JP5270474B2 - High-frequency connection wiring board and optical modulator module having the same - Google Patents

Description

  The present invention relates to a high-frequency connection wiring board applied to connection between an optical device or an electronic device operated at a high speed of several tens of GHz in optical communication or the like and an electric driver for driving them, and an optical modulator module including the same About.

  As a typical optical device to which high-speed electrical connection wiring is applied, there is an optical modulator using a dielectric material. In recent years, high-speed and large-capacity optical communication systems have been put into practical use. However, development of high-speed, small, and low-cost optical modulation devices for incorporation into such high-speed and large-capacity optical communication systems is required. Yes.

As an optical device that meets such demands, an optical waveguide such as lithium niobate (LiNbO ₃ ) is applied to a substrate having a so-called electro-optic effect (hereinafter referred to as an LN substrate) whose refractive index changes by applying an electric field. And a traveling wave electrode type lithium niobate light modulator (hereinafter abbreviated as an LN light modulator). This LN optical modulator is applied to a large capacity optical communication system of 2.5 Gbit / s and 10 Gbit / s because of its excellent chirping characteristics. Recently, application to a 40 Gbit / s ultra-high capacity optical communication system is also being studied.

  Hereinafter, an outline of a conventional LN optical modulator and a high-frequency connection wiring board necessary for actually modularizing the LN optical modulator will be described.

(First prior art)
FIG. 8 shows a perspective view of an LN optical modulator chip 30 using a z-cut LN substrate disclosed in Patent Document 1. As shown in FIG. FIG. 9 is a cross-sectional view taken along the line AA ′ of FIG. An optical waveguide 3 is formed on the z-cut LN substrate 1. This optical waveguide 3 is an optical waveguide formed by thermally diffusing metal Ti at 1050 ° C. for about 10 hours, and constitutes a Mach-Zehnder interference system (or Mach-Zehnder optical waveguide) as described later. Therefore, two interacting optical waveguides 3a and 3b, that is, two arms of a Mach-Zehnder optical waveguide are formed in a portion (referred to as an interacting portion) where the electrical signal and light of the optical waveguide 3 interact.

A Si conductive layer 2 for suppressing temperature drift caused by a pyroelectric effect peculiar to an LN modulator manufactured using a SiO ₂ buffer layer 2 on the upper surface of the optical waveguide 3 and a z-cut LN substrate 1 thereon. ′ Is formed. Further, a traveling wave electrode 4 is formed on the upper surface of the Si conductive layer 2 '. As the traveling wave electrode 4, a coplanar waveguide (CPW) having one central conductor 4a and two ground conductors 4b and 4c is used. Normally, the traveling wave electrode 4 is made of Au.

  When a high-frequency electric signal of 10 Gbps or more for modulation is supplied to the center conductor 4a and the ground conductor 4b of the LN optical modulator chip 30, an electric field is applied between the center conductor 4a and the ground conductors 4b and 4c. Since the z-cut LN substrate 1 has an electro-optic effect, a refractive index change is caused by this electric field, and a shift occurs in the phase of light propagating through the two interactive optical waveguides 3a and 3b. When this deviation becomes π, the higher-order mode is excited in the multiplexing portion of the optical waveguide 3 as the Mach-Zehnder optical waveguide, and as a result, the light is turned off. When a voltage is applied between the center conductor 4a and the ground conductor 4b, the optical signal (or optical output) repeats ON → OFF → ON.

  When the LN optical modulator chip is actually used, it is used as a so-called module contained in a package. FIG. 10 shows a schematic top view thereof. Here, 5 is a housing, and the LN optical modulator chip 30 shown in FIGS. 8 and 9 is fixed to a pedestal 6 from which a part of the housing 5 protrudes (or a separate member). Reference numerals 7a and 7b denote single-mode optical fibers for light incidence and single-mode optical fibers for light emission, 8 is a high-frequency connector, and 9 is a core wire of the high-frequency connector. Reference numeral 5 ′ denotes a cavity provided in the housing 5, and a characteristic impedance of approximately 50Ω is realized by setting with the core wire 9 of the high frequency connector.

  In order to simplify the description of the figure, the pedestal 6 is provided only below the LN optical modulator chip 30 and the high-frequency connection wiring board I, but the scope of application of the present invention is not limited to this. It goes without saying that it is not.

  I is a high-frequency connection wiring board that plays an extremely important role of electrically connecting the high-frequency connector (or RF connector) 9 and the LN optical modulator chip 30, and has the configuration disclosed in Patent Document 2. is there. In addition, 10 is a main body substrate (hereinafter referred to as a substrate) which is a main body of the high-frequency connection wiring board, 11 is a central conductor of the high-frequency connection wiring board, 12 and 13 are ground conductors of the high-frequency connection wiring board, and 14 is grounded with the base 6. A via hole 15 for establishing electrical continuity with the conductors 12 and 13 is a wire for electrically connecting the high-frequency connection wiring board 30 with the via hole 15. These configurations up to inputting a high-frequency electrical signal from the outside to the LN optical modulator chip 30 constitute a high-frequency connection wiring structure.

FIG. 11 is a partial perspective view of the high-frequency connection wiring board, and FIG. 12 is a partial enlarged view. As can be seen from this figure, the high-frequency connection wiring board disclosed in Patent Document 2 is a microstrip line in the region II including the portion electrically connected to the core wire 9 of the high-frequency connector (that is, the input portion of the high-frequency electrical signal). In the region III including a portion (that is, a high-frequency electric signal output portion) that is electrically connected to the LN optical modulator chip 30 having the CPW traveling wave electrode structure, CPW (strictly speaking, a CPW with a ground conductor) is provided. ). Therefore, this structure is called a microstrip-CPW conversion structure. FIG. 13 is a cross-sectional view taken along the line BB ′ of FIG. For later explanation, the lengths of the microstrip region II and the CPW region III are L ₂ and L ₃ , respectively.

For example, consider a high-frequency connection wiring substrate when Al ₂ O ₃ having a thickness of 500 μm is used as the substrate 10. The width S of the connection portion of the central conductor of the high frequency connection wiring board I with the high frequency connector is 500 μm. As for the connection portion with the LN optical modulator chip 30, the width S ₁ of the center conductor 11 is 250 μm, and the gap W ₁ between the center conductor 11 and the ground conductors 12 and 13 is 120 μm.

  Here, FIG. 14 shows a cross-sectional view taken along the line CC ′ of FIG. Here, 9 'is solder for electrically connecting the core wire 9 of the high-frequency connector and the central conductor 11 of the high-frequency connection wiring board I. In order to simplify the drawing, the solder 9 ′ is omitted in FIGS. 10 to 13. Also, the solder 9 'is not shown in most drawings in this specification.

  In FIG. 14, 40 is a line of electric force. Since the connecting portion between the center conductor 11 and the core wire 9 of the high-frequency connector has a microstrip structure, as can be seen from this figure, all the electric lines of force 20 'emitted from the center conductor 11 and the core wire 9 of the high-frequency connector are made of metal. It falls on a pedestal 6.

With respect to the high-frequency connection wiring board according to the first prior art, frequency characteristics of S parameters S ₂₁ and S ₁₁ are shown by dotted lines in FIG. As can be seen from the figure, the characteristics of S ₂₁ and S ₁₁ at low frequencies are relatively good in this first prior art, but S ₂₁ and S ₁₁ deteriorate significantly at higher frequencies.

  Next, the reason for this will be considered. In the microstrip region II, the upper surface of the substrate 10 is naturally not at the same potential as the base 6 of the housing 5, but in the CPW region III, the ground conductors 12 and 13 formed on the upper surface of the substrate 10 are via holes. 14 is at the same potential as the pedestal 6 of the housing 5 which is ground.

Therefore, the high-frequency electric signal that has propagated through the microstrip region II must have a potential as an earth on the upper surface of the substrate 10 in the CPW region III. Therefore, the phase as a high-frequency electric signal changes abruptly at the boundary between the microstrip region II and the CPW region III. This becomes significant as the wavelength of the electric signal becomes shorter (that is, the frequency becomes higher). Therefore, as shown in FIG. 18, the microstrip-CPW conversion structure of the first prior art has its S _{21 at} high frequency. characteristics of the S ₁₁ is deteriorated.

Characteristics of _{S 21} and _{S 11} in a high frequency when the sum of the length _{L 3} of a length _{L 2} and the CPW area III of the microstrip region II is constant in FIG. 19, and changing the length _{L 3} of the CPW area III Show about. From the figure, the longer the length _{L 3} of the CPW area III, that the phase shift of the high frequency electric signal in the microstrip region II and CPW region III becomes large is _{accumulated, S 21} and _{S 11} are both characteristics deteriorate Recognize. This tendency becomes more prominent as the frequency increases.

(Second prior art)
FIG. 15 is a perspective view of a high-frequency connection wiring board having a CPW structure, that is, a so-called CPW-CPW conversion structure, as a second prior art, and FIG. 16 is a top view thereof. This second prior art is shown as a prior art in Patent Document 2. In FIG. 16, the width S _{1 of the} center conductor 16 and the gap W ₁ between the center conductor 16 and the ground conductors 17 and 18 in the region V on the side connected to the LN optical modulator chip 30 are the same as those in the first conventional technique shown in FIG. Same as technology.

On the other hand, the region IV including the connection portion with the high frequency connector 9 (that is, the input portion of the high frequency electric signal) has a normal CPW structure unlike the microstrip structure of the first prior art shown in FIG. Here, the gap _W of width _{S 2} and the center conductor 16 of the central conductor 16 and the ground conductor 17, 18 ₂ was respectively 400 [mu] m, 140 .mu.m consider the impedance matching between the high-frequency connector (not shown). The gap G between the high frequency connector 9 and the side wall of the cavity 5 ′ provided in the housing 5 is about 200 μm. In general, a relationship of G> W ₂ has been used between the gap G and the gap W ₂ . Reference numeral 19 denotes a via hole that is electrically connected to the ground conductors 17 and 18 and a base (not shown) of the housing 5 (see 6 in FIG. 10).

  FIG. 17 is a cross-sectional view taken along the line DD ′ of FIG. As can be seen from this figure, the region IV including the connection portion with the core wire 9 of the high-frequency connector has a complete CPW structure with a relatively small gap, and the diameter of the core wire 9 of the high-frequency connector is as large as about 300 μm. For this reason, most of the electric force lines 41 fly from the core wire 9 and the center conductor 16 (and also the solder 9 ') of the high-frequency connector to the ground conductors 17 and 18, and the amount of the electric force lines 41 falling on the base 6 is small.

FIG. 18 shows the characteristics of S ₂₁ and S ₁₁ of the second prior art by a one-dot chain line. As can be seen from FIG. 18, in the second prior art, the degradation of the characteristics of S ₂₁ and S ₁₁ in the high frequency region is not as great as in the first prior art. However, since the influence of the capacitance generated between the core wire 9 of the high-frequency connector, which is a large conductor, and the ground conductors 12 and 13 is large, the characteristics of S ₂₁ and S ₁₁ are deteriorated in the lower frequency region than in the first conventional technique. Is remarkable. In addition, since the characteristics deteriorated at the low frequency are not improved at the high frequency, the characteristics are deteriorated as a whole.

Japanese Patent Publication No. 7-013711 JP 2003-060403 A

  As described above, in the prior art, the conversion efficiency of the high-frequency electrical signal from the high-frequency connector, that is, the transmission efficiency is poor. In addition, when used when inputting a high-frequency electrical signal to an LN optical modulator, which is one of optical devices, there is a problem that the modulation efficiency of the LN optical modulator is deteriorated as a result. It was. The present invention has been made in view of such circumstances, and is small in size. When used for the conversion efficiency of a high-frequency electrical signal from a high-frequency connector, and further for input to an LN optical modulator, the LN light is used. An object of the present invention is to provide a high-frequency connection wiring board in which the conversion efficiency of a high-frequency electric signal to a traveling wave electrode of a modulator is greatly improved.

In order to solve the above problems, a high-frequency connection wiring board according to claim 1 of the present invention has a center conductor and a ground conductor on a main body board, and a high-frequency electric signal of 10 Gbps or more is input from one end side of the center conductor. A high-frequency connection wiring board from which the high-frequency electrical signal is output from the other end side of the central conductor, wherein the high-frequency electrical signal is externally applied to a casing to which the high-frequency connection wiring board is attached via a base. A high-frequency connector for inputting is fixed to the housing with a core wire having a predetermined distance G from the housing, and the core wire of the high-frequency connector is connected to the one end side of the central conductor. and, in the one end of the center conductor, the distance W ₃ between the center conductor and the ground conductor in the one end side of the front Symbol center conductor and the distance G has a relation of W _3> G DOO To, the distance W ₃ is set to 400Myuemu～3mm, it is characterized by having the transmission characteristics of the S ₂₁ and S ₁₁ to thereby excellent.

In order to solve the above-mentioned problem, the high-frequency connection wiring board according to claim 2 of the present invention is the high-frequency connection wiring board according to claim 1, wherein the distance W ₃ and the distance G have a relationship of W ₃ > 3G. It is characterized by.
In order to solve the above-mentioned problems, the high-frequency connection wiring board according to claim 3 of the present invention is the high-frequency connection wiring board according to claim 1 or 2, wherein the thickness of the high-frequency connection wiring board is approximately 500 μm or thinner than 500 μm. It is characterized by that.

  In order to solve the above-mentioned problem, a high-frequency connection wiring board according to claim 4 of the present invention is the high-frequency connection wiring board according to any one of claims 1 to 3, wherein a via hole is formed in the ground conductor. It is a feature.

  In order to solve the above-mentioned problem, the high-frequency connection wiring board according to claim 5 of the present invention is the high-frequency connection wiring board according to claim 4, wherein the via hole is the central conductor at a portion to which the core wire of the high-frequency connector is connected. It is also characterized in that it is also formed on the ground conductor at a portion opposite to the ground conductor.

  In order to solve the above-described problems, an optical modulator module according to a sixth aspect of the present invention includes an optical modulator chip disposed in the housing, and the high-frequency connection wiring substrate according to any one of the first to fifth aspects. The high-frequency electrical signal is input to the optical modulator chip.

In the present invention, CPW-CPW conversion is used. Therefore, unlike a high-frequency connection wiring board including a conventional microstrip-CPW conversion structure, there is no discontinuity where the phase changes rapidly when a high-frequency electrical signal propagates. In addition, at the location where the core wire of the high frequency connector is connected, the gap between the center conductor of the high frequency connection wiring board and the ground conductor is sufficiently large so that the capacitance formed between the core wire of the high frequency connector and the center conductor and the ground conductor is extremely small. It is spreading. As a result, the high-frequency connection wiring board of the present invention has an advantage of having transmission characteristics with respect to S ₂₁ and S _{11 which} are excellent from the low frequency region to the high frequency region.

The perspective view of the high frequency connection wiring board concerning a 1st embodiment of the present invention. The top view which expanded partially about the high frequency connection wiring board concerning the 1st embodiment of the present invention. Simplified sectional view seen from EE 'in FIG. The figure explaining the principle of this invention The figure explaining the principle of this invention The perspective view of the high frequency connection wiring board concerning a 2nd embodiment of the present invention. The top view which expanded partially about the high frequency connection wiring board concerning the 2nd Embodiment of this invention. The perspective view which shows schematic structure of the conventional LN optical modulator chip | tip. Simplified sectional view seen from AA 'in FIG. A top view showing a schematic configuration of an LN optical modulator module manufactured by applying the high frequency connection wiring board of the first prior art to a conventional LN optical modulator. The perspective view which shows schematic structure about the high frequency connection wiring board of 1st prior art. The top view which shows schematic structure about the high frequency connection wiring board of 1st prior art Simplified sectional view seen from BB 'in FIG. Simplified sectional view seen from CC 'in FIG. The perspective view which shows schematic structure about the high frequency connection wiring board of 2nd prior art The top view which shows schematic structure about the high frequency connection wiring board of 2nd prior art Simplified sectional view seen from DD 'in FIG. The figure explaining a problem about the high frequency connection wiring board of 1st prior art and 2nd prior art The figure explaining a problem about the high frequency connection wiring board of 1st prior art

  Hereinafter, embodiments of the present invention will be described. Here, the case where the present invention is applied to an optical modulator module will be described. Since the same reference numerals as those in the prior art shown in FIGS. 8 to 19 correspond to the same functional units, the description of the functional units having the same reference numerals is omitted here. The aspect of the LN optical modulator module is the same as that of the prior art shown in FIG.

(First embodiment)
FIG. 1 is a perspective view and FIG. 2 is a top view of one embodiment of the high-frequency connection wiring board of the present invention. Moreover, FIG. 3 shows a cross-sectional view taken along line EE ′ of FIG. Here, 20 is a central conductor, 21 and 22 are ground conductors, and 23 is a via hole that establishes electrical continuity between the ground conductors 21 and 22 and the base 6.

For the central conductor 20 of the high-frequency connection wiring board, the width of the connection portion with the core wire 9 of the high-frequency connector is S ₃ and the gap between the ground conductors 21 and 22 is W ₃ . In FIG. 2, the width S _{1 of the} center conductor 20 and the gap W ₁ between the center conductor 20 and the ground conductors 21 and 22 on the side connected to the LN optical modulator chip 30 (that is, the output portion of the high-frequency electrical signal) are This is the same as the first prior art shown in FIG.

Next, the operation principle of the present invention will be described. In the present invention, the gap W ₃ between the center conductor 20 and the ground conductors 21 and 22 is shown in FIG. It is configured to be significantly wider than the gap W ₂ between the center conductor 16 and the ground conductor 17, 18 in the second prior art shown in. Further, the gap W ₃ between the center conductor 20 and the ground conductors 21 and 22 of the high-frequency connection wiring board is wider than the gap G between the core wire of the high-frequency connector in the cavity 5 ′ provided in the housing 5 and the side wall of the cavity 5 ′. (That is, G <W ₃ ). Specifically, with respect to the gap G of about 200 μm, the gap W ₃ between the center conductor 20 and the ground conductors 21 and 22 of the high-frequency connection wiring board was changed from 400 μm to 3 mm.

  As a result, when the electric lines of force distributed symmetrically from the core wire 9 of the high frequency connector to the side wall of the cavity 5 ′ provided in the housing 5 are transferred to the high frequency connection wiring board, this embodiment is the same as FIG. It has a CPW structure. The amount of electric lines of force flying from the core wire 9 and the central conductor 20 (and also the solder 9 ') of the high-frequency connector to the ground conductors 21 and 22 is sufficiently reduced. This can be understood from FIG. That is, a very small amount of the electric force lines 42 are flying to the ground conductors 21 and 22, but most of the electric force lines 42 are falling on the base 6. As described above, in this embodiment, the influence of the capacitance formed between the core wire 9 of the high-frequency connector and the ground conductors 21 and 22 is configured to be extremely small.

  What is important in this embodiment is that, unlike the first prior art shown in FIG. 12, this embodiment does not have a microstrip-CPW conversion structure and is connected to the core wire 9 of the high-frequency connector. Both the region VI and the region VII in which the high-frequency electrical signal propagates for transmission to the LN optical modulator chip 30 (not shown) have a CPW structure.

  Thus, like the second prior art shown in FIG. 16, this embodiment can also be referred to as a CPW-CPW conversion structure. As a result, there is no disturbance in the mode of the high-frequency electrical signal due to the phase shift at the connection between the microstrip region II and the CPW region III, which is a problem in the first prior art of FIG. In order to realize stable transmission with low loss at high frequencies, it is extremely important not to cause a phase shift due to this structural change. In the case of this embodiment, the via conductors 23 are also provided in the connection region VI with the core wire 9 of the high-frequency connector, so that the ground conductors 21 and 22 and the base 6 are electrically connected.

  Since the pedestal 6 and the casing 5 are electrically connected, the ground conductors 21 and 22 and the wall of the casing 5 may be connected by using ribbons or wires instead of the via holes 23. . Furthermore, since the ground conductors 21 and 22 are also provided in the connection region VI with the core wire 9 of the high frequency connector, the connection between the microstrip region and the CPW region can be achieved without using the via hole 23 or a ribbon or a wire. There is no phase shift in the portion, and characteristics superior to those of the first conventional technique can be realized.

FIG. 4 shows the characteristics of S ₂₁ and S ₁₁ of the high-frequency connection wiring board according to the first embodiment of the present invention by solid lines. For comparison, the characteristics of the first prior art and the second prior art are indicated by a dotted line and an alternate long and short dash line, respectively. As can be seen from FIG. 4, this embodiment can stably obtain excellent S ₂₁ and S ₁₁ from low frequency to high frequency.

FIG. 5 shows the characteristics of S ₁₁ with respect to the ratio W ₃ / G of the gap W ₃ between the center conductor 20 and the ground conductors 21 and 22 and the gap G between the core wire of the high frequency connector and the side wall of the cavity 5 ′. Here, the frequency was about 30 GHz. As can be seen from the figure, G <W ₃ is necessary to obtain a reflection characteristic superior to −10 dB which is generally required in practice, but it is even better than that of −10 dB to −15 dB. In order to obtain the reflection characteristic, about 3G <W _{3 is} necessary, and a characteristic that can be said to be almost perfect in practice can be realized. To obtain a reflection characteristic superior to −15 dB, 4G <W ₃ or more, and most preferably 5G <W ₃ You can see that

(Second Embodiment)
FIG. 6 shows a perspective view of the second embodiment of the present invention. FIG. 7 shows a top view thereof. In this embodiment, the via hole 26 is provided in the region IX including the portion connected to the LN optical modulator chip 30 (not shown). However, the center conductor 20 and the core wire 9 of the high-frequency connector are connected to the ground conductors 24 and 25. The via hole 26 is not provided in the region VIII to be connected.

  As described above, since solder is generally used for connection between the center conductor 20 and the core wire 9 of the high-frequency connector, mechanical stress is applied due to a difference in coefficient of thermal expansion of the member when the solder is melted. Therefore, the absence of the via hole 26 in this region VIII has the merit that the mechanical strength is improved and the yield at the time of manufacture is high. Even without the via hole 26, unlike the first embodiment, since the ground conductors 24 and 25 are provided in the region VIII, the phase shift of the high-frequency electric signal at the boundary between the region VIII and the region IX can be almost ignored. .

  Unlike the second prior art, in the present invention, the capacitance between the center conductor 20 or the core wire 9 of the high-frequency connector and the ground conductors 24 and 25 is set to be sufficiently small. As described above, the second embodiment not only has high mechanical strength, but also has the advantage that it is very advantageous in terms of characteristics over the first and second embodiments. However, if the length of the region VIII connecting the center conductor 20 and the core wire 9 of the high-frequency connector is increased, the first embodiment shown in FIG. 2 is more advantageous in terms of characteristics.

(Various embodiments)
In the above, an optical device called an LN optical modulator has been taken up as a device to which the high-frequency connection wiring board of the present invention is applied, but it is not limited to this, and an electroabsorption type or traveling wave electrode type semiconductor optical device may be used. An electronic device may be used. Further, the substrate for forming the high-frequency connection wiring substrate may be an Al ₂ O ₃ substrate, an ALN, or another insulator substrate such as a quartz substrate or an LN substrate, or a semiconductor substrate. Further, the configuration using a CPW electrode having a symmetrical structure has been described as the electrode configuration. However, a CPW electrode having an asymmetric structure may be used. Other configurations such as a strip (CPS) may be used. In the present embodiment, the case where there is one CPW (that is, one central conductor) in the high-frequency connection wiring board has been described. However, the present embodiment is also applicable to an embodiment that includes a plurality of CPWs (that is, a plurality of central conductors). is there.

  As described above, according to the present invention, it is possible to provide a high-frequency connection wiring board in which propagation characteristics of a high-frequency electrical signal from a high-frequency connector to a device are significantly improved.

1: z-cut LN substrate (LN substrate)
2: SiO ₂ buffer layer _{2 ′} : Si conductive layer 3: Mach-Zehnder optical waveguide (optical waveguide)
3a, 3b: Interaction optical waveguide 4: Traveling wave electrode (electrode)
4a: Center conductor 4b, 4c: Ground conductor 5: Housing 5 ': Cavity 6: Base 7a: Single mode optical fiber for light incidence 7b: Single mode optical fiber for light emission 8: High frequency connector 9: Core wire of high frequency connector 9 ': Solder 10: Main board (board) of the high-frequency connection wiring board
11, 16, 20: Center conductor of substrate of high-frequency connection wiring board 12, 13, 17, 18, 21, 22, 24, 25: Ground conductor of substrate of high-frequency connection wiring board 14, 19, 23, 26: Via hole 15 : Wire 30: LN optical modulator chip 40, 41, 42: Electric lines of force I: High frequency connection wiring board

Claims (6)

A high-frequency connection wiring having a center conductor and a ground conductor on a main body substrate, wherein a high-frequency electrical signal of 10 Gbps or more is input from one end side of the center conductor, and the high-frequency electrical signal is output from the other end side of the center conductor A substrate,
A high-frequency connector for inputting the high-frequency electrical signal from the outside is provided in a housing to which the high-frequency connection wiring board is attached via a pedestal, with the core wire having a predetermined distance G from the housing. The core wire of the high-frequency connector and the one end side of the center conductor are connected,
In the one end of the center conductor, together with the distance W ₃ between the center conductor and the ground conductor in the one end side of the front Symbol center conductor and the distance G has a relation of W _3> G, the distance W ₃ Is set to 400 μm to 3 mm , and thereby has excellent transmission characteristics for S ₂₁ and S ₁₁ . RF connection wiring board according to claim 1, wherein the distance W3 and the distance G is characterized by having a W _3> 3 G relationship. The high-frequency connection wiring board according to claim 1 or 2 , wherein the high-frequency connection wiring board has a thickness of about 500 µm or less than 500 µm .   The high-frequency connection wiring board according to claim 1, wherein a via hole is formed in the ground conductor.   The high-frequency connection wiring board according to claim 4, wherein the via hole is also formed in the ground conductor in a portion opposite to the central conductor in a portion to which the core wire of the high-frequency connector is connected.   An optical modulator chip is disposed in the housing, and the high-frequency electrical signal is input to the optical modulator chip via the high-frequency connection wiring board according to claim 1. Optical modulator module.

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