JPH042203A - Directional coupler - Google Patents

Abstract

PURPOSE:To easily change the frequency band of an operating signal by adjusting a land made of a conductor so that the length of a line coupled respectively with 1st and 2nd coupling lines is always nearly the same length as 1/4 of an effective wavelength lambdag of the operating signal. CONSTITUTION:Lands 7, 9 and lands 8, 10 made of a conductor coupled with a 1st coupling line 5 connecting to a 1st strip line 1 and a 2nd strip line 2 and coupled with a 3rd strip line 3 and a 4th strip line 4 and coupled with a 2nd coupling line 6 connecting to the 3rd strip line 3 and the 4th strip line 4 and coupled with the 1st strip line 1 and the 2nd strip line 2 to vary the length of the coupling line equivalently are provided to the coupler. Thus, even after the circuit pattern is once decided, the length of the line by which the coupling lines 5, 6 are coupled is varied to adjust the length nearly equal to the wavelength lambdag/4 equivalently. Thus, the frequency band of the operating signal is easily changed.

Description

[Detailed description of the invention] [Summary] The length of the mutually coupled lines is 4 times the effective wavelength λg of the signal used.
The input signal from the first strip line is output to the second strip line and the third strip line, but the input signal from the fourth strip line is Regarding the directional coupler, which has almost no output to the strip line, even after the circuit pattern has been decided,
The purpose of the present invention is to provide a directional coupler that can easily adjust the length of the coupled line section to λg/4 by changing the line length of the coupled line section when changing the frequency of the used signal. , first and second conductor lands are provided that are coupled to each other to equivalently change and adjust the length of the coupled line, and the length of the mutually coupled line is always a quarter of the effective wavelength λg of the signal used. The land of the conductor is adjusted so that it has approximately the same length as 1.

(Industrial Application Field) The present invention relates to a directional coupler for a microwave circuit, and particularly to a directional coupler using a microstrip line.

A directional coupler using a microstrip line requires a strip line with a length close to a quarter of the effective wavelength λg of the signal used as the coupling line part, but a directional coupler using a waveguide It has the advantage of being significantly smaller than the . It is desired that this directional coupler can flexibly respond to changes in the frequency of the signal used.

[Prior Art] In a conventional directional coupler, as shown in the circuit pattern diagram in FIG. , strip lines 1.2 and 3.4 having a reference impedance of 50Ω are connected to their respective ends. In the directional coupler shown in the figure, for example, an input signal from the first strip line 1 is output to the second strip line 2 and the third strip line 3, and is hardly output to the fourth strip line 4. Have direction. In this case, the lengths of the coupled line sections 5 and 6 must always be approximately the same length as λg/4, which is one-fourth of the effective wavelength λ of the signal to be used.

[Problem to be solved by the invention]

However, in the conventional directional coupler described above, once the circuit pattern is determined, the line lengths of the coupled line sections 5 and 6 are changed to λ, λ, etc. when the frequency of the signal to be used is changed, etc.
A problem has arisen in that the length cannot be adjusted to approximately the same length as /4 length. An object of the present invention is to provide a directional coupler using a microstrip line, so that even after the circuit pattern is once determined, the line length of the coupling ia path can be easily changed to a length that is approximately the same as the λ,/4 length. The object of the present invention is to provide a directional coupler that can be adjusted to

[Means to solve the problem]

As shown in the principle diagram of FIG. 1 showing the basic configuration of the present invention, this problem is solved by connecting a first strip line and a second strip line 2 to a third strip line 3 and a fourth strip line 4. A first coupled line section 5 that couples together, and a second coupled line section 6 that connects to the third strip line 3 and fourth strip line 4 and couples to the first strip line 1 and second strip line 2. conductor lands 7.9 and 8.9, respectively, are conductor lands 7.9 and 8.9 that are coupled to each other to vary the length of the coupled line with equal deflection.
This problem is solved by the directional coupler of the present invention, which is provided with 10 directional couplers.

[Effect]

In the directional coupler of the present invention, the land 7 of the conductor is added to the coupled line section 5, and the land 9 is attached to the first strip line 1.
added to. Also, the land 8 is added to the coupled line section 6, the land 10 is added to the third strip line 3,
The lengths of the lines that are coupled to each other by the coupled line portions 5 and 6 are changed equivalently. Therefore, the directional coupler of the present invention has a first stripline line, a second stripline line 2.
Third stripline3. Fourth strip g-way 4 and first coupled line section 5. Even after the circuit pattern of the second coupled line section 6 is once determined, the coupled line section 5 and the coupled line section 6 can be
By changing the length of the lines that are coupled to each other, the polarization is equal to λ, /4
Since the length can be adjusted to be approximately the same as the length, conventional problems such as when changing the frequency of the signal used are solved.

〔Example〕

FIG. 2 is a circuit pattern diagram showing the configuration of a directional coupler according to an embodiment of the present invention.

In the circuit pattern diagram of FIG. 2, the land 9, which is added to the first strip line 1 of the present invention in a tl manner and is electromagnetically connected to the coupled line portion 5 via the land 7, is a conductor. This is carried out with ribbon 11. Then, the ends of the first strip line 1 and the coupled line section 5 are bonded directly to each other by soldering or the like.

Then, the land 7 is electromagnetically coupled to the conductive ribbon 11. Furthermore, a land 10 added to the third strip line 1a path 3 and connected to the coupled line section 6 via the land 8 is implemented with a conductor ribbon 12, and is connected to the third strip line 3 and the coupled line. It is directly attached to the portion 6 by soldering or the like. and conductor ribbon 11. Land 7 and conductor ribbon 12. As shown in the figure, the lands 8 are arranged vertically symmetrically with respect to the center line between the coupled line parts 5 and 6. By doing this, in the directional coupler according to the embodiment of the present invention shown in FIG. 2, the line length of the coupling line is always λg/4, which is one quarter of the wavelength λg of the signal used, for equal polarization. Well, there's no problem.

〔Effect of the invention〕

As explained above, according to the present invention, the line length of the coupling line of a directional coupler using a microstrip line is always set to λ, /4 length, which is one-fourth of the wavelength λg of the signal used. This provides the effect that the frequency band of the signal used can be easily changed.

[Brief explanation of drawings]

Figure 1 is a principle diagram showing the basic configuration of the directional coupler of the present invention, Figure 2 is a circuit pattern diagram showing the configuration of the directional coupler of the embodiment of the present invention, and Figure 3 is a conventional directional coupler. It is a circuit pattern diagram of the device. In the figure, 1 is the first strip line, 2 is the second strip line, 3 is the third strip line, 4 is the fourth strip line, 5 is the first coupled line section, and 6 is the second coupled line. Line part, 7 is a land for adjusting the first coupled line part, 8
9 is a land for adjusting the second coupled line portion; 9 is a land for adjusting the first strip line; 10 is a land for adjusting the second strip line; 11 is the first conductor ribbon;
is the second conductor ribbon. 8 Principles of national policy showing the basic configuration of the directional coupler of the present invention 1
figure

Claims (1)

[Claims] The length of the mutually coupled lines is the effective wavelength λ_g of the signal used.
The first (5) and second (6) are approximately the same length as a quarter of the
The input signal from the first stripline (1) is transmitted to the second stripline (2) and the third stripline by the coupled line section of
In the directional coupler, the output is output to the first (5) and second (6) coupled line sections, but almost no output is output to the fourth strip line (4). , the first (
7, 9) and a second (8, 10) conductor land, and the length of the lines that connect each other is always equal to the effective wavelength λ_ of the signal used.
A directional coupler characterized in that lands (7, 9; 8, 10) of the conductor are adjusted to have a length substantially equal to one-fourth of g.