JPH05304408A - Antenna device of cordless telephone system - Google Patents

Abstract

PURPOSE:To realize an antenna device capable of obtaining excellent gain and sharing two frequencies by combining an incorporated antenna with an external antenna trimmer. CONSTITUTION:The antenna device is provided with an incorporated antenna 13 for sharing two frequencies which is formed by pattern and parts on a substrate 17, a stretchable external antenna 12 and a pipe 18 which is composed of non-conductive material and is for the storage of the external antenna. The antenna device where the degradation of gain at the time of the contraction of the external antenna is reduced and two frequencies are possible to be shared and realized by bringing a conducting part 12a into contact with a contact 12c of the external antenna 12 and connecting the external antenna with the incorporated antenna 13 via a conducting line 21 from a joint part 19 when the external antenna is stretched for a transmission, and by disconnecting this connection and performing a reception only by the incorporated antenna 13 when the external antenna is contracted for a reception of the antenna device baving little deterioration of gain at the time of outer antenna contraction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna device for a cordless telephone device such as a cordless telephone, a mobile telephone, a portable radio communication device or the like.

[0002]

2. Description of the Related Art Conventionally, as a mobile station antenna of a cordless telephone device, there are three methods of construction: a fixed type external antenna, a telescopic type external antenna, and a built-in antenna.
In recent years, portable mobile stations are becoming mainstream, and fixed type external antennas are not so suitable from the viewpoint of portability, usability, and design, and it seems desirable to use telescopic external antennas or built-in antennas. Became.

The structure of a conventional telescopic external antenna is shown in FIG.
Shown in. In FIG. 4, 1 is a mobile station case, 2 is an external antenna, 3 is an antenna housing pipe, 4 is a wireless unit, 5 is a power feeding portion, 6 is an antenna side joint portion, and 7 is a conducting wire. The antenna housing pipe 3 is made of metal and has a length capable of housing the external antenna 2. The antenna housing pipe 3 keeps contact with the external antenna 2 during expansion and contraction, and extends from the antenna side joint 6 to the conducting wire 7
Is connected to the power feeding unit 5 of the wireless unit 4 via.
In general, the performance or gain of the antenna is improved as the height of the antenna, that is, the length from the lower end to the upper end is increased. Therefore, by extending the external antenna 2, the communication distance of radio waves is extended, and when contracted, the communication distance is Shorter but more portable.

FIG. 5 shows a conventional built-in antenna.
The built-in antenna 8 accommodated in the mobile station case 1 has various construction methods such as one using a pattern on a substrate or one in which wires are arranged. As in the case of FIG. 4, the antenna-side joint portion 6 and the power feeding portion 5 of the wireless unit 4 are connected by the conductor wire 7. Although the gain of the external antenna 2 of FIG. 4 cannot be obtained due to the height limitation, it is advantageous in terms of cost.

[0005]

However, the above conventional example has the following problems. First, the telescopic antenna shown in FIG. 4 has a high gain when expanded, but the gain is greatly deteriorated when contracted. At the time of contraction, in addition to the decrease in height gain of the external antenna 2,
Since the conducting wire 7 connecting the power feeding portion 5 and the joint portion 6 is arranged side by side in the opposite direction to the external antenna 2, the phases cancel each other, and the external antenna 2 is placed at a considerably lower portion of the mobile station case 1. Since it is arranged, the influence of holding the set in the hand is large, and the element length of the external antenna 2 seen from the power feeding section 5 is also short, so the impedance matching is deviated, and the total antenna at the time of storage is eventually ended. Performance will be considerably low. In addition, from the point of view of actual use, it is important to extend the communication distance when the antenna is extended, but when contracting and using it there is a call connection etc. when receiving an incoming call, so it is necessary to secure the communication distance to some extent, This is a big problem in the conventional antenna. Further, it is difficult to have a structure that uses two frequencies for transmission and reception because of the structure, and there is a problem in impedance matching because two frequencies are used by single tuning.

On the other hand, in the built-in antenna shown in FIG. 5, the decrease in gain is only a problem in height, and there is no problem in arrangement such as phase or influence when held in the hand, and dual frequency sharing can be easily realized. A better gain is obtained than when the telescopic antenna is contracted. However, compared to when the telescopic external antenna is extended,
The gain becomes more disadvantageous as the degree of shortening of the antenna height with respect to the wavelength increases, and the frequency is lower than the reception frequency.
The gain was low for transmission frequencies with long wavelengths.

[0007] As described above, in the conventional mobile station antenna system that emphasizes portability, if a telescopic external antenna is used with an emphasis on the communication distance, there is a significant deterioration in performance when contracted.
In addition, using the built-in antenna gives better performance than when the retractable antenna is stored, but the maximum communication distance is not as great as when the retractable extension is used because the gain for the transmission frequency is low. It was

The present invention solves such a conventional problem, and provides an excellent antenna device for a cordless telephone device, which makes use of the advantages of a retractable external antenna and a built-in antenna to compensate for the disadvantages. To aim.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides an impedance adjusting coil and a coil.
A built-in antenna having a parallel resonance element for providing frequency resonance characteristics, a base end portion of which is connected to the wireless unit, and an intermediate joint portion between the parallel resonance element and the tip end portion; An expandable external antenna having an external antenna side joint connected to the intermediate joint is provided, and when the external antenna is extended, the conducting portion at the lower end thereof comes into contact with the external antenna side joint and conducts with the internal antenna,
At the time of contraction, the conducting portion at the lower end is separated from the joint portion on the external antenna side so that conduction with the built-in antenna is cut off.

The present invention also has a coil for impedance adjustment and a parallel resonant element for providing a dual-frequency resonant characteristic, wherein the base end is connected to the radio unit and the front end is joined to the external antenna side. When the antenna expands and contracts, the conducting part at the lower end contacts the joint on the external antenna side, and when contracting, the conducting part at the upper end contacts the joint on the external antenna side, and conducts to the internal antennas respectively. Is configured.

The present invention also uses a telescopic external antenna for transmission and a built-in antenna connected when the external antenna expands and contracts, and another dedicated built-in antenna for reception.

[0012]

According to the present invention, with the above structure, when the external antenna is expanded, the built-in antenna and the external antenna are connected with respect to the transmission frequency, and the antenna height can be sufficiently obtained. Obtained,
In addition, for the reception frequency where the degree of gain reduction when the antenna is built-in is small, the built-in antenna works only and the parallel resonance element loaded in the built-in antenna allows the two-frequency resonance characteristics to be taken exactly, so the level is the same as that of the external antenna. The gain of is obtained. Further, when the external antenna contracts, both the transmission and reception switch to the operation of the built-in antenna, and as described above, a better gain can be obtained than when the conventional telescopic antenna contracts. That is, the same communication distance as that of the external antenna can be obtained, and even when the antenna is contracted and used, the gain does not decrease so much. Further, in terms of cost, the conventional external antenna has a complicated structure such as a helical structure for the antenna element in order to obtain tuning. However, the external antenna used in the present invention only obtains the height, so it is a simple rod. It does not matter if it is an upper conductor, and since the built-in antenna can be composed of a board and a number of parts, it does not cost much.

Further, according to the present invention, when the connection with the built-in antenna is maintained when the external antenna contracts, the external antenna functions as a tip portion of the built-in antenna when contracted, so that the size of the built-in antenna can be reduced. Further, it is more advantageous in terms of downsizing and cost of the mobile station.
In this case, the gain at the time of contraction is disadvantageous because the direction of the tip is reversed compared to the method of disconnecting the connection, but the position of the connection is higher than that of the conventional telescopic antenna, and phase cancellation This is advantageous because it is reduced and the impedance is less likely to shift.

Further, according to the present invention, when the antenna is divided into a transmitter and a receiver, two built-in antennas are required. However, the antenna duplexer of the radio unit and the parallel resonant element of the built-in antenna can be omitted. The circuit configuration can be simplified.

[0015]

Embodiments of the present invention will be described below.
FIG. 1 shows the configuration of the first embodiment of the present invention.
In FIG. 1, 11 is a mobile station case, 12 is an external antenna, 13 is a built-in antenna, 14a to 14c are coils, 1
Reference numeral 5 is a parallel resonant element, 16a and 16b are patterns for built-in antennas, 17 is a board for built-in antennas, 18 is a pipe for housing an external antenna, 19 is a joint part on the external antenna side, 20 is a middle joint part of the built-in antenna, and 21 is a built-in antenna. Reference numeral 22 is a wireless unit, and 23 is a power feeding unit, which joins 13 and the external antenna 12. 24 is a built-in antenna joint,
Reference numeral 25 is a conducting wire connecting the power feeding portion 23 and the built-in antenna joint portion 24.

The external antenna 12 has a hatched portion 12 at its lower end, as shown in an enlarged view in FIG. 1 (b).
a is a conducting portion, and the portion other than the conducting portion 12a is covered with a non-conductive material. Reference numeral 12b is a conductive cylindrical guide member that slidably holds the external antenna 12, and has a contactor 12c elastically contacting the external antenna 12 on the inner peripheral surface and a conductor 21 connected to the outer peripheral surface. The antenna side joint portion 19 is provided. External antenna 12
Is extended, the conducting portion 12a at the lower end of the
2c, and is connected to the built-in antenna 13 through the cylindrical guide member 12b, the external antenna joint portion 19, and the conductor 21. Further, when the external antenna 12 is contracted and housed in the external antenna housing pipe 18, the contact between the conducting portion 12a and the contact 12c is cut off, and the connection between the conductor 21 and the built-in circuit 13 at the end is cut off. Be done. The pipe 18 for housing the external antenna is formed of a non-conductive material such as vinyl chloride so as to have a bottom, and the upper portion thereof is fitted into the lower portion of the cylindrical guide member 12b. Such an external antenna 12
The structure of the cylindrical guide member 12b has a conductor 21 fixed to the upper portion of the mobile station case 11 as compared with the conventional example shown in FIG.
Since the antenna characteristics are not changed when the external antenna 12 is extended or accommodated in the pipe 18,
When the external antenna 12 is extended, the external antenna 1
Even if rainwater enters through the space between the cylindrical guide member 12b and the cylindrical guide member 12b, the inside of the mobile station 11 is not wet because the pipe 18 has a bottom.

Next, the operation of the first embodiment will be described. First, with respect to the reception frequency, the parallel resonance element 15 has a characteristic that it has an anti-resonance point at the reception frequency, so that the entire length acts as an antenna cut at this portion, and the length of the pattern 16a up to this point is By adjusting the element value of the coil 14a, impedance matching can be performed and tuning can be performed for reception. Next, with respect to the transmission frequency, the parallel resonant element 15 becomes equivalent to the coil 14a, operates as an antenna from the feeding portion 23 through the built-in antenna 13 and the conductor 21 to the external antenna 12 when expanded, and when contracted, Conducting part 12a of the external antenna 12
The external antenna 12 is separated from the built-in antenna 13 because the contact between the contact 12c and the contact 12c is cut off, so that the entire surface of the built-in antenna 13 functions as an antenna. External antenna 12
Is set to a length at which the required gain is obtained, and impedance matching is achieved by adjusting the element value of the coil 14b. Further, by adjusting the values of the pattern 16b of the built-in antenna 13 and the elements of the coil 14c, impedance matching during contraction is achieved.

FIG. 2 shows a second embodiment of the present invention. The difference between this embodiment and the first embodiment is that the built-in antenna 13 does not have the pattern 16b and the external antenna 12 has a pattern. Since the conducting portion 12d is also provided at the upper end portion and the other portions are the same as those in the first embodiment, duplicate description of the configuration will be omitted.

Next, the operation of the second embodiment will be described. First, with respect to the reception frequency, the same operation as in the first embodiment is performed. Further, with respect to the transmission frequency, the same operation as that of the first embodiment is performed at the time of extension, but at the time of contraction, the conductive portion 12d at the upper end portion is formed by the contact 12c and the guide member 1.
By connecting to the external antenna side joint portion 19 via 2b, the internal antenna 13 and the external antenna 12 are connected to each other inside the mobile station case 11 via the conductor 21, and the internal antenna in the first embodiment is incorporated. The pattern 16b of the antenna 13 is unnecessary. In this embodiment, even when the external antenna 12 contracts, the portion from the upper end to the lower end of the external antenna 12 functions as the tip of the built-in antenna 13. Therefore, the element length is secured, impedance matching is achieved, and the built-in antenna is 13 can be miniaturized. In the intermediate state of expansion and contraction of the external antenna 12, since the diameter of the intermediate portion of the external antenna 12 is smaller than the diameter of the upper and lower conducting portions 12a and 12d, the intermediate portion should contact the contactor 12c. Therefore, since the external antenna 12 and the internal antenna 13 are not held in a disconnected state, impedance matching can be ensured. As another means, the external antenna 12 is attached to the external antenna storage pipe 18.
The same effect can be obtained by providing a conductor portion having a half length.

FIG. 3 shows a third embodiment of the present invention. In this embodiment, the internal antenna is divided into an internal antenna 13a for transmission and an internal antenna 13b for reception. Accordingly, the power supply section of the wireless unit 22 is 2
It is divided into 3a and 23b, and the joining portion 24a of the internal transmitting antenna 13a and the power feeding portion 23a are connected by a conducting wire 25a, and the joining portion 24b of the internal receiving antenna 13b and a feeding portion 23b are connected by a conducting wire 25b. .. The transmitting internal antenna 13a includes two patterns 26a and 26b connected via a coil 14a, and a built-in antenna substrate 27a.
It is provided above, and the built-in receiving antenna 13b is
Two patterns 26 connected via the coil 14b
c and 26d are provided on the built-in antenna substrate 27d.

Next, the operation of the third embodiment will be described. In this embodiment, since the radio system and the antenna are separated for transmission and reception, the antenna duplexer in the radio unit 22 and the parallel resonant element on the built-in antenna are unnecessary.
First, with respect to the reception frequency, the built-in antenna 13b functions as an independent antenna, and tuning is performed by the lengths of the patterns 26c and 26d and the element value of the coil 14b. With respect to the transmission frequency, it functions as an antenna in which the built-in antenna 13a and the external antenna 12 are connected, and when the external antenna 12 is extended as in the second embodiment, the conducting portion 12a and the external antenna side joint portion 19 are connected. , When it contracts again, the conductive part 12d
And the internal antenna 1 at the external antenna side joint 19 respectively.
3a, and tuning is performed by the lengths of the patterns 26a and 26d, the element value of the coil 14a, and the length of the external antenna 12. As another means, the built-in transmitting antenna substrate 2
It is also possible to increase the pattern to 7a for synchronization.

[0022]

As described above, according to the present invention, when the external antenna is extended, the same performance as when the conventional telescopic antenna is extended can be obtained, and the improvement of the transmission gain, which is a problem with the conventional built-in antenna, can be improved. Can be planned. Further, when the external antenna contracts, the same performance as that of the conventional built-in antenna is obtained, and it is possible to suppress a significant performance deterioration at the time of storage, which is a problem with the conventional telescopic antenna.

In addition to the above effects, by adopting a structure in which the external antenna is connected to the built-in antenna at the upper end even when the external antenna contracts, the external antenna can be operated as the tip portion of the built-in antenna when contracted. Since the size can be reduced, it is advantageous for downsizing the set.

In addition to the above effects, the transmission and the reception are separated, the transmission is performed by a combination of the built-in antenna and the external antenna, and the reception is operated by the built-in antenna. It is possible to reduce the number of circuit components such as the above parallel resonant element.

[Brief description of drawings]

FIG. 1A is a schematic configuration diagram of a first embodiment of the present invention. FIG. 1B is an enlarged sectional view of an external antenna when it is extended in the first embodiment.

FIG. 2A is a schematic configuration diagram of the second embodiment of the present invention. FIG. 2B is an enlarged cross-sectional view of the external antenna when the external antenna is contracted in the second embodiment.

FIG. 3 is a schematic configuration diagram of a third embodiment of the present invention.

FIG. 4 is a schematic configuration diagram of a conventional telescopic external antenna.

FIG. 5 is a schematic configuration diagram of a conventional built-in antenna.

[Explanation of symbols]

 11 Mobile Station Case 12 External Antenna 13 Built-in Antenna 14 Coil 15 Parallel Resonance Element 16 Built-in Antenna Pattern 17 Built-in Antenna Substrate 18 External Antenna Storage Pipe 19 External Antenna Side Joint 20 Built-in Antenna Intermediate Joint 21 Conductive Wire 22 Radio Unit 23 Feeding unit 24 Built-in antenna junction 25 Conductor 26 Built-in antenna pattern 27 Built-in antenna substrate

Claims (3)

[Claims] 1. A coil for impedance adjustment and 2
A built-in antenna having a parallel resonant element for imparting frequency resonance characteristics, a base end portion of which is connected to the wireless unit, and an intermediate junction between the parallel resonant element and the tip portion; It has an external antenna side joint part connected to the intermediate joint part, and the conducting part at the lower end contacts the external antenna side joint part when conducting, and conducts with the built-in antenna. An antenna device of a cordless telephone device, comprising: a retractable external antenna, which is separated from a joint portion on the external antenna side and is disconnected from the built-in antenna. 2. A coil for impedance adjustment and 2
It has a parallel resonant element for providing frequency resonance characteristics, the base end is connected to the wireless unit, and the tip is connected to the joint on the external antenna side. Of the cordless telephone device having a telescopic external antenna that is in contact with the external antenna-side joint portion and the conducting portion of the upper end portion is in contact with the external antenna-side joint portion when contracted, and is electrically connected to the built-in antenna. Antenna device. 3. An antenna device for a cordless telephone device, which has a telescopic external antenna for transmission and a built-in antenna connected when the external antenna is extended, and has another dedicated built-in antenna for reception.