JP3237943B2 - transceiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable telephone, a portable radio transmitter and a receiver used for mobile communication.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No. 4-179302 has been proposed for the purpose of preventing deterioration of characteristics due to leakage of antenna current when touching a housing of a wireless device. According to this technique, a housing 12 covered with a conductor and an antenna 1 fed from a central conductor 5a of a coaxial feed line 5 and a radio device forming a dipole antenna by a ground wire 7 of the antenna 1 as shown in FIG. A super-top is formed between the conductor 1 and the conductor 13 covering the upper surface so as to have a high impedance when viewed from the antenna 1 side, thereby suppressing an antenna current from flowing through the housing.

[0003]

However, the structure in which the housing 12 is covered with a conductor and the upper surface of the housing 12 is covered with a conductor 13 for forming a supertop as in the prior art is not only costly but also costly. However, in contrast to the recent thinner housings, the housings have become larger, and there is a mounting problem. In particular, in the case of transmitting weak power such as a cordless telephone, since the weak power does not affect the internal circuits and the like, it is not necessary to cover the housing with a conductor. This increases the cost and the size of the device.

In order to solve the above-mentioned problems of the prior art, the present invention is directed to a radio device that obtains good sensitivity in a call state by using a supertop, and is particularly used for a radio device that transmits weak power such as a cordless telephone. It is an object of the present invention to provide a suitable low-cost wireless device that can be easily miniaturized.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems of the prior art, the present invention provides a dipole antenna, which is a balanced antenna, in which a super-top is provided between an outer conductor of a coaxial feed line inside a radio equipment housing. This is a radio device in which a conductor is arranged so as to be formed and converted into unbalanced by a formed supertop to break a loop of a high-frequency current.

Specifically, an n / 4 wavelength antenna (n is an odd number) having a feeding point on the center conductor of the coaxial feed line, and an n / 4 wavelength (n is an odd number) connected to the outer conductor of the coaxial feed line ), Wherein the dipole antenna is constituted by the n / 4 wavelength antenna and the ground wire, and the dipole is arranged by arranging the coaxial feeder in a horizontal direction. An antenna is configured in a vertical direction, and an outer conductor of the coaxial feed line is connected to the feed point by n / 4 wavelength (n
Is grounded to a ground conductor on the circuit board at a distance, and one end of a linear conductor having a length of n / 4 wavelength (n is an odd number) is connected to the grounded position. A wireless device in which a supertop is formed with an end parallel to the coaxial power supply line with an end near the power supply point, and a radio device housing that covers the ground wire and the supertop formation portion is made of an insulator.

[0007]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of a wireless device showing one embodiment of the present invention, and includes a quarter-wave antenna 1, a housing 3, a circuit board 4,
The radio is constituted by a coaxial feed line 5, a ground wire 7 having a length of 1/4 wavelength, and a conductor 10 having a length of 1/4 wavelength.

The 波長 wavelength antenna 1 is connected to the center conductor 5 a of the coaxial feed line 5 at the feed point 2. A ground wire 7 having a length of 1/4 wavelength is formed on the circuit board 4 and is connected to the outer conductor 5b of the coaxial feed line 5 at a position 11 near the feed point 2 so that the antenna 1 and the ground wire 7 are connected. And a dipole antenna. The outer conductor 5b of the coaxial feed line 5 is connected to the ground conductor of the circuit board 4 for grounding at a ground point 6 which is 1/4 wavelength away from the feed point 2 and has a length of 1/4 wavelength. It is connected to one end of the conductor 10. This conductor 1
Numeral 0 is arranged in parallel with the coaxial feed line 5 from the grounding point 6 to the vicinity of the feed point 2, and forms a supertop between the conductor 10 and the coaxial feed line 5.

FIG. 2 is a diagram showing the operation principle of FIG.
The impedance between the outer conductor 5b of the coaxial feeder 5 and the conductor 10 in the direction from the vicinity 11 of the ground to the ground point 6 is the conductor 1
Since 0 is grounded to the ground conductor of the circuit board 4 inside the housing 3 at the grounding point 6, the impedance becomes high and a supertop is formed. Therefore, the outer conductor 5 of the coaxial feed line 5
The high frequency current flowing in the direction of arrow 8 flowing outside b
The current efficiently flows through the ground wire 7 having a length of four wavelengths, and becomes a current distribution 9. As a result, the leakage current of the antenna does not flow to the ground conductor of the circuit board 4, preventing deterioration of characteristics when the wireless device housing 3 is touched, reducing unnecessary radiation due to leakage of the antenna current, and improving antenna efficiency. The performance of a mobile phone, a portable wireless transmitter, and a receiver can be improved.

In order to improve the characteristics of the supertop and improve the current distribution 9, at least the conductor 10 and the ground wire 7 cannot be covered with the conductor. For this reason, it is necessary that at least the portion of the housing 3 that is in the vicinity of the ground wire 7 and the supertop formation portion and covers them is made of at least an insulator. Particularly in the case of a wireless device having extremely low transmission power, such as a cordless telephone, even if the housing 3 is made of an insulating material, the transmission power does not adversely affect the circuit inside the board. Good sensitivity can be obtained. Therefore, it is not necessary to further cover the housing 3 with a conductor, which facilitates downsizing and contributes to significant cost reduction.

In the description of the embodiment of the present invention, it is natural that the antenna 1 and the ground wire 7 can be similarly applied even if the wavelength is n / 4 (n is an odd number).
And the length of the conductor 10 are also n / 4 wavelength (n is an odd number)
Can be. Further, the antenna 1 and the ground wire 7 can be miniaturized by being spirally wound.

[0012]

As described above, the present invention is particularly suitable for use in a wireless device for transmitting weak power, such as a cordless telephone, in which a supertop is formed in the housing of the wireless device to reduce the in-phase component of the high-frequency current. Breaking the loop can reduce unnecessary radiation due to antenna current leakage and prevent deterioration of characteristics when touching the wireless device housing, so that good sensitivity can be obtained in a call state and the size of the housing can be easily reduced. This contributes to a large cost reduction.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a wireless device showing one embodiment of the present invention.

FIG. 2 is an operation principle diagram of FIG. 1;

FIG. 3 is a cross-sectional view of a wireless device showing a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Antenna 2 Feeding point 3 Housing 4 Circuit board 5 Coaxial feeding line 5a Center conductor 5b Outer conductor 6 Grounding point 7 Ground wire 8 Arrow 9 Current distribution 10 Conductor of length of n / 4 wavelength (n is an odd number)

Continued on the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01Q 9/16-9/18 H01P 5/10 H04B 1/18-1/58

Claims (1)

(57) [Claims] An n-type coaxial feeder having a feed point at the center conductor thereof.
A / 4 wavelength antenna (n is an odd number), and a ground wire having a length of n / 4 wavelength (n is an odd number) connected to the outer conductor of the coaxial feeder. A wireless device in which a dipole antenna is configured with a ground wire,
The dipole antenna is configured in a vertical direction by arranging the coaxial feed line in a horizontal direction, and an outer conductor of the coaxial feed line is n / 4 wavelength (n is an odd number) away from the feed point on a circuit board. A ground is connected to the ground conductor, and one end of a linear conductor having a length of n / 4 wavelength (n is an odd number) is connected to the ground position. A wireless device, wherein a supertop is formed parallel to an electric wire, and a radio device housing portion covering the ground wire and the supertop formation portion is formed of an insulator.