JP3386332B2 - Antenna structure of small radio - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna structure in a small wireless device such as a portable telephone and a PC card. 2. Description of the Related Art In recent years, portable telephones and PC cards having a wireless communication function have become widespread as small wireless devices for performing wireless communication. Note that a PC card having a wireless communication function is PCMCIA (personal computer memory c).
ard international association) is installed in an interface slot to provide a mobile computing environment. Incidentally, these portable telephones and PC cards usually have an antenna structure protruding from a main body, such as a helical antenna or a whip antenna. For example, a PC card has a rotatable external antenna 20 as shown in FIG. 7, and the external antenna 20 is housed during wireless communication (see FIG. 7A).
There is a configuration in which a predetermined level of reception sensitivity is ensured by turning the sensor from the first position to a projected state (see FIG. 7B). [0004] However, in the above-described antenna structure of the small wireless device, since the external antenna 20 is protruded during wireless communication, for example, an external device such as a fall of the body of the small wireless device. If a shock is applied,
The external antenna 20 and its peripheral components may be damaged. Further, since this antenna structure requires the external antenna 20 and its rotating mechanism, a large occupied area is required, and it is difficult to reduce the size of the wireless device main body. [0005] For this purpose, it is conceivable to incorporate an antenna chipped by a semiconductor element (hereinafter referred to as a chip antenna) into the main body of the radio, but in this case,
The chip antenna must be mounted on an electronic board incorporated in the wireless device. In other words, the chip antenna
Since it is mounted on the same plane (on the same electronic board) as other circuit components required for wireless communication (such as a modulator and an amplifier), the size of the electronic board in the wireless device itself increases, As a result, it becomes difficult to reduce the size of the wireless device itself. Further, a chip antenna usually has a directivity of radiating radio waves in a direction parallel to a mounting surface of the chip antenna, but when the chip antenna is mounted on another circuit component on the same substrate, However, there is a possibility that the radiated radio wave is affected by reflection or absorption by other circuit components, and as a result, its performance cannot be sufficiently exhibited. Therefore, the present invention prevents the antenna from being damaged by incorporating the chip antenna, and also enables the miniaturization of the radio unit itself and the full performance of the antenna even if the chip antenna is incorporated. It is an object of the present invention to provide an antenna structure of a small wireless device. [0008] The present invention is an antenna structure of a small radio set devised to achieve the above object. That is, the present invention provides a chip antenna for transmitting and receiving signals by radio waves, a radio board mounted with circuit components necessary for radio communication using the chip antenna ,
Chip antenna is mounted and formed separately from the wireless board
Antenna substrate, and the antenna substrate is
Installed in a small wireless device so as to be substantially orthogonal to the wireless board
Antenna structure of a small wireless device,
By covering the board from above and below, the wireless board and the antenna
Shields the antenna board and locks the antenna board
Each shield case provided with an engaging portion
Condition that the case covers the wireless board from above and below
With a fixed sheet metal for connecting these shield cases.
The fixed sheet metal is fixed to the antenna to be locked to the engagement portion.
The antenna substrate is energized and the antenna substrate is
While being fixed to the case, the antenna
Grounding the substrate and each shield case
Characterized in that: According to the antenna structure having the above-described structure, signals are transmitted and received by wireless radio waves using the chip antenna, so that it is not necessary to project an external antenna or the like from the small wireless device during wireless communication. In addition, the antenna board on which the chip antenna is mounted and the wireless board on which circuit components necessary for wireless communication are mounted are separated from each other, and are arranged so as to be substantially orthogonal to each other. Can be used effectively. Furthermore, since the antenna board and the wireless board are arranged so as to be substantially orthogonal, even if the chip antenna has directivity, the radiated wireless wave may be affected by other components on the wireless board. There is no.
Moreover, each seal that shields the wireless board and the antenna board
The case is connected by the fixed
The antenna board is urged by the fixing
Backlash etc. may occur on the antenna substrate and each shield case.
As well as being securely fixed.
Ensure grounding of the tena board and each shield case
Will be done. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an antenna structure of a small radio device according to the present invention will be described with reference to the drawings. However, here, a case where the small wireless device is a PC card, that is, a case where the antenna structure of the present invention is applied to a PC card will be described as an example. FIG . 1 shows a PC car according to the present embodiment.
1 shows an outline of the antenna structure of the antenna 10. PC card 10
Is configured as shown in FIG. More specifically, as shown in FIG.
0 is a control board 11, a wireless board 12, a chip antenna 13, an antenna board 14, a shield case 15,
16 are provided. The control board 11 is for controlling wireless communication by the PC card 10, and has a CPU (Central
Peripheral components such as Processing Unit) and ROM (Read Only Memory), general-purpose LSI such as modem and voice codec
(Large Scale Integration), channel codec,
It is equipped with a custom LSI such as a card interface and a power control unit. Wireless board 12
Performs signal processing required for wireless communication in accordance with control by the control board 11. Therefore, the wireless board 12
Has mounted therein circuit components such as a signal modulator and an amplifier. The wireless board 12 has a coaxial cable 1 to be described later.
A coaxial connector 12a for 4a is provided. The control board 11 and the wireless board 12 are
are electrically connected via a. The control board 1
1 and the wireless board 12 may be provided integrally. The chip antenna 13 transmits a signal processed by the wireless board 12 to a communication partner by radio waves, or receives a signal transmitted wirelessly from the communication partner and sends the signal to the wireless board 12. is there. That is,
The chip antenna 13 is for transmitting and receiving signals by radio waves. However, the chip antenna has a directivity of emitting a radio wave in a direction parallel to the mounting surface. The antenna substrate 14 is a substrate on which the chip antenna 13 is mounted. However, the antenna substrate 14
Are formed separately from the wireless board 12, and are electrically connected to the wireless board 12 via the coaxial cable 14a. The shield case 15 is integrally formed of a resin material or the like, and has its surface plated with chrome or the like, and is formed so as to cover the upper surface of the wireless board 12. In the vicinity of both ends of one side surface of the shield case 15, an engagement portion 15a having a U-shaped cross section is provided. Similarly to the shield case 15, the shield case 16 is integrally formed of a resin material or the like, and the surface thereof is plated, and is formed so as to cover the lower surface of the wireless board 12. The shield case 16 also has engaging portions 16 near both ends on one side surface thereof.
a is provided. A PC card 10 having these components
In FIG. 1, as shown in FIG. 1A, a wireless board 12, a chip antenna 13, an antenna board 14, and shield cases 15, 16 are housed in an extended portion 10a, and a wireless unit is configured by these. I have. The extended section 10a is a PCMCI
The extended type PC card provided in A, which is a portion protruding from the card slot when the PC card is inserted into the card slot. In the extended portion 10a, the upper surface of the wireless substrate 12 is covered with the shield case 15, and the lower surface is
Covered in. At this time, each shield case 15, 1
The antenna substrate 14 is locked to the engaging portions 15a and 16a of the sixth. That is, each engagement portion 15a,
Both ends of the antenna substrate 14 are engaged with the grooves formed by 16a. Thus, the antenna substrate 14 is fixed by the shield cases 15 and 16 in a state substantially orthogonal to the wireless substrate 12. For example, if the wireless board 12 is arranged in the horizontal direction, the antenna board 14 is fixed in the vertical direction. The engagement between the antenna board 14 and each of the shield cases 15 and 16 allows them to be grounded (connected to ground). Therefore, when the shield cases 15 and 16 cover the wireless board 12, the antenna board 14 and the wireless board 12
They will be shielded from each other. In this PC card 10, an antenna board fixed so that the wireless board 12 covered by the shield cases 15 and 16 and the mounting surface of the chip antenna 13 face the outside (the direction in which the PC card 10 is removed). 14 is connected by a coaxial cable 14a, so that the chip antenna 13 can transmit and receive signals by radio waves. As described above, the PC card 1 shown in FIG.
0, the built-in chip antenna 1
Since signals are transmitted and received by the method 3, even when an external impact such as a drop of the PC card 10 occurs, the possibility of breakage or the like is reduced as compared with the case where the antenna is protruded. Further, since the wireless board 12 and the antenna board 14 are provided separately and are disposed so as to be substantially orthogonal to each other, the space (capacity) in the extended portion 10a can be effectively used, Chip antenna 13
Is mounted on the same board as other circuit components.
The size of the wireless unit can be easily reduced. Furthermore, since the wireless board 12 and the antenna board 14 are disposed so as to be substantially orthogonal to each other, the chip antenna 1 on the antenna board 14
Even if 3 has directivity, the radiated radio wave is not affected by other circuit components on the radio board 12 (such as reflection and absorption), and the radiation characteristics of the chip antenna 13 are improved. The antenna performance can be fully exhibited. In the antenna structure of the PC card 10 shown in FIG. 1, the radio board 12 is covered by the shield cases 15 and 16 so that the radio board 12 and the antenna board 14 are shielded. Therefore, the chip antenna 13 on the antenna substrate 14 is less likely to receive noise or the like from other circuit components on the wireless substrate 12, and further improvement in the radiation characteristics of the chip antenna 13 can be expected. In the antenna structure of the PC card 10 shown in FIG.
a and 16a are provided by integral molding.
The antenna substrate 14 and the shield cases 15 and 16 are locked by utilizing a and 16a. That is, the engaging portions 15 provided on the shield cases 15 and 16 are provided.
The antenna substrate 14 is fixed by a and 16a. Therefore, the structure for fixing the antenna board 14 can be simplified, the size of the wireless unit can be further reduced, and the cost can be reduced by reducing the number of parts and the number of assembly steps. Next, an antenna structure according to the present invention will be described.
Then, it will be described in more detail. Antenna structure according to the present invention
In addition to the configuration of FIG. 1 described above,
As shown in FIG. 1A, a fixed metal plate 1 formed in a leaf spring shape.
7 is provided. In addition, shield case 1
It is assumed that concave portions 15b and 16b for fitting the ends of the fixed sheet metal 17 are provided in each of the members 5 and 16. In the antenna structure shown in FIG . 2 as well, the upper surface of the radio board 12 is covered with the shield case 15 and the lower surface is covered with the shield case 16, similarly to the antenna structure of FIG. However, the description here
In the antenna structure shown in FIG. 2B, as shown in FIG. 2B, the ends of the fixed sheet metal 17 are fitted into the recesses 15b and 16b of the shield cases 15 and 16, whereby the shield cases 15 and 16 are connected. It is supposed to be. Further, in the antenna structure described here , as shown in FIG. 2 (c), the antenna substrate 14 separates the shield cases 15, 1
6 are urged toward the mounting surface of the chip antenna 13 in a state of being engaged with the engaging portions 15a and 16a. A ground terminal (earth pattern) is provided in the vicinity of both sides of the antenna substrate 14 on the chip antenna 13 mounting surface side or at a location corresponding to the fixed metal plate 17 on the chip antenna 13 non-mounting surface side. Substrate 1
It is assumed that the engagement between the shield case 4 and each of the shield cases 15 and 16 causes them to be grounded to each other. That is, according to the antenna structure of the PC card shown in FIG. 2, the shield cases 15 and 16 are connected by the fixing
Of the chip antenna 1 due to the elasticity of the
3 is urged toward the mounting surface. Thereby, the antenna substrate 14 and the shield cases 15, 16
These can be securely fixed without generating backlash or the like. Further, the fixing metal plate 17 is
, The grounding between the antenna substrate 14 and each of the shield cases 15 and 16 is reliably performed, and the shielding effect of the shield cases 15 and 16 is improved. Therefore, the radiation characteristics of the chip antenna 13 on the antenna substrate 14 are further improved. In the above-described embodiment , the case where the antenna structure of the present invention is applied to a PC card has been described as an example, but the present invention is not limited to this.
For example, besides a PC card, like a mobile phone,
The present invention is applicable to any small wireless device that performs communication using wireless radio waves. As described above, in the antenna structure of the small wireless device according to the present invention, signals are transmitted and received by the built-in chip antenna, so that even if there is an external shock, Therefore, the possibility of breakage and the like is reduced as compared with the case where the antenna is protruded. In addition, since the chip antenna is mounted on an antenna substrate separate from the wireless substrate, and these are arranged so as to be substantially orthogonal to each other, the space in the small wireless device can be effectively utilized, and the chip antenna can be effectively used. Can be easily reduced in size as compared with a case in which is mounted on the same substrate as other circuit components. Furthermore, since the wireless board and the antenna board are arranged so as to be substantially orthogonal to each other, even if the chip antenna has directivity, the radiated radio wave does not affect other circuit components on the wireless board. Therefore, the radiation characteristics of the chip antenna 13 are improved, and the antenna performance can be sufficiently exhibited.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing an outline of an antenna structure of a small wireless device according to the present invention, where (a) is a schematic perspective view and (b) is an exploded perspective view. It is. FIG. 2 is an implementation of the antenna structure of the small wireless device according to the present invention.
It is a diagram showing the form, (a) shows the exploded perspective view thereof,
(B) is a perspective view (part 1) showing the main part, and (c) is a perspective view (part 2) showing the main part. 3A and 3B are perspective views illustrating an antenna structure of a conventional PC card, wherein FIG. 3A is a diagram illustrating a stored state of an external antenna, and FIG. 3B is a diagram illustrating a protruding state of the external antenna. [Description of Signs] 10 PC card 12 Wireless board 13 Chip antenna 14 Antenna board 14a Coaxial cables 14b, 14c, 15a, 16a Engagement parts 15, 16 Shield case 17 fixing sheet metal

Continuation of the front page (56) References JP-A-8-293717 (JP, A) JP-A-7-131241 (JP, A) JP-A-7-288415 (JP, A) JP-A 8-186422 (JP) , A) JP-A-9-270731 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04B 1/38-1/58 H01Q 1/24

Claims (1)

(57) and a chip antenna for transmitting and receiving of the Claims 1 radio wave by the signal, and the wireless board mounted with the circuit components necessary for wireless communication using said chip antenna, said chip antenna
Antenna and an antenna formed separately from the wireless board
And the antenna substrate is mounted inside the small radio device.
A small wireless device disposed substantially orthogonal to the wireless substrate.
Antenna structure of the machine, wherein the wireless board is
The antenna board is shielded from the antenna board.
Each shield case provided with an engagement portion for locking the plate, and each shield case covers the wireless board from above and below.
With the fixed sheet metal connecting the shield cases
Wherein the fixing sheet metal, the antenna base for engaging with the engaging portion
Energizing the plate to attach the antenna substrate to each of the shield cases.
To the antenna substrate by the urging.
And each shield case to ground.
Antenna structure for a small radio, characterized in that.