JP3947812B2 - Card device, electronic device and wireless device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a small card device or the like that is detachably inserted into a slot of an electronic device, and more particularly to a wireless device that can achieve diversity effects even if it is small.
[0002]
[Prior art]
In recent years, wireless devices such as card devices that are equipped with antennas and provide wireless communication functions to electronic devices have been widely used. Typical examples of this type of card device include a wireless LAN card, a card-type modem, and the like. In addition to the addition of the wireless communication function, there is also the addition of system resources such as memory. The present invention is intended for any type of wireless device as long as it is equipped with an antenna.
[0003]
Some wireless devices of this type have a plurality of antennas and realize antenna diversity. This is preferable because antenna diversity reduces an adverse effect due to fading and facilitates obtaining a good communication state.
[0004]
More specifically, spatial diversity is used in which two or more antennas are arranged physically apart and an antenna having a better communication state is selected. That is, the antennas are separated from each other so that the antennas are not electrically coupled, and each antenna has its own radiation characteristics.
[0005]
[Problems to be solved by the invention]
There is a demand for this type of wireless device to be “smaller and lighter”. Here, for example, when a 2.4 GHz band radio wave is used, it is possible to somehow mount two antennas in a wireless device as long as the size is about the size of a PCMCIA (Personal Computer Memory Card Association Association) card.
[0006]
However, if the size is smaller than that, in reality, it is difficult to mount two antennas apart from each other due to space problems, and it is often possible to mount only one antenna. If it becomes like this, the effect by space diversity will not be acquired.
[0007]
In this regard, in recent years, antennas with small chips have begun to be marketed, but even if such small antennas are used, there are problems similar to those described above.
[0008]
Accordingly, an object of the present invention is to provide a card device that can obtain an effect similar to antenna diversity while using a single antenna.
[0009]
It is another object of the present invention to provide a wireless device that can achieve the diversity effect even if it is a small wireless device that is difficult to obtain the effect of space diversity.
[0010]
[Means for Solving the Problems]
A card device according to the present invention is inserted into a slot of an electronic device having an electronic device ground and is electrically connected to the electronic device, and a carrier, a single antenna provided in the carrier, and the carrier And a card ground electrically connected to the antenna, and a switch for connecting / disconnecting the card ground to / from the electronic equipment ground at high frequency when inserted in the slot.
[0011]
With this configuration, an effect similar to antenna diversity can be obtained while using a single antenna. That is, it can contribute to further downsizing the card device.
[0012]
In addition, a wireless device according to the present invention includes an antenna and a coupling element that is electrically coupled to the antenna, the electrical characteristics of the coupling element can be changed, and a plurality of radiation characteristics can be obtained by the antenna. I did it.
[0013]
With this configuration, it is possible to obtain the diversity effect even in a small wireless device in which it is difficult to obtain the space diversity effect.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
The card device according to claim 1 is inserted into a slot of an electronic device having an electronic device ground and is electrically connected to the electronic device, and a carrier, a single antenna provided on the carrier, and a carrier. A card ground disposed in the body and electrically connected to the antenna, and a switch for connecting / disconnecting the card ground to / from the electronic device ground in a high frequency state when inserted in the slot.
[0015]
In this configuration, even if only a single antenna is used by switching the switch, (1) a state in which the card ground and the electronic device ground are connected at a high frequency, and (2) the card ground and the electronic device ground are Two types of radiation characteristics can be obtained, that is, a state where they are not connected in a high frequency manner.
[0016]
In general, the radiation characteristics of an antenna are determined by the characteristics of the antenna itself and the pattern of the card ground. However, when the card ground is connected to the electronic equipment ground at a high frequency, the radiation characteristics of the antenna are Will be affected.
[0017]
It is not possible to know which of these two states is more preferable. However, when the electronic equipment ground resonates well, the antenna performance (antenna gain) is better in the connected state than in the unconnected state. , Directivity, etc.) can be expected.
[0018]
As described above, since two types of radiation characteristics can be selected using only a single antenna, an effect similar to that of antenna diversity can be enjoyed, and the communication status can be improved. In addition, this makes it possible to practically reduce the size of the card device.
[0019]
3. The card device according to claim 2, wherein the demodulating means for inputting and demodulating the signal received by the antenna, the determining means for inputting the signal demodulated by the demodulating means and determining the quality of the communication status of the antenna, and the determination result of the determining means And a control means for controlling the switch.
[0020]
With this configuration, the card device itself selects a more preferable state, so that convenience can be improved. Further, there is no need to control antenna switching on the electronic device side, and no additional burden is placed on the electronic device.
[0021]
In the card device according to claim 3, the antenna is a λ / 4 chip antenna exposed to the outside of the carrier.
[0022]
With this configuration, the card device can be more easily downsized. Incidentally, this antenna uses a high dielectric constant material, and can be downsized to a size of λ / 4√ (εr) where the relative dielectric constant is εr.
[0023]
In another aspect, the wireless device includes an antenna and a coupling element that is electrically coupled to the antenna, the electrical characteristics of the coupling element can be changed, and a plurality of radiation characteristics can be obtained by the antenna. did.
[0024]
In another aspect of the wireless device, an antenna, a wireless module that feeds the antenna and communicates information via the antenna, and a coupling that is disposed in proximity to the antenna and that is electrically coupled to the antenna And an impedance variable unit provided between the coupling element and the ground point. The wireless module operates the impedance variable unit to change the impedance between the coupling element and the ground point, and a plurality of antenna modules are operated by the antenna. So that the radiation characteristics can be obtained.
[0025]
In the prior art, only the direction in which a plurality of antennas have their own radiation characteristics, that is, avoiding electrical coupling between the antennas has been studied.
[0026]
On the other hand, in the present invention, this electrical coupling is tried to be used for the reverse hand, and as described later in the section of the embodiment, the degree of electrical coupling is changed to change per one antenna. And found that multiple radiation characteristics can be obtained (that is, there is a diversity effect).
[0027]
In the present invention, because it is configured as described above based on this finding,
(1) Diversity effect can be obtained without preparing a plurality of antennas.
{Circle around (2)} Since only the electrical characteristics of the coupling element are changed, and the antenna itself is not switched, the path for receiving a signal from the antenna is not interrupted as in normal antenna diversity.
(3) It is not necessary to separate the antenna and the coupling element (in the conventional technology, a component corresponding to another antenna in terms of layout). This is advantageous when mounted on a small wireless device.
There are advantages such as.
[0028]
In the wireless device according to another aspect , the impedance variable device changes the impedance in two stages of high impedance and low impedance.
[0029]
With this configuration, two types of radiation characteristics can be obtained with a simple configuration, and a diversity effect can be obtained. For example, the impedance variable device may be a simple switch (impedance 0 when on, impedance infinity when off).
[0030]
In the wireless device according to another aspect , the coupling element is an antenna element that is not fed.
[0031]
With this configuration, since the coupling element can be the same type of component as the antenna, the number of component types can be reduced and the cost can be reduced.
[0032]
In a wireless device in another aspect , the coupling element is a circuit pattern.
[0033]
With this configuration, an element that originally exists in the wireless device can be used as a coupling element, and costs can be reduced.
[0034]
In the wireless device according to another aspect , the coupling element is a component of an electronic device to which the wireless device is attached.
[0035]
With this configuration, it is possible to reduce the number of components by diverting the components of the electronic device as coupling elements, which is advantageous in terms of cost and layout.
[0036]
In a wireless device according to another aspect , a substrate, a plurality of surface-mounted antennas that are disposed in close proximity to one surface of the substrate and electrically coupled to each other, and an antenna used for communication are selected from these antennas. An antenna switch to be selected, and a radio module that outputs an antenna switching signal to the antenna switch, feeds power to the antenna selected by the antenna switch, and communicates information through the antenna.
[0037]
With this configuration, even when the antenna mounting area is small and it is difficult to obtain the effect of space diversity, the effect of directivity diversity can be obtained. In addition, since the surface-mounted antenna is concentrated on one surface of the substrate, the thickness of the wireless device can be reduced.
[0038]
Embodiments of the present invention will be described below with reference to the drawings.
(Embodiment 1)
FIG. 1 is a schematic plan view of a card device and an electronic apparatus according to Embodiment 1 of the present invention.
[0039]
As shown in FIG. 1, the card device 10 is detachably inserted into a slot 101 of the electronic device 100 (in the direction of arrow N1), and provides the electronic device 100 with a wireless communication function.
[0040]
Here, as the electronic device 100, various information processing apparatuses such as a personal computer (which may be a notebook type or a desktop type), a PDA (personal digital assistant), a digital camera, and the like are conceivable.
[0041]
These electronic devices 100 have an electronic device ground 102 therein. However, the size of the electronic device ground 102 varies depending on the individual device, and whether or not the electronic device ground 102 contributes to improving the characteristics of the antenna 12 is generally unknown.
[0042]
The card device 10 includes a carrier 11 formed in a card shape and a single antenna 12 provided on the carrier 11. Here, a λ / 4 chip antenna is used as the antenna 12 when the wavelength of a radio wave used for communication is λ. According to this, it is easy to miniaturize the card device, which is convenient.
[0043]
Instead of this, the antenna 12 can also be configured with a circuit pattern. And the card apparatus 10 also has the card ground 13 inside the carrier 11 like the electronic device 100. Usually, the card ground 13 and the electronic device ground 102 are formed as circuit patterns on a printed circuit board. Note that a printed circuit board is usually provided inside the carrier 11.
[0044]
Next, the configuration of the card device 10 which is the wireless device in the first embodiment will be described with reference to FIG. FIG. 2 is a functional block diagram of the card device according to Embodiment 1 of the present invention.
[0045]
In FIG. 2, when the card device 10 is inserted into the slot 101, the switch 14 connects / disconnects the card ground 13 and the electronic device ground 102 in high frequency according to a switching signal from the control means 17. To do. When the card device 10 is inserted into the slot 101, the card ground 13 and the electronic device ground 102 are electrically connected regardless of the switching signal from the control means 17.
[0046]
Further, the demodulating means 15 receives the received signal from the antenna 12, demodulates it, and outputs the demodulated signal to the determining means 16.
[0047]
The determination unit 16 receives the demodulated signal from the demodulation unit 15 and determines whether the current communication status of the antenna 12 is good. The determination means of the determination means 16 is arbitrarily selected as long as it provides an objective index of the communication status of the antenna 12 such as bit error rate (CR), CRC (Cyclic Redundancy Check), and demodulated signal strength. it can.
[0048]
The control unit 17 controls the demodulation unit 15, the determination unit 16, the switch 14, and the like. The control unit 17 stores the determination result of the determination unit 16 in the memory 18 and refers to the information stored in the memory 18, and switches the switch 14. In addition, a switching signal is output so that a more preferable communication state is obtained.
[0049]
It should be noted that the control means 17 may always output a switching signal so that the switch 14 takes one state with reference to the information in the memory 18, or a plurality of channels having different frequencies are used. When communication is performed, the switch 14 may be switched as necessary for each channel.
[0050]
In the first embodiment, the demodulation unit 15, the determination unit 16, the control unit 17, and the memory 18 correspond to the wireless modules in the second and subsequent embodiments.
[0051]
(Embodiment 2)
Next, a radio apparatus according to Embodiment 2 of the present invention will be described. First, the wireless device includes an antenna and a coupling element that is electrically coupled to the antenna.
[0052]
As shown in a measurement example described later, when the electrical characteristics of the coupling element change, the radiation characteristics of the antenna electrically coupled to the coupling element change. By utilizing this fact, a plurality of radiation characteristics can be obtained by a single antenna, and the effect of antenna diversity can be obtained by switching these radiation characteristics.
[0053]
In this embodiment, the antenna and the coupling element are intentionally electrically coupled, and the degree of coupling is changed.
[0054]
FIG. 3 is a block diagram of a radio apparatus according to Embodiment 2 of the present invention. In FIG. 3, the antenna 20 and the coupling element 21 are arranged close to each other, and the coupling element 21 is electrically coupled to the antenna 20.
[0055]
The antenna 20 does not need to be a special one. For example, the frequency band is about 2.4 GHz or 5 GHz. When a small wireless device is configured, a surface mount type multilayer ceramic chip antenna, a microstrip line is used. An antenna, a patch antenna, a spiral antenna, or the like can be used.
[0056]
The coupling element 21 is preferably one whose specification is clear at the design stage (antenna similar to the antenna 20), but one whose specification is unknown at the design stage (component of electronic equipment to which this wireless device is mounted). Etc.) can also be used.
[0057]
An important point in the present embodiment is that the antenna 20 is supplied with power to communicate information, but the coupling element 21 is not supplied with power. Therefore, even if a component that is originally assumed to be used as an antenna is used for the coupling element 21, this component does not operate as an antenna, but operates only as a coupling element coupled to the antenna 20.
[0058]
A matching circuit 22 is connected to the subsequent stage of the antenna 20, and a matching circuit 23 is connected to the subsequent stage of the coupling element 21. Each of these matching circuits 22 and 23 includes a filter.
[0059]
The wireless module 24 is connected to the subsequent stage of the matching circuit 22 via the feeder line L. Further, an impedance variable device 25 is connected to the subsequent stage of the matching circuit 23, and the impedance variable device 25 is further connected to the ground point of the wireless device.
[0060]
The impedance variable device 25 determines the impedance between the coupling element 21 and the ground point. Here, as the impedance variable device 25, a switch that changes impedance in two stages of high impedance (impedance infinite) and low impedance (impedance 0) is used.
[0061]
When this impedance is changed, the electrical characteristics of the coupling element 21 change, and the radiation characteristics of the antenna 20 change under the influence. Therefore, in this way, two types of radiation characteristics of the antenna 20 are obtained.
[0062]
Here, the impedance variable device 25 may be constituted by an impedance bridge or a variable resistor, and in this way, the impedance can be changed in a multi-stage or continuously, and more types of radiation characteristics can be obtained. .
[0063]
The wireless module 24 has the following elements. First, the switch 241 selectively switches the feeder line L between the transmission side and the reception side. The output end of the power amplifier 242 is connected to the transmission side, and the input end of the low noise amplifier 243 is connected to the reception side. The power source 244 is connected to the power amplifier 242 and the low noise amplifier 243.
[0064]
Further, the radio module 24 includes a modulation / demodulation circuit 245. The modulation / demodulation circuit 245 modulates transmission information obtained from outside the radio apparatus at the time of transmission and outputs it to the power amplifier 242, and obtains it from the low noise amplifier 243 at the time of reception. The received information is output to the outside of the wireless device.
[0065]
Further, the modem circuit 245 outputs an impedance control signal S1 to the impedance variable device 25 and controls the impedance between the coupling element 21 and the ground point. That is, when the impedance control signal S1 changes, the radiation characteristic of the antenna 20 changes.
[0066]
(Implementation example 1)
Next, using FIG. 4 and FIG. 5, a mounting example 1 in the second embodiment and a measurement example of the radiation characteristics of the antenna 20 based thereon will be described.
[0067]
In this mounting example, as shown in FIG. 4, a multilayer ceramic chip antenna 211 is used as the antenna 20. The antenna 20 and the multilayer ceramic chip antenna 211 are arranged close to each other on one side of the printed circuit board 26 so that the multilayer ceramic chip antenna 211 is electrically coupled to the antenna 20.
[0068]
More specifically, the size of the printed circuit board 26 is 50 mm in length and 25 mm in width. As the antenna 20 and the multilayer ceramic chip antenna 211, a Yokoo model number YCE-5208 is used, and the impedance variable device 25 is manufactured by NEC. A switch with model number UPG152TA was used.
[0069]
Also, in a carefully prepared measurement room, a frequency of 2.44 GHz is used at a height of 2.5 m above the floor and a distance of 4 m from the receiving side, and the wireless device according to this implementation is placed on the transmitting side. The measurement was performed.
[0070]
An example of the result is as shown in FIG. FIG. 5A shows the radiation characteristics of the antenna 20 measured with the switch open (that is, infinite impedance), where the direction of 0 [deg] is the X direction and the direction of −90 [deg] is the Y direction. .
[0071]
Similarly, FIG. 5B shows the measurement results when the switch is short-circuited (that is, impedance 0).
[0072]
As is clear from comparison between FIGS. 5A and 5B, the switch corresponding to the impedance variable device 25 is turned on / off by the single antenna 20 (the multilayer ceramic chip antenna 211 does not operate as an antenna). Only by turning it off, different radiation characteristics are obtained.
[0073]
(Mounting example 2)
As shown in FIG. 6, in this example, unlike the mounting example 1, a microstrip line antenna 212 formed with a circuit pattern of the printed board 26 was used as the coupling element 21. The other points are the same as those of the mounting example 1, and the measurement examples are as shown in FIGS. 7 (a) and 7 (b).
[0074]
7A and 7B, the switch corresponding to the impedance variable device 25 is turned on / off by a single antenna 20 (the microstrip line antenna 212 does not operate as an antenna). Only by turning it off, different radiation characteristics are obtained.
[0075]
(Mounting examples 3 and 4)
In the mounting examples 1 and 2, the coupling element 21 whose specifications are clear at the design stage is used. However, as shown in FIGS. 8 and 9, it is also possible to use a coupling element 21 whose specifications are unknown at the design stage.
[0076]
In the example of FIG. 8, a conductive connection point 213 is provided on the side of the printed circuit board 26, and the impedance variable device 25 is connected to the connection point 213. When this wireless device is used by being mounted on an electronic device such as a personal computer, the impedance variable device 25 is connected to the ground 102 of the electronic device via the connection point 213.
[0077]
In the end, the configuration is almost the same as that of the first embodiment. By turning on / off the impedance variable device 25, two types of radiation characteristics can be obtained for the single antenna 20.
[0078]
Furthermore, as shown in FIG. 9A, the present invention can also be applied to a headphone 30 having an inverted U-shaped belt portion 33 and two pad portions 31 and 32 fixed to both ends thereof. Such a headphone 30 usually includes a metal wire frame 331 inside the belt portion 33 for reinforcement or other purposes.
[0079]
9B, a member similar to the connection point 213 shown in FIG. 8 is provided on the printed board 26, and the connection point 213 is electrically connected to the wire frame 331. It is good to connect.
[0080]
In addition, various mounting examples are conceivable, but even if the coupling element 21 whose specification is unknown at the design stage is used, the radiation characteristics of the antenna 20 cause some change by turning on / off the impedance variable device 25. As long as the diversity effect can be obtained.
[0081]
(Embodiment 3)
FIG. 10 is a block diagram of a radio apparatus according to Embodiment 3 of the present invention. In the figure, the same components as those of the second embodiment are denoted by the same reference numerals, and the description thereof is omitted.
[0082]
As shown in FIG. 11, in the third embodiment, two surface mount antennas 20 and 40 are arranged close to one side of the printed circuit board 26, and these antennas 20 and 40 are electrically connected to each other. Try to combine.
[0083]
Further, the antennas 20 and 40 do not need to be special ones. For example, the frequency band is about 2.4 GHz or 5 GHz, and when configuring a small wireless device, a surface mount type multilayer ceramic chip antenna is used. A microstrip line antenna, a patch antenna, a spiral antenna, or the like can be used.
[0084]
As shown in FIG. 10, the antenna switching signal S <b> 2 is output from the modem circuit 245 to the antenna switch 41. The antenna switch 41 alternatively selects an antenna to be used for communication from these antennas 20 and 40 in accordance with the antenna switching signal S2.
[0085]
Here, unlike the second embodiment, the selected antenna (including the antenna 40) is fed by the feeder line L and operates as an antenna.
[0086]
According to this embodiment, even when the antenna mounting area is small and it is difficult to obtain the effect of space diversity, the effect of directivity diversity can be provided.
[0087]
Furthermore, since the surface-mounted antenna is concentrated on one surface of the substrate, the wireless device can be configured to be thin.
[0088]
In the above description of Embodiments 2 and 3, the example in which the wireless module 24 performs both modulation and demodulation has been described. However, the present invention is similarly applied when the wireless module 24 performs only one of these. Applicable.
[0089]
【The invention's effect】
According to the first aspect of the present invention, even with only a single antenna, two types of radiation characteristics can be obtained, an effect similar to antenna diversity can be obtained, and the communication status can be improved.
[0090]
According to the invention described in claim 2, the convenience can be improved and an additional burden is not imposed on the electronic device.
[0091]
According to the third aspect of the present invention, the card device can be more easily downsized.
[Brief description of the drawings]
FIG. 1 is a schematic plan view of a card device and an electronic device according to a first embodiment of the present invention. FIG. 2 is a functional block diagram of the card device according to a first embodiment of the present invention. FIG. 4 is a plan view of the wireless device according to the second embodiment of the present invention. FIG. 5 (a) is a graph showing the radiation characteristics of the antenna according to the second embodiment of the present invention. FIG. 6 is a plan view of a radio apparatus according to the second embodiment of the present invention. FIG. 7A is a graph showing the radiation characteristics of the antenna according to the second embodiment of the present invention. (B) A graph showing the radiation characteristics of the antenna according to the second embodiment of the present invention. FIG. 8 is a plan view of the radio apparatus according to the second embodiment of the present invention. Wireless device in 2 FIG. 10 is a block diagram of the wireless device in the third embodiment of the present invention. FIG. 11 is a plan view of the wireless device in the third embodiment of the present invention. Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Card apparatus 11 Carrier 12, 20, 40 Antenna 13 Card ground 14 Switch 15 Demodulation means 16 Determination means 17 Control means 18 Memory 100 Electronic equipment 101 Slot 102 Electronic equipment ground 21 Coupling element 22, 23 Matching circuit 24 Wireless module 26 Print Substrate 30 Headphone 31, 32 Pad part 33 Belt part 41 Antenna switch

Claims (4)

A card device inserted into a slot of an electronic device having an electronic device ground and electrically connected to the electronic device,
Carrier,
A single antenna provided on the carrier;
A card ground disposed in the carrier and electrically connected to the antenna;
A card device comprising: a switch for connecting / disconnecting the card ground to / from the electronic device ground at a high frequency in a state of being inserted into the slot. Demodulation means for receiving and demodulating a signal received by the antenna;
A determination unit that inputs a signal demodulated by the demodulation unit and determines whether the communication status of the antenna is good;
The card device according to claim 1, further comprising a control unit that controls the switch with reference to a determination result of the determination unit. The card device according to claim 1, wherein the antenna is a λ / 4 chip antenna exposed to the outside of the carrier. An electronic device in which the card device according to claim 1 is inserted into a slot.

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