JP2009253424A - Directional coupler - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve close coupling even in side coupling, and suppress variation of the coupling degree by manufacturing precision. <P>SOLUTION: The coupler includes: a first strip conductor 2 prepared on a front surface of an dielectric substrate 1; a second strip conductor 3 which is similarly prepared on the front surface of the dielectric substrate 1, and arranged to be parallel to the first strip conductor 2; a first floating conductor 4 which is prepared on the front surface of the dielectric conductor 1 between the first strip conductor 2 and the second strip conductor 3, and does not connect to either the first and the second strip conductors 2, 3; a ground conductor 5 which is prepared on a backside of the dielectric conductor 1 so as to be located near the first strip conductor 2 and the second strip conductor 3; short stubs 6 which connect the second strip conductor 3 and the ground conductor 5 while connecting the first conductor 2 and the ground conductor 5; and input and output lines 7 to 10 prepared in both ends of the first strip conductor 2 and the both ends of the second strip conductor 3. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a directional coupler, and more particularly to a directional coupler used for an antenna, a waveguide, or the like.

  Directional couplers are widely used for power monitoring. As a configuration of a directional coupler using a general strip line, there is a configuration in which two strip lines are arranged close to each other in parallel and side-coupled (see, for example, Patent Document 1 and Non-Patent Document 1). ).

Japanese Patent Laid-Open No. 5-90809 (FIG. 1 etc.) Ikalainen, PK and Matthaei, GL, “Wide-Band, Forward-Coupling Microstrip Hybrids with High Directivity,” IEEE Trans. On Microwave Theory and Techniques., Vol. MTT-35, No. 8, pp.719-725, Aug . 1987

  In a conventional directional coupler having such a forward coupling, the degree of coupling increases as the difference between the phase velocity in the coupled line in the even mode and the phase velocity in the coupled line in the odd mode increases. In practice, the difference in phase velocity cannot be increased, and there is a problem in that a directional coupler for tightly coupled forward coupling cannot be realized.

  Also, in order to obtain as tight a coupling as possible, it is necessary to make the two strip lines as close as possible. However, if the distance between the strip lines is narrowed, fine processing is required, and the degree of coupling greatly varies depending on the processing accuracy. As a result, there is a problem that the product performance may vary.

  The present invention has been made to solve such problems, and an object thereof is to obtain a directional coupler capable of realizing close coupling in side coupling and suppressing variation in coupling degree due to processing accuracy. Yes.

  The present invention is provided between the first strip conductor, the second strip conductor arranged in parallel to the first strip conductor, the first strip conductor and the second strip conductor, A first floating conductor that is not connected to any conductor, a ground conductor disposed in the vicinity of the first strip conductor and the second strip conductor, and the first strip conductor and the ground conductor are connected to each other. A first connection conductor; and a second connection conductor for connecting the second strip conductor and the ground conductor, and the first connection conductor is inserted into both ends of the first strip conductor and both ends of the second strip conductor. A directional coupler including an output line.

  The present invention is provided between the first strip conductor, the second strip conductor arranged in parallel to the first strip conductor, the first strip conductor and the second strip conductor, A first floating conductor that is not connected to any conductor, a ground conductor disposed in the vicinity of the first strip conductor and the second strip conductor, and the first strip conductor and the ground conductor are connected to each other. A first connection conductor; and a second connection conductor for connecting the second strip conductor and the ground conductor, and the first connection conductor is inserted into both ends of the first strip conductor and both ends of the second strip conductor. Since the directional coupler is characterized in that an output line is provided, close coupling can be realized even in side coupling, and variation in the coupling degree due to processing accuracy can be suppressed.

Embodiment 1 FIG.
1 is a top view showing a configuration of a directional coupler using a microstrip line according to Embodiment 1 of the present invention. FIG. 2 is a cross-sectional view taken along the line AA ′ in FIG. 1 and 2, reference numeral 1 denotes a polygonal dielectric substrate made of ceramic or the like. 2 is a substantially T-shaped first strip conductor (first strip line) provided on the surface of the dielectric substrate 1, and 3 is provided on the surface of the dielectric substrate 1, and is also substantially T-shaped. The second strip conductor (second strip line) 4 is provided on the surface of the dielectric substrate 1 so as to be disposed between the first strip conductor 2 and the second strip conductor. The first floating conductor is substantially rectangular. Reference numeral 5 denotes a ground conductor provided on the back surface of the dielectric substrate 1. Reference numeral 6 denotes a short stub that connects the first strip conductor 2 and the ground conductor 5 and the second strip conductor 3 and the ground conductor 5. Therefore, the short stub 6 constitutes a first connection conductor that connects the first strip conductor 2 and the ground conductor 5, and a second connection conductor that connects the second strip conductor 3 and the ground conductor 5. is doing.

  In the directional coupler according to the first embodiment, as shown in FIG. 1, the first strip conductor 2 and the second strip conductor 3 are arranged in parallel on the surface of the dielectric substrate 1, The first floating conductor 4 provided between them is not connected to any one of the first strip conductor 2 and the second strip conductor 3, and a gap of a predetermined distance ((gap) between these conductors ( There are gaps 11 to 14. In the example of FIG. 1, the first strip conductor 2 and the second strip conductor 3 are arranged so as to be symmetric with respect to the B-B ′ line in the drawing. The AA line and BB ′ line indicate the horizontal and vertical center lines of the dielectric substrate 1, but it goes without saying that both are imaginary lines shown for explanation. Yes.

  In the example of FIG. 1, the dielectric substrate 1 is polygonal, and the first and second strip conductors 2 and 3 are substantially T-shaped. However, both are limited to this. It is not a thing.

  In FIG. 1, reference numerals 7 and 8 denote input / output lines provided at both ends of the first strip conductor 2 on the surface of the dielectric substrate 1 of the directional coupler. Reference numerals 9 and 10 denote input / output lines provided at both ends of the second strip conductor 3 on the surface of the dielectric substrate 1 of the directional coupler. In the example of FIG. 1, the input / output lines 7 and 8 are arranged to be line-symmetric with respect to the AA ′ line, and the input / output lines 9 and 10 are connected to the AA ′ line. The axes are arranged so as to be line symmetric. Further, the input / output lines 7 and 9 are arranged so as to be line-symmetric with respect to the BB ′ line, and the input / output lines 8 and 10 are arranged with the line BB ′ as an axis. They are arranged symmetrically.

  Reference numeral 11 denotes an input / output gap existing between the first strip conductor 2 and the input / output line 7 and between the first floating conductor 4 and the input / output line 7. This is an input / output gap existing between the strip conductor 2 and the input / output line 8 and between the first floating conductor 4 and the input / output line 8. Reference numeral 13 denotes an input / output gap that exists between the second strip conductor 3 and the input / output line 9 and between the first floating conductor 4 and the input / output line 9, and 14 denotes the second This is an input / output gap that exists between the strip conductor 3 and the input / output line 10 and between the first floating conductor 4 and the input / output line 10.

  In FIG. 2, reference numeral 15 denotes a first unit cell including a first strip conductor 2, a second strip conductor 3, a first floating conductor 4, and a short stub 6.

  As shown in FIG. 2, in the first embodiment, an example in which the ground conductor 5 is provided on the back surface of the dielectric substrate 1 will be described. However, the present invention is not limited to this, and the ground conductor 5 It suffices if they are arranged in the vicinity of the first strip conductor 2 and the second strip conductor 3.

  FIG. 3 shows an equivalent circuit assuming a state in which a magnetic wall is disposed in a cross section (referred to as a cross section BB ′) along the line BB ′ in FIG. A conductor 2, a first floating conductor 4 on the first strip conductor 2 side from the cross section BB ′, a short stub 6 on the first strip conductor 2 side from the cross section BB ′, an input / output line 7, 8 shows an equivalent circuit of a directional coupler using a strip line composed of 8. That is, the equivalent circuit shown in FIG. 3 is an equivalent circuit during the even mode operation of the directional coupler according to the first embodiment. In FIG. 3, 16 is an even-mode transmission line model of the input / output lines 7 and 8, 17 is a series capacitance in the even mode due to the input / output gaps 11 and 12, and 18 is the first strip conductor 2 and the first floating conductor. 4 is a serial inductance in the even mode by the first strip conductor 2 and the first floating conductor 4, and 20 is a parallel capacitance in the even mode of the first strip conductor 2 and the short stub 6. Represents inductance.

  FIG. 4 shows an equivalent circuit in a case where an electric wall is arranged on the cross section BB ′ of FIG. 1, and therefore, the first strip conductor 2 and the first of the cross section BB ′ are the first. Direction using a strip line composed of the first floating conductor 4 on the strip conductor 2 side, the short stub 6 on the first strip conductor 2 side from the cross-section BB ′, and the input / output lines 7 and 8. 1 shows an equivalent circuit of a sex coupler. That is, the equivalent circuit shown in FIG. 4 is an equivalent circuit during the odd mode operation of the directional coupler according to the first embodiment. In FIG. 4, reference numeral 21 denotes a transmission line model of the odd-mode input / output lines 7 and 8, 22 denotes an odd-mode series capacitance due to the input / output gaps 11 and 12, and 23 denotes the first strip conductor 2 and the first floating conductor 4. The odd-mode series inductance by, 24 is the odd-mode parallel capacitance by the first strip conductor 2 and the first floating conductor 4, and 25 is the odd-mode parallel inductance by the first strip conductor 2 and the short stub 6.

Next, the operation of the directional coupler according to the first embodiment will be described.
The propagation constants of portions other than the transmission line model 16 or 21 of the circuit shown in FIG. 3 or FIG. 4 are expressed by the following equations (1) to (3).

L _R is the inductance value of the series inductance 18 or 23, _{C R} is the capacitance value of the parallel capacitance 19 or 24, _{L L} is the inductance value of the parallel inductor 20 or 25, _{C L} is the capacitance value of the series capacitance 17 or 22, omega is Each frequency, α is an attenuation constant, and β is a phase constant. FIG. 5 shows the frequency characteristics of the phase constant when L _R C _L > L _L C _R. Reference numeral 26 denotes a band end frequency f _cl on the low frequency side of a band where the value of the phase constant is other than 0, and 27 denotes a band end frequency f _se on the high frequency side of a band where the value of the phase constant is other than 0. The following expressions (4) to (8) are expressed.

  In the first embodiment, as shown in FIG. 1, the first strip conductor 2, the short stub 6, and the input / output lines 7 and 8 are routed from the cross section BB ′ via the first floating conductor 4. Therefore, the influence from the cross section BB ′ is small. On the other hand, since the first floating conductor 4 is connected to the cross section BB ′, the cross section BB ′ becomes a magnetic wall during the even mode operation, so the first floating conductor 4 is not connected to any conductor. Although it becomes a conductor, since the cross section BB ′ becomes an electric wall during the odd mode operation, the first floating conductor 4 becomes a ground conductor.

Therefore, in the even mode operation (FIG. 3), the portion where the input / output line 7 and the first floating conductor 4 face each other also contributes to the capacitance 17, but in the odd mode operation (FIG. 4), Since one floating conductor 4 serves as a ground conductor, the portion where the input / output line 7 and the first floating conductor 4 face each other does not contribute to the capacitance 22. That is, when the value of the even-mode series capacitance 17 is C ^e _L and the value of the odd-mode series capacitance 22 is C ⁰ _L , C ^e _L > C ⁰ _L.

  Therefore, the band edge frequency 27 on the high frequency side in the even mode operation moves to the high frequency side in the odd mode operation from the equation (5). At this time, when the dimensions are determined by the series capacitances 17 and 22 so that the low-frequency side band-end frequency 26 moves to the high-frequency side as in the high-frequency side band-end frequency 27, the characteristics of the phase constant are as shown in FIG. It becomes like this. In FIG. 6, 28 represents the frequency characteristic of the phase constant in the even mode, and 29 represents the frequency characteristic of the phase constant in the odd mode.

From the foregoing, in the first embodiment, by providing the first floating conductor 4, it is possible to increase the difference between the values of C _L in even-odd mode, the even-odd mode as shown in FIG. 6 The characteristics change so that the phase constant of the phase shifts in parallel, and even in the case of side coupling, a directional coupler with forward coupling and a broadband coupling with a tight coupling is obtained. Further, if the amount of coupling is the same, the size can be reduced as compared with the forward coupling directional coupler by the conventional method.

  In the above description of the first embodiment, the first floating conductor 4 is arranged on the same surface as the first strip conductor 2 and the second strip conductor 3, but the present invention is not limited to this. As shown in the cross-sectional view, the first floating conductor 4 may be arranged on a different surface from the first strip conductor 2 and the second strip conductor 3. In this case, it goes without saying that the same effect can be obtained.

Embodiment 2. FIG.
FIG. 7 is a top view showing a configuration of a directional coupler using a microstrip line according to Embodiment 2 of the present invention. 7, 1, 4, 7-10, 15 are the same as those in FIG. 1, and are denoted by the same reference numerals, and description thereof is omitted here. 7 is different from FIG. 1 in that one first unit cell 15 is provided in FIG. 1, whereas three first unit cells 15 are provided in FIG. However, also in the configuration of FIG. 7, the first unit cell 15 includes the first strip conductor 2, the second strip conductor 3, the first floating conductor 4, and the short stub 6. This is exactly the same as the configuration shown in FIG. In FIG. 7, reference numeral 30 denotes an inter-unit cell gap that exists between the first unit cells 15. In the second embodiment, the first unit cell 15 is placed between the unit cells so that the left and right ends of the first strip conductor 2 and the left and right ends of the second strip conductor 3 face each other. A plurality are arranged side by side through the gap 30, and three are connected in cascade through the short stub 6 and the ground conductor 5.

  Since the second embodiment can change the phase constant during the even / odd mode operation as in the first embodiment, a directional coupler similar to the first embodiment can be configured. . Further, in the second embodiment, the first unit cell 15 is arranged so that the left and right terminals of the first strip conductor 2 and the left and right ends of the second strip conductor 3 face each other. Since three cascade connections are made via the inter-cell gap 30, the coupling line portion is longer than that in the first embodiment, so that a tighter coupled directional coupler can be realized.

  In the second embodiment, the shapes of the input / output gaps 11 to 14 and the unit cell gap 30 are linear (that is, the side surface shape of the first and second strip conductors 2 and 3 and the side surface of the first floating conductor 4). However, the present invention is not limited to this case, and as shown in FIG. 8, it may be an interdigital capacitor having a shape with fine irregularities, and in this case, the same effect can be obtained. Further, by using an interdigital capacitor, the capacitance value between the inter-cell gaps 30 can be increased, and a directional coupler that is tightly coupled at a lower frequency can be realized.

  In the second embodiment, the first floating conductor 4 is rectangular. However, the present invention is not limited to this, and as shown in FIG. 9, the distance between the first floating conductors 4 is increased. The same effect can be obtained even if the shape is a substantially square shape that is concave toward the inside. In this way, by making the first floating conductor 4 concave inward, the coupling between the first floating conductors 4 is reduced, and the characteristics of the equivalent circuit shown in FIGS. 3 and 4 are closer to each other. A directional coupler with good characteristics can be obtained.

  In the second embodiment, three first unit cells 15 are connected in cascade. However, the present invention is not limited to this, and the number may be two, or four or more first unit cells 15 may be connected in cascade. You may connect. In those cases, it goes without saying that the same effect can be obtained.

Embodiment 3 FIG.
FIG. 10 is a top view showing a configuration of a directional coupler using a microstrip line according to Embodiment 3 of the present invention. 11 is a cross-sectional view taken along a section CC ′ in FIG. 12 is a cross-sectional view taken along a section DD ′ in FIG. In FIG. 10, FIG. 11 and FIG. 12, 31 is arranged at the lower part of the portion where the first strip conductor 2 and the input / output lines 7 and 8 and the second strip line 3 and the input / output lines 9 and 10 face each other. A second floating conductor that is not connected to any conductor. That is, the configuration of the directional coupler in the third embodiment is a configuration in which the second floating conductor 31 is further added to the configuration of the first embodiment shown in FIGS. 1 and 2.

  Also in the third embodiment, similarly to the first embodiment, an electric wall and a magnetic wall can be assumed in the cross section BB ′ serving as a symmetry plane, and the equivalent circuits at that time are shown in FIGS. 3 and 4, respectively. It becomes. That is, as in the first embodiment, since the difference in phase constant during even / odd mode operation can be increased, a directional coupler similar to that in the first embodiment can be configured. Further, since the second floating conductor 31 exists in the vicinity of the input / output gaps 11 to 14 (see FIG. 1), the values of the series capacitances 17 and 22 are increased, and a directional coupler that is tightly coupled at a lower frequency can be obtained. Can be realized.

  In the above description, the second floating conductor 31 is formed at the lower portion of the portion where the first strip conductor 2 and the input / output lines 7 and 8 and the second strip line 3 and the input / output lines 9 and 10 face each other. However, the present invention is not limited to this example, and the first strip conductor 2 and the input / output lines 7 and 8 and the second strip line 3 and the input / output lines 9 and 10 are disposed above the portions facing each other. Needless to say, the same effect can be obtained even in such a case.

Embodiment 4 FIG.
FIG. 13 is a top view showing a configuration of a directional coupler using a microstrip line according to Embodiment 4 of the present invention. In FIG. 13, reference numeral 32 denotes a lower part of a portion where the left and right terminals of the first strip conductor 2 and the left and right terminals of the second strip conductor 3 face each other. 3 is a third floating conductor that is not connected to any of the three. In the fourth embodiment, as shown in FIG. 13, three first unit cells 15 are cascade-connected through a third floating conductor 32. Also in the fourth embodiment, as in the third embodiment shown in FIG. 10, the second floating conductor 31 is arranged below the input / output gap. Therefore, the configuration of the directional coupler according to the fourth embodiment is the same as that of the second embodiment shown in FIG. 7, but the second floating conductor 31 of the third embodiment and the third configuration of the fourth embodiment. The floating conductor 32 is further added.

  Since the fourth embodiment can change the phase constant during the even / odd mode operation as in the third embodiment, a directional coupler similar to the third embodiment can be configured. In addition, since three first unit cells 15 are connected in cascade through the third floating conductor 32, the coupling line portion is longer than that in the third embodiment, so that a more tightly coupled directional coupler is provided. Can be realized.

  In the fourth embodiment, an example has been described in which four second and third floating conductors 31 and 32 are arranged and three first unit cells 15 are connected in cascade. However, this is not the only case. Alternatively, two or four or more first unit cells 15 may be connected in cascade, and a plurality of third floating conductors 32 may be arranged in each unit cell gap. In this case, it goes without saying that the same effect can be obtained.

  In the fourth embodiment, the second floating conductor 31 and the third floating conductor 32 are disposed below the input / output gap or the inter-unit cell gap. You may arrange | position to the upper part of the gap between cells. In this case, it goes without saying that the same effect can be obtained.

Embodiment 5 FIG.
FIG. 14 is a top view showing a configuration of a directional coupler using a microstrip line according to Embodiment 5 of the present invention. 15 is a sectional view taken along a section CC ′ in FIG. 14, and FIG. 16 is a sectional view taken along a section DD ′ in FIG. 14, 15, and 16, reference numeral 33 denotes a portion where the input / output lines 7, 8 and the first strip conductor 2 face each other, and the input / output lines 9, 10 and the second strip line 3 face each other. A fourth floating conductor disposed at a lower portion of each of the portions and not connected to any of the first and second strip conductors. The fourth floating conductor 33 faces the input / output lines 9 and 10 and the second strip line 3 from the lower part of the input / output gap where the input / output lines 7 and 8 and the first strip conductor 2 face each other. It extends to the bottom of the input / output gap. Further, reference numeral 34 in FIG. 14 denotes a second unit cell composed of the first strip conductor 2, the second strip conductor 3, and the short stub 6. That is, the configuration of the fifth embodiment is a configuration in which the first floating conductor 4 is removed from the configuration of the first embodiment shown in FIG. 1 and the fourth floating conductor 33 is disposed instead. Similar to the first unit cell 15 shown in FIG. 1, the second unit cell 34 is arranged.

  In the fifth embodiment, as in the first embodiment, an electric wall and a magnetic wall can be assumed in the cross section BB ′ serving as a symmetry plane, and the equivalent circuits at that time are shown in FIG. 3 and FIG. 4 That is, since the phase constant at the time of even / odd mode operation can be changed as in the first embodiment, a directional coupler similar to that in the first embodiment can be configured. Further, since the fourth floating conductor 33 is present below the input / output gaps 11 to 14, the values of the capacitances 17 and 22 are increased, and a directional coupler that is tightly coupled at a lower frequency can be realized. Further, a simple structure can be obtained as compared with the third embodiment.

  In the fifth embodiment, the fourth floating conductor 33 is disposed below the first and second strip conductors 2 and 3. However, the present invention is not limited to this, and the first and second strip conductors 2 are not limited thereto. , 3 may be arranged at the upper part. In this case, it goes without saying that the same effect can be obtained.

Embodiment 6 FIG.
FIG. 17 is a top view showing a configuration of a directional coupler using a microstrip line according to Embodiment 6 of the present invention. Reference numeral 35 in FIG. 17 denotes a fifth floating conductor disposed below the portion where the second unit cells 34 face each other. The fifth floating conductor 35 has a unit cell in which the left and right ends of the second strip conductor 3 are opposed to each other from the unit cell gap 30 in which the left and right ends of the first strip conductor 2 are opposed to each other. It extends to the gap and is not connected to any of the first and second strip conductors 2 and 3. In the sixth embodiment, three second unit cells 34 are connected in cascade through a fifth floating conductor 35. A plurality of second unit cells 34 are arranged via unit cell gaps 30 such that the left and right ends of the first strip conductor 2 and the left and right ends of the second strip conductor 3 face each other. They are arranged side by side and connected in cascade through the short stub 6 and the ground conductor 5. Therefore, in the configuration of the directional coupler in the sixth embodiment, the first floating conductor 4 is removed from the configuration of the second embodiment shown in FIG. 7, and the fourth floating conductor of the fifth embodiment is used instead. 33 and the fifth floating conductor 35 of the sixth embodiment is further added.

  Since the sixth embodiment can change the phase constant during even / odd mode operation as in the fifth embodiment, a directional coupler similar to the fifth embodiment can be configured. In addition, since the three second unit cells 34 are connected in cascade through the fifth floating conductor 35, the coupled line portion is longer than that in the fifth embodiment, so that a tightly coupled directional coupler is provided. Can be realized.

  In the sixth embodiment, three second unit cells 34 are connected in cascade. However, the present invention is not limited to this, and two or four or more second unit cells 34 are connected in cascade. May be. In this case, it goes without saying that the same effect can be obtained.

  In the sixth embodiment, the fourth floating conductor 33 and the fifth floating conductor 35 are arranged below the first and second strip conductors 2 and 3, but the first and second strip conductors are used. You may arrange | position in the upper part rather than 2,3. In this case, it goes without saying that the same effect can be obtained.

Embodiment 7 FIG.
FIG. 18 is a top view showing a configuration of a directional coupler using a microstrip line according to Embodiment 7 of the present invention. FIG. 19 is a sectional view taken along a section DD ′ in FIG. In FIG. 18 and FIG. 19, reference numeral 36 denotes a lower part (or upper part) of a part of the input / output gap where the input / output lines 7 and 8 and the first strip conductor 2 face each other, and the input / output lines 9 and 10 and the second strip. This is a sixth floating conductor that is disposed near the end in the longitudinal direction of the fourth floating conductor 33 at the lower part (or upper part) of a part of the input / output gap facing the line 3. The sixth floating conductor 36 is not connected to any of the first and second strip conductors 2 and 3. That is, in the configuration of the seventh embodiment, the extended fourth floating conductor 33 of the fifth embodiment shown in FIG. 14 is slightly shortened, and a separate sixth floating conductor is provided at both ends of the shortened ends. In this configuration, a conductor 36 is provided.

  Also in the seventh embodiment, similarly to the first embodiment, an electric wall and a magnetic wall can be assumed in the cross section BB ′ serving as a symmetry plane, and equivalent circuits at that time are shown in FIG. 3 and FIG. 4. That is, as in the first embodiment, since the phase constant during even / odd mode operation can be changed, a directional coupler similar to that in the first embodiment can be configured. Further, due to the even / odd mode, the value of the capacitance contributing to the series capacitances 17 and 22 in FIGS. 3 and 4 by the portion where the input / output lines 7 and 8 and the sixth floating conductor 36 face each other is Since there is almost no change in the odd mode, the difference between the even-mode series capacitance 17 and the odd-mode series capacitance 22 is smaller than that in the fifth embodiment. From this, when the coupling amount is too large due to the large difference between the series capacitances 17 and 22 in the fifth embodiment, the structure of the seventh embodiment has the effect of realizing a loosely coupled directional coupler. is there.

Embodiment 8 FIG.
FIG. 20 is a top view showing a configuration of a directional coupler using a microstrip line according to Embodiment 8 of the present invention. Reference numeral 37 in FIG. 20 denotes a fifth floating conductor 35 at the lower part (or upper part) of a part of the input / output gap where the left and right terminals of the first or second strip conductor of the second unit cell 34 face each other. This is a seventh floating conductor disposed in the vicinity of the end in the longitudinal direction. The seventh floating conductor 37 is not connected to any of the first and second strip conductors 2 and 3. In the eighth embodiment, three second unit cells 34 are cascade-connected so that the left and right terminals of the first strip conductor 2 and the left and right terminals of the second strip conductor 3 face each other. That is, in the configuration of the eighth embodiment, the extended fourth floating conductor 33 and the fifth floating conductor 35 of the sixth embodiment shown in FIG. In this configuration, a sixth floating conductor 36 and a seventh floating conductor 37 are provided separately.

  In the eighth embodiment, the phase constant during the even / odd mode operation can be changed as in the seventh embodiment, so that a directional coupler similar to that in the seventh embodiment can be configured. Further, in the present embodiment, three second unit cells 34 are cascade-connected through the fifth floating conductor 37, so that the coupled line portion is longer than that in the seventh embodiment, so that the denser unit cell 34 is more dense. A coupled directional coupler can be realized.

  In the eighth embodiment, three second unit cells 34 are connected in cascade. However, the present invention is not limited to this, and two or four or more second unit cells 34 are connected to a plurality of fifth unit cells 34. The floating conductor 36 and the seventh floating conductor 37 may be connected in cascade. In such a case, it goes without saying that the same effect can be obtained.

  In the eighth embodiment, the fourth floating conductor 33, the fifth floating conductor 35, the sixth floating conductor 36, and the seventh floating conductor 37 are connected to the input / output lines 7, 8, 9, 10 respectively. However, the present invention is not limited to this, and may be arranged above the input / output lines 7, 8, 9, and 10. In that case, it goes without saying that the same effect can be obtained.

  In the eighth embodiment, the fourth floating conductor 33 and the fifth floating conductor 35 are rectangular (rectangular). However, the present invention is not limited to this, and as shown in FIG. In order to increase the distance between the end portion and the end portion of the fifth floating conductor 35 or the distance between the end portions of the fifth floating conductor 35, the substantially E-shape that is recessed inward may be used. Similar effects can be obtained. Since the fifth floating conductor 35 is recessed in this way, the coupling between the fifth floating conductors 35 is reduced, and the equivalent circuit characteristics shown in FIGS. 3 and 4 are obtained. Thus, a directional coupler with better characteristics can be realized and the design can be facilitated.

  In the eighth embodiment, the first strip conductor 2, the sixth floating conductor 36, and the seventh floating conductor 37 are not connected. However, as shown in FIG. The strip conductors 2 and 3 may be connected to the sixth floating conductor 36 and the seventh floating conductor 37 by the third connection conductor 38. In this case, the same effect can be obtained. 23 is a cross-sectional view taken along a section EE ′ in FIG. As shown in FIG. 23, the connection conductor 38 is disposed so as to penetrate the dielectric substrate 1 from the first and second strip conductors 2 and 3 to the sixth floating conductor 36 or the seventh floating conductor 37. Has been. In this way, the sixth floating conductor 36 and the seventh floating conductor 37 and the first and second strip conductors 2 and 3 are connected via the third connection conductor 38, so that parallelism on the equivalent circuit is achieved. Capacitances 17 and 22 are increased, and a tightly coupled directional coupler can be realized at a lower frequency.

Embodiment 9 FIG.
FIG. 24 is a top view showing a configuration of a directional coupler using a microstrip line according to Embodiment 9 of the present invention. In the ninth embodiment, the inter-unit cell gap 30 is set so that the interval between the unit cell gaps 30 is approximately twice the interval between the input / output gaps 11 to 14 in the second embodiment shown in FIG. The input / output lines 7 to 10 and the first unit cell 15 are connected in cascade. Since other configurations are the same as those of the second embodiment, the description thereof is omitted here.

  25 shows the first unit cell 15 on the side of the input / output lines 7 and 8 from the cross section BB ′ and the input / output line 7 when the cross section BB ′ in FIG. , 8 is an equivalent circuit of the directional coupler according to the ninth embodiment using a strip line composed of. In FIG. 25, 17a is the series capacitance in the even mode due to the input / output gaps 11 and 12. In addition, 17b in FIG. 26 is a series capacitor that is about half the capacitance value of the series capacitance 17a in FIG.

  Since the capacitance 17a in FIG. 25 is connected in series, it can be replaced with a capacitance 17b that is about half the capacitance value of the capacitance 17a, so the equivalent circuit of FIG. 25 is as shown in FIG. On the other hand, in FIG. 24, since the gap between the unit cells 30 is about twice as large as the gap between the input / output gaps 11 to 14, the gap between the unit cells is larger than the capacitance of the input / output gaps 7 to 10. The capacitance of the gap 30 is about ½. Therefore, according to the ninth embodiment, since the configuration is closer to the equivalent circuit shown in FIG. 26, there is an effect that a directional coupler having excellent reflection characteristics with impedance matching can be obtained.

  In the ninth embodiment, three first unit cells 15 are connected in cascade. However, the present invention is not limited to this, and two or four or more first unit cells 15 may be connected in cascade. good. In this case, it goes without saying that the same effect can be obtained.

Embodiment 10 FIG.
FIG. 27 is a top view showing a configuration of a directional coupler using a microstrip line according to Embodiment 11 of the present invention. Second capacitance is set so that the capacitance value due to the input / output gaps 11 to 14 and the fourth floating conductor 33 is approximately twice the capacitance value due to the portion where the second unit cells 34 face each other and the fifth floating conductor 35. The widths of the first strip conductor 2 and the second strip conductor 3 on the side where the unit cells 34 face each other are narrowed. Alternatively, as shown in FIG. 28, the size (width) of the fifth floating conductor 35 is arranged as about half of the size (width) of the fourth floating conductor 33. 27 and 28, three unit cells 34 are cascade-connected to the input / output lines 7 to 10 in both cases. The other configuration is basically the same as the configuration of the sixth embodiment in FIG. Note that the configuration of FIG. 27 and the configuration of FIG. 28 may be combined.

  In the tenth embodiment, the capacitance value of the input / output gaps 11 to 14 and the fourth floating conductor 33 is approximately twice the capacitance value of the portion where the second unit cells 34 face each other and the fifth floating conductor 35. Therefore, the configuration is closer to the equivalent circuit shown in FIG. 26 than in the sixth embodiment, so that there is an effect that a directional coupler having excellent reflection characteristics with impedance matching can be obtained.

  In the tenth embodiment, three second unit cells 34 are cascaded. However, the present invention is not limited to this, and two or four or more unit cells 34 and a fifth floating conductor 35 are cascaded. You may connect.

Embodiment 11 FIG.
FIG. 29 is a top view showing a configuration of a directional coupler using a coplanar line according to Embodiment 11 of the present invention. FIG. 30 is a cross-sectional view taken along a line CC ′ in FIG. In the eleventh embodiment, ground conductor 5 is provided on the surface of dielectric substrate 1 between input / output lines 7 and 9 and between input / output lines 8 and 10. Further, a ground connected to the first and second strip conductors 2 and 3 on the surface of the dielectric substrate 1 between the input / output lines 7 and 8 and between the input / output lines 9 and 10. A conductor 5 is provided.

  Also in the present embodiment, an electric wall and a magnetic wall can be assumed in the cross section BB ′ that is a symmetric plane as in the first embodiment, and the equivalent circuits at that time are shown in FIGS. It becomes. That is, also in the eleventh embodiment, as in the first embodiment, the phase constant during the even / odd mode operation can be changed, so that the directional coupler similar to the first embodiment can be configured. In the eleventh embodiment, the ground conductor 5 is formed on the same plane with respect to the first and second strip lines 2 and 3, the input / output lines 7 to 10, and the first floating conductor 4. Therefore, a structure for connecting the conductor on the upper surface and the conductor on the lower surface of the dielectric substrate 1 becomes unnecessary, and the configuration can be simplified as compared with the first embodiment.

It is the top view which showed the structure of the directional coupler which concerns on Embodiment 1 of this invention. FIG. 2 is a cross-sectional view taken along the line A-A ′ of FIG. 1 showing the configuration of the directional coupler according to Embodiment 1 of the present invention. FIG. 3 is a circuit diagram showing an equivalent circuit when a magnetic wall is assumed in the B-B ′ cross section of FIG. 1 in the directional coupler according to Embodiment 1 of the present invention. FIG. 3 is a circuit diagram showing an equivalent circuit in the case of assuming an electric wall in the B-B ′ cross section of FIG. 1 in the directional coupler according to Embodiment 1 of the present invention. It is explanatory drawing which showed the frequency characteristic in the directional coupler which concerns on Embodiment 1 of this invention with the graph. It is explanatory drawing which showed the frequency characteristic in the directional coupler which concerns on Embodiment 1 of this invention with the graph. It is the top view which showed the structure of the directional coupler which concerns on Embodiment 2 of this invention. It is the top view which showed the structure of the modification of the directional coupler which concerns on Embodiment 2 of this invention. It is the top view which showed the structure of the modification of the directional coupler which concerns on Embodiment 2 of this invention. It is the top view which showed the structure of the directional coupler which concerns on Embodiment 3 of this invention. FIG. 11 is a cross-sectional view taken along the line C-C ′ of FIG. 10 illustrating a configuration of a directional coupler according to Embodiment 3 of the present invention. It is D-D 'sectional drawing of FIG. 10 which showed the structure of the directional coupler which concerns on Embodiment 3 of this invention. It is the top view which showed the structure of the directional coupler which concerns on Embodiment 4 of this invention. It is the top view which showed the structure of the directional coupler which concerns on Embodiment 5 of this invention. FIG. 15 is a cross-sectional view taken along the line C-C ′ of FIG. 14 showing the configuration of a directional coupler according to Embodiment 5 of the present invention. It is D-D 'sectional drawing of FIG. 14 which showed the structure of the directional coupler which concerns on Embodiment 5 of this invention. It is the top view which showed the structure of the directional coupler which concerns on Embodiment 6 of this invention. It is the top view which showed the structure of the directional coupler which concerns on Embodiment 7 of this invention. It is D-D 'sectional drawing of FIG. 18 which showed the structure of the directional coupler which concerns on Embodiment 7 of this invention. It is the top view which showed the structure of the directional coupler which concerns on Embodiment 8 of this invention. It is the top view which showed the structure of the modification of the directional coupler which concerns on Embodiment 8 of this invention. It is the top view which showed the structure of the modification of the directional coupler which concerns on Embodiment 8 of this invention. It is E-E 'sectional drawing of FIG. 22 which showed the structure of the directional coupler which concerns on Embodiment 8 of this invention. It is the top view which showed the structure of the modification of the directional coupler which concerns on Embodiment 9 of this invention. FIG. 25 is a circuit diagram showing an equivalent circuit when a magnetic wall or an electric wall is assumed in the B-B ′ cross section of FIG. 24 in the directional coupler according to Embodiment 9 of the present invention. FIG. 26 is a circuit diagram showing an equivalent circuit of the circuit of FIG. 25 in the directional coupler according to Embodiment 9 of the present invention. It is the top view which showed the structure of the directional coupler which concerns on Embodiment 10 of this invention. It is the top view which showed the structure of the modification of the directional coupler which concerns on Embodiment 10 of this invention. It is the top view which showed the structure of the directional coupler which concerns on Embodiment 11 of this invention. It is C-C 'sectional drawing of FIG. 29 which showed the structure of the directional coupler which concerns on Embodiment 11 of this invention. It is A-A 'sectional drawing which showed the structure of the modification of the directional coupler which concerns on Embodiment 1 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Dielectric board | substrate, 2 1st strip conductor, 2nd strip conductor, 1st floating conductor, 5 Ground conductor, 6 Short stub, 7, 8, 9, 10 Input / output line, 11, 12, 13 , 14 Input / output gap, 15 First unit cell, 16, 21 Transmission line model, 17, 22 Series capacitance, 18, 23 Series inductance, 19, 24 Parallel capacitance, 20, 25 Parallel inductance, 30 Unit cell gap, 31 Second floating conductor, 32 Third floating conductor, 33 Fourth floating conductor, 34 Second unit cell, 35 Fifth floating conductor, 36 Sixth floating conductor, 37 Seventh floating conductor

Claims (10)

A first strip conductor;
A second strip conductor disposed parallel to the first strip conductor;
A first floating conductor provided between the first strip conductor and the second strip conductor and not connected to any conductor;
A ground conductor disposed in the vicinity of the first strip conductor and the second strip conductor;
A first connection conductor connecting the first strip conductor and the ground conductor;
A second connecting conductor connecting the second strip conductor and the ground conductor;
An directional coupler comprising input / output lines provided at both ends of the first strip conductor and both ends of the second strip conductor. A first unit cell is constituted by the first strip conductor, the second strip conductor, the first floating conductor, the first connection conductor, and the second connection conductor,
The plurality of first unit cells are arranged side by side so that the end portions of the first strip conductors face each other and the end portions of the second strip conductors face each other. The directional coupler according to 1.   The first and second portions are disposed above or below a portion where the first strip conductor and the input / output line face each other and above or below a portion where the second strip conductor and the input / output line face each other. 3. The directional coupler according to claim 1, further comprising a second floating conductor that is not connected to any of the two strip conductors.   The first and second strip conductors are provided above or below the portion where the end portions of the first strip conductor face each other and above or below the portion where the end portions of the second strip conductor face each other. 4. The directional coupler according to claim 2, further comprising a third floating conductor that is not connected to any of the first and second floating conductors. A first strip conductor;
A second strip conductor disposed parallel to the first strip conductor;
The first strip conductor and the input / output line are extended from an upper part or a lower part to an upper part or a lower part of a part where the second strip conductor and the input / output line are opposed to each other. A fourth floating conductor not connected to any of the second strip conductors;
A ground conductor disposed in the vicinity of the first strip conductor and the second strip conductor;
A first connection conductor connecting the first strip conductor and the ground conductor;
A second connecting conductor connecting the second strip conductor and the ground conductor;
An directional coupler comprising input / output lines provided at both ends of the first strip conductor and both ends of the second strip conductor. A second unit cell is constituted by the first strip conductor, the second strip conductor, the first connection conductor, and the second connection conductor,
The plurality of second unit cells are arranged side by side so that the end portions of the first strip conductors face each other and the end portions of the second strip conductors face each other. 5. The directional coupler according to 5.   The first and second strips extend from the upper or lower portion of the portion where the end portions of the first strip conductor face each other to the upper or lower portion of the portion where the end portions of the second strip conductor face each other. The directional coupler according to claim 6, further comprising a fifth floating conductor that is not connected to any of the conductors.   The fourth floating is provided above or below the portion where the first strip conductor and the input / output line face each other and above or below the portion where the second strip conductor and the input / output line face each other. 8. A directional coupling according to claim 5, further comprising a sixth floating conductor provided close to an end of the conductor and not connected to any of the first and second strip conductors. vessel.   An end portion of the fifth floating conductor is provided at an upper portion or a lower portion of a portion where the end portions of the first strip conductor face each other and an upper portion or a lower portion of the portion where the end portions of the second strip conductor face each other. 9. A directionality according to any one of claims 6 to 8, further comprising a seventh floating conductor provided adjacent to the first and second strip conductors and not connected to any of the first and second strip conductors. Combiner.   A third connection conductor is provided for connecting at least one of the sixth and seventh floating conductors and at least one of the first and second strip conductors and the input / output line. The directional coupler according to claim 9.

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