JPH08111610A - Antenna system - Google Patents

Abstract

PURPOSE: To easily and precisely measure a transmission output of an antenna circuit whose antenna system is removed even when the antenna circuit is mounted on a main printed circuit board by connecting a transmission output measurement terminal to a feeding part via a capacitor. CONSTITUTION: A feeding part 52 is connected to a transmission line 66 for antenna feeding formed to a main printed circuit board 53a, and a lamination chip capacitor 68 and a transmission output measurement terminal are connected to the transmission line 66. Through the constitution above, the effect of the inductance of the feeding section 52 onto a measured value of a transmission output from the feeding part 52 in the transmission output measurement terminal is corrected by the capacitance of the capacitor 68 and then the transmission output of an antenna switch circuit is precisely measured. Thus, even when the feeding part 52 is provided to the board 53a, the radiation section is separated and the transmission output of the antenna switch circuit in the state that the antenna system is removed that is in compliance with the Radio Wave Law is easily and precisely measured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna device used in mobile communication equipment such as a mobile phone.

[0002]

2. Description of the Related Art As an antenna used in a conventional mobile communication device, Japanese Patent Application No. 6-81 filed by the present applicant.
No. 652 proposes a substrate surface mount antenna having a dielectric substrate. This board surface mount type antenna is shown in FIG. 7, and as the antenna circuit, for example, a board surface mount type antenna equipped with an antenna switch circuit is shown in FIGS.
It is shown in FIG.

In FIG. 7, reference numeral 1 denotes a rectangular parallelepiped dielectric substrate made of ceramic or resin. The ground electrodes 2 and 2 are formed on both sides of the dielectric substrate 1 on the long side and both sides of the short side are formed. The connection electrodes 3a, 3b, 3c are formed on the.
Reference numeral 4 denotes a metal chassis made of, for example, copper or a copper alloy and having a substantially U-shaped cross section. The metal chassis 4 is a rectangular radiating portion 5 and is vertically downward from both ends on the short side of the radiating portion 5. It has two fixing parts 6 and 7 that are bent at the same time, and a power supply terminal 8 and a ground terminal 9 are integrally formed at the tip of the fixing part 6. Here, the fixed portion 6 is formed shorter than the fixed portion 7 by providing the power supply terminal 8 and the ground terminal 9, and the length of the fixed portion 6 including the power supply terminal 8 and the ground terminal 9 and the fixed portion 7 is the dielectric substrate. It is set larger than the thickness of 1.

Then, the dielectric substrate 1 is inserted into the metal chassis 4, and the side surface on the short side of the dielectric substrate 1 is brought into contact with the inside of the fixing portions 6 and 7 of the metal chassis 4, and
Between the radiation part 5 of the metal chassis 4 and the surface of the dielectric substrate 1, the length of the fixed part 6 and the fixed part 7 including the power supply terminal 8 and the ground terminal 9 and the dimensional difference in the thickness of the dielectric substrate 1 A space 10 is provided by the connection electrode 3a of the dielectric substrate 1, the fixing portion 7 of the metal chassis 4, and the connection electrode 3 of the dielectric substrate 1.
The board surface mounted antenna 13 is formed by joining the power supply terminals 8 and the ground terminals 9 of the metal chassis 4 with solder by soldering.

Further, 15 is a main wiring board, and the main wiring board 15 is a microstrip line 16 for antenna feeding, which is a transmission line connected to an antenna switch circuit (not shown) as an antenna circuit on the surface. The microstrip line 16 and the insulated ground electrode 17 a are formed, and the ground electrode 1 is formed on almost the entire back surface of the main wiring board 15.
7b is formed.

The board surface mount antenna 13 is
It is placed on the surface of the main wiring board 15, the power supply terminal 8 and the microstrip line 16 are soldered, and the ground electrodes 2, 2
And the ground terminal 9 to the ground electrode 17 on the surface of the main wiring board 15.
It is soldered to a and mounted on the surface, and radio waves are transmitted and received from the radiator 5 of the metal chassis 4.

Further, in FIGS. 8 and 9, reference numeral 21 denotes a multi-layered rectangular parallelepiped dielectric substrate made of ceramic or resin, which is used as an external electrode on both sides of the dielectric substrate 21 for transmitting the antenna switch circuit. Input part TX, reception output part RX, control input parts VC1 and VC2, and a plurality of ground electrodes 2
2 is formed, and the connection electrodes 23 are formed on both sides of the short side.
a, 23b, and 23c are formed. Further, as a circuit element, the strip line 24a is provided inside the dielectric substrate 21.
And a capacitor 24b are formed, and a diode 24c and a printed resistor 24d are mounted on the surface of the dielectric substrate 21,
The antenna switch circuit 24 is configured. The antenna output section 24e of the antenna switch circuit 24 is connected from the inside of the dielectric substrate 21 to the connection electrode 23b on the side surface, and the respective circuit elements are connected by internal electrodes or via holes.

Further, 26 is a metal chassis made of copper or a copper alloy and having a substantially U-shaped cross section.
Is a radiating portion 27 formed in a rectangular and planar shape, and the radiating portion 27
Has two fixing portions 28 and 29 which are vertically bent downward from both ends on the short side, and a power supply terminal 30 and a ground terminal 31 are integrally formed at the tip of the fixing portion 28. Here, the fixing portion 28 is formed shorter than the fixing portion 29 by providing the power supply terminal 30 and the ground terminal 31, and the lengths of the fixing portion 2 including the power supply terminal 30 and the ground terminal 31 and the fixing portion 29 are the dielectric substrate. It is set larger than the thickness of 1.

Then, the dielectric substrate 21 is inserted into the metal chassis 26, and the side surfaces on the short side of the dielectric substrate 21 are brought into contact with the insides of the fixing portions 28 and 29 of the metal chassis 26, and at the same time, the metal chassis Between the radiation part 27 of 26 and the surface of the dielectric substrate 21, the power supply terminal 30 and the ground terminal 31 are provided.
A space 32 is provided due to a dimensional difference between the lengths of the fixed portion 28 and the fixed portion 29 and the thickness of the dielectric substrate 1, and the connection electrode 23a of the dielectric substrate 21 and the fixed portion 29 of the metal chassis 26, and the dielectric Connection electrodes 23b and 23c of the body substrate 21
The power supply terminal 30 and the ground terminal 31 of the metal chassis 26 are soldered to each other to form the board surface mount antenna 35.

Reference numeral 36 denotes a main wiring board, and the main wiring board 36 has connection electrodes 37, 38, 39, 40 on its surface.
A ground electrode 41a insulated from the connection electrodes 37 to 40 is formed, and the ground electrode 41b is formed on almost the entire back surface of the main wiring board 36.
Is formed.

Then, the antenna device 35 is placed on the surface of the main wiring board 36, and the transmission input section TX and the reception output section RX are placed.
And, the control input sections VC1 and VC2 are soldered to the connection electrodes 37 to 40, the ground electrode 22 and the ground terminal 31 are soldered to the ground electrode 41a for surface mounting, and radio waves are transmitted and received from the radiation section 27 of the metal chassis 26. To do.

FIG. 10 shows a concrete example of the antenna switch circuit 24, which is well known, and a block diagram of the antenna 35 is shown in FIG. In addition to the antenna circuit 24 shown in FIG. 10, an antenna circuit such as a low pass filter or a band pass filter can be mounted.

[0013] Further, Japanese Patent Application No. Hei 6 filed by the present applicant.
No. 034759 proposes a dielectric-loaded monopole antenna that can be surface-mounted on a substrate. This dielectric loaded monopole antenna is shown in FIG. In FIG. 12, reference numeral 71 denotes a substantially rectangular parallelepiped dielectric substrate. Inside the dielectric substrate 71, a substantially cylindrical through hole 72 is formed so as to open to the opposite side surface, and the surface of the through hole 72 is formed. Has
A radiation electrode 73 made of, for example, copper is formed. Through hole 7
On one side surface of the dielectric substrate 71 where the opening 2 is formed, a power supply terminal 74 that is electrically connected to the radiation electrode 73 is continuously formed from the side surface to the back surface. Ground terminals 75a and 75b are formed on both sides of the power supply terminal 74, and a ground terminal 75c is formed on the other side surface of the dielectric substrate 71 in which the through hole 72 is opened, and the dielectric loaded monopole antenna 76 is formed. Composed.

On the other hand, 77 is a main wiring board, and the main wiring board 77 is a microstrip line 78 for feeding an antenna, which is a transmission line connected to an antenna switch circuit (not shown) as an antenna circuit on the surface. A microstrip line 78 and an insulated ground electrode 79 a are formed, and the ground electrode 7 is formed on almost the entire back surface of the main wiring board 77.
9b is formed.

Then, the dielectric loaded monopole antenna 76 is placed on the surface of the main wiring board 77, and the feeding terminal 74 is mounted.
The microstrip line 78 is soldered, the ground terminals 75a, 75b, and 75c are soldered to the ground electrode 79a on the surface of the main wiring board 77 to be surface-mounted, and the radiation electrode 73 transmits and receives radio waves.

[0016]

Since the transmission output of an antenna circuit such as an antenna switch circuit with the antenna removed is regulated by the Radio Law, its value must be accurately measured.

However, in the above-mentioned conventional board surface mount type antenna 13, the feeding terminal 8, the ground electrodes 2, 2 and the ground terminal 9 are provided.
Since it is soldered and surface-mounted on the main wiring board 15,
There is a problem that it is difficult to remove once mounted on the main wiring board 15. On the other hand, after the board surface-mounted antenna 13 is surface-mounted on the main wiring board 15, the power supply terminal 8 is connected to the antenna switch circuit via the microstrip line 16, so that the transmission of the antenna switch circuit is performed. For output, the substrate surface mount antenna 13
Since a single impedance is loaded, there is a problem that the transmission output of the antenna switch circuit cannot be accurately measured.

Also in the above-mentioned conventional board surface mount type antenna 35, the transmission input section TX, the reception output section RX, the control input sections VC1 and VC2, the ground electrode 22 and the ground terminal 3 are provided.
Since 1 is soldered and surface-mounted on the main wiring board 36, there is a problem that it is difficult to remove once mounted on the main wiring board 36. On the other hand, after the board surface-mounted antenna 35 is surface-mounted on the main wiring board 36, the power supply terminal 30 is connected to the antenna output section 24e of the antenna switch circuit 24.
Since the impedance of the substrate surface-mounted antenna 35 alone is loaded on the transmission output of, the transmission output of the antenna switch circuit 24 cannot be accurately measured.

Further, also in the above-mentioned conventional dielectric loaded monopole antenna 76, the feeding terminal 74 and the ground terminal 7 are provided.
Main wiring board 77 by soldering 5a, 75b, 75c
Since it is surface-mounted on the main wiring board 77, it is difficult to remove it once it is surface-mounted on the main wiring board 77. On the other hand, when the dielectric loaded monopole antenna 76 is surface-mounted on the main wiring board 77, the feeding terminal 74 is connected to the antenna switch circuit via the microstrip line 78, so that the transmission of the antenna switch circuit is performed. The output is loaded with the impedance of the dielectric loaded monopole antenna 76 alone, which causes a problem that the transmission output of the antenna switch circuit cannot be accurately measured.

Therefore, in order to accurately measure the transmission output of an antenna circuit such as an antenna switch circuit after mounting the above-mentioned antenna on the main wiring board, conventionally, an electrical or switching method for switching to a transmission output measuring terminal has been used. A mechanical switch was required, and the cost was high.

The present invention has been made to solve these problems, and the transmission output of the antenna circuit, which is regulated by the Radio Law and with the antenna device removed, is surface-mounted on the main wiring board. It is another object of the present invention to provide an antenna device which can be easily and accurately measured without using an electrical or mechanical switch for switching to a transmission output measuring terminal.

[0022]

In order to achieve the above object, the present invention has a power feeding section and a radiation section which is separate from the power feeding section and is separable from each other. It is characterized in that the transmission output measurement terminal is connected via a capacitor.

The power supply unit provided on the main wiring board,
With respect to an exterior case that houses the main wiring board, the radiation section is housed and attached in a space formed between the main wiring board and the exterior case, and one main surface of the radiation section is It is characterized in that it faces the power feeding unit.

The feeding section is connected to a first transmission line for feeding an antenna formed on the main wiring board, and the multilayer chip capacitor and the transmission output measuring terminal are connected to the first transmission line. It is connected to the transmission line of.

Further, the power feeding section is formed by inserting a dielectric substrate inside a metal chassis, and inside the dielectric substrate, a first capacitor electrode connected to the first transmission line,
The second for transmitting power measurement formed on the main wiring board
By providing a second capacitor electrode connected to the transmission line, the built-in capacitor connected to the transmission output measuring terminal is formed.

Further, a space is provided between the metal chassis and the dielectric substrate.

[0027]

According to the above structure, the power feeding portion is provided on the main wiring board, and the radiation portion is provided to the outer case that accommodates the main wiring board.
The radiation case can be easily removed by removing the outer case from the main wiring board even after the power feeding section is provided on the main wiring board, by storing and attaching it in the space formed between the main wiring board and the outer case. It can be separated from the power supply.

Further, since the transmission output measuring terminal is connected to the power feeding portion via the multilayer chip capacitor or the built-in capacitor, the transmission output from the power feeding portion at the transmission output measuring terminal is laminated type. The capacitance of the chip capacitor is added. Thus, the influence of the inductance of the power supply unit on the measured value of the transmission output from the power supply unit at the transmission output measurement terminal can be corrected by the capacitance of the multilayer chip capacitor connected to the power supply unit. Therefore, the transmission output of the antenna circuit can be accurately measured by removing the influence of the inductance of the power feeding unit.

As described above, the transmission output of the antenna circuit can be easily and accurately obtained even after the power feeding portion is provided on the main wiring board by separating the radiation portion and removing the antenna device regulated by the Radio Law. Can be measured.

Further, the electrical or mechanical switch for switching to the transmission output measuring terminal, which has been conventionally required for measuring the transmission output, becomes unnecessary.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an antenna device according to the present invention will be described below with reference to the drawings. 1 and 2 show an antenna device 51a and a power feeding section 52 according to the first embodiment of the present invention. The antenna device 51a is in a state of being built in the mobile phone 61, and FIG. 1A is a perspective view from an oblique direction.
1B is a perspective view from the front direction, FIG. 1C is a perspective view from the lateral direction, and FIG. 2 is a perspective view of the power feeding portion 52.

1 and 2, the antenna device 51a
Places the power supply unit 52 on the main surface of the main wiring board 53a,
The radiator 56a is connected to the first microstrip line 66, which is the first transmission line for feeding the antenna formed on the main wiring board 53a, and the radiating portion 56a is attached to the outer case 55 accommodating the main wiring board 53a. Then, it is housed and attached in a space formed between the main wiring board 53a and the outer case 55. Then, the power feeding portion 52 is formed on the main wiring board 53a so as to be insulated from the first microstrip line 66, and the ground electrode 6 is formed.
7a, the radiation part 56a is grounded to the exterior case 55, and one main surface of the radiation part 56a faces the power supply part 52 and is in contact with each other.

In order to protect the main wiring board 53a, the shield cases 54a and 54b are connected to the main wiring board 53.
It is attached to both surfaces of a so as to cover almost all the portions except the portion where the power feeding portion 52 is placed.

On the other hand, 54 is a metal chassis made of, for example, copper or a copper alloy and having a substantially U-shaped cross section, which is opposed to the facing portion 52a which is formed in a rectangular plane shape and faces the main surface of the radiating portion 56a in parallel. And two foot portions 52b and 52c vertically bent downward from both ends on the short side of the portion 52a,
A power supply terminal 52d is integrally formed at the tip of the foot portion 52b, and a ground terminal 52e is integrally formed at the tip of the foot portion 52c.

A ground electrode 67b is formed on almost the entire back surface of the main wiring board 53a. The first microstrip line 66 is connected to, for example, an antenna switch circuit (not shown).

The metal chassis 54 is connected to the main wiring board 5
Place on the surface of 3a, solder the power supply terminal 52d and the first microstrip line 66, and ground terminal 52e.
And ground electrodes 67a are soldered and surface-mounted.

Further, the multilayer chip capacitor 68 is placed on the surface of the main wiring substrate 53a, and the external electrodes 68a and 68b of the multilayer chip capacitor 68 and the first microstrip line 66 are soldered to be surface-mounted. Further, the power supply section 52 is configured by connecting the transmission output measurement terminal (not shown) of the antenna switch circuit from the power supply terminal 52d to the first microstrip line 66 via the multilayer chip capacitor 68. It

In the present embodiment, the power feeding portion 52 and the radiation portion 56a are provided in contact with each other, but the power feeding portion 52 and the radiation portion 56a may be provided so as to be separated from each other by a space for electromagnetically connecting them. Further, the shape of the power feeding portion 52 is not limited to that shown in FIG. 1, and is provided with at least one power feeding terminal 52d and at least one ground terminal 52e, and electrically or electromagnetically transmits the transmission radio wave output to the radiation portion 56a. I wish I had it. For example, the power supply unit 52 may be formed of a metal block. The positional relationship between the power supply terminal 52d and the ground terminal 52e is not limited to that shown in FIG. 2, and may be formed on the long side of the power supply section 52, for example.

Further, although the microstrip line is used as the transmission line in this embodiment, a coplanar line or the like may be used.

FIG. 3 is a block diagram showing the connection relationship of the antenna device 51b. In FIG. 3, the power feeding portion 52 and the radiation portion 56a that are in contact with each other are electrically connected to each other,
The transmission output from the power feeding unit 52 is radiated by the radiation unit 56a. The transmission output measurement terminal is connected to the power supply unit 52. Here, C1 is the stray capacitance of the radiation part 56a.

The antenna device 51a thus constructed
Provides the power supply unit 52 on the main wiring board 53a, and the radiation unit 56
The power supply unit 52 is provided on the main wiring board 53a by storing and mounting a in the space formed between the main wiring board 53a and the outer case 55 with respect to the outer case 55 housing the main wiring board 53a. After that, the outer case 55 is attached to the main wiring board
The radiation part 56a can be easily separated from the power feeding part 52 by removing it from 3a.

Further, since the transmission output measuring terminal is connected to the power feeding portion 52 via the multilayer chip capacitor 68, the power feeding portion 52 at the transmission output measuring terminal is connected.
The capacitance of the multilayer chip capacitor 68 is added to the transmission output from. As a result, the influence of the inductance of the power feeding unit 52 on the measurement value of the transmission output from the power feeding unit 52 at the transmission output measuring terminal
Since it can be corrected by the capacitance of the multilayer chip capacitor 68 connected to the power supply unit 52,
The transmission output of the antenna switch circuit can be accurately measured by removing the influence of the inductance of the power feeding unit 52.

From the above, the power feeding section 52 is connected to the main wiring board 53a.
Even when the antenna device 51a is installed in the antenna, the transmission output of the antenna switch circuit can be easily and accurately measured in a state in which the radiation section 56a is separated and the antenna device 51a regulated by the Radio Law is removed. Therefore, it is possible to easily check the transmission output level at the time of shipping. Further, the electric or mechanical switch for switching to the transmission output measuring terminal, which has been conventionally required for measuring the transmission output, is unnecessary, so that the cost can be reduced.

FIGS. 4 and 5 show an antenna device 51b and a feeding portion 52z according to a second embodiment of the present invention. It should be noted that parts that are the same as or the same as those in FIGS. 1 and 2 are given the same numbers, and the description thereof is partially omitted. The antenna device 51b is
The mobile phone 61 is in a built-in state, as shown in FIG.
Is a perspective view from an oblique direction, FIG. 4 (B) is a perspective view from the front, FIG. 4 (C) is a perspective view from a lateral direction, and FIG. 5 is a perspective view of the power feeding portion 52z.

4 and 5, the antenna device 51b
Is mounted on the main surface of the main wiring board 53a by the first microstrip line 66a, which is the first transmission line for antenna feeding, and the second transmission line for transmission output measurement. A second microstrip line 6
6b, the feeding part 52z is grounded to the ground electrode 67a, and one main surface of the radiating part 56a is opposed to the feeding part 52z and is in contact with each other.

Here, the first microstrip line 66a and the second microstrip line 66b are
The second microstrip line 66b is formed on the main wiring board 53a, is insulated from the first microstrip line 66a and the ground electrode 67a, and is connected to a transmission output measurement terminal (not shown). There is.

On the other hand, reference numeral 81 is a rectangular parallelepiped dielectric substrate made of ceramic or resin, and a transmission output measuring electrode 82 is formed on one side surface of the dielectric substrate 81 on the long side.
Connection electrodes 83a and 83b are formed on both side surfaces on the short side. Inside the dielectric substrate 81, a first capacitor electrode 85a connected to the connection electrode 83a and a second capacitor electrode 85b connected to the transmission output measurement electrode 82 are provided to form a built-in capacitor 85.

Reference numeral 84 is a metal chassis made of, for example, copper or a copper alloy and having a substantially U-shaped cross section. The power supply terminal 52d and the ground terminal 52e are formed to the thickness of the dielectric substrate 81. Foot 52 including ground terminal 52e
The lengths of b and 52c are set larger than the thickness of the dielectric substrate 81.

Then, the dielectric substrate 81 is inserted into the metal chassis 84, and the side surface of the dielectric substrate 81 on the short side is connected to the power supply terminal 52d and the ground terminal 52 of the metal chassis 84.
While being in contact with the inside of e, between the facing portion 52a of the metal chassis 84 and the surface of the dielectric substrate 81, the power supply terminal 5
2d and the length of the foot portions 52b and 52c including the ground terminal 52e and the thickness of the dielectric substrate 81 cause a space 9
0 is provided, and the connection electrode 83a of the dielectric substrate 81 and the power supply terminal 52d of the metal chassis 84, and the connection electrode 83b of the dielectric substrate 81 and the ground terminal 52e of the metal chassis 84 are joined with solder. Then, the metal chassis 84 in which the dielectric substrate 81 is inserted is placed on the surface of the main wiring substrate 53a,
The power supply terminal 52d and the first microstrip line 66
a, the ground terminal 52e and the ground electrode 67a, the transmission output measuring electrode 82, and the second microstrip line 66b.
Is soldered and surface-mounted to form the power feeding portion 52z.

FIG. 6 is a block diagram showing the connection relationship of the antenna device 51b. The same or equivalent parts as in FIG. 3 are designated by the same reference numerals, and the description thereof is partially omitted. In FIG. 6, the power feeding portion 52z and the radiation portion 56 that are in contact with each other.
a is electrically connected to each other, and the transmission radio wave output from the power feeding unit 52 is radiated by the radiating unit 56a. Further, the transmission output measurement terminal is connected to the power supply unit 52z.

In the power feeding portion 52z thus configured, the power feeding portion 52z is provided on the main wiring board 53a, and the radiation portion 56a is housed in the main wiring board 53a. It is housed in a space formed between them and attached, and instead of the multilayer chip capacitor 68 in the power feeding section 52 of the first embodiment, the power feeding section 52 is used.
By connecting the transmission output measuring terminal to z through the built-in capacitor 85, the same effect as that obtained by the first embodiment described above can be obtained.

Further, in the power feeding portion 52z, the dielectric substrate 81 is inserted inside the metal chassis 84, so that the capacitance of the power feeding portion 52z becomes large, and the resonance frequency of the antenna device 51b can be lowered. it can. In addition, the facing portion 52 a of the metal chassis 84 and the dielectric substrate 8
Since the space 90 is provided between the surfaces of the facing portions 1,
The eddy current in the ground plane caused by the magnetic field generated around the high-frequency current flowing through 2a is suppressed, and the electric field caused by the magnetic field is less likely to concentrate inside the dielectric substrate 81. Therefore, the efficiency of transmitting the transmission output to the radiation unit 56a is further enhanced, and the gain of the antenna device 51b is further enhanced. Further, by forming the built-in capacitor 85 inside the dielectric substrate 81, the power feeding unit 52z
Since the impedance of the power feeding part 52z can be adjusted at the time of designing, when the power feeding part 52z is surface-mounted on the main wiring board 53a,
It is not necessary to select and adjust the capacitance value of the capacitor connected to z. Further, the mounting area of the power supply section 52z on the main wiring board 53a can be reduced.

[0053]

As described above, according to the antenna device of the present invention, the main wiring board and the outer case are provided in contrast to the outer case in which the power feeding portion is provided on the main wiring board and the radiation portion accommodates the main wiring board. The radiation part can be easily separated from the power feeding part by removing the outer case from the main wiring substrate even after the power feeding part is provided on the main wiring substrate because it is housed in the space formed and attached. You can

Further, since the transmission output measuring terminal is connected to the power feeding portion via the multilayer chip capacitor or the built-in capacitor, the transmission output from the power feeding portion at the transmission output measuring terminal is connected to the multilayer chip capacitor. Capacitance is added. As a result, the influence of the inductance of the power feeding unit on the measured value of the transmission output from the power feeding unit at the transmission output measuring terminal can be corrected by the capacitance of the multilayer chip capacitor connected to the power feeding unit. , The transmission output of the antenna circuit,
It is possible to perform accurate measurement excluding the influence of the inductance of the power supply section.

As described above, the transmission output of the antenna circuit can be easily and accurately obtained even after the power feeding portion is provided on the main wiring board, the radiation portion is separated, and the antenna device regulated by the Radio Law is removed. Can be measured. Therefore,
It is also possible to easily check the transmission output level at the time of shipment.

Further, since the electrical or mechanical switch for switching to the transmission output measuring terminal, which has been conventionally required for measuring the transmission output, is unnecessary, the cost can be reduced.

By inserting the dielectric substrate inside the metal chassis in the power feeding section, the capacitance of the power feeding section is increased, and the resonance frequency of the antenna device can be lowered. Further, in the power feeding portion, since a space is provided between the facing portion of the metal chassis and the dielectric substrate,
The eddy current in the ground plane caused by the magnetic field generated around the high-frequency current flowing through the facing portion is suppressed, and the electric field caused by the magnetic field is less likely to concentrate inside the dielectric substrate. Therefore, the efficiency of transmitting the transmission output to the radiating section is further enhanced, and the gain of the antenna device is further enhanced. Furthermore, by forming a built-in capacitor inside the dielectric substrate, the impedance of the power feeding part can be adjusted at the time of designing, so when surface mounting the power feeding part on the main wiring board,
It is not necessary to select and adjust the capacitance value of the capacitor connected to the power supply section. Further, the mounting area of the power supply unit on the main wiring board can be reduced.

[Brief description of drawings]

FIG. 1 is a perspective view of an antenna device according to a first embodiment of the present invention, where (A) is a perspective view from an oblique direction, (B) is a front perspective view, and (C) is a lateral perspective view. It is a figure.

FIG. 2 is a perspective view showing a power feeding portion of the antenna device according to the first embodiment of the present invention.

FIG. 3 is a block diagram showing a connection relationship of the antenna device according to the first embodiment of the present invention.

FIG. 4 is a perspective view of an antenna device according to a second embodiment of the present invention, where (A) is a perspective view from an oblique direction, (B) is a front perspective view, and (C) is a lateral perspective view. It is a figure.

FIG. 5 is a perspective view showing a power feeding portion of the antenna device according to the second embodiment of the present invention.

FIG. 6 is a block diagram showing a connection relationship of an antenna device according to a second embodiment of the present invention.

FIG. 7 is a perspective view of a conventional substrate surface mount antenna.

FIG. 8 is a perspective view of a conventional substrate surface-mount antenna that incorporates an antenna switch circuit.

9 is a cross-sectional view of FIG.

FIG. 10 is a circuit diagram of an antenna switch circuit.

11 is a block diagram of the antenna of FIG.

FIG. 12 is a perspective view of a conventional dielectric loaded monopole antenna.

[Explanation of symbols]

 51a, 51b Antenna device 52, 52z Feeding part 52a Opposing part 53a Main wiring board 54, 84 Metal chassis 55 Exterior case 56a Radiating part 68 Multilayer chip capacitor 81 Dielectric substrate 85 Built-in capacitor 85a First capacitor electrode 85b Second Capacitor electrode 90 space

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kenji Asakura Inventor Kenji Ara 226-10 Tenjin, Nagaokakyo City, Kyoto Murata Manufacturing Co., Ltd.

Claims (5)

[Claims] 1. A power supply unit and a radiation unit which is separate from the power supply unit and separable from each other, and a transmission output measuring terminal is connected to the power supply unit through a capacitor. Antenna device. 2. The power supply unit provided on a main wiring board and an outer case that houses the main wiring board, and the housing is attached by being housed in a space formed between the main wiring board and the outer case. The antenna device according to claim 1, further comprising a radiation part, wherein one main surface of the radiation part faces the power feeding part. 3. The feed unit is connected to a first transmission line for feeding an antenna, which is formed on the main wiring board, and the multilayer chip capacitor and the transmission output measuring terminal are connected to each other.
The antenna device according to claim 1, wherein the antenna device is connected to the first transmission line. 4. The power feeding unit is formed by inserting a dielectric substrate inside a metal chassis, and inside the dielectric substrate, a first capacitor electrode connected to the first transmission line and the main wiring. A second capacitor electrode connected to a second transmission line for measuring a transmission output formed on a substrate is provided to form a built-in capacitor connected to the transmission output measuring terminal. The antenna device according to claim 1 or 2, wherein 5. The antenna device according to claim 4, wherein a space is provided between the metal chassis and the dielectric substrate.