JPH10142278A - Measuring antenna device for radio terminal machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the accuracy of measurement by removing a mutual positional slippage between a transmission-reception antenna and a measuring antenna. SOLUTION: The measuring antenna device of this radio terminal machine is composed of a loop coil antenna 5 into which the rod-shaped transmission- reception antenna 2a of the radio terminal machine 2 can be inserted; a high frequency terminal 8 connected to the loop coil antenna 5; and a guide block 6 made of ferrite which has an inserting hole for a rod-shaped transmission- reception antenna, and holds the loop coil antenna, and moreover inserts the rod-shaped transmission-reception antenna into an inserting hole for holding the rod-shaped transmission-reception antenna in a state where it is inserted to the loop coil antenna.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a measurement antenna device used for transmission / reception inspection of a wireless terminal such as a portable telephone.

[0002]

2. Description of the Related Art In recent years, mobile phones such as mobile phones, wireless data terminals, and the like (hereinafter, referred to as mobile wireless terminals or mobile wireless terminals) have been remarkably developed and spread, and demand has further increased. Expected. Along with this, the development cycle of these wireless terminals has become shorter,
The number of repairs etc. has also increased significantly.

[0003] When a mobile radio terminal of this type is developed, or a product is shipped or repaired, a performance test (performance test) of the device is indispensable. As one of the performance inspections, there is an inspection of the quality of transmission radio waves (transmission power, occupied frequency bandwidth, frequency deviation, etc.) and reception sensitivity (hereinafter, referred to as transmission / reception inspection).

Conventionally, a mobile radio terminal has a detachable high-frequency terminal (connector), and a transmitting / receiving antenna is attached to this high-frequency terminal. Also, even if the transmitting and receiving antenna is directly attached to the main body of the mobile wireless terminal,
A high-frequency terminal was separately provided. Therefore, a tester having a wattmeter, a spectrum analyzer, a standard signal generator, or the like is connected to a high-frequency terminal by a high-frequency cable to perform a transmission / reception test.

However, with the spread of mobile radio terminals in recent years, mobile radio terminals have been required to be smaller and lighter and have lower prices. For this reason, models without a high-frequency terminal and having a transmitting / receiving antenna directly attached to the main body have been developed.

Therefore, a mobile radio terminal not equipped with such a high-frequency terminal must use a measurement method generally called air coupling. The air coupling is a method in which a measurement antenna is installed at a predetermined distance (close place) from a transmission / reception antenna attached to a mobile wireless terminal, and test radio waves are transmitted / received using the measurement antenna.

However, according to the air coupling, radio waves are transmitted from the transmitting / receiving antenna and the measurement antenna of the mobile radio terminal, which affects nearby base stations. These antennas also receive radio waves from nearby base stations and unnecessary radio waves such as noise. Further, reflected waves generated when the radio waves transmitted from these antennas hit a nearby building or the like cannot be ignored.

Therefore, such transmission / reception inspection by air coupling is ideally performed in an anechoic chamber in which the electromagnetic field is mutually cut off from the outside world and there is no internal reflection, but the anechoic chamber is extremely expensive. Not so easily adopted. Therefore, inexpensive and easy shield boxes have been developed and used in place of such expensive anechoic chambers.

FIG. 9 is an example of a conventional shield box, and is a perspective view showing the entire structure. The seed box 101 includes a housing 101a and a lid 101b, both of which are formed of a metal having a shielding effect against a high-frequency electromagnetic field.

The housing 101a has an opening on one surface (the upper surface in FIG. 9).
(Mobile radio terminal). Also,
The lid 101b has a shape that covers the opening surface, and shields the mobile phone 102 stored inside the shield box 101.

A radio wave absorber 101c is affixed to the entire inner surface of both the housing 101a and the lid 101b. Although various types of the radio wave absorber 101c have been developed, they are well known and will not be described in detail here.

The housing 101a has a table (not shown) on which the cellular phone 102 is mounted, and a dipole antenna (measurement antenna) below the table (not shown). This table is made of a material that transmits electromagnetic waves without any problem, and allows air coupling between the antenna 102a attached to the mobile phone 102 and the dipole antenna.

A high frequency terminal 103a is provided on the wall of the housing 101a.
And a control terminal 103b. This high-frequency terminal 103a is connected to the above-mentioned dipole antenna (not shown). The control terminal 103b is connected to a voice terminal of the mobile phone 102 or a data terminal when measuring a wireless data terminal.

[0014]

As described above, in the conventional shield box 101, the dipole antenna for measurement is arranged below the table on which the mobile phone 102 is mounted. The misalignment causes the mutual position of the antenna 102a of the mobile phone 102 and the dipole antenna for measurement to be shifted from each other, so that there is a problem that a measurement error is likely to occur. In the case of a dipole antenna, the antenna 102 of the mobile phone 102 is used.
Since it is necessary to set a and the dipole antenna a certain distance apart from each other, a large measurement space (measurement area) is required.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a measurement antenna device which can improve the measurement accuracy in consideration of the above circumstances and can test a wireless terminal in a relatively small measurement space. .

[0016]

In order to solve the above-mentioned problems, a first aspect of the present invention provides a loop coil antenna into which a rod-shaped transmitting / receiving antenna of a wireless terminal can be inserted, and a loop coil antenna connected to the loop coil antenna. A high-frequency terminal and an insertion hole for the rod-shaped transmission / reception antenna, holding the loop coil antenna, and inserting the rod-shaped transmission / reception antenna into the insertion hole, thereby changing the rod-shaped transmission / reception antenna to a loop coil antenna. And a guide block that is held in an inserted state with respect to.

According to a second aspect of the present invention, in the first aspect, the guide block is formed of a ferrite cylinder, and the loop coil antenna is mounted in the ferrite cylinder.

According to a third aspect of the present invention, in the first or second aspect, a stopper for positioning the rod-shaped transmitting / receiving antenna inserted into the insertion hole at one position in a radial direction of the insertion hole. And a spring for urging the stopper in the positioning direction.

When the shield box of the present invention is used, a rod-shaped transmitting / receiving antenna of a wireless terminal is inserted into an insertion hole of the guide block. Then, the transmission / reception antenna is held in a state where the rod-shaped transmission / reception antenna is inserted into the loop coil antenna used as the measurement antenna. When the measurement is performed in that state, since the transmitting and receiving antennas are inserted into the loop coil antenna, the positional relationship between the two antennas is less likely to shift, and the measurement is performed under a constant positional relationship. Therefore, measurement accuracy can be improved. In the case of a loop coil antenna, a rod-shaped transmission / reception antenna may be inserted into the loop coil antenna, so that a large measurement space is not required.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a configuration of a measurement antenna device F1 of the first embodiment, and FIG. 2 is a side sectional view showing a state when a shield box M equipped with the measurement antenna device F1 is used. In this embodiment, an example in which the mobile phone 2 is applied as a mobile wireless terminal will be described.

Since the measuring antenna device F2 of the embodiment is mounted on the shield box M, the configuration of the shield box M will be described first. The shield box M shown in FIG. 2 is mainly composed of a cubic shield box body 1 composed of a housing 1a having an open upper surface and a lid 1b for closing the upper surface. Both the housing 1a and the lid 1b are formed of a metal (for example, aluminum or the like) having a shielding effect against a high-frequency electromagnetic field. Therefore, the electromagnetic wave is shielded from the inside of the shield box body 1 and the outside world.

A measurement mat 3 made of silicone resin or the like for mounting the mobile phone 2 is laid on the inner bottom surface of the housing 1a, so that the mounted mobile phone 2 does not easily move. I have.

In the housing 1a, a loop coil antenna 5 is provided.
The measurement antenna device F1 according to the first embodiment, which is provided with the above, is provided. The loop coil antenna 5 is connected to the mobile phone 2
1 is mounted inside a cylindrical guide block 6 made of ferrite as shown in FIG. Is connected to the high-frequency terminal 8 provided at the first position. The high frequency terminal 8 is for connecting to an external cable. The guide block 6 has an insertion hole 6a for inserting the rod-shaped antenna 2a at the center, and the loop coil antenna 5 is mounted in a recess (not shown) formed on the inner periphery of the insertion hole 6a. A coaxial cable 7 having a high-frequency terminal 8 at the end is drawn out of the guide block 6.

As shown in FIG. 2, a flexible conductive net 10 is disposed inside the housing 1a. The conductive network 10 is connected to the wireless terminal 2 placed on the measuring mat 3.
Can be covered from above.
The winding can be performed by a winding device 11 installed at a corner in the housing 1a.

As the conductive net 10, various types can be used, such as those developed for the purpose of preventing EMI (electromagnetic interference) of a liquid crystal display panel. In this embodiment,
For example, a material in which fine fibers are electrically conductive-coated, a material having a plurality of minute holes in an ultra-thin conductor plate, and the like can be applied.
However, in this case, the size of the conductive mesh is selected so as to obtain a sufficient shielding effect in accordance with the frequency of the electromagnetic wave transmitted / received by the transmitting / receiving antenna 2a or the loop coil antenna 5.

When using this shield box M,
As shown in FIG. 2, by passing the rod-shaped transmission / reception antenna 2a through the cylindrical guide block 6, the transmission / reception antenna 2a can be inserted into the loop coil antenna 5 mounted inside. In this state, the mobile phone 2 is placed on the measurement mat 3 in the housing 1a, and if necessary, the conductive net 10 is pulled out from the winding device 11 and put on the mobile phone 2, and then the cover 1b is closed. close.

In this state, a test transmission / reception is performed between the loop coil antenna 5 and the transmission / reception antenna 2a. At this time, the loop coil antenna 5 and the transmitting / receiving antenna 2a
Since they are fitted to each other, mutual positional deviation hardly occurs, and the measurement accuracy is improved. Further, since the positional relationship between the transmission and reception antennas 2a is simply set by inserting the transmission / reception antenna 2a through the loop coil antenna 5, the measurement space can be reduced, and the size of the entire shield box can be reduced.

In particular, since the cylindrical guide block 6 is made of ferrite, the sensitivity of the radio terminal 2 to the outside can be reduced due to the electromagnetic wave blocking effect of the ferrite, and even if the shielding effect of the shield box body 1 is small, It is no longer affected by the surrounding electric field. In addition, internal reflection can be ignored, and when the shielding effect is weak,
As described above, it can be dealt with only by covering the conductive net 10. Therefore, it is not necessary to attach a radio wave absorber to the entire inner surface of the shield box main body 1 in order to improve the shielding performance of the entire shield box main body 1, and the cost can be reduced. Further, since the radio wave absorber, the table and the like can be omitted, the size of the shield box M can be reduced.

The antenna guides 20A, 20B and 20C made of a material that transmits electromagnetic waves as shown in FIG. 3 are fitted into the inner periphery of the insertion hole 6a of the guide block 6, and the rod-shaped antenna 2a of the portable telephone 2 is attached. It is also possible to facilitate positioning at one or several positions in the radial direction within the insertion hole 6a. In this case, the antenna guide 2 shown in FIG.
0A has a substantially elliptical cross section in which both ends are sharpened at an acute angle. The antenna guide 20B in FIG. 2B has a square cross section. The antenna guide 20C in FIG. 3C has a triangular cross section. According to these antenna guides,
The rod-shaped antenna 2a can be positioned at each vertex.

FIG. 4 shows the configuration of a measurement antenna device F2 according to the second embodiment. In this antenna device F2, an antenna guide 20C having a triangular cross section is fitted into the inner periphery of the insertion hole 6a of the cylindrical guide block 6 made of ferrite.
The loop coil antenna 5 is mounted inside the guide block 6. The rod-shaped antenna 2 inserted in the antenna guide 20C is provided on the end face of the guide block 6.
a is positioned at one position in the radial direction of the insertion hole 6a, that is, at the upper vertex of the antenna guide 20C.
Is provided.

The stopper 23 has an arm shape.
One end is rotatably connected to the end face of the guide block 6 by a pin 24, and can be moved in a direction crossing the insertion hole 6a. The rod-shaped antenna 2a is moved toward the upward apex of the antenna guide 20C. It can be pressed and positioned. The arm-shaped stopper 23 is urged in a positioning direction, that is, upward by a spring 25 having both ends locked to the stopper 23 and the guide block 6.

When using the measurement antenna device F2, the rod-shaped antenna 2a is inserted into the antenna guide 20C with the stopper 23 pressed down, and the stopper 23 is released in that state. By doing so, the stopper 23 can lift and position the antenna 2a to the vertex of the antenna guide 20C. Therefore, the positional relationship between the loop coil antenna 5 and the antenna 2a becomes constant, and the measurement accuracy can be improved.

FIG. 5 shows the configuration of a measurement antenna device F3 according to the third embodiment. Although not shown, the antenna device F3 includes a loop coil antenna inside a cylindrical guide block 6 made of ferrite. Further, the antenna guide is not fitted into the inner periphery of the insertion hole 6a of the guide block 6. The end face of the guide block 6 is provided with a stopper 33 for positioning the rod-shaped antenna 2a inserted into the insertion hole 6a at one position in the radial direction of the insertion hole 6a, that is, at the upper end.

The stopper 33 is formed of a slide plate having a circular through hole 33a formed at the center, and is engaged with a pair of guide rails 34, 34 provided on the end surface of the guide block 6. It is slidable up and down along 34, can be moved in a direction traversing the insertion hole 6a, and can push and position the rod-shaped antenna 2a toward the upper end of the insertion hole 6a. It has become. The stopper 33 is urged in a positioning direction, that is, upward by a spring 35 having both ends locked to the stopper 33 and the guide block 6. The spring 35 is inserted into the notch 34a of one of the guide rails 34 and urges the stopper 33 only within the range of the notch 34a. Therefore, the movement limit of the stopper 33 is determined by the spring 35.

When the measurement antenna device F3 is used, the rod-shaped antenna 2a (see FIG. 4) is inserted into the insertion hole 6a of the guide block 6 through the through hole 33a of the stopper 33 with the stopper 33 pressed down. 4), and release the stopper 33 in that state. Then, the stopper 33 is lifted by the force of the spring 35, and
is shifted from the insertion hole 6a, the antenna 2a passed through the through hole 33a is lifted to the upper end of the insertion hole 6a, and is pressed against the upper end of the insertion hole 6a to be positioned. Therefore, the positional relationship between the loop coil antenna 5 and the antenna 2a becomes constant, and the measurement accuracy can be improved.

The through hole of the stopper 33 can be variously changed as shown in FIG. Stopper 33 in FIG.
Has a circular through-hole 33a, the stopper 33 in FIG. 4B has a triangular through-hole 33b, and the stopper 33 in FIG. 4C has a through-hole 33c in which an ellipse is crushed.

FIG. 7 shows the configuration of a measurement antenna device F4 according to the fourth embodiment. This antenna device F4 has a cylindrical guide block 6 made of ferrite (not shown) attached to the side surface, a loop antenna coil inside, and a coaxial cable 7 having a high-frequency terminal (not shown) at the tip. It is connected. Further, the antenna guide is not fitted into the inner periphery of the insertion hole 6a of the guide block 6. On the end surface of the guide block 6, circular antenna insertion holes 46a penetrating in a horizontal direction through a rectangular parallelepiped guide block 46 made of resin are formed on both sides.

A slide hole 46b is formed in the upper end surface of the guide block 46.
A cylindrical stopper 43 is inserted so as to be slidable up and down. When the stopper 43 is pushed down to the lower end position, the insertion hole 4
A circular through-hole 43a overlapping with 6a is formed, and the rod-shaped antenna 2a (see FIG. 4) can be inserted through the through-hole 43a and the insertion hole 46a with the stopper 43 at the lower end position. It has become.

A metal base 47 is embedded in the inner bottom of the guide block 46, and a plurality of guide rods 44 projecting from the lower surface of the stopper 43 slide with respect to the upper end surface of the metal base 47. The vertical movement of 43 is guided smoothly. In this case, a coil spring 45 is fitted around the guide rod 44, and the stopper 43 is urged upward by the spring 45. The upper limit of the movement of the stopper 43 is determined by, for example, engaging the guide rod 44 with the metal base 47.

When using the measurement antenna device F4, the rod-shaped antenna 2a (see FIG. 3) is inserted into the insertion hole 46a of the guide block 46 through the through hole 43a of the stopper 43 with the stopper 43 pressed down. 4)
Is inserted, and the stopper 43 is released in that state. Then, the stopper 43 is lifted by the force of the coil spring 45, so that the through hole 43a is displaced from the insertion hole 46a,
The antenna 2a passed through 3a is lifted to the upper end of the insertion hole 46a, pressed against the upper end of the insertion hole 46a, and positioned. Therefore, the positional relationship between the loop coil antenna 5 and the antenna 2a becomes constant, and the measurement accuracy can be improved.

The through hole of the stopper 43 can be variously changed as shown in FIG. Stopper 43 in FIG.
Has a circular through-hole 43a, the stopper 43 in FIG. 4B has a triangular through-hole 43b, and the stopper 43 in FIG. 4C has a through-hole 43c in which an ellipse is crushed.

[0042]

As described above, according to the first aspect of the present invention, transmission / reception of electromagnetic waves is performed with the rod-shaped transmission / reception antenna of the wireless terminal inserted into the loop antenna for measurement. Therefore, it is possible to eliminate the misalignment between the measurement antenna and the wireless terminal antenna,
Measurement can be performed under a fixed positional relationship, thereby increasing measurement accuracy. In the case of a loop coil antenna, a rod-shaped transmission / reception antenna may be inserted into the loop coil antenna, so that a large measurement space is not required. In particular, by simply inserting the rod-shaped transmitting and receiving antenna into the insertion hole of the guide block, the antenna can be properly inserted into the loop coil antenna, so that the set is simple and the positional relationship between the antennas can be properly adjusted. I can keep it.

According to the second aspect of the present invention, since the guide block is made of ferrite, the sensitivity of the wireless terminal to the outside world can be reduced due to the electromagnetic wave blocking effect of the ferrite, and even if the shielding effect of the shield box is small. , No longer affected by the surrounding electric field. In addition, since the internal reflection can be neglected, it is possible to cope with a weak shielding effect by covering the conductive net. Therefore, it is not necessary to attach the radio wave absorber to the entire inner surface of the shield box in order to improve the shielding performance of the entire shield box, and the cost can be reduced. In addition, since a radio wave absorber, a table, and the like can be omitted, the size of the shield box can be reduced.

According to the third aspect of the present invention, since the transmitting / receiving antenna inserted into the insertion hole can be positioned by the stopper biased by the spring, the positional deviation can be more strictly eliminated, and the measurement can be performed. Accuracy can be further improved.

[Brief description of the drawings]

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

FIG. 2 is a side sectional view showing a state where a shield box equipped with the measurement antenna device of the first embodiment is used.

FIGS. 3 (a), (b), and (c) show insertion holes in a guide block of the measurement antenna device of the first embodiment;
It is a front view showing the state where different types of antenna guides were fitted.

FIG. 4 is a perspective view illustrating a configuration of a measurement antenna device according to a second embodiment of the present invention.

FIG. 5 is a perspective view illustrating a partial configuration of a measurement antenna device according to a third embodiment of the present invention.

FIGS. 6A to 6C are diagrams showing different types of through holes of a stopper according to the third embodiment.

FIG. 7 is a perspective view illustrating a configuration of a measurement antenna device according to a fourth embodiment of the present invention.

FIGS. 8A to 8C are diagrams showing different types of through holes of a stopper according to the fourth embodiment.

FIG. 9 is a perspective view showing a configuration of a conventional shield box.

[Explanation of symbols]

 F1, F2, F3, F4 Measurement antenna device 2 Mobile phone (wireless terminal) 2a Rod-shaped transmission / reception antenna 5 Loop coil antenna 6, 46 Guide block 23, 33, 43 Stopper 25, 35, 45 Spring 8 High frequency terminal

Claims (3)

[Claims] 1. A loop coil antenna (5) into which a rod-shaped transmitting / receiving antenna (2a) of a wireless terminal (2) can be inserted, a high-frequency terminal (8) connected to the loop coil antenna, and the rod-shaped antenna By inserting the rod-shaped transmitting / receiving antenna into the loop coil antenna by holding the loop coil antenna and inserting the rod-shaped transmitting / receiving antenna into the insertion hole, the rod-shaped transmitting / receiving antenna is inserted into the loop coil antenna. A measurement antenna device for a wireless terminal, comprising: a guide block (6) for holding a state. 2. The antenna device according to claim 1, wherein the guide block is formed of a ferrite cylinder, and the loop coil antenna is mounted in the ferrite cylinder. 3. A stopper (23, 33, 4) for positioning a rod-shaped transmitting / receiving antenna inserted into the insertion hole at one position in a radial direction of the insertion hole.
3) and a spring (2) for urging the stopper in the positioning direction.
The antenna device for measuring a wireless terminal according to claim 1 or 2, wherein (5, 35, 45) is provided.