JPH114113A - Surface mount antenna and communication apparatus using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a bond wide and to use plural frequencies without enlarging the dimensions by forming each end of plural power feeding electrodes to the opening ends of radiation electrodes through gaps, gathering the other ends of the plural power feeding electrodes into one and connecting it to a connection electrode. SOLUTION: A ground electrode 3 is formed on one main face of a base 2 in a rectangular parallelopiped form and the two strips of radiation electrodes 4 and 5 approximately the λ/4 length on the other main face. The radiation electrodes 4 and 5 are bent in a miandaing form and each end forms the opening end and the other end is connected to the ground electrode 3 through one end face of the base 2. Each end of the feeding electrodes 6 and 7 is formed with each end of the radiation electrodes 4 and 5 through the gaps g1 and g2 and the other end is connected to the connection electrode 8 at the other end face facing one end face of the base 2. They are connected to the connection electrode 8. The radiation electrode 4 is formed slightly longer than the radiation electrode 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface-mounted antenna and a communication device using the same, and more particularly, to a surface-mounted antenna used for a mobile communication device such as a portable telephone supporting a wide frequency band and a plurality of frequencies. It relates to a communication device using the same.

[0002]

2. Description of the Related Art Generally, when broadening an antenna,
The radiation resistance of the antenna was reduced, and the width of the radiation electrode was increased. When it is desired to handle signals of a plurality of frequencies, a plurality of antennas are used.

[0003]

However, if the width of the radiating electrode is increased in order to maintain the antenna gain by widening the band, the size of the antenna becomes large, and there is a limit to miniaturization. Further, in order to use a plurality of antennas, the area required for mounting the antenna on the mounting board becomes large, which hinders downsizing of a communication device on which the antenna is mounted.

Accordingly, an object of the present invention is to provide a surface mount antenna capable of achieving a wider band and a plurality of frequencies without increasing the size, and a communication device using the same.

[0005]

In order to solve the above-mentioned problems, a surface-mounted antenna according to the present invention comprises a rectangular parallelepiped base made of an insulator, a ground electrode formed on one principal surface of the base, A surface-mounted antenna in which a plurality of strip-shaped radiation electrodes are formed on at least the other main surface, and one end of each of the plurality of radiation electrodes forms an open end on the other main surface or any end surface of the base. The other end is connected to the ground electrode, and one end of each of the plurality of feed electrodes is formed at one end of each of the plurality of radiation electrodes via a gap, and the other end of each of the plurality of feed electrodes is one of the bases. Characterized by being connected to the coupling electrode formed on the surface.

The surface-mounted antenna according to the present invention is characterized in that a rectangular parallelepiped base made of an insulator is provided with a plurality of ground electrodes and a strip-shaped substrate on at least one of one main surface, the other main surface and four end surfaces. A plurality of radiation electrodes are formed, wherein one end of each of the plurality of radiation electrodes forms an open end, the other end is connected to each of the plurality of ground electrodes, and the plurality of radiation electrodes Forming one end of a plurality of power supply electrodes via a gap at one end thereof,
The other ends of the plurality of power supply electrodes are connected to coupling electrodes formed on any surface of the base.

The surface mount antenna according to the present invention is characterized in that ground electrodes are formed close to the open ends of the plurality of radiation electrodes via gaps.

In the surface mount antenna according to the present invention, the plurality of radiation electrodes have different resonance frequencies from each other.

A communication device according to the present invention is characterized in that the above-mentioned surface mount antenna is mounted.

With this configuration, according to the surface mount antenna of the present invention, it is possible to form an antenna that can be used at a plurality of frequencies or to form a broadband antenna by adding frequency bands. it can. Also,
The degree of freedom in the layout of the radiation electrodes is increased, and mutual interference between the radiation electrodes can be reduced.

Further, in the communication device of the present invention, miniaturization and improvement of characteristics can be achieved.

[0012]

FIG. 1 shows an embodiment of a surface mount antenna according to the present invention. In FIG. 1, a surface-mounted antenna 1 includes a rectangular parallelepiped base 2 made of a dielectric such as ceramics or resin, which is one of insulators, a ground electrode 3 formed on one main surface of the base 2, and a base 2. And two radiating electrodes 4 and 5 having a length of approximately λ / 4, two feeding electrodes 6 and 7 and a coupling electrode 8 which are formed on the other main surface of the. Among these, the radiation electrodes 4 and 5 are bent in a meandering shape, one end of which forms an open end, and the other end is connected to the ground electrode 3 via one end surface of the base 2. One end of each of the feeding electrodes 6 and 7 is connected to one end of each of the radiation electrodes 4 and 5 and the gaps g1 and g, respectively.
2, and the other end is connected to the coupling electrode 8 at another end face facing one end face of the base 2. Further, the radiation electrode 4 is formed slightly longer than the radiation electrode 5. Reference numeral 9 denotes a fixed electrode, which is soldered to an electrode on the substrate when the surface mount antenna 1 is mounted on the substrate.

FIG. 2 shows an electrical equivalent circuit of this embodiment.
In FIG. 2, an equivalent circuit of the surface-mount antenna 1 has inductors L1 and L2, which are self-inductances of the radiation electrodes 4 and 5, and a resistance as a resistance when the energy radiated from the radiation electrodes 4 and 5 is replaced by a loss due to resistance. Capacitor C1 which is a capacitance formed between the resistances R1 and R2 and the radiation electrodes 4 and 5 and the ground electrode 2.
And C2, capacitors C3 and C4 which are capacitances formed between one ends of the radiation electrodes 4 and 5 and one ends of the feed electrodes 6 and 7, and a signal input terminal p1. The inductor L1 and the resistor R1 are connected in series, a capacitor C1 is connected in parallel to the inductor L1, and one end is grounded, and the other end is connected to the signal input terminal p1 via the capacitor C3. Further, the inductor L2 and the resistor R2 are connected in series, a capacitor C2 is connected in parallel with the inductor L2 and one end thereof is grounded, and the other end is connected to the capacitor C2.
4 is also connected to the signal input terminal p1.

Next, the operation of the surface mount antenna 1 will be described with reference to the equivalent circuit shown in FIG. The surface-mounted antenna 1 has two resonance circuits, one of which is mainly an inductor L1,
It comprises a resistor R1 and a capacitor C1, and the other mainly comprises an inductor L2, a resistor R2 and a capacitor C2. The resonance frequencies of the two resonance circuits are different.

When a signal is input from the signal input terminal p1 to each of the resonance circuits via the capacitors C3 and C4, one or both of the resonance circuits resonate in accordance with the frequency of the signal, and a part of the energy is regenerated. Is radiated into the air and functions as an antenna. This radiated energy is represented as energy consumed by the resistors R1 and R2 in an equivalent circuit.

FIG. 3 and FIG. 4 show the reflection characteristics of the surface mount antenna of the present embodiment. FIG. 3 shows a case where the difference between the resonance frequencies of the two resonance circuits is large and there is no overlap between them.
Shows a case where the difference between the resonance frequencies of the two resonance circuits is small and there is mutual overlap. Thus, when the difference between the resonance frequencies is large as shown in FIG. 3, the antenna operates as an antenna corresponding to two different frequencies, and when the difference between the resonance frequencies is small as shown in FIG. Works as a wide antenna.

As described above, by providing two resonance circuits having different resonance frequencies on one base to function as an antenna having two frequencies, or by reducing the difference between the resonance frequencies of the two resonance circuits. It is also possible to extend the frequency band of the antenna. By providing the feed electrodes 6 and 7 for the two radiating electrodes 4 and 5, respectively, the degree of freedom of the layout of the radiating electrodes is increased, and the connection between the two feeding electrodes 6 and 7 and the radiating electrodes 4 and 5 is increased. Since the capacitance between the two radiation electrodes 4 and 5 is sufficiently larger than the capacitance between the two radiation electrodes 4 and 5, mutual interference between the two radiation electrodes 4 and 5 can also be suppressed. Furthermore,
By changing the shape and arrangement of the radiation electrodes 4 and 5, the directivity pattern of the antenna can be changed. By forming two radiation electrodes on one base, it is possible to reduce the size and to reduce the mounting cost as compared with the case where two antennas are used.

FIG. 5 shows another embodiment of the surface mount antenna of the present invention. In FIG. 5, the same or equivalent parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. In the surface-mounted antenna 10 shown in FIG. 5, two radiating electrodes 11 and 12 having a strip-like length λ / 4 approximation are formed from the other main surface of the base 2 to one end surface, and one end of the radiating electrode 11 is An open end is formed at the end face, and the other end is connected to the ground electrode 3 via another opposing end face.
In addition, on the end face where the open ends of the radiation electrodes 11 and 12 are formed, one end of each of the radiation electrodes 11 and 12 is connected to two power supply electrodes 13 via gaps g3 and g4, respectively.
And 14 are formed at one end, and the other end is connected to the coupling electrode 8 at the same end face. Further, the radiation electrode 11 is formed slightly longer than the radiation electrode 12.

In FIG. 5, the radiation electrodes 11 and 12
Is different from the embodiment of FIG. 1 only in that one end of the substrate 2 and the power supply electrodes 13 and 14 are formed on one end face instead of the other main surface of the base 2, but are equivalent in terms of an equivalent circuit. 1
It functions in the same way as the embodiment of the present invention and exhibits the same operation and effect.

FIG. 6 shows still another embodiment of the surface mount antenna according to the present invention. 6, the same or equivalent parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. FIG.
In the surface-mounted antenna 20 shown in FIG. 2, two radiation electrodes 21 and 22 having a strip-like length λ / 4 approximation.
Is formed on the other main surface of the base 2, one end of which forms an open end on the same other main surface, and the other end is connected to the ground electrode 3 via two opposing end surfaces. Further, on the other main surface of the base 2, the radiation electrode 21
And 22 and one end of two power supply electrodes 23 and 24 are formed via gaps g5 and g6, respectively, and the other end is connected to the coupling electrode 8 at an adjacent end face.
It is connected to the. Further, the radiation electrode 21 is the radiation electrode 2
It is formed slightly longer than 2.

In FIG. 6, the radiation electrodes 21 and 22 are shown.
Is different from the embodiment of FIG. 1 only in that the other end is connected not to the same end face of the base 2 but to the ground electrode 3 via two end faces opposed to each other, but equivalent to an equivalent circuit. , Functioning in the same way and exhibiting the same operation and effect.

FIG. 7 shows still another embodiment of the surface mount antenna of the present invention. 7, the same or equivalent parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. In FIG. 7, the surface-mounted antenna 30 includes a rectangular parallelepiped base 2, ground electrodes 31 and 32 provided on one end face of the base 2, and two strip-shaped radiations formed on the other main surface of the base 2. It is composed of electrodes 33 and 34, two feeding electrodes 35 and 36, and a coupling electrode 8. Among them, the radiation electrodes 33 and 34 are formed in a U shape, one end of which forms an open end, and the other end is connected to the ground electrodes 31 and 32, respectively. In addition, the power supply electrode 35
And 36 are formed on the other main surface of the base 2 with the ends of the radiation electrodes 33 and 34 via gaps g7 and g8, respectively, and the other end is formed on one end surface adjacent to the other main surface of the base 2, Both are connected to the coupling electrode 8. Further, the radiation electrode 33 is formed slightly longer than the radiation electrode 34. Reference numeral 37 denotes a fixed electrode, which is soldered to an electrode on the substrate when the surface mount antenna 30 is mounted on the substrate.

The electric equivalent circuit of this embodiment is composed of the radiation electrodes 4 and 5 formed on the other main surface of the base 2 and the ground electrode 3 formed on one main surface of the base 2 in the embodiment of FIG.
Capacitors C1 and C2, which represent capacitances between the first and second substrates, are radiating electrodes 33 and 34 formed on the other main surface of the base 2 and ground electrodes 31 and 32 formed on one end surface of the base 2, and a surface mount type. 2 is the same as the equivalent circuit of FIG. 2 except that the capacitance is replaced by a capacitance between the antenna 30 and the ground electrode formed on the substrate on which the antenna 30 is mounted. Is shown.

FIG. 8 shows still another embodiment of the surface mount antenna according to the present invention. In FIG. 8, the same or equivalent parts as those in FIG. 7 are denoted by the same reference numerals, and description thereof will be omitted. FIG.
In the surface-mounted antenna 40 shown in FIG. 1, the two strip-shaped radiation electrodes 41 and 42 are formed in a U-shape from one end surface of the base 2 to the other main surface, another end surface, and the other main surface. Has an open end on one end face, and the other end is connected to ground electrodes 31 and 32 on the same end face. Further, on one end face of the base 2, one ends of the radiation electrodes 41 and 42 and one ends of the feed electrodes 43 and 44 are formed via gaps g9 and g10, respectively, and the other ends are connected to the coupling electrode 8 together on the same end face. Have been. Further, the radiation electrode 4
1 is formed slightly longer than the radiation electrode 42. In addition,
Reference numeral 45 denotes a fixed electrode, which is connected to the radiation electrodes 41 and 42 at one end face, and is soldered to an electrode on the substrate when the surface mount antenna 40 is mounted on the substrate.

In FIG. 8, the radiation electrodes 41 and 42
Is different from the embodiment of FIG. 7 only in that the first main surface is formed over two end surfaces facing each other and the one end and the power supply electrodes 43 and 44 are formed on one end surface.
It is equivalent in terms of an equivalent circuit, functions in the same manner as the embodiment of FIG. 7, and shows the same operation and effect.

FIG. 9 shows still another embodiment of the surface mount antenna according to the present invention. In FIG. 9, the same or equivalent parts as those in FIG. 7 are denoted by the same reference numerals, and description thereof will be omitted. FIG.
In the surface-mounted antenna 50 shown in FIG. 2, the two strip-shaped radiation electrodes 51 and 52 are formed in a U-shape from one end face of the base 2 to the other main face, and one end thereof forms an open end on one end face. The other end is connected to the ground electrodes 31 and 32 on the same end surface.
On the end surfaces of the radiation electrodes 51 and 52 where the open ends are formed, ground electrodes 53 and 54 are formed at the open ends of the radiation electrodes 51 and 52 via gaps g13 and g14, respectively. Further, gaps g11 and g1 are provided at one end of the same radiation electrodes 51 and 52, respectively.
One end of each of the two power supply electrodes 55 and 56 is formed adjacent to each other via the second electrode 2, and the other end is connected to the coupling electrode 8 at an adjacent end face. Further, the radiation electrode 51
Are formed slightly longer than the radiation electrode 52.

In FIG. 9, radiation electrodes 51 and 52 are shown.
Is formed over the other main surface and one end surface, ground electrodes 53 and 54 are formed at the open ends via gaps g13 and g14, and feed electrodes 55 and 56 are adjacent to one ends of radiation electrodes 51 and 52, respectively. It differs from the embodiment of FIG. 7 in that it is formed. In terms of an equivalent circuit, the capacitance between the feed electrodes 55 and 56 and the radiation electrodes 51 and 52 corresponds to c3 and C4 in FIG.
2 and the capacitance between the open ends of the ground electrodes 53 and 54 are added to the equivalent circuit of FIG.
In order to enter in parallel with the capacitors C1 and C2, which have a capacity between 1 and 32, the capacitors can be absorbed and combined into the capacitors C1 and C2, and finally the same as the equivalent circuit of FIG. it can. Therefore, it functions in the same manner as the embodiment of FIG. 7 and shows the same operation and effect.

In each of the above embodiments, the length of one radiating electrode is formed longer than the length of the other radiating electrode, but this may be reversed. Further, although the number of the radiation electrodes is two, the number is not limited to two, and three or more radiation electrodes may be provided. Also, it is assumed that the lengths of the two radiating electrodes are slightly different. However, if the resonance frequencies of the two resonance circuits are different from each other, the length of the gap between the radiating electrode and the feeding electrode is different. The shape may be different. Although the meandering or U-shaped radiating electrode is employed, the same operation and effect can be obtained even if the radiating electrode is formed in another shape such as a linear shape or an L-shaped shape. Further, although a dielectric is used as an insulator constituting the base, a magnetic material may be used.

FIG. 10 shows an embodiment of the communication device of the present invention. In FIG. 10, a communication device 60 includes a mounting board 62 provided in a housing 61, and the mounting board 62 has a ground electrode 6.
3 and a power supply electrode 64 are formed. Mounting board 62
The surface mount antenna 1 of the present invention is mounted on the end of the antenna. The coupling electrode and the ground electrode (not shown) of the surface mount antenna 1 are connected to the feed electrode 64 and the ground electrode 63 of the mounting board 62, respectively. Further, the power supply electrode 64 is connected to a transmission circuit 66 and a reception circuit 67 similarly formed on the mounting board 62 via a switching circuit 65 formed on the mounting board 62.

As described above, by mounting the surface mount antenna 1 of the present invention at the end of the mounting board 62, two antenna functions are realized by one antenna, and the size and cost of the communication device 60 can be reduced. Can be planned. At the same time, it is possible to improve characteristics such as broadening the frequency band of the communication device 60.

In the embodiment shown in FIG. 10, the communication device 60 is configured by mounting the surface mount antenna 1;
To the surface mount antennas 10, 20, 3 shown in FIG.
Even if a communication device is configured by mounting 0, 40 or 50, the same operation and effect can be obtained.

[0032]

According to the surface mount antenna of the present invention,
At the open end of the radiation electrode, one end of each of a plurality of power supply electrodes is formed with a gap therebetween, and the other ends of the plurality of power supply electrodes are collectively connected to a coupling electrode, thereby achieving a small size and a plurality of frequencies. To form an antenna that can be used with
A broadband antenna can be formed by adding frequency bands. Further, the degree of freedom of the layout of the radiation electrodes is increased, and mutual interference between the radiation electrodes can be reduced. Further, the antenna can be downsized and the mounting cost can be reduced.

Further, according to the communication device of the present invention, by mounting and configuring the surface mount antenna of the present invention, it is possible to reduce the size, reduce the cost, and improve the characteristics.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a surface mount antenna according to the present invention.

FIG. 2 is a circuit diagram showing an equivalent circuit of the surface mount antenna of FIG.

FIG. 3 is a diagram showing reflection characteristics of the surface-mount antenna of FIG. 1;

FIG. 4 is another diagram showing the reflection characteristics of the surface mount antenna of FIG. 1;

FIG. 5 is a perspective view showing another embodiment of the surface mount antenna according to the present invention.

FIG. 6 is a perspective view showing still another embodiment of the surface mount antenna according to the present invention.

FIG. 7 is a perspective view showing still another embodiment of the surface mount antenna according to the present invention.

FIG. 8 is a perspective view showing still another embodiment of the surface mount antenna according to the present invention.

FIG. 9 is a perspective view showing still another embodiment of the surface mount antenna according to the present invention.

FIG. 10 is a perspective view showing an embodiment of the communication device of the present invention.

[Explanation of symbols]

1, 10, 20, 30, 40, 50: surface mount antenna 2: base 3, 31, 32: ground electrode 4, 5, 11, 12, 21, 22, 33, 34, 41,
42, 51, 52 ... radiation electrodes 6, 7, 13, 14, 23, 24, 35, 36, 43,
44, 55, 56: feeding electrode 8: coupling electrode g1, g2, g3, g4, g5, g6, g7, g8, g
9, g10, g11, g12 ... gap 60 ... communication equipment

Claims (5)

[Claims] 1. A surface-mounted antenna in which a ground electrode is formed on one main surface of a rectangular parallelepiped base made of an insulator, and a plurality of strip-shaped radiation electrodes are formed on at least the other main surface of the base. One end of each of the plurality of radiation electrodes forms an open end on the other main surface or any end surface of the base, and the other end is connected to the ground electrode, respectively. A surface-mounted antenna, wherein one end of a plurality of feed electrodes is formed via a gap, and the other end of the plurality of feed electrodes is connected to a coupling electrode formed on any surface of the base. . 2. A rectangular parallelepiped base made of an insulator, which is provided on at least one surface of one main surface, the other main surface, and four end surfaces.
A plurality of ground electrodes and a surface-mounted antenna on which a plurality of strip-shaped radiation electrodes are formed, wherein one ends of the plurality of radiation electrodes form open ends, respectively.
The other end is connected to each of the plurality of ground electrodes, one end of each of the plurality of feed electrodes is formed at one end of the plurality of radiation electrodes via a gap, and the other end of each of the plurality of feed electrodes is one of the bases. A surface-mounted antenna connected to a coupling electrode formed on a surface of the antenna. 3. The surface mount antenna according to claim 1, wherein a ground electrode is formed close to each of the open ends of the plurality of radiation electrodes via a gap. 4. The surface mount antenna according to claim 1, wherein the plurality of radiation electrodes have different resonance frequencies from each other. 5. A communication device comprising the surface-mounted antenna according to claim 1.