JP2557888B2 - Multi-terminal directional coupler - Google Patents

Description

TECHNICAL FIELD The present invention relates to a multi-terminal directional coupler.

[Prior Art] FIG. 3 is a circuit diagram of a 4-input and 4-output multi-terminal directional coupler. In FIG. 3, the signals input to the signal input terminals 1 and 2 are input to a hybrid directional coupler 9a having a coupling degree of 3 dB, and each signal is divided into two in the directional coupler 9a and coupled to each other. , The divided and combined signals are input to hybrid directional couplers 9c and 9d having a coupling degree of 3 dB. Further, the signals input to the signal input terminals 3 and 4 are input to a hybrid directional coupler 9b having a coupling degree of 3 dB, and each signal is divided into two in the directional coupler 9b and coupled to each other, The split and combined signals are input to hybrid directional couplers 9c and 9d having a coupling degree of 3 dB. Further, the signals input to the directional coupler 9c are each divided into two and combined, and the divided and combined signals are output to the signal output terminals 5 and 6. Furthermore, the signals input to the directional coupler 9d are each divided into two parts and combined with each other, and the divided and combined signals are output to the signal output terminals 7 and 8.

In the multi-terminal directional coupler configured as described above, each signal having 1/4 the input power of the signal input to the signal input terminals 1 to 4 is output to the signal output terminal 5 or 8 respectively. . This multi-terminal directional coupler is applied to a Butler matrix or the like that can arbitrarily control the directivity of a radiation beam, and its application range is very wide.

FIG. 4 (A) is a plan view of the multi-terminal directional coupler when the multi-terminal directional coupler of FIG. 3 is configured by using four branch line type directional couplers. FIG. 4B is a vertical sectional view taken along the line CC ′ of FIG.

4 (A) and (B), a dielectric substrate having a rectangular planar shape and a ground conductor 11 formed on the entire back surface.
A branch line type directional coupler 9a is formed in the upper left portion of the figure on the upper surface of 10. Branch line type directional coupler 9a
Is a rectangular strip conductor 21 with a width d ₁ and a length λg / 4.
And 22, and rectangular strip conductors 23 and 24 having a width d ₂ and a length λg / 4, the strip conductors 21 and 22, and the strip conductors 23 and 24 are parallel to each other and the strip conductors 21 to 24 are It is formed in a square shape on the dielectric substrate 10. Here, λg is a guide wavelength. Strip conductors 21 and 23, strip conductors 22 and 23, strip conductor 22 and
The conductors at the connection points of 24 and the strip conductors 21 and 24 are designated as 25 to 28. This branch-line type directional coupler 9a is constructed by appropriately determining the widths d ₁ and d ₂ of the strip conductors 21 to 24 so that the conductors 25 to 28 at the connection point have microwave lines of a constant characteristic impedance Z ₀ as is known. Paths can be connected in alignment and conductors 25 to 28 at each connection point
It can be configured to have a coupling degree of 3 dB between.

The branch line type rectangular couplers 9d, 9c and 9d have the same dielectric substrate 1 as the branch line type directional coupler 9a.
Are formed on the upper surface in the lower left part of the figure, the upper right part of the figure, and the lower right part of the figure. Hereinafter, for convenience, reference numerals 21 to 28 of the directional coupler 9a will be used for the directional couplers 9b, 9c and 9d.

Further, the conductors 25, 26, 27, and 28 at the connection points of the directional coupler 9a are connected strip conductors 31, 32, 35 having a width d, respectively.
Via the signal input terminals 1 and 2, and the conductor 25 at the connection point of the directional coupler 9c and the conductor 25 at the connection point of the directional coupler 9d, and the connection point of the directional coupler 9b. The conductor of
25, 26, 27 and 28 are respectively connected to the signal input terminals 3 and 4 and the conductor 26 at the connection point of the directional coupler 9c and the directional coupler via the connecting strip conductors 33, 34, 37 and 38 having the width d. Combiner 9d
Is connected to the conductor 26 at the connection point. Here, the strip conductors 36 and 37 are three-dimensionally intersected at the three-dimensional intersection 30 with the insulator 43 interposed therebetween. The conductors 28 and 27 at the connection point of the directional coupler 9c are connected to the signal output terminals 5 and 6 via the connection strip conductors 39 and 40, respectively, and the conductors 28 and 27 at the connection point of the directional coupler 9d are connected. Are connected to the signal output terminals 7 and 8 via connecting strip conductors 41 and 42, respectively. In addition, in order to output the signals having the power of 1/4 of each signal input to the signal input terminals 1 to 4 to the signal output terminals 5 to 8 with a constant phase difference from each input signal, connection is made. The lengths of the strip conductors 31 to 34 for connection, the lengths of the strip conductors 35 to 38 for connection, and the lengths of the strip conductors 39 to 42 for connection are adjusted to the same length.

In the multi-terminal directional coupler configured as described above, the connecting strip conductors 31 to 42 and the ground conductor 11 each operate as a microstrip line, and the multi-terminal directional coupler is the directional coupler of FIG. Works like a container. When the characteristic impedance of the microstrip line is given, the width of each of the connecting strip conductors 31 to 42 is determined as is well known.

[Problems to be Solved by the Invention] In the conventional directional coupler shown in FIGS. 4A and 4B, the strip conductor 36 is formed at the three-dimensional intersection 30 of the connecting strip conductors 36 and 37. There is a problem in that the signals propagating along with and the signals propagating along the strip conductor 37 interfere with each other, and uniform output signals cannot be obtained at the signal output terminals 5 to 8.

In the multi-terminal directional coupler, as described above, the signal input terminals 1 to 4 are connected to the connecting strip conductors 31, 35, 39, the connecting strip conductors 32, 36, 41, and the connecting strip conductors 33, 37, respectively. , 40, and strip conductors for connection
Although it is necessary to make the electrical lengths of the signals propagating to the signal output terminals 5 to 8 along 34, 38, 42 uniform, in the configuration of the conventional example shown in FIGS. It is necessary to adjust the length of each strip conductor 31 to 42 according to the shape of 30, and there is also a problem in that manufacture is difficult.
Further, in the portions other than the hybrid couplers 9a to 9d, it is necessary to widen the line spacing in order to minimize the coupling between the connecting strip conductors 31 to 42, but in the configuration of the conventional example of FIG. Eight input / output strip conductors 31 to 34 and 39 to 42, and four strip conductors 35 to connect between directional couplers on a dielectric substrate 10.
38 is required, and there is a problem that the overall shape of the 4-input and 4-output multi-terminal directional coupler becomes large.

An object of the present invention is to solve the above problems, to be smaller and lighter than the conventional example, to be easily manufactured, and to input good electrical characteristics without causing interference between signals propagating to each strip conductor. An object is to provide a multi-terminal directional coupler capable of power-dividing a signal.

[Means for Solving the Problems] The present invention is provided with a plurality of first directional couplers provided on both sides of a ground conductor via dielectric substrates, and the plurality of first directional couplers are provided. Two coupling conductors, which are respectively connected to each other, are formed on both sides of the ground conductor via the dielectric substrate, and a gap is provided in the ground conductor formed between the coupling conductors. A plurality of second directional coupling groups for coupling the coupling conductors are provided.

[Operation] In the second directional coupler configured as described above, the signals of the two coupling conductors are mode-coupled via the missing portion of the ground conductor, and the second directional coupling is performed. The device operates similarly to the conventional branch line type directional coupler shown in FIGS. 4 (A) and 4 (B). That is, for example, when the strip conductors of the first and second microstrip lines formed on the dielectric substrates and each having two signal terminals are connected to the coupling conductors, the first and second microphones are connected. A tostrip line couples in the second directional coupler. At this time, for example, the microwave signal input to one of the signal terminals of the first microstrip line passes through the coupling conductor of the directional coupler and then the first
Output to the other signal terminal of the microstrip line and connected to the coupling conductor connected to the first microstrip line, the missing part of the ground conductor, and the second microstrip line. The signal is output to the other signal terminal of the second microstrip line via the coupling conductor. The microwave signal input to one signal terminal of the second microstrip line is output to the other signal terminal of the first microstrip line as described above.

Further, as the first directional coupler, for example, a plurality of well-known branch line type, interdigitated type or tandem type directional couplers are provided on both sides of the ground conductor via the dielectric substrate. By connecting the second directional coupler configured as described above, a multi-terminal directional coupler having a plurality of inputs and a plurality of outputs can be configured. Therefore, the first directional coupler divides each input signal, combines the divided signals and outputs the combined signal to the second directional coupler, and then the second directional coupler Each input signal is divided and the divided signals are combined and output.
For example, the multi-terminal directional coupler comprises two first directional couplers and two second directional couplers, each coupling of the first and second directional couplers. When the degree is 3 dB, as in the conventional example of FIGS. 4 (A) and 4 (B), 1/1 / th of the signal input to each input terminal of each of the first directional couplers
A power signal of 4 is output to each output terminal of each of the second directional couplers.

As described above, the first directional coupler is provided on both sides of the ground conductor via the dielectric substrate, while the coupling conductors of the second directional coupler are provided on the respective dielectric substrates. Since it is installed in the
A multi-terminal directional coupler having a size of 1/2 can be constructed, and it is not necessary to provide a three-dimensional intersection as in the conventional example. Therefore, the conductor pattern of the circuit can be accurately formed, and the signal can be output with good electrical characteristics without causing signal interference at the grade intersection unlike the conventional example.

[Embodiment] FIG. 1 (A) is an embodiment of the present invention in which four inputs and four inputs are provided.
A plan view of the output multi-terminal directional coupler seen from the upper surface, FIG. 1 (B) is a plan view seen from the lower surface of the directional coupler of FIG. 1 (A), and FIG. 1 (C). Is a plan view of the ground conductor 11 of the directional coupler of FIG. 1 (A), and FIG. 1 (D) is of FIG. 1 (A).
3A and 3B are vertical cross-sectional views taken along the line AA ′ of FIGS. In FIGS. 1A to 1D, components having the same functions as those in the above drawings are designated by the same reference numerals.

The multi-terminal directional coupler of the present invention is different from the conventional example of FIGS. 4A and 4B in that (1) the branch line type directional couplers 9a and 9b of the conventional example.
Are formed on both sides of the ground conductor 11 via the dielectric substrates 10a and 10b, respectively. (2) Branch line type directional couplers 9c and 9d of the conventional example.
However, two coupling conductors are provided on both sides of the ground conductor and the dielectric substrate 10
that the ground conductor formed via the a and 10b and formed between the coupling conductors is replaced by two directional couplers provided with a coupling lacking portion of the ground conductor; and (3) above ( According to 1) and (2), the signal input terminal 1,
2, signal output terminals 5, 7, strip conductors for connection 31, 32, 35, 3
6, 39 and 41 are formed on the upper surface of the dielectric substrate 10a on the upper surface side of the multi-terminal directional coupler, and the signal input terminals 3, 4,
Signal output terminals 6, 8, connecting strip conductors 33, 34, 37, 38, 4
0 and 42 are dielectric substrates 1 on the upper surface side of the multi-terminal directional coupler 1
It was formed on the lower surface of 0b. Hereinafter, the difference will be described in detail.

In FIGS. 1 (A) to (D), in the upper right part of the figure and the lower right part of the figure of the rectangular plate-shaped ground conductor 11 having a thickness t ₀ ,
The short side length W penetrating the ground conductor 11 and the long side length λ
g / 4 coupling holes 17a and 17b are provided, and the coupling holes 17a and
17b is filled with coupling dielectrics 10ca and 10cb. The ground conductor 2 is narrowly provided by two dielectric substrates 10a and 10b having a thickness t.

A rectangular shape having a short side length S and a long side length λg / 4 in the upper right portion of the upper surface of the dielectric substrate 10a in the upper right part of the drawing of FIG. 1A, just above the coupling dielectric 10ca. Is formed on the lower surface of the lower surface of the dielectric substrate 10b, which is immediately below the coupling dielectric 10ca.
A coupling conductor 19a having the same shape as that of is formed. In order to form the input and output terminals of the multi-terminal directional coupler on the same side and to make the electrical lengths between the input and output terminals the same,
The coupling conductors 18a and 19a are formed such that the longitudinal directions of the coupling conductors 18a and 19a are parallel to the longitudinal directions of the dielectric substrates 10a and 10b. The coupling conductors 18a and 19a
When a microwave signal is input to one end of the short side of the, the mode coupling occurs between the coupling conductors 18a and 19a and the ground conductor 11 via the coupling dielectric 10ca of the coupling hole 17a, and the power of each signal is increased. It is divided into two and is coupled to each other, and is output to the other ends of the short sides of the coupling conductors 18a and 19a.

In FIGS. 1 (A) and (B), coupling holes 17a and 17b are formed.
Is indicated by a dotted line.
Each short side of 17a and each short side of the coupling conductors 18a and 19a are in contact with two identical vertical sections. Further, the dielectric substrates 10a and 10b and the coupling dielectric 10ca have the same permittivity and are integrally formed.

2 (A) and (B) are respectively B- of FIG.
FIG. 6 is a vertical sectional view showing electric field distributions of an odd mode and an even mode by a known orthogonal mode excitation method at a joint portion of B ′ line. In the even mode of FIG. 2 (A), each coupling conductor
A power line is generated between 18a and 19a and the ground conductor 11, and the missing portion becomes a magnetic wall. On the other hand, in the odd mode shown in FIG. 2 (B), lines of electric force are generated between the coupling conductors 18a, 19a and the ground conductor 11, and the missing portion becomes an electric wall.

Therefore, the coupling conductors 18a, 19a and the grounding conductor 11 formed on the dielectric substrates 10a and 10b constitute a directional coupler 9ca having a predetermined degree of coupling, and the dielectric substrates 10a and 10b.
, The width S of the coupling conductors 18a and 19a, and the coupling hole 1a
A four-terminal directional coupler 9ca having a coupling degree of 3 dB can be constructed by appropriately determining the width W of the.
In this embodiment, the coupling degree is 3 dB. In order to increase the degree of coupling, the width W of the coupling hole 11 may be increased.

Further, a coupling conductor 18b having the same shape as the conductor 18a is formed on the upper surface of the dielectric substrate 10a at the lower right portion of the drawing of FIG. 1A and immediately above the coupling dielectric 10cb. A coupling conductor 19b having the same shape as the conductor 19a is formed on the lower surface of the body substrate 10b in the lower left part of the figure in FIG. 1 (B) and immediately below the engaging dielectric 10cb. Therefore, the coupling conductors 18b and 19b and the ground conductor 11 constitute a directional coupler 9da having a coupling degree of 3 dB, like the directional coupler 9ca.

Further, a branch line type directional coupler 9a having a coupling degree of 3 dB is formed on the upper surface of the dielectric substrate 10a at the left center of the figure of FIG. A branch line type directional coupler 9b having a coupling degree of 3 dB is formed on the lower surface of the dielectric substrate 10b at the center of the right side of FIG. 1 (b) as in the above-mentioned conventional example.

On the upper surface of the dielectric substrate 10a, the signal input terminals 1 and 2 are connected to the connecting strip conductors 31 and 32 of width d, respectively.
Via the connecting point conductors 25 and 26 of the directional coupler 9a, and the connecting point conductors 27 and 28 of the directional coupler 9a via the connecting strip conductors 36 and 35 of the width d, respectively, The directional coupler 9da is connected to the upper side end of the coupling conductor 18b in the figure and the upper and lower side ends of the coupling conductor 18a of the directional coupler 9ca, respectively, and the directional coupler 9ca. Connecting conductor 18a
The upper end of the short side of the figure and the upper and lower ends of the coupling conductor 18b of the directional coupler 9da are connected to the signal output terminals 5 and 7 through the connecting strip conductors 39 and 41, respectively. It

On the other hand, on the lower surface of the dielectric substrate 10b, the signal input terminals 3 and 4 are connected to the connecting strip conductor 33 having the width d.
Via the conductors 25 and 34 at the connection point of the directional coupler 9b and
Conductors 27 and 28 connected to the directional coupler 9b at the connection point of the directional coupler 9b.
Through the connecting strip conductors 38 and 37 having the width d, respectively, on the upper and lower ends of the coupling conductor 19b of the directional coupler 9da and on the short side of the coupling conductor 19a of the directional coupler 9ca. Connected to the upper end in the figure, the upper and lower ends of the upper and lower sides of the coupling conductor 19a of the directional coupler 9ca and the upper and lower sides of the coupling conductor 19b of the directional coupler 9da in the figure. Are signal output terminals 6 and 8 via connecting strip conductors 40 and 42, respectively.
Connected to.

Here, the signal input terminals 1 and 2 and the signal output terminals 5 and 7 are formed outside the left and right sides of the dielectric substrate 10a in the drawing, while
The signal input terminals 3 and 4 and the signal output terminals 6 and 8 are the dielectric substrate 10b.
Are formed outside the left and right sides in the figure. Therefore, when connecting the lead wires to each of the signal input / output terminals 1 to 8, there is an advantage that the lead wires can be easily connected because the connecting positions do not overlap.

Further, as in the conventional example, in order to output a signal having a power of 1/4 of each signal input to the signal input terminals 1 to 4 to the signal output terminals 5 to 8 with the same phase difference as each input signal. In addition, the electrical length from each of the signal input terminals 1 to 4 to the input ends of the directional couplers 9ca and 9da, that is, the connection strip conductors 31 and 35, and the connection strip conductor 32,
36, the strip conductors 33 and 37 for connection, the strip conductors 34 and 38 for connection are made uniform in electric length, and the directional coupler 9c
The electrical lengths from the output terminals of a and 9da to the signal output terminals 5 to 8, that is, the electrical lengths of the connecting strip conductors 39 to 42 are made uniform.

The multi-terminal directional coupler configured as described above includes the second
It is equivalent to the circuit shown in the figure and operates in the same manner as in FIGS. 4 (A) and 4 (B). In the above embodiments, 1 to 4 are signal input terminals and 5 to 8 are signal output terminals, but the multi-terminal directional coupler of the present invention is a reversible circuit, and 1 to 4 are signal output terminals. 5 to 8 may be signal input terminals.

With the structure of this embodiment, it is possible to reduce the size by about half as compared with the conventional example shown in FIGS. 4 (A) and 4 (B). Also, the fourth
Since the three-dimensional intersection 30 formed by the strip conductors 37 as shown in FIGS. 7A and 7B is not necessary, the input signal can be divided with equal power with good uniformity. Further, in this embodiment, since the grade crossing portion 30 is not necessary, the circuit line pattern can be accurately formed, and the electrical length between the input and output terminals can be easily and uniformly manufactured. Therefore, an accurate phase relationship between the input / output terminals can be obtained.

In the above embodiment, the power distribution in the same plane lung
Although the branch line type hybrid directional couplers 9o and 9b are used for the engagement, the present invention is not limited to this, and for example, hybrid directivity for dividing and combining a plurality of known signals such as an interdigitated type and a tandem connection type. A combiner may be used. In this case, the size can be further reduced as compared with the case where the branch line type hybrid directional coupler is used.

Further, in the above embodiments, the case where each of the signal input / output terminals is four has been described, but the present invention is not limited to this, and the present invention can be easily applied to the case of multiple terminals of five or more. Alternatively, a multi-terminal directional coupler having three or more directional couplers 9a and 9b and three or more directional couplers 9ca and 9da may be configured.

Furthermore, in the above embodiments, the coupling conductors 18a, 18b,
Although the planar shapes of 19a, 19b and the coupling holes 17a, 17b are rectangular, the present invention is not limited to this, and the coupling conductors 18a and 19a, 18b and 19b are not limited thereto.
The above-mentioned shape is not limited as long as a missing portion is formed in which the ground conductor 11 is not formed, and mode coupling can be performed between the coupling conductors 18a and 19a and 18b and 19b.

[Effects of the Invention] As described in detail above, according to the present invention, a plurality of first directional couplers are provided on both sides of the ground conductor via the dielectric substrate, and the plurality of first directional couplers are provided. Two coupling conductors respectively connected to the coupling device are formed on both sides of the ground conductor via the dielectric substrate, and the ground conductor formed between the coupling conductors is provided with a cutout portion. Since the plurality of second directional couplers for coupling the respective coupling conductors are provided, the second directional coupler is the branch line type directional direction of the conventional example shown in FIGS. 4 (A) and 4 (B). Operating in the same way as a directional coupler, for example by providing two known first directional couplers and two said second directional couplers,
The multi-terminal directional coupler of the present invention operates similarly to the conventional example.

As described above, the first directional coupler is provided on both sides of the ground conductor via the dielectric substrate, while the coupling conductors of the second directional coupler are provided on the respective dielectric substrates. Since it is provided, about 1 / compared to the conventional multi-terminal directional coupling
A multi-terminal directional coupler having a size of 2 can be configured, and it is not necessary to provide a grade intersection as in the conventional example. Therefore, there is an advantage that the conductor pattern of the circuit can be accurately formed, and a signal can be output with good electrical characteristics without causing signal interference at a grade intersection as in the conventional example.

[Brief description of drawings]

FIG. 1 (A) is a plan view seen from the upper surface of a 4-input and 4-output multi-terminal directional coupler which is an embodiment of the present invention, and FIG. 1 (B) is a plan view of FIG. 1 (A). FIG. 1 (C) is a plan view of the ground conductor of the directional coupler of FIG. 1 (A), and FIG. 1 (D) is FIG. 1 (A). ) And (B) are longitudinal cross-sectional views taken along the line AA ', and FIGS. 2A and 2B are known in the joint portion along the line BB' in FIGS. 1A and 1B, respectively. FIG. 3 is a vertical cross-sectional view showing the electric field distributions of an even mode and an odd mode by the orthogonal mode excitation method of FIG. 3, FIG. 3 is the four inputs and four outputs of the embodiment of FIG. 1A and the conventional example of FIG. FIG. 4A is a circuit diagram of the multi-terminal directional coupler of FIG. 4, and FIG. 4A is a plan view of a 4-input and 4-output multi-terminal directional coupler using four branch line type directional couplers. Figure (B) FIG. 4 is a vertical sectional view taken along the line CC ′ of FIG. 1,2,3,4 …… Signal input terminal, 5,6,7,8 …… Signal output terminal, 9a, 9b, 9c, 9d …… Branch line type hybrid directional coupler, 9ca, 9da …… Hybrid Directional coupler, 10, 10a, 10b ... Dielectric substrate, 10ca, 10cb ... Coupling dielectric, 11 ... Ground conductor, 17a, 17b ... Coupling hole, 31 to 42 ... Strip conductor.

 ─────────────────────────────────────────────────── ───Continued from the front page (56) Bibliographic references Sho 53-76741 (JP, U) US Patent 3575674 (US, A) US Patent 3571739 (US, A)

Claims (1)

(57) [Claims] 1. A plurality of first directional couplers provided on both sides of a ground conductor via a dielectric substrate, each of which is connected to the plurality of first directional couplers.
Individual coupling conductors are formed on both sides of the ground conductor via the dielectric substrate, and a gap is provided in the ground conductor formed between the coupling conductors to couple the coupling conductors. A multi-terminal directional coupler comprising a plurality of second directional couplers.