JP2001313511A - Gps antenna system for mobile terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize enhancement of the stability of the performance of a GPS antenna system at a low cost, to attain high performance of a mobile terminal when it is in use by one hand, and to solve a problem caused at soldering. SOLUTION: The GPS antenna system 13 is configured by fitting a GPS antenna 14 to a reception printed circuit board 15 to have a tilt angle with respect to the reception printed circuit board 15 via a bracket 16. When a feed pin 17 of an antenna element 14b of the GPS antenna 14 is soldered to the reception printed circuit board 15, solder B is supplied while the tip of the feed pin 17 is inserted into a through-hole 15d by directing a rear side 15a of the reception printed circuit board 15 upward. When the supply of the solder B is excessive, the solder B flows to a space C formed by the GPS antenna 14 and the reception printed circuit board 15. In this case, since a blocking member 18 of a ring shape is mounted on the feed pin 17, the flowing of the solder B furthermore is blocked and it is prevented that the solder B approaches the bracket 16 or short-circuits it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a GPS antenna device of a portable terminal for receiving information from a GPS satellite.

[0002]

2. Description of the Related Art Conventionally, as a portable terminal, 1 GPS
A portable map display terminal provided with a GPS antenna device for receiving waves and which can be used for mountain climbing, hiking, or walking around town is provided. Recently, map data required for map display is stored in an external database through a portable telephone. 2. Description of the Related Art A small-sized portable information terminal that is downloaded from the Internet and displayed is known.

[0003]

SUMMARY OF THE INVENTION In the above-mentioned known devices,
As the GPS antenna device in the above portable terminal,
The GPS antenna is provided in a housing, and the housing is mounted on the terminal body so that the mounting angle can be freely set. However, in the case of this GPS antenna, when there is a metal body having a length of several wavelengths or less of its resonance frequency, the characteristics must be considered in consideration of mutual coupling with the metal body. GP with free corners
In the S antenna device, mutual coupling with a nearby metal body (a circuit board, an electronic component, or the like) changes, and stable characteristics cannot be realized. In addition, it is necessary to provide a complicated mechanism in order to make the mounting angle of the GPS antenna device free, and there is a problem that the cost is increased.

The present invention has been made in view of the above circumstances, and has as its object to improve the performance stability at low cost, and to achieve high performance when the portable terminal is used with one hand. It is an object of the present invention to provide a GPS antenna device for a portable terminal, which can improve the performance and can solve the problem that occurs when the power supply pin is soldered to a circuit board.

[0005]

SUMMARY OF THE INVENTION GP of portable terminal of the present invention
According to the S antenna device, since it is built into the mobile terminal,
As a GPS antenna, it is possible to determine reception performance including mutual coupling with a nearby metal body (a circuit board, an electronic component, or the like), thereby stabilizing and improving the performance. Since a complicated mechanism for making the corners free is unnecessary, it can be realized at low cost.

Further, according to the GPS antenna device for a portable terminal of the present invention, the GPS antenna has an inclination angle with respect to the circuit board, so that when the portable terminal is used with one hand, the directivity of the SPS antenna may be reduced. Instead of facing in the direction, it faces in the zenith direction, and it is possible to achieve high performance during use.

By the way, when the bracket is provided to hold the GPS antenna so as to have an inclination angle on the circuit board as in the present invention, when the power supply pin is soldered to the circuit board, the power supply pin is soldered. Since the part to be covered is covered with the bracket, it is necessary to turn the circuit board upside down so that the back surface is upward. In this case, the circuit board and the G
Since there is a space between the antenna and the PS antenna, the molten solder flows through the power supply pin due to its surface tension and flows into the space, and depending on the amount of the solder that has flowed in, the solder may flow through the GPS.
Close to the ground conductor of the antenna, electrical coupling occurs between them and the performance becomes unstable, and in the worst case,
It is conceivable that the solder may short-circuit to the ground conductor of the GPS antenna and impair the function of the GPS antenna.

On the other hand, according to the present invention, the ring-shaped blocking member is mounted on the power supply pin so as to be located in the space formed between the circuit board and the GPS antenna, so that the power supply pin flows into the space. The amount of solder to be used can be reduced as much as possible, and unstable performance due to electrical coupling between the solder and the ground conductor of the GPS antenna can be prevented.
Short circuit of the solder to the ground conductor can also be prevented.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a portable information terminal as a portable terminal will be described below with reference to the drawings. In FIG. 4 showing the entire appearance, a terminal main body 2 of the portable information terminal 1 is composed of a front case 3 and a rear case 4 each having a rectangular shape made of plastic and formed in a size that can be held by one hand. Have been. An LCD panel 5 corresponding to a display is provided on the front (front) of the terminal body 2. A matrix-type panel-shaped touch switch (not shown) is formed on the entire surface of the LCD panel 5. In particular, a plurality of icons 5a to 5g representing a switch function are provided on the lower edge in the figure. Are formed by printing.

[0010] Of the icons 5a to 5g, the leftmost icon 5a functions as a menu switch, and when this icon 5a is pressed by the touch pen 6,
Various menus are listed on the LCD panel 5. When a desired menu is pressed from the menu displayed on the LCD panel 5 with the touch pen 6, the menu is selected. In the following description,
The pressing operation is performed with the touch pen 6 unless otherwise specified.

The icon 5b located to the right of the left end icon 5a functions as a map menu selection switch, the icon 5c located third from the left end functions as an e-mail menu selection switch, and the icon 5d located fourth. Functions as a menu selection switch for instructing connection with a mobile information service called "mopera", and the fifth and sixth icons 5e and 5f
Function as selection switches for the Internet and schedule menus, respectively. Of course, menus such as map, e-mail, mobile information service, Internet, and schedule can be selected from a menu list, but since they are particularly frequently used, by providing a special menu selection switch, LC
The user can directly select a menu list without performing the troublesome operation of displaying a menu list on the D panel 5 and selecting from the menu list. The icon 5g at the right end functions as an “off” switch for shutting off the power after shutting down a built-in microcomputer system described later.

A scroll key 7 as an operation key for operating the screen of the LCD panel 5 is provided at a position slightly above the center of the left side surface of the terminal body 2. The scroll key 7 is an up key 7
a, a down key 7b, and an enter key 7c. These keys 7a to 7c are arranged vertically one on top of another, for example, with a membrane switch (not shown) arranged in the terminal body 2. . That is, the scroll key 7
As shown in FIG. 5, is provided at a position slightly above the center of the left side surface of the terminal body 2 so that it can be operated with a finger (for example, thumb) of the hand (for example, left hand) holding the terminal body 2. The keys 7a to 7c are protruded from the left side surface of the terminal body 2 to facilitate operation. A power switch 8 having an operation knob 8a for turning on and off the power in a hardware manner is provided on the upper cotton portion of the terminal body 2.

A communication cable (indicated by reference numeral 9a in FIG. 6) connected to a mobile telephone (indicated by reference numeral 9 in FIG. 6) is provided on the right side of the lower surface of the terminal body 2. Terminal box 10 is provided.
A terminal box 11 for a communication cable connected to a personal computer (not shown) is provided on the left side of the upper surface of the computer.

As shown in FIG. 1, a main circuit board 12 is provided in the terminal body 2 so as to be parallel to the rear surface (rear surface).
The GPS antenna device 13 is disposed at an upper part on the front side of the GPS antenna. Hereinafter, the GPS antenna device 13 will be described with reference to FIGS.

In the GPS antenna 14, a thin conductor antenna element 14b is formed on the surface of a rectangular block 14a made of a dielectric material such as ceramic by vapor deposition, and a ground pattern 14 serving as a ground conductor is formed on the back surface of the block 14a.
c is formed by vapor deposition, and the upper end is held by the L-shaped positioning portions 16a, 16a at the upper end of the bracket 16 functioning as a ground conductor on the receiving circuit board 15, and the back surface is It is supported via a double-sided adhesive tape, and is attached to the receiving circuit board 15 so as to have an inclination angle θ such that the lower end is separated from the receiving circuit board 15. In this case, the receiving circuit board 15 is provided so as to be parallel to the main circuit board 12.

The power received by the antenna element 14 b is supplied to the power supply pattern of the receiving circuit board 15 by the power supply pin 17. Specifically, the power supply pin 17 has a head 17a at a base end serving as one end, and the head 17a is electrically connected to the antenna element 14b by contact with the antenna element 14b. It is electrically connected to the power supply pattern by being soldered to the receiving circuit board 15. The power supply pin 17 is located in a space defined by the antenna element 14 and the circuit board 15,
A ring-shaped blocking member 18 described later is mounted.

At the lower end of the bracket 16, a plurality of, for example, two inverted L-shaped holding pieces 16b are integrally provided. Is electrically connected to the ground pattern of the circuit board 15 for use. Electronic components such as a transistor, a resistor, and a capacitor are mounted on the receiving circuit board 15 and are pre-amplified (low-noise amplifier).
19 (see FIG. 6).

FIG. 6 shows a schematic internal configuration of the portable information terminal 1 and a peripheral configuration related thereto by a combination of functional blocks, which are configured on the main board 12. In FIG. 6, the portable information terminal 1 mainly includes a CPU 20 as control means. An internal bus 21 connected to the CPU 20 has a ROM 22 storing a control program and the like, and a storage area serving as a working storage area. A RAM 23 as a means, a flash memory 24 as a storage means for storing various data, and an input device 25 to which the LCD panel 5 is connected and which includes a touch switch (not shown)
Is connected.

The internal bus 21 is connected to data communication devices 26 and 27 for mobile phones and personal computers. Then, by connecting the mobile phone 9 to the terminal box 10 via the communication cable 9a,
It is configured so that it can be dial-up connected to the Internet 28 via the mobile phone 9 and can connect to various servers via the Internet 28 to obtain various information, or connect to other mobile phones and personal computers. It is configured to be able to send an e-mail.

Further, the internal bus 21 is connected to a GPS receiving unit 29 as position information acquiring means.
The GPS receiving unit 29 includes the GPS antenna device 1
3 is connected to the preamplifier 19. And CPU
20 is the map server 30 when the map menu is selected.
Dial-up connection, and the GPS receiving unit 29
The location information from the GPS satellite received via the PS antenna 14 is transmitted to the map server 30 via the mobile phone 9.
Is transmitted.

Note that the mobile phone 9 constantly communicates with the base station 31 as long as the main switch is turned on, and the control station 32 knows which base station the mobile phone 9 is currently in the communication area. . Therefore, the map server 30 roughly grasps the current location of the mobile phone 9 based on the information from the control station 32, determines a GPS artificial satellite capable of analyzing the location information most efficiently at the current location, and sends the information to the mobile phone 9. Send. The GPS receiving unit 29 receives position information from the artificial satellite designated by the map server 30.

The map server 30 analyzes the position data from the GPS satellite transmitted from the portable information terminal 1 and acquires the current location of the portable information terminal 1. Since the current location obtained at this time is a single positioning that receives a radio wave from a GPS artificial satellite and performs radio wave positioning, an error of several hundred meters is included. Therefore, the map server 30
The position information from the artificial satellite is transmitted to the differential server via the Internet 28 to obtain the difference information for D-GPS, and the difference information is used to obtain the position information whose accuracy is improved to about several meters. Then, the map server 30 transmits to the mobile phone 9 map data in a predetermined range centered on the current location of the mobile information terminal 1 based on the position information acquired by the D-GPS.

The CPU 20 of the portable information terminal 1 temporarily stores the map data received by the portable telephone 9 in the RAM 23, and displays a map of the surroundings centered on the current position of the user from the map data on the LCD panel 5. indicate.
The form of the map displayed on the LCD panel 5 can be changed by, for example, pressing an icon displayed on the upper edge of the map. In the following, a map around the current location of the user is referred to as an initial map.

The icons for changing the form of the map include a scroll icon (scroll operation unit) for up / down and left / right, a reduction / enlargement icon (enlargement / reduction operation unit), and an initial map return icon (return operation unit). Up, down, left,
When each of the right scroll icons is pressed, the map displayed on the LCD panel 5 moves (scrolls) upward (north), downward (south), left (west), and right (east). By pressing each of the icons for reduction and enlargement, the size of the map displayed on the LCD panel 5 becomes smaller or larger. When the initial map return icon is pressed, L
The map displayed on the CD panel 5 returns to the initial map.

Scrolling the map up and down,
In addition to pressing the icon with the touch pen 6, the operation can also be performed by pressing the scroll key 7 (see FIGS. 4 and 5) provided on the terminal body 2 with a finger. That is, of the three keys 7a to 7c, the upper up key 7a has a function of scrolling the display map upward, and the down key 7b in the middle has a function of scrolling the display map downward. , The lower determination key 7c has a function of determining a display map. And
When the keys 7a to 7c are pressed, the membrane switch is turned on, and the CPU 20 changes the mode of the map according to the turned on membrane switch.
These membrane switches are connected to the input device 2 shown in FIG.
5 are included.

Next, the operation of the embodiment constructed as described above will be described by taking a case where a map menu is selected as an example. In order for the user to obtain information on his / her current position, FIG.
As shown in (1), the map icon 5b on the LCD panel 5 is pressed with the finger of the right hand or the touch pen 6 held by the right hand while holding the terminal body 2 with the left hand to select the map menu. As a result, the CPU 20 dial-up connects the mobile phone 9 to the map server 30, and the map server 30 transmits map data in a predetermined range centering on the current location of the mobile phone 9 to the mobile phone 9 as described above. When the map data is transmitted from the map server 30 to the mobile phone 9, C
The PU 20 stores the map data in the RAM 23 and displays a map (initial map) around the current location on the LCD panel 5.

Now, when searching for a destination on the map displayed on the LCD panel 5, when the destination is not displayed on the map displayed on the LCD panel 5, the map is scrolled up, down, left and right. To scroll the map, each of the scroll icons of up, down, left, and right is pressed by the touch pen 6 held in the right hand. Scrolling the map upward and downward can be performed by pressing a scroll key 7 (see FIGS. 4 and 5) provided on the terminal body 2 with a finger, in addition to pressing the icon with the touch pen 6. Can be. That is, when the display map is to be scrolled upward, the upward movement key 7a is pressed with the thumb of the left hand, and when the displayed map is scrolled downward, the downward movement key 7b is pressed with the left thumb.

As described above, when the portable information terminal 1 is used, as shown in FIG.
Is operated with the touch pen 6 with the left hand, for example, but in this case, the receiving circuit board 15 does not become parallel to the ground as a whole or inclined. In this case, for example, G
If the PS antenna 14 is arranged in parallel with the receiving circuit board 15, the directivity of the GPS antenna 14 will be directed toward the human body, and the receiving performance will be degraded. On the other hand, in the present embodiment, the GPS antenna 14 is
The GPS antenna 14 is disposed on the receiving circuit board 15 so as to be inclined with the inclination angle θ.
Is directed toward the zenith, not toward the human body.

FIG. 7 shows the inclination angle θ of the GPS antenna 14.
FIG. 9 shows a measurement result obtained by measuring an average gain (dB) of the upper hemisphere (the entire reception area in the GPS satellite sky) when (°) is changed. From this measurement result, it has been found that when the tilt angle θ is provided, the gain is better than when the tilt angle θ is not provided (0 (°)), and it is best to set the gain to 10 (°).

On the other hand, when the bracket 16 is provided to hold the GPS antenna 14 so as to have the inclination angle θ on the receiving circuit board 15 as in the present embodiment, the feeding pin 17 is provided on the receiving circuit board 15. When soldering,
Since the portion to which the power supply pin 17 is to be soldered is covered with the bracket 16, the receiving circuit board 15 needs to be turned upside down so that the back surface is upward. 8 and 9 show the procedure of this soldering operation.
This will be described with reference to FIG.

When the terminal body 2 is accidentally dropped, the bracket 16 (GP
In order to prevent the S antenna 14) from falling off from the receiving circuit board 15, a plurality of (for example, two) inverted L-shaped holding pieces 1 are provided.
6b is provided, and the holding piece 16b is locked to the back surface 15a of the circuit board 15 for reception. Therefore, as shown in FIG. 8, a through hole 15c for inserting the inverted L-shaped holding piece portion 16b from the front surface 15b side to the back surface 15a side of the receiving circuit board 15 is formed in a long hole shape. As shown by the arrow, the holding piece 16b
After being inserted through the through-hole 15c, is moved along the back surface 15a of the receiving circuit board 15 to be locked on the back surface 15a (see FIG. 9). Therefore, the through-hole 15d through which the power supply pin 17 is inserted is also formed in a long hole shape so as to correspond to the behavior of the holding piece 16b.

In this way, as shown in FIG. 9, the holding piece 16b of the bracket 16 and the tip of the power supply pin 17 are soldered to the back surface 15a of the receiving circuit board 15, and the holding piece 16b Is electrically connected to the ground pattern by solder A (via through-hole 15c as necessary), and the tip of power supply pin 17 is connected to solder B (through through-hole 15d as necessary).
Is electrically connected to the power supply pattern.

When the tip of the power supply pin 17 inserted into the elongated through hole 15d of the receiving circuit board 15 is soldered to its back surface 15a, what is the case of a normal small diameter through hole? On the other hand, the amount of solder used increases, and it is difficult to determine an appropriate amount of solder to use. The presence of the bracket 16 causes the receiving circuit board 15
Since the space C is generated between the space and the GPS antenna 14, it is conceivable that the molten solder B flows through the power supply pin 17 by the surface tension as shown by the arrow in FIG. .

In this case, as shown in FIG. 11, if the blocking member 18 as in this embodiment does not exist, the solder B becomes the ground conductor of the GPS antenna 14 depending on the amount of solder flowing into the space C. When the antenna approaches the bracket 16, an electrical coupling D occurs between them, and the performance of the GPS antenna 14 becomes unstable. In the worst case, the solder B is short-circuited E to the bracket 16 (the ground conductor of the GPS antenna 14). Therefore, a problem that the function of the GPS antenna 14 is impaired may occur.

FIG. 12 is an antenna performance characteristic diagram showing the length (use amount) [mm] of the thread solder used on the horizontal axis and the antenna performance (voltage standing wave ratio: VSWR) on the vertical axis. As is apparent from FIG. 12, when the amount of solder used exceeds a certain amount (35 mm), the antenna performance sharply decreases.

On the other hand, in the present embodiment, a ring-shaped blocking member 18 is mounted on the feed pin 17 in the space C formed by the antenna element 14 and the receiving circuit board 15. . The blocking member 18 is formed of a tube made of an insulating material, for example, a tube made of a synthetic resin having heat shrinkage. The tube is formed such that the inner diameter thereof becomes smaller than the outer diameter of the power supply pin 17 when thermally shrunk. ing. Then, the tube is mounted on the outer periphery of the power supply pin 17 and then thermally contracted to form the blocking member 18. In this case, one end (upper end) of the blocking member 18 is
a and the other end (lower end) of the block 14a
Of the receiving circuit board 15 and the front surface 15b of the receiving circuit board 15 (see FIGS. 9 and 10).

As shown in FIG. 10, when the molten solder B flows into the space C along the power supply pin 17 in the same manner as in FIG. When the solder B reaches the position, the solder B is prevented from passing through the power supply pin 17 by the blocking member 18, and further inflow into the space C is stopped. Then, even if the solder B is excessively supplied thereafter, as shown by an arrow in FIG.
It becomes a state of being unilaterally accumulated on the a side.

As described above, according to the present embodiment, the GPS antenna device 13 is built in and fixed to the terminal main body 2, so that the GPS antenna 14 can be formed by a nearby metal body (circuit board, electronic component, etc.). Since the receiving performance can be determined including the mutual coupling of the components, it is possible to improve the stability of the performance. Further, since a complicated mechanism for making the mounting angle freely as in the conventional case is unnecessary, , At low cost.

Further, according to the present embodiment, the GPS antenna 1
4 has an inclination angle θ with respect to the receiving circuit board 15, so that when the terminal body 2 is used with one hand, the directivity of the SPS antenna 14 is directed to the zenith direction instead of the human body direction, High performance during use can be achieved.

In addition, according to the present embodiment, the power supply pin 17
When the ring-shaped blocking member 18 is mounted so as to be positioned in the space C formed by the receiving circuit board 15 and the GPS antenna 14, the power supply pin 17 is soldered to the receiving circuit board 15. In addition, the amount of the solder B flowing into the space C through the power supply pins 17 through the through holes 15d can be reduced as much as possible.
It is possible to prevent instability in performance due to electrical coupling of the S antenna 14 with the bracket 16 serving as a ground conductor,
It is also possible to prevent the function of the GPS antenna 14 from being impaired due to the short circuit of the solder B to the bracket 16 serving as the ground conductor.

The present invention is not limited to the embodiment described above and shown in the drawings, and the following modifications and extensions are possible. Ground pattern 1 of GPS antenna 14
The portion 4c may be provided as needed, but becomes necessary, for example, when the bracket 16 does not have a function as a ground conductor. The electrical connection between the antenna element 14a and the feed pin 17 may be made by soldering irrespective of the head 17a of the feed pin 17. The through hole 15d into which the end of the terminal pin 17 is inserted is formed into a long hole. However, if the through hole is relatively large, a similar problem may occur at the time of soldering. The shape is not particularly limited.

The GPS antenna may be one in which a loop-shaped antenna element is formed on the surface of a block made of a dielectric material. The present invention is not limited to the portable information terminal, and may be applied to a known portable map display terminal.

[Brief description of the drawings]

FIG. 1 is an overall side view showing a cross section of a main part of an embodiment of the present invention.

FIG. 2 is a front view of a GPS antenna device.

FIG. 3 is a side view of the same.

FIG. 4 is an overall perspective view.

FIG. 5 is a perspective view of a state where the terminal body is gripped.

FIG. 6 is a block diagram showing an electrical configuration.

FIG. 7 is a characteristic diagram showing a relationship between a tilt angle and a gain of a GPS antenna.

FIG. 8 is a sectional view showing a procedure of a soldering operation (part 1).

FIG. 9 is a sectional view showing the procedure of the soldering operation (part 2).

FIG. 10 is a cross-sectional view showing a state in which an appropriate amount of solder has been supplied.

FIG. 11 is a diagram corresponding to FIG. 10 showing a comparative example.

FIG. 12 is a diagram showing antenna performance characteristics;

[Explanation of symbols]

In the drawings, 1 is a portable information terminal (portable terminal), 2 is a terminal body, 5 is an LCD panel, 12 is a main circuit board, 13 is a GPS antenna device, 14 is a GPS antenna, 14a is a block, 14b is an antenna element, 14c Is a ground pattern, 15 is a receiving circuit board (circuit board), 15c and 15d are through holes, 16 is a bracket, 16b
Denotes a holding piece, 17 denotes a power supply pin, and 18 denotes a blocking member.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04M 11/00 302 H04M 11/00 302 F term (Reference) 5J045 AA05 AA21 AB05 AB06 DA10 EA07 MA04 NA02 5J046 AA04 AA09 AB13 PA07 5J047 AA04 AA09 AB13 BE03 BE05 FD01 5J062 AA06 BB01 BB05 CC07 DD21 GG02 HH05 5K101 KK03 KK16 LL12 MM04 MM05 MM07 NN18 NN22 NN25 NN40 QQ02 SS07 TT03

Claims (1)

[Claims] A GPS antenna having a GPS wave antenna element on a surface thereof; a GPS antenna mounted on the circuit board; and a tilt angle with respect to the circuit board. A power supply pin, one end of which is electrically connected to the antenna element of the GPS antenna, and the other end of which is soldered to the circuit board through a through hole thereof; A GPS antenna device for a portable terminal, comprising: a ring-shaped blocking member mounted in a space defined by a substrate and the GPS antenna.