JP2003032013A - Directional coupler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a directional coupler that is configured to have a high directivity of 20 dB or more while eliminating the need for manual adjustment. SOLUTION: The directional coupler is configured to couple a coupling line formed on a base with a coaxial line in terms of high frequencies. A delay line whose length can be adjusted through trimming is also formed on the board, two paths extract an input signal from the opposite side, the signal on the one path is delayed on the delay line to bring the phase of the one signal into an opposite phase to the opposite signal so as to weaken the two signals, thereby configuring the directional coupler having the directivity improved by 20 dB or more to attain the purpose above.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a directional coupler used in a mobile communication base station.

[0002]

2. Description of the Related Art A conventional directional coupler has a structure in which a window is opened in an outer conductor of a coaxial line and a central conductor of a sub-coaxial line which is a coupling line is formed into a loop shape to be coupled to the coaxial line at a high frequency. Was there.

[0003]

However, the directions of the currents induced by the magnetic fields in the three-dimensionally formed loop-shaped coupling line are opposite to each other depending on the signal input from the forward direction and the signal input from the reverse direction. Since the directionality is secured by utilizing the direction, the characteristics of the loop are likely to deteriorate due to the error in the position and shape of the loop, and a base station for mobile communication that requires a high directionality of 20 dB or more. There is a problem that it is necessary to manually adjust the loop position and the shape in order to use it for facing.

SUMMARY OF THE INVENTION The present invention is intended to solve the above-mentioned conventional problems, and an object of the present invention is to construct a directional coupler having a high directional property having a directional property of 20 decibels or more, which does not require manual adjustment. is there.

[0005]

In order to achieve the above object, the present invention secures a high directivity of 20 decibels or more by forming a coupling line in a plane on a substrate and using a delay line. .

By arranging the coupling line and the delay line in a plane on the substrate, it is possible to reduce the error in the position and the dimension in the structure as compared with the three-dimensional structure. Since the directionality is secured by using the delay line, the directionality can be adjusted by trimming the delay line length, and the adjustment can be automated.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present invention is a coaxial line comprising a central conductor and an outer conductor, and a window portion provided along the central conductor in a plane portion of the coaxial line, A coupling line substrate provided so as to cover the window portion, and a coupling line substrate which is provided at a position facing the window portion of the coupling line substrate and is coupled to the coaxial line through the window portion in a high frequency manner. Both sides of the coupling line provided, a delay line connected to the coupling line via at least two through holes on the coupling line substrate on the opposite side to which the coupling line is provided, At least one of the through holes and the central conductor thereof are connected to the ground portion which is electrically connected to the ground portion of the coupling line substrate. A directional coupler comprising a coaxial line for out has the effect that constitutes an unnecessary direction highly directional coupler manual adjustment.

According to a second aspect of the present invention, the length of the coupling line is set to approximately 1 / 4λ and the length of the window portion is set to be longer than that. The directional coupler has a small size and does not require manual adjustment.

The invention according to claim 3 of the present invention is the directional coupler according to claim 1, wherein the window portion is formed so as to intersect the central conductor at a predetermined angle.
It has the effect of constructing a directional coupler with high directivity that does not require manual adjustment.

The invention according to claim 4 of the present invention is characterized in that the length of the coupled line is made shorter than 1 / 4λ by increasing the permittivity of the substrate for the coupled line.
The directional coupler described has an effect of configuring a directional coupler with high directivity that does not require manual adjustment in a small size.

The invention according to claim 5 of the present invention is the directional coupler according to claim 1, characterized in that the coupling line is provided separately on the coupling line substrate. This has the effect of constructing a directional coupler with high directivity that does not require adjustment by.

According to a sixth aspect of the present invention, instead of the take-out coaxial line, a take-out line is connected to the through hole and a detection circuit is connected to the delay line. It is a directional coupler, and has the action of forming a directional coupler with high directivity that does not require manual adjustment.

FIG. 1 shows an embodiment of the present invention.
And it demonstrates using FIG.

(Embodiment 1) FIG. 1 shows a directional coupler according to Embodiment 1 of the present invention, in which 11 is a center conductor, 12 is an outer conductor, 13 is a coaxial line, and a center conductor 11 And an outer conductor 12 to propagate a high frequency signal. Reference numeral 14 denotes a window portion provided on the coaxial line 13 in parallel with the central conductor 11, 15 denotes a coupling line substrate using a dielectric and is provided so as to cover the window portion 14, and 16 denotes a coupling line substrate 15. The coaxial line 13 is a provided coupling line having a length of about a quarter wavelength of a high frequency signal and provided at a position facing the window 14 with a length shorter than that of the window 14.
Coupled with high frequency.

Reference numeral 17 is a through hole A, 18 is a through hole B, 19 is a delay line, and the coupling line 16
It is formed on the substrate for the coupled line on the opposite side, and its length can be adjusted by trimming, and it is electrically connected to the coupled line 16 by the through hole A17 and the through hole B18. Reference numeral 20 is a ground portion provided on both surfaces of the coupling line substrate 15, 21 is a take-out coaxial line, the center conductor of which is connected to the through hole A17 and the ground is connected to the ground portion 20.

Reference numeral 22 is an input end, and 23 is an output end provided on the opposite side of the input end 22. The high-frequency signal input from the input end 22 is output to the output end 23, and a part of the high-frequency signal is output to the extraction coaxial line 21. The difference between the input power to the input end 22 and the power output to the extraction coaxial line 21 is the coupling degree. The high-frequency signal input from the output end 23 is output to the input end 22 and
A part thereof is taken out to the taking-out coaxial line 21.
When a high frequency signal is input to the input end 22 or the output end 23, the difference in the power of the high frequency signal extracted to the extraction coaxial line 21 is the directivity.

In this directional coupler, the high frequency signal inputted from the output end 23 of the coaxial line 13 is coupled to the coupled line 16.
And is taken out to the take-out coaxial line 21 by two paths through the through hole A17 and the through hole B18. At that time, the high-frequency signal taken out through the through hole B18 is coupled to the coupling line substrate 15
Since it is composed of a dielectric material, a delay occurs in the delay line 19 and the phase is inverted with respect to the high frequency signal taken out through the through hole A17, and the signals weaken each other.
It is attenuated by 0 decibels or more and taken out to the taking-out coaxial line 21. When the directivity is lowered due to the position or dimension error of the coupling line substrate 15, the delay amount can be adjusted by trimming the length of the delay line 19 to increase the directivity to 20 decibels or more.

On the other hand, the high-frequency signal input from the input end 22 of the coaxial line 13 is coupled to the coupling line 16 in a high frequency manner, and the extraction coaxial line 21 is taken out through two paths via the through hole A17 and the through hole B18. Taken out. The high frequency signal extracted from the through hole B18 propagates on the coaxial line 13 and returns on the delay line 19 via the through hole B18. Therefore, unlike the case where the high frequency signal is input from the output end 23, A
Since the phase is not inverted with respect to the high frequency signal taken out via 17, it is taken out to the taking-out coaxial line 21 with attenuation within 1 decibel.

In the first embodiment of the present invention, the window portion 14
Are provided in parallel with the central conductor 11, but the same effect can be obtained even if they are provided so as to intersect at a predetermined angle.

In the first embodiment of the present invention, the length of the coupling line 16 is set to be about a quarter wavelength of the high frequency signal. However, the dielectric constant of the coupling line substrate 15 is increased to delay the delay line. By increasing the wavelength shortening rate of 19, the same effect can be obtained even if the wavelength is shorter than about one quarter wavelength of the high frequency signal.

Although only one coupling line 16 is provided in the first embodiment of the present invention, the same effect can be obtained even if two or more coupling lines 16 are provided separately.

In the first embodiment of the present invention, the application has been described as a base station for mobile communication, but the same effect can be obtained by using it as a directional coupler for other applications.

(Second Embodiment) The second embodiment has the same configuration as that of the first embodiment except that a detection circuit is provided on the coupling line substrate 15 and a high frequency signal is taken out from the through hole B as a direct current. Are denoted by the same reference numerals and detailed description thereof will be omitted.

FIG. 2 shows a directional coupler according to the second embodiment of the present invention, in which 24 is a detection circuit, 25 is an extraction line and is composed of a lead line. Through hole B18
The high frequency signal output from is detected by the detection circuit 24,
It is taken out from the lead wire 25 as direct current.

Although the lead wire is used as the lead wire 25 in the second embodiment of the present invention, the same effect can be obtained by using a coaxial line.

[0026]

As described above, according to the present invention, it is possible to construct a highly directional coupler having a directivity of 20 decibels or more, which does not require manual adjustment.

[Brief description of drawings]

FIG. 1 is a perspective view of a directional coupler according to a first embodiment of the present invention.

FIG. 2 is a perspective view of a directional coupler according to a second embodiment of the present invention.

[Explanation of symbols]

11 center conductor 12 outer conductor 13 coaxial line 14 windows 15 Coupling line substrate 16 coupled lines 17 Through hole A 18 through hole B 19 delay lines 20 ground section 21 Extraction coaxial line 22 Input end 23 Output end 24 Detection circuit 25 Take-out line

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yuki Sato             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd.

Claims (6)

[Claims] 1. A coaxial line composed of a central conductor and an outer conductor, a window portion provided along the central conductor in a plane portion of the coaxial line, and a coupling line substrate provided so as to cover the window portion. And a coupling line which is provided at a position facing the window portion of the coupling line substrate and which is provided so as to be coupled to the coaxial line through the window portion in a high frequency manner, and the coupling line. A delay line connected to the coupling line via at least two through holes on the opposite side of the coupling line substrate; and a ground portion provided on both sides of the coupling line substrate and electrically connected to each other. A directional coupler comprising at least one of the through holes and a center conductor thereof, and a take-out coaxial line whose ground is connected to a ground portion of the coupling line substrate. 2. The directional coupler according to claim 1, wherein the length of the coupled line is set to approximately 1 / 4λ and the length of the window portion is set to be longer than that. 3. The directional coupler according to claim 1, wherein the window portion is formed so as to intersect the center conductor at a predetermined angle. 4. The directional coupler according to claim 1, wherein the length of the coupling line is made shorter than 1 / 4λ by increasing the permittivity of the coupling line substrate. 5. The directional coupler according to claim 1, wherein the coupling line is provided separately on the coupling line substrate. 6. The directional coupler according to claim 1, wherein a lead-out line is connected to the through hole and a detection circuit is connected to the delay line instead of the lead-out coaxial line.