstrip antenna as will be described later, and it is lower than the first antenna 13, that is, the ground conductor plate. 1
The height from 0 is the height of the first antenna 13 (short-circuit plate 15
(The height of the plate-shaped portion that is almost vertical to the ground conductor plate 10)
It is designed to be lower.

First and second radio circuits 21, 22 are connected to the first and second feeding points 11, 12 from the back side of the ground conductor plate 10, respectively. Radio circuit 21,
Reference numeral 22 denotes a transmission circuit, a reception circuit, or a transmission / reception circuit, which has at least one of a transmission function and a reception function. The first radio circuit 21 is connected to the first antenna 1
The signal of the first frequency is transmitted, received, or transmitted / received via (3). The first radio device circuit 22 transmits, receives, or transmits / receives a signal of a second frequency different from the first frequency via the second antenna 16. The transmission operation, reception operation, or transmission / reception operation of the radio device circuits 21 and 22 may be performed continuously or intermittently.

As described above, in the antenna device of this embodiment, the short-circuit plate 15 of the first antenna 13 is arranged on the ground conductor plate 10 between the first feeding point 11 and the second feeding point 12. By this, the short-circuit plate 15 causes the first antenna 1 to
Since it functions as a shield member between the third antenna 16 and the second antenna 16, mutual coupling between the two antennas 13 and 16 can be reduced.

In particular, since the short-circuit element of the first antenna 13 is plate-shaped rather than linear, the first antenna 13 and the second antenna 13
The area separating the antennas 16 is increased. Further, since the second antenna 16 has a lower posture than the first antenna 13, the antenna element 14 of the first antenna 13 which can be seen from the second antenna 16 becomes narrow. For these reasons, the shield effect of the short-circuit plate 15 is further improved. According to this embodiment, more specifically, the following effects can be expected.

(1) There is little change in characteristics due to mutual coupling between the antennas 13 and 16, and it is possible to prevent adverse effects on communication. Since the influences of the antennas 13 and 16 on the mutual antenna characteristics are reduced, each antenna 13, 1
6 can be designed independently, and the antenna device can be easily designed.

(2) One of the antennas 13 and 16 transmits,
When the other performs reception, the radio waves radiated from the transmitting antenna are less likely to leak into the receiving antenna as unnecessary waves, so that deterioration of communication quality due to the radio wave leakage is reduced. Therefore, it is possible to simplify the filter to be inserted into the receiving section of the radio circuit 21, 22, which contributes to reduction in size, weight and cost of the entire radio including the antenna device. There is also no risk that a preamplifier such as an LNA (low noise amplifier) inserted in the receiving section of the radio circuit 21 or 22 will be damaged by the leaked transmission signal.

(3) Since the mutual influence of the antennas 13 and 16 is reduced, the antennas 13 and 16 can be used continuously at the same time. Therefore, it is possible to switch between a plurality of antennas. Compared with this, it is possible to reliably perform transmission and reception. This is particularly effective in, for example, a navigation system that uses GPS signals and an emergency call that uses a telephone line.

(4) Since the short-circuit plate 15 which is a component of the first antenna 13 also serves as a shield member, the number of components is smaller than that when a shield member is separately provided between the antennas 13 and 16. In addition, since it is not necessary to secure a space for installing the shield member, the entire antenna device can be downsized.

Next, a preferred arrangement of the short circuit plate 15 of the first antenna 13 in this embodiment will be described. The short-circuit plate 15 is basically installed so as to cross the shortest path indicated by the broken line on the ground conductor plate 10 connecting the first feeding point 11 and the second feeding point 12 as shown in FIG. In particular, as shown in FIG. 3, it is more preferable to dispose the short-circuit plate 15 so as to vertically cross the shortest path on the ground conductor plate 10 connecting the first feeding point 11 and the second feeding point 12. By arranging the short-circuit plate 15 in this way, the length of the antenna element 14 of the first antenna 13 which can be seen from the second antenna 16 becomes smaller, so that the shielding effect of the short-circuit plate 15 can be further enhanced.

Further, when the first antenna 13 is an inverted F antenna, it is desirable that the antenna element 14 extends substantially perpendicular to the width direction of the short circuit plate 15 as shown in FIG. 4 (a). In contrast, FIG. 4B shows the antenna element 1
4 is an example in which the short circuit plate 15 extends obliquely with respect to the width direction. In FIGS. 4A and 4B, diagonal lines indicate a range (blind spot range) hidden behind the short-circuit plate 15 when the direction from the second feeding point 12 to the first feeding point 11 is seen. The feeding point 11 is arranged within this blind spot range.

As is apparent from FIGS. 4 (a) and 4 (b), the range that does not fall within the dead angle range as seen from the second feeding point 12, in other words, the length of the antenna element 14 that can be seen from the second antenna 16 side. (The length of the antenna element 14 protruding from the blind spot range) is smaller in the case of (a) than in the case of (b), so that the shielding effect of the short-circuit plate 15 can be maximized, Inverse F that is the first antenna 13
Mutual coupling between the antenna and the second antenna 16 is reduced even more effectively.

(Second Embodiment) FIG. 5 shows the configuration of an antenna device according to a second embodiment of the present invention. This embodiment differs from the first embodiment in that a one-side short-circuited microstrip antenna is used as the first antenna 23. The first antenna 23, which is a one-sided short-circuited microstrip antenna, is composed of an antenna element 24 in which a microstrip line is provided on a dielectric plate and a short circuit plate 25, and the microstrip line of the antenna element 24 is first fed by a feed line 26. Is connected to the feeding point 11.
One end of the antenna element 24 is connected to one end of the short circuit plate 25, and the other end is open. The other end of the short circuit plate 25 is connected to the ground conductor plate 10.

The microstrip antenna is an antenna which utilizes radiation from a magnetic current flowing at an end of a microstrip line provided in parallel with a ground conductor plate. On the other hand, in the one-side short-circuited microstrip antenna which is the first antenna 23 in the present embodiment, as shown in FIG. 5, the feeding line 2 is fed from the first feeding point 11 on the ground conductor plate 10.
The microstrip antenna whose power is supplied to the microstrip line through 6 is short-circuited by connecting the grounding conductor plate 10 at the center line of the antenna element by the short-circuit plate 25, and one half of the antenna element is removed to form the antenna element 24. We are trying to make it smaller.

According to this embodiment, the same effect as that of the first embodiment can be obtained. That is, the first antenna 23
Of the short-circuit plate 25 on the ground conductor plate 10 to the first feeding point 11
And the second feeding point 12, the short-circuit plate 25 functions as a shield member between the first antenna 23 and the second antenna 16. As a result, mutual coupling between the antennas 23 and 16 is reduced, and radio waves radiated from the transmitting antenna are less likely to leak into the receiving antenna as unnecessary waves.
There is little deterioration in communication quality due to the leakage of radio waves, and there is no risk of damage to the preamplifier inserted in the receiving section of the radio device circuits 21 and 22.

Further, also in this embodiment, the short-circuit plate 25 of the first antenna 23 is basically the ground conductor plate 10 connecting the first feeding point 11 and the second feeding point 12 as shown in FIG. It is installed so as to cross the shortest path (shown by the broken line) above. In this case, in particular, as shown in FIG. 7, by arranging the short-circuit plate 25 so as to vertically cross the shortest path on the ground conductor plate 10 connecting the first feeding point 11 and the second feeding point 12, The antenna element 24 of the first antenna 23 that can be seen through from the second antenna 16 becomes narrower, and the short-circuit plate 2
The shield effect of No. 5 can be further enhanced.

(Third Embodiment) Next, as a fourth embodiment of the present invention, the operating frequencies of the first and second antennas, that is, the frequencies of the radio waves for transmission or reception or transmission and reception (hereinafter referred to as antenna resonance). The preferable relationship of the frequency) will be described. According to this embodiment, the resonance frequency f1 of the first antenna in the first or second embodiment is set lower than the resonance frequency f2 of the second antenna. At this time, if the width of the short-circuit plate is x and the height is y,
The following formula holds.

F1 <f2 λ1 = c / f1, λ2 = c / f2 (λ: wavelength, c: speed of light) ∴λ1> λ2 ∴ (x / λ1) <(x / λ2), (y / λ1) <( y / λ2) From this, the electrical size of the short-circuit plate viewed from the second antenna, that is, the frequency f2, is the electrical size of the short-circuit plate viewed from the first antenna, that is, the frequency f1. You can see that it is larger than the size. Therefore, the shield effect of the short-circuit plate can be enhanced, and the first antenna and the second antenna
It is possible to further reduce mutual coupling with the antenna and the leakage of radio waves from the transmitting antenna to the receiving antenna. On the contrary, the electrical size of the short-circuit plate seen at the frequency f1 is smaller than the electrical size of the short-circuit plate seen at the frequency f2, so that the influence of the short-circuit plate on the radiation pattern of the first antenna is reduced. be able to.

FIG. 8 is a diagram showing the relationship between the first and second feeding points 11, 12 and the first antenna 13 and the second antenna 30 in the antenna device according to this embodiment.
Further, FIG. 9 shows an example of dimensions of each part in FIG. The first antenna 13 is an inverted F antenna, and the second antenna 30 is a low-profile T-type monopole antenna like the inverted F antenna. The T-shaped monopole antenna 30 is composed of a single linear element 31 and a feeding line 32 connecting the linear element 31 and the second feeding point 12. Linear element 31
Are provided parallel to the surface of the ground conductor plate (not shown).

Here, the resonance frequency f1 of the first antenna 13 is 800 MHz corresponding to the frequency of PDC (Personal Digital Cellular), and the resonance frequency f2 of the second antenna 30 is the frequency of GPS corresponding to 1.
Assume 5 GHz. That is, according to the present embodiment, the resonance frequencies of the first and second antennas 13 and 30 are f
The relationship is 1 <f2. Under such conditions of the resonance frequency and the dimensions of each part shown in FIG. 9, the first antenna (inverse F antenna) 13 and the second antenna (T-type monopole antenna) are formed on the infinitely grounded conductor plate as shown in FIG. ) 30 is installed, the position of the T-type monopole antenna 30 is changed, and the mutual coupling (maximum coupling amount) between both antennas 13 and 30 is calculated.

FIGS. 10A and 10B are plan views showing the positional relationship between the first and second feeding points 11 and 12 and the short circuit plate 15 of the first antenna 13. In FIG. 10A, a short-circuit plate 15 is installed between the first feeding point 11 and the second feeding point 12, and in FIG. 10B, the first and second feeding points 11 and 12 are short-circuited plate 15. Are placed on the same side as.

FIG. 11 shows the maximum coupling amount obtained by the above calculation for the mutual coupling between the antennas 13 and 30 in the arrangement shown in FIGS. 10 (a) and 10 (b). From the results of FIG. 11, it can be seen that the mutual coupling is smaller in the arrangement of FIG. 10A for both frequencies f1 and f2. That is, the short-circuit plate 15 is provided between the first feeding point 11 and the second feeding point 12.
, The resonance frequencies f1 and f2 of the first and second antennas 13 and 30 are selected to satisfy the relationship of f1 <f2. It is possible to effectively reduce the leakage of radio waves into the antenna and to reduce the influence of the short-circuit plate 15 on the radiation pattern of the first antenna 13.

(Fourth Embodiment) FIG. 12 shows the configuration of an antenna device according to the fourth embodiment of the present invention. Although the T-shaped monopole antenna 30 is used as the second antenna in the third embodiment, the microstrip antenna 40 is used as the second antenna in the present embodiment.
The microstrip antenna 40 is composed of a dielectric plate 41 arranged on the ground conductor plate 10 with its back surface in contact, and a radiation conductor (microstrip line) 42 provided on the front surface of the dielectric plate 41.

As described above, in the present embodiment, only the configuration of the second antenna 40 is different, and other configurations, for example, the first antenna 13 is provided between the first feeding point 11 and the second feeding point 12. The short-circuit plate 15 is installed, and the second antenna 40 is the first antenna (the inverted F antenna 1 in FIG. 12).
3) The ground conductor plate 10 has a low attitude, and the short-circuit plate 15 connects the first feeding point 11 and the second feeding point 12 to each other.
It is installed so as to cross the above shortest path, and more preferably, it is arranged so as to vertically cross the shortest path on the ground conductor plate 10 that connects the first feeding point 11 and the second feeding point 12, and Inverse F, which is preferably the first antenna 13.
The antenna element 14 of the antenna extends substantially perpendicularly to the width direction of the short circuit plate 15, and the relationship between the resonance frequencies f1 and f2 of the first and second antennas 13 and 40 is f1 <.
The fact that f2 is selected is the same as in the previous embodiments.

Further, although the first antenna is the inverted F antenna 13 in this embodiment, it may be the one-side short-circuited microstrip antenna 23 as in the second embodiment shown in FIG. In short, the combination of the first and second antenna types is not particularly limited.

(Fifth Embodiment) Next, FIGS.
A fifth embodiment of the present invention will be described using. In this embodiment, the configuration of the antenna device described above is expanded to include a first feeding point provided on the ground conductor plate, a first antenna connected to the first feeding point, and a first radio circuit. Number from 1 to n (n is an integer of 1 or more),
The number of the second feeding point provided on the ground conductor plate, the number of the second antenna connected to the second feeding point, and the number of the second wireless device circuit are each 1 to m (m is an integer of 1 or more). It is increasing to each. Note that, in FIGS. 13 to 16, the second antenna is not shown in order to simply and clearly show the positional relationship between the first and second feeding points and the short-circuit plate of the first antenna.

In FIGS. 13A, 13B, 13C and 13D, m is 1
FIG. 3 is a plan view schematically showing a case in which n is fixed to n = 1, 2, 3, 4 respectively. One second feeding point 1
11 and 1 to 4 first feeding points 101 to 104 are provided, and 1 to 4 first antennas 121 to 124 having short-circuit plates 131 to 134 are provided. Here, FIG.
As shown in 3 (a), (b), (c), and (d), the first feeding points 101 to 104 are indicated by diagonal lines hidden behind the short-circuit plates 131 to 134 when viewed from the second feeding point 111. It is located within the blind spot.

In order to arrange the first feeding points 101 to 104 within the blind spot range as seen from the second feeding point 111, the following is desirable. First, when there is one first antenna 121, the first feeding point 111 is arranged on the extension line of the antenna element of the first antenna 121 as shown in FIG. When there are two first antennas 121 and 123, as shown in FIG. 13B, the antenna elements are arranged on the same straight line, and the second feeding point 111 is arranged on this straight line. When there are three or more first antennas 121 to 123 or 121 to 124, the respective antenna elements are arranged at equal angular intervals (120 ° intervals, 90 ° intervals) as shown in FIGS. The second feeding point 111 is arranged on the intersection of the extension lines of the antenna elements.

In FIGS. 14 (a), (b), (c) and (d), m is 2
FIG. 3 is a plan view schematically showing a case in which n is fixed to n = 1, 2, 3, 4 respectively. Two second feeding points 1
11, 112 and 1 to 4 first feeding points 101 to 104
Are provided, and 1 to 4 first antennas 121 to 124 having short-circuit plates 131 to 134 are provided. Also in this case, as shown in FIGS. 14A, 14B, 14C, and 14D, the first feeding points 101 to 104 have the short-circuit plates 131 to 134 as viewed from the second feeding points 111 and 112. It is placed within the blind spot that is hidden behind.

In order to arrange the first feeding points 101 to 104 within the blind spot range as viewed from the second feeding points 111 and 112, the following is desirable. First one first
14A, the second feeding points 111 and 112 are connected to the first antenna 12 as shown in FIG.
It is arranged on the extension line of the antenna element 1. When there are two first antennas 121 and 122, as shown in FIG. 14B, the respective antenna elements are arranged on the same straight line, and the second feeding points 111 and 112 are arranged on this straight line. To place. When there are three or more first antennas 121 to 123 or 121 to 124, FIG.
Each antenna element is equiangularly spaced (1
20 ° intervals, 90 ° intervals), and the second feeding point 11
The feeding points 111 and 112 are arranged such that the midpoint of the antennas 1 and 112 is located on the intersection of the extension lines of the antenna elements.

In FIGS. 15 (a), (b), (c) and (d), m is 3
FIG. 3 is a plan view schematically showing a case in which n is fixed to n = 1, 2, 3, 4 respectively. Three second feeding points 1
11-113 and 1-4 first feeding points 101-104
Are provided, and 1 to 4 first antennas 121 to 124 having short-circuit plates 131 to 134 are provided. Also in this case, as shown in FIGS. 14A, 14B, 14C, and 14D, the first feeding points 101 to 104 are short-circuit plates 131 to 134 when viewed from the second feeding points 111 to 113. It is placed within the blind spot that is hidden behind.

In order to arrange the first feeding points 101 to 104 within the blind spot range as seen from the second feeding points 111 to 113, the following procedure may be performed. First, the second feeding points 111 to 113 are arranged on the three vertices of an equilateral triangle. If there is one first antenna 121,
As shown in FIG. 5A, the midpoint (center of the equilateral triangle) of the second feeding points 111 to 113 is arranged on the extension line of the antenna element of the first antenna 121. When there are two first antennas 121 and 122, as shown in FIG. 15B, the respective antenna elements are arranged on the same straight line, and the second feeding points 111 to 113 are arranged on this straight line. Place the midpoint. When there are three or more first antennas 121 to 123 or 121 to 124, the antenna elements are arranged at equal angular intervals (12
The second feeding points 111 are arranged at 0 ° intervals and 90 ° intervals).
The feeding points 111 to 113 are arranged such that the midpoint of the to 113 is located on the intersection of the extension lines of the antenna elements.

In FIGS. 16A, 16B, 16C and 16D, m is 4
FIG. 3 is a plan view schematically showing a case in which n is fixed to n = 1, 2, 3, 4 respectively. 4 second feeding points 1
11-114 and 1-4 first feeding points 101-104
Are provided, and 1 to 4 first antennas 121 to 124 having short-circuit plates 131 to 134 are provided. Also in this case, as shown in FIGS. 16 (a), (b), (c), and (d), the first feeding points 101 to 104 are short-circuit plates 131 to 134 when viewed from the second feeding points 111 to 114. It is placed within the blind spot that is hidden behind.

In order to arrange the first feeding points 101 to 104 within the blind spot range as viewed from the second feeding points 111 to 114, the following procedure may be performed. First, the second feeding point 11
1-114 are arranged on four vertices of a quadrangle (preferably a square). When there is one first antenna 121, as shown in FIG. 16A, the second feeding points 111 to 1
At the midpoint of 14 (center of the four triangles), the first antenna 12
It is arranged on the extension line of the antenna element 1. When there are two first antennas 121 and 122, as shown in FIG. 16B, the respective antenna elements are arranged on the same straight line, and the second feeding points 111 to 114 are arranged on this straight line. Place the midpoint. Three or more first antennas 121 to 1
If there are 23 or 121 to 124, FIG.
As shown in (d), the antenna elements are arranged at equal angular intervals (120 ° intervals, 90 ° intervals), and the midpoints of the second feeding points 111 to 114 are on the intersections of the extension lines of the antenna elements. The feeding points 111 to 114 are arranged so as to be located.

As described above, according to this embodiment, the first antennas 121 to 124 are short-circuited to each other by the short-circuit plate 131.
~ 1st feed point 1 to which each is connected by
01 to 104 are arranged to be separated from each other, and the short circuit plates 131 to 1 are arranged.
In the space surrounded by 34, the second feeding points 111 to 11
By arranging 4 between the first antennas and the first antenna
Of short-circuit plates 131 to 134 between the second antenna and the second antenna
Since it functions as a shield member, mutual coupling between the antennas can be reduced, and leakage of radio waves from the transmitting-side antenna to the receiving-side antenna can be reduced.

In FIGS. 13 to 16, the first antenna 12 is used.
Although 1 to 124 are all inverted F antennas, other one-side short-circuited microstrip antennas may be used, or different types of antennas such as an inverted F antenna and one-sided short-circuit microstrip antennas may be mixed.

Further, in the antenna device of FIGS. 13 to 16, the first feeding points 101 to 104 and the second feeding point 1
The short-circuit plates 131 to 134 of the first antennas 121 to 123 are installed between the antennas 11 to 114, and the second antenna (not shown) has a low attitude with respect to the first antennas 121 to 124. In addition, the short circuit plates 131 to 1
34 is the first feeding points 101 to 104 and the second feeding point 11
1 to 114 are installed so as to cross the shortest path on the ground conductor plate, and more preferably, they are arranged so as to vertically cross the shortest path, and preferably the first antennas 121 to 124 are inverted F antennas. In this case, the antenna element extends substantially perpendicular to the width direction of the short-circuit plates 131 to 134, and the resonance frequency f of the first and second antennas.
The relationship between 1 and f2 is the same as in the previous embodiments, such that f1 <f2 is preferable.

[0051]

As described above, according to the present invention, it is possible to reduce the deterioration of communication quality due to mutual coupling between a plurality of antennas and the leakage of radio waves from the transmitting side antenna to the receiving side antenna. it can.

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration of an antenna device according to a first embodiment of the present invention.

FIG. 2 is a schematic plan view for explaining basic arrangement conditions of the short-circuit plate of the first antenna in the same embodiment.

FIG. 3 is a schematic plan view for explaining a more preferable arrangement condition of the short-circuit plate of the first antenna in the same embodiment.

FIG. 4 is a schematic plan view for explaining more preferable arrangement condition of the antenna elements of the first antenna in the same embodiment.

FIG. 5 is a perspective view showing a configuration of an antenna device according to a second embodiment of the present invention.

FIG. 6 is a schematic plan view for explaining basic arrangement conditions of the short-circuit plate of the first antenna in the same embodiment.

FIG. 7 is a schematic plan view for explaining more preferable arrangement condition of the short-circuit plate of the first antenna in the same embodiment.

FIG. 8 is a perspective view showing a configuration of a main part of an antenna device according to a third embodiment of the present invention.

FIG. 9 is a diagram showing an example of dimensions of each part of the first and second antennas in the same embodiment.

FIG. 10 is a plan view showing the positional relationship between the first and second feeding points and the short-circuit plate of the first antenna in the same embodiment.

FIG. 11 is a diagram showing calculation results of mutual coupling between the first and second antennas in the arrangements of FIGS.

FIG. 12 is a perspective view showing a configuration of an antenna device according to a fourth embodiment of the present invention.

FIG. 13 is a plan view schematically showing a configuration example of an antenna device according to a fifth embodiment of the present invention when m = 1 and n = 1 to 4;

FIG. 14 is a plan view schematically showing a configuration example of an antenna device according to a fifth embodiment of the present invention when m = 2 and n = 1 to 4;

FIG. 15 is a plan view schematically showing a configuration example of an antenna device according to a fifth embodiment of the present invention when m = 3 and n = 1 to 4.

FIG. 16 is a plan view schematically showing a configuration example of an antenna device according to a fifth embodiment of the present invention when m = 4 and n = 1 to 4;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Ground conductor plate 11 ... 1st feeding point 12 ... 2nd feeding point 13 ... 1st antenna (inverted F antenna) 14 ... Antenna element 15 ... Short-circuit board (plate-shaped short-circuit element) 16 ... 2nd antenna 21 ... 1st radio | wireless machine circuit 22 ... 2nd radio | wireless machine circuit 23 ... 1st antenna (one side short circuit microstrip antenna) 24 ... Antenna element 25 ... Short circuit board (plate-shaped short circuit element) 30 ... 2nd antenna ( T-type monopole antenna) 31 ... Linear element 32 ... Feed line 40 ... Second antenna (microstrip antenna) 41 ... Dielectric plate 42 ... Radiating conductor (microstrip line) 101-104 ... First feeding point 111 -114 ... 2nd feeding point 121-124 ... 1st antenna 131-134 ... Short-circuit board

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H01Q 13/08 H01Q 13/08 (72) Inventor Shuichi Sekine 1 Komukai Toshiba-cho, Kawasaki-shi, Kanagawa Incorporated company Toshiba Research and Development Center (72) Inventor Hiroki Shoki 1 Komukai Toshiba-cho, Kouki-ku, Kawasaki-shi, Kanagawa F-term in Toshiba Research and Development Center (Reference) 5J021 AA02 AA13 AB02 AB06 CA03 HA07 HA10 JA03 5J045 AA03 AB05 DA08 DA10 EA04 EA07 FA01 HA02 JA11 JA20 LA01 NA02 NA04 5J046 AA04 AA14 AB06 AB13 UA02 UA03

Claims (6)

[Claims] 1. A ground conductor plate, at least one first feed point and at least one second feed point installed on the ground conductor plate, and an antenna element connected to the first feed point. And installed on the ground conductor plate at a position between the first feed point and the second feed point substantially vertically to the ground conductor plate and electrically short-circuiting a part of the antenna element. At least one first antenna including a plate-like shorting element having a portion of a predetermined height, and the height of the plate-like shorting element connected to the second feeding point and installed on the ground conductor plate Second low height
Antenna device including the antenna of. 2. The first feeding point is arranged within a range hidden behind the short-circuit plate when viewed from the second feeding point.
The antenna device described. 3. The plate-shaped short-circuit element has a plate-shaped portion that is substantially perpendicular to a line connecting the first feeding point and the second feeding point, and one end of the plate-shaped portion has the plate-shaped portion. The antenna device according to claim 1, which is connected to a ground conductor plate. 4. The antenna device according to claim 1, wherein the antenna element has a linear portion extending substantially horizontally with respect to the ground conductor plate and substantially perpendicular to a width direction of the plate-like short-circuit element. 5. The first antenna is configured to perform at least one of transmission and reception of a radio wave of a first frequency, and the second antenna is a second frequency higher than the first frequency. The antenna device according to claim 1, wherein the antenna device is configured to perform at least one of transmission and reception of the radio wave. 6. The antenna device according to claim 1, wherein the antenna device is connected to the first feeding point, and transmits and receives a signal of a first frequency via the first antenna. At least one first radio circuit that performs at least one of the above, and at least one of transmitting and receiving a signal of a second frequency via the second antenna, which is connected to the second feeding point. A radio including one second radio circuit.