JP5750410B2 - Waveguide, waveguide manufacturing method, waveguide mounting structure, waveguide mounting method, and high-frequency communication module - Google Patents

Description

 The present invention relates to a waveguide, a waveguide manufacturing method, a waveguide mounting structure, a waveguide mounting method, and a high-frequency communication module.

Conventionally, as a waveguide for transmitting high-frequency electromagnetic waves such as microwaves and millimeter waves (synonymous with a waveguide), a hollow waveguide composed of a hollow metal tube having a rectangular or circular cross-sectional shape, or a dielectric A dielectric integrated substrate waveguide (SIW) in which a pseudo waveguide wall is formed by filling a hole provided in a metal, and a dielectric using a polymer material such as a liquid crystal polymer as a dielectric A waveguide or the like is known.
Patent Document 1 below discloses a technique in which a coupler, which is one of components constituting a millimeter wave front end, is configured with a hollow waveguide or a dielectric waveguide.

JP 2004-7365 A

  In recent years, millimeter-wave communication, which does not require a license and performs wireless transmission using a widely open millimeter-wave band, has attracted attention as a large-capacity transmission technology for homes and offices. The recent development of CMOS technology has made it possible to reduce the cost of millimeter-wave IC chips, so the development of millimeter-wave communication modules is proceeding at a rapid pace. Miniaturization and low loss of the analog front end are required.

  As described above, a technique using a hollow waveguide or a dielectric waveguide as a component constituting an analog front end has been conventionally known. However, a hollow waveguide cannot obtain a wavelength shortening effect due to a dielectric, and has dimensions. On the other hand, a dielectric waveguide using a polymer dielectric such as a liquid crystal polymer has a large transmission loss because the thickness dimension cannot be increased and the dielectric loss tangent (tan δ) is large. There is a drawback.

  In addition, it is conceivable to apply SIW, which has been developed in recent years, to the components that make up the analog front end, but this SIW has a low manufacturing cost because the manufacturing process is complicated even if it can be downsized. In addition to the copper loss and the dielectric loss, there is a disadvantage that the total transmission loss is increased due to the occurrence of electromagnetic radiation loss, surface wave excitation loss, and the like.

  Miniaturization and low loss of the analog front end lead to miniaturization and low loss (improvement of transmission efficiency) of the entire millimeter wave communication module. However, as described above, conventional waveguides such as hollow waveguides, dielectric waveguides, and SIW have drawbacks of large dimensions and large transmission loss, and constitute an analog front end of a millimeter wave communication module. The performance required for the parts to be

 The present invention has been made in view of the above-described circumstances, and a waveguide, a waveguide manufacturing method, a waveguide mounting structure, a waveguide mounting method, and a high-frequency communication module that can achieve downsizing and low loss as compared with the prior art. The purpose is to provide.

を満足する伝播モードに応じた長さの前記長辺及び前記短辺を有する矩形の断面形状に形成されることが好ましい。
本発明に係る導波路において、前記硬質誘電体は、純石英、石英化合物、アルミナ、或いはセラミックのいずれかであることが好ましい。
本発明に係る導波路において、前記導波路基体は、アナログ回路部品として付加すべき機能に応じた平面形状を有することが好ましい。
本発明に係る導波路において、前記金属被覆層は、金属メッキによって形成された金属メッキ層であることが好ましい。
本発明に係る導波路において、前記金属メッキ層は、銅メッキによって形成された銅メッキ層であることが好ましい。
本発明に係る導波路において、前記金属被覆層は、前記金属メッキ層と前記導波路基体との密着性を高める目的で形成された下地層を有することが好ましい。 In order to solve the above-described problems, a waveguide according to the present invention is a waveguide that transmits an electromagnetic wave, is made of a hard dielectric, and extends in the propagation direction of the electromagnetic wave, and the surface of the waveguide base The waveguide substrate has a long side of a, a short side of b, a frequency of the electromagnetic wave of f, a speed of light of c, and a relative dielectric constant of the hard dielectric of εr. When

Preferably, it is formed in a rectangular cross-sectional shape having the long side and the short side having a length corresponding to the propagation mode that satisfies the above .
In the waveguide according to the present invention, it is preferable that the hard dielectric is one of pure quartz, a quartz compound, alumina, or ceramic.
In the waveguide according to the present invention, it is preferable that the waveguide base has a planar shape corresponding to a function to be added as an analog circuit component.
In the waveguide according to the present invention, the metal coating layer is preferably a metal plating layer formed by metal plating.
In the waveguide according to the present invention, it is preferable that the metal plating layer is a copper plating layer formed by copper plating.
In the waveguide according to the present invention, it is preferable that the metal coating layer has a base layer formed for the purpose of improving adhesion between the metal plating layer and the waveguide base.

を満足する伝播モードに応じた長さの前記長辺及び前記短辺を有する矩形の断面形状に形成することが好ましい。
本発明に係る導波路製造方法において、前記硬質誘電体として、純石英、石英化合物、アルミナ、或いはセラミックのいずれかを用いることが好ましい。
本発明に係る導波路製造方法において、前記硬質誘電体を加工して、アナログ回路部品として付加すべき機能に応じた平面形状を有する導波路基体を作製することが好ましい。
本発明に係る導波路製造方法において、前記導波路基体の表面に、前記金属被覆層として金属メッキによる金属メッキ層を形成することが好ましい。
本発明に係る導波路製造方法において、前記金属メッキ層として、銅メッキによる銅メッキ層を形成することが好ましい。
本発明に係る導波路製造方法において、前記導波路基体の表面に、前記金属メッキ層と前記導波路基体との密着性を高める目的で下地層を形成した後、前記下地層の表面に前記金属メッキ層を形成することが好ましい。

Further, the waveguide manufacturing method according to the present invention includes a step of processing a hard dielectric material to manufacture a waveguide substrate extending in the propagation direction of the electromagnetic wave in the method of manufacturing a waveguide for transmitting an electromagnetic wave, Forming a metal coating layer on the surface of the waveguide substrate, wherein the waveguide substrate has a long side a, a short side b, the electromagnetic wave frequency f, the speed of light c, and the hard dielectric When the relative dielectric constant is εr,

Preferably, it is formed in a rectangular cross-sectional shape having the long side and the short side having a length corresponding to the propagation mode satisfying the above .
In the waveguide manufacturing method according to the present invention, it is preferable to use any of pure quartz, quartz compound, alumina, or ceramic as the hard dielectric.
In the waveguide manufacturing method according to the present invention, it is preferable that the hard dielectric is processed to produce a waveguide substrate having a planar shape corresponding to a function to be added as an analog circuit component.
In the waveguide manufacturing method according to the present invention, it is preferable to form a metal plating layer by metal plating as the metal coating layer on the surface of the waveguide substrate.
In the waveguide manufacturing method according to the present invention, it is preferable to form a copper plating layer by copper plating as the metal plating layer.
In the waveguide manufacturing method according to the present invention, a base layer is formed on the surface of the waveguide base for the purpose of improving the adhesion between the metal plating layer and the waveguide base, and then the metal is formed on the surface of the base layer. It is preferable to form a plating layer.

Further, in the waveguide mounting structure according to the present invention, the above-described waveguide is embedded and mounted in a groove provided on the surface of the circuit board or in the circuit board, or is mounted on the surface of the circuit board. It is characterized by that.
The waveguide mounting method according to the present invention includes a step of embedding and mounting the above-described waveguide in a groove provided on a surface of the circuit board, a step of embedding and mounting the waveguide in the circuit board, or the A step of surface-mounting the waveguide onto the surface of the circuit board is provided.
Furthermore, a high-frequency communication module according to the present invention includes an analog front end configured by the waveguide mounting structure described above.

 According to the present invention, a waveguide, a waveguide manufacturing method, a waveguide mounting structure, and a waveguide mounting capable of realizing a reduction in size and a loss compared with a conventional hollow waveguide, dielectric waveguide, SIW, and the like. A method and a high-frequency communication module can be provided.

They are the perspective view (a) and sectional drawing (b) of the waveguide 1 which concern on this embodiment. It is a figure which shows the result of having measured the a dependence of the cutoff frequency of the waveguide 1 provided with the waveguide base | substrate 10 of pure quartz. It is a figure which shows the result of having measured the a dependence of the transmission loss of the waveguide 1 provided with the waveguide base | substrate 10 of pure quartz. It is a figure which shows the result of having measured the b dependence of the transmission loss of the waveguide 1 provided with the waveguide base | substrate 10 of pure quartz. It is a figure which shows the result of having measured the frequency dependence of the transmission loss of the waveguide 1 provided with the waveguide base | substrate 10 of the pure quartz with which the width dimension a was set to 2 mm and the thickness dimension b was 1 mm. It is a figure which shows the result of having measured the frequency dependence of the transmission loss of the waveguide 1 provided with the waveguide base | substrate 10 of the pure quartz in which the width dimension a was set to 2 mm and the thickness dimension b was set to 0.5 mm. It is a figure which shows the result of having measured the frequency dependence of the transmission loss of the conventional dielectric waveguide using the liquid crystal polymer by which the width dimension a was set to 2 mm and the thickness dimension b was set to 0.1 mm. It is a figure which shows the modification of the cross-sectional shape of the waveguide base. It is a figure which shows the modification of the planar shape of the waveguide base. It is a figure which shows the manufacturing method of the waveguide 1 which concerns on this embodiment. It is a figure which shows the mounting structure of the waveguide 1 which concerns on this embodiment. It is a figure which shows the mounting method of the waveguide 1 which concerns on this embodiment. It is a circuit block diagram of the millimeter wave communication module 100 which concerns on this embodiment. 1 is a diagram showing a mounting structure of a millimeter wave communication module 100. FIG.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1A is a perspective view of the waveguide 1 according to this embodiment, and FIG. 1B is a cross-sectional view of the waveguide 1 according to this embodiment. As shown in these drawings, a waveguide 1 according to this embodiment is made of a hard dielectric, extends in the propagation direction of electromagnetic waves such as millimeter waves, and has a rectangular waveguide base 10 having a rectangular cross-sectional shape. And a metal coating layer 20 formed on the surface of the waveguide substrate 10.

 The hard dielectric material, which is a constituent material of the waveguide substrate 10, has a large dielectric constant (dielectric loss tangent tanδ is small) compared to a polymer dielectric material such as a liquid crystal polymer used in a conventional dielectric waveguide. It is a dielectric with high hardness. As such a hard dielectric, for example, pure quartz, quartz compound, alumina, or ceramic is preferably used, but is not limited thereto, and other hard dielectrics may be used. In the following, it is assumed that pure quartz (relative dielectric constant εr = 3.82, dielectric loss tangent tanδ = 0.00053) is used as the hard dielectric.

 The metal coating layer 20 is a metal plating layer formed on the surface of the waveguide substrate 10 by metal plating. The metal plating layer is preferably a copper plating layer formed by copper plating, but is not limited thereto, and may be a metal plating layer made of a metal other than copper. The metal coating layer 20 is not limited to a single layer structure, and may have a multilayer structure. Moreover, you may form the metal coating layer 20 not only by metal plating but by other means, such as sputtering and vapor deposition.

In the waveguide 1 having such a configuration, an electromagnetic wave can be propagated in a specific propagation mode by setting the width dimension a and the thickness dimension b of the waveguide substrate 10. For example, by setting the width dimension a and the thickness dimension b of the waveguide base 10 so as to satisfy the following expression (1) (specifically, width dimension a> thickness dimension b), For example, it can be propagated in TE10 mode. In the following formula (1), f is the frequency of the electromagnetic wave, c is the speed of light, and εr is the relative dielectric constant of the hard dielectric.

 The inventor of the present application measured various characteristics of the waveguide 1 having the above-described configuration, and verified the superiority over the conventional waveguide. Hereinafter, the verification result will be described.

 FIG. 2 shows a case where the thickness dimension b of the waveguide base 10 made of pure quartz is 1 mm, and the thickness of the metal coating layer 20 (copper plating layer) is 0.3 μm or more. It is the result of having measured the relationship with a frequency (namely, a dependence of cut-off frequency) about each of two propagation modes (TE10 mode, TE20 mode). From this measurement result, when the waveguide 1 of the present embodiment is applied to millimeter wave communication in the 60 to 70 GHz band, the width dimension a of the waveguide substrate 10 may be set to 1.26 mm or more and 2.19 mm or less. Recognize.

 FIG. 3 shows the transmission loss of the 60 GHz band and the waveguide substrate 10 when the thickness dimension b of the waveguide substrate 10 made of pure quartz is 1 mm and the thickness of the metal coating layer 20 (copper plating layer) is 0.3 μm or more. It is the result of measuring the relationship with width dimension a (that is, a dependence of transmission loss). From this measurement result, it can be seen that the transmission loss in the 60 GHz band becomes smaller as the width dimension a of the waveguide substrate 10 becomes larger.

 FIG. 4 shows the transmission loss in the 60 GHz band and the thickness of the waveguide substrate 10 when the width dimension a of the waveguide substrate 10 made of pure quartz is 2 mm and the thickness of the metal coating layer 20 (copper plating layer) is 0.3 μm or more. It is the result of measuring the relationship with the height dimension b (that is, b dependence of transmission loss). From this measurement result, it can be seen that the transmission loss in the 60 GHz band decreases as the thickness dimension b of the waveguide base 10 increases.

 Based on the above measurement results, FIG. 5 shows the results of measuring the frequency dependence of the transmission loss of the waveguide 1 including the pure quartz waveguide substrate 10 in which the width dimension a is set to 2 mm and the thickness dimension b is set to 1 mm. Shown in FIG. 6 shows the results of measuring the frequency dependence of the transmission loss of the waveguide 1 including the pure quartz waveguide substrate 10 in which the width dimension a is set to 2 mm and the thickness dimension b is set to 0.5 mm. From these measurement results, it can be seen that the transmission loss in the 60 GHz band can be minimized by appropriately setting the width dimension a and the thickness dimension b of the waveguide substrate 10. It can also be seen that the transmission loss in the 60 GHz band can be further reduced as the thickness dimension b of the waveguide substrate 10 is increased.

 On the other hand, FIG. 7 shows a conventional dielectric using a liquid crystal polymer (relative permittivity εr = 3.16, dielectric loss tangent tan δ = 0.003) having a width dimension a of 2 mm and a thickness dimension b of 0.1 mm. It is the result of having measured the frequency dependence of the transmission loss of a body waveguide. From this measurement result, it can be seen that the conventional dielectric waveguide using the liquid crystal polymer has a very large transmission loss in the 60 GHz band as compared with the waveguide 1 of the present embodiment.

 As described above, the reason why the transmission loss of the conventional dielectric waveguide using the liquid crystal polymer is large is that the thickness dimension b cannot be increased, and the waveguide substrate 10 made of a hard dielectric such as pure quartz is used. This is probably because the dielectric loss tangent tan δ is large. On the other hand, the waveguide base body 10 made of a hard dielectric material has a high degree of design freedom in dimensions and a small dielectric loss tangent tan δ. Therefore, by appropriately setting the width dimension a and the thickness dimension b, it is desired to The transmission loss in the frequency band can be minimized.

 Further, as described above, the conventional hollow waveguide has a large size because the wavelength shortening effect by the dielectric cannot be obtained. According to the calculation of the present inventor, for example, in order to realize a cut-off frequency comparable to that of the waveguide 1 of the present embodiment with a hollow waveguide (in other words, the hollow waveguide is used for millimeter wave communication in the 60 GHz band. In order to apply, the width of the hollow waveguide needs to be about 3.7 mm, which is about twice as large as the waveguide 1 (width dimension a = 2 mm) of the present embodiment. That is, the waveguide 1 of the present embodiment can be made smaller than the conventional hollow waveguide.

 As described above, the conventional SIW can be downsized, but transmission loss is large due to generation of electromagnetic radiation loss, surface wave excitation loss, etc. in addition to copper loss and dielectric loss. On the other hand, the waveguide 1 of the present embodiment does not generate electromagnetic radiation loss and surface wave excitation loss, so that transmission loss can be reduced compared with SIW.

 As described above, the waveguide 1 of the present embodiment can realize a reduction in size and a loss compared to a conventional hollow waveguide, a dielectric waveguide using a liquid crystal polymer, SIW, and the like, which will be described below. The performance required as a component constituting the analog front end 110 of the millimeter wave communication module 100 can be satisfied.

 In the above-described embodiment, the case where the waveguide base 10 having a rectangular cross-sectional shape is used is exemplified. However, for example, the waveguide base 11 having a trapezoidal (trapezoidal) cross-sectional shape as shown in FIG. A waveguide base 12 having a circular cross-sectional shape as shown in FIG. 8B or a waveguide base 13 having an elliptical cross-sectional shape as shown in FIG. 8C may be used.

 For example, as shown in FIGS. 9A and 9B, waveguide bases 14 and 15 having a planar shape corresponding to a function to be added as an analog circuit component may be used. As described above, by using the waveguide bases 14 and 15 having a planar shape in which the width changes with respect to the propagation direction of the electromagnetic wave or has a curved portion, for example, as an analog circuit component such as a filter or a resonator. These functions can be added to the waveguide 1.

 In the above-described embodiment, the case where a metal plating layer (for example, a copper plating layer) is formed as the metal coating layer 20 on the surface of the waveguide base 10 is illustrated. However, the metal plating layer and the conductive layer are formed on the surface of the waveguide base 10. After forming a base layer for the purpose of improving the adhesion to the waveguide substrate 10, a metal plating layer may be formed on the surface of the base layer. Further, for the purpose of preventing surface oxidation of the metal plating layer, a gold plating layer by gold plating may be formed on the surface of the metal plating layer.

Next, the manufacturing method of the waveguide 1 mentioned above is demonstrated.
The manufacturing method of the waveguide 1 of the present embodiment includes a processing step of processing a hard dielectric material to produce a waveguide substrate 10 extending in the propagation direction of the electromagnetic wave, and a waveguide substrate 10 obtained from the processing step. A coating layer forming step of forming the metal coating layer 20 on the surface of the substrate. As shown in FIG. 10A, first, in the processing step, a glass substrate made of pure quartz is laser-processed to form a rectangular cross-sectional shape having a width dimension a = 2 mm and a thickness dimension b = 0.5 mm, for example. The rod-shaped waveguide substrate 10 having the same is produced.

 In this processing step, the cross-sectional shape of the waveguide substrate 10 may be processed into a trapezoidal shape, a circular shape, or an elliptical shape as shown in FIG. 8 instead of a rectangular shape. Further, the planar shape of the waveguide substrate 10 may be processed into a shape corresponding to a function to be added as an analog circuit component, as shown in FIG. Further, as the hard dielectric material that is a raw material of the waveguide substrate 10, a quartz compound other than pure quartz, alumina, ceramic, or the like may be used.

 Subsequently, in the coating layer forming step, as shown in FIG. 10B, the electroless copper plating layer 21 having a thickness of about 0.3 μm is formed on the surface of the waveguide base 10 processed into a rectangular shape by electroless plating. Further, as shown in FIG. 10C, the surface of the waveguide substrate 10 is formed by forming an electrolytic plating layer 22 having a thickness of about 1 μm by electrolytic plating on the surface of the electroless copper plating layer 21. The metal coating layer 20 is formed.

 In this coating layer forming process, the metal plating layer (here, a copper plating layer having a multilayer structure of the electroless copper plating layer 21 and the electrolytic plating layer 22) and the waveguide substrate 10 are adhered to the surface of the waveguide substrate 10. In order to improve the properties, a base layer (for example, a titanium layer) may be formed by sputtering or the like, and then a metal plating layer may be formed on the surface of the base layer. Further, for the purpose of preventing surface oxidation of the metal plating layer, a gold plating layer by gold plating may be formed on the surface of the metal plating layer.

Next, the mounting structure of the waveguide 1 described above will be described.
As shown in FIG. 11A, the waveguide 1 according to the present embodiment can be embedded and mounted in a groove 31 provided on the surface of the circuit board 30 or inside the circuit board 30. It can be surface mounted on the surface. In addition, since the waveguide 1 of the present embodiment is hard, it can be surface-mounted so that a part of the waveguide 1 protrudes from the end of the circuit board 30 as shown in FIG.

  For connection between the groove 31 of the circuit board 30 or the waveguide 1 mounted inside and the wiring pattern 32 formed on the back surface of the circuit board 30, for example, as shown in FIG. 33 may be used. In this case, the through hole 33 needs to be formed so as to penetrate the metal coating layer 20 of the waveguide 1 and reach the waveguide base 10. Further, in order to connect the waveguide 1 surface-mounted on the circuit board 30 and the wiring pattern 34 formed on the same surface, as shown in FIG. 11C, the metal coating layer 20 at the end is peeled off. The waveguide 1 may be bonded to the wiring pattern 34 via an adhesive sheet with the waveguide base 10 exposed.

  Such a method of mounting the waveguide 1 includes a step of embedding and mounting the waveguide 1 in a groove portion 31 provided on the surface of the circuit board 30, a step of embedding and mounting the waveguide 1 inside the circuit board 30, Although the process of surface-mounting the waveguide 1 on the surface of the circuit board 30 is included, the process of embedding and mounting the waveguide 1 inside the circuit board 30 will be described below.

  As shown in FIG. 12A, first, after the first adhesive sheet 50 is bonded to the upper surface of the first polyimide sheet 40, the same thickness as that of the waveguide 1 is obtained as shown in FIG. 12B. The second polyimide sheet 60 having openings 61 formed in accordance with the shape and size of the waveguide 1 is bonded to the first adhesive sheet 50. Then, as shown in FIG. 12C, the waveguide 1 is embedded in the opening 61 of the second polyimide sheet 60 and bonded to the first adhesive sheet 50.

  Then, as shown in FIG. 12 (d), after the second adhesive sheet 70 is bonded to the upper surface of the second polyimide sheet 60 and the upper surface of the waveguide 1, the third polyimide sheet 80 is attached to the second polyimide sheet 80. By bonding to the adhesive sheet 70, a multilayer substrate (circuit board 30) in which the waveguide 1 is embedded is obtained. After the circuit board 30 is heated and pressurized, the circuit board 30 is cut so that the cross section of the waveguide 1 is exposed, and the mounting process is completed. If necessary, a through hole for connecting the waveguide 1 and a wiring pattern (not shown) is also formed.

Next, the millimeter wave communication module 100 according to the present embodiment will be described.
FIG. 13 is a circuit configuration diagram of the millimeter wave communication module 100. As shown in this figure, a millimeter wave communication module 100 includes an analog front end 110 that performs analog processing of, for example, a 60 GHz band millimeter wave signal, and a digital back end 130 that performs digital processing of baseband signals and IF signals (intermediate frequency signals). And.

  In the analog front end 110, a local signal (a signal having a frequency in the millimeter wave band) output from the local oscillator 111 is input to the first mixer 113 via the first phase shifter 112. The first mixer 113 receives the local signal and the transmission IF signal output from the digital back end 130 (an intermediate frequency band signal including information to be transmitted). The first mixer 113 mixes (multiplies) the local signal and the transmission IF signal to generate a transmission millimeter wave signal in the millimeter wave band.

  The transmission millimeter wave signal output from the first mixer 113 is subjected to a band limiting process and an amplification process through the first band pass filter 114, the power amplifier 115, and the second band pass filter 116, and then the duplexer. It is input to the ksar 117. The duplexer 117 outputs the transmission millimeter wave signal to the third band pass filter 118. The transmission millimeter wave signal output from the duplexer 117 is transmitted from the transmission antenna 120 via the third band pass filter 118 and the power divider 119.

  On the other hand, the received millimeter wave signal received by the receiving antenna 121 is input to the duplexer 117 through the second phase shifter 122, the power divider 119, and the third band pass filter 118. The duplexer 117 outputs the received millimeter wave signal to the fourth band pass filter 123. The received millimeter wave signal output from the duplexer 117 is subjected to band limiting processing and amplification processing via the fourth bandpass filter 123, the linear amplifier 124, and the fifth bandpass filter 125, and then the second Input to the mixer 126.

  The second mixer 126 receives the received millimeter wave signal after being subjected to band limiting processing and amplification processing, and the local signal output from the local oscillator 111. The second mixer 126 mixes the local signal and the reception millimeter wave signal to generate a reception IF signal (an intermediate frequency band signal including the received information), and outputs the reception IF signal to the digital back end 130. .

  The digital back end 130 includes an IF processor 131 that digitally processes an IF signal, and a baseband processor 132 that digitally processes a baseband signal. The IF processor 131 frequency-converts the transmission baseband signal (baseband signal including information to be transmitted) input from the baseband processor 132 into a transmission IF signal, and the analog front end 110 (first mixer 113). ).

  Further, the IF processor 131 converts the reception IF signal input from the analog front end 110 (second mixer 126) into a reception baseband signal (baseband signal including received information) by performing frequency conversion. The data is output to the band processor 132. On the other hand, the baseband processor 132 performs modulation processing and encoding processing on information to be transmitted, thereby generating a transmission baseband signal and outputting it to the IF processor 131, and receiving baseband input from the IF processor 131. The received information is extracted from the received baseband signal by performing demodulation processing and decoding processing on the signal.

  In the millimeter-wave communication module 100 configured as described above, the local oscillator 111, the first mixer 113, the power amplifier 115, the linear amplifier 124, and the second mixer 126 are excluded from the components constituting the analog front end 110. All (including the signal transmission path) can be configured by the waveguide 1 of the present embodiment. When the components other than the signal transmission path are configured by the waveguide 1, as described above, the planar shape of the waveguide base 10 may be a shape corresponding to a function to be added as an analog circuit component. Thereby, functions such as a phase shifter, a band pass filter, a duplexer, a power divider, and an antenna can be added to the waveguide 1.

  FIG. 14 is a diagram illustrating a mounting structure of the millimeter wave communication module 100. As shown in FIG. 14A, the millimeter wave communication module 100 includes a first circuit board 140 and a second circuit board 150 bonded thereto. The first circuit board 140 includes a first circuit block 141 corresponding to the digital back end 130, and a local oscillator 111, a first mixer 113, a power amplifier 115, a linear oscillator among components constituting the analog front end 110. A second circuit block 142 including an amplifier 124 and a second mixer 126 is mounted.

  As shown in FIG. 14B, the second circuit board 150 includes a first phase shifter 112, a first bandpass filter 114, a second one of the components constituting the analog front end 110. Bandpass filter 116, duplexer 117, third bandpass filter 118, power divider 119, transmission antenna 120, reception antenna 121, second phase shifter 122, fourth bandpass filter 123, and fifth bandpass filter A waveguide 1 corresponding to 125 (including a simple signal transmission path) is embedded and mounted.

  The first circuit block 141 and the second circuit block 142 on the first circuit board 140 are electrically connected by a normal wiring pattern 143, but are configured with the waveguide 1 on the second circuit board 150. The millimeter wave analog circuit thus formed and the second circuit block 142 of the first circuit board 140 are electrically connected by a coupler 144 that penetrates the first circuit board 140 and the second circuit board 150. .

According to the millimeter wave communication module 100 configured as described above, the analog front end 110 is configured by the waveguide 1 of the present embodiment and the mounting structure of the waveguide 1 shown in FIG. And a reduction in loss can be realized, and as a result, the entire module can be reduced in size and loss (improvement in transmission efficiency).
The circuit configuration of the millimeter wave communication module 100 shown in FIG. 13 and the mounting structure of the millimeter wave communication module 100 shown in FIG. 14 are merely examples, and the present invention is not limited to this.

  DESCRIPTION OF SYMBOLS 1 ... Waveguide, 10 ... Waveguide base | substrate, 20 ... Metal coating layer, 100 ... Millimeter wave communication module (high frequency communication module), 110 ... Analog front end, 130 ... Digital back end

Claims (15)

In a waveguide that transmits electromagnetic waves,
A waveguide base made of a hard dielectric and extending in the propagation direction of the electromagnetic wave;
A metal coating layer formed on the surface of the waveguide substrate;
Equipped with a,
The waveguide substrate has a long side of a, a short side of b, the frequency of the electromagnetic wave f, the speed of light c, and the relative dielectric constant of the hard dielectric εr.

A waveguide having a rectangular cross section having the long side and the short side having a length corresponding to a propagation mode satisfying the above . 2. The waveguide according to claim 1 , wherein the hard dielectric is any one of pure quartz, quartz compound, alumina, or ceramic. It said waveguide substrate, a waveguide according to claim 1 or 2, characterized in that it has a planar shape corresponding to the function to be added as an analog circuit components. The metal coating layer, waveguide according to any one of claims 1 to 3, characterized in that a metal plating layer formed by metal plating. The waveguide according to claim 4 , wherein the metal plating layer is a copper plating layer formed by copper plating. 6. The waveguide according to claim 4 , wherein the metal coating layer has a base layer formed for the purpose of improving adhesion between the metal plating layer and the waveguide substrate. In a method of manufacturing a waveguide that transmits electromagnetic waves,
Processing a hard dielectric to produce a waveguide substrate extending in the propagation direction of the electromagnetic wave;
Forming a metal coating layer on the surface of the waveguide substrate;
Have
When the waveguide base is a long side, a short side is b, the electromagnetic wave frequency is f, the speed of light is c, and the relative dielectric constant of the hard dielectric is εr,

A method of manufacturing a waveguide, characterized by forming a rectangular cross-sectional shape having the long side and the short side having a length corresponding to a propagation mode that satisfies the above . 8. The waveguide manufacturing method according to claim 7 , wherein any one of pure quartz, a quartz compound, alumina, or ceramic is used as the hard dielectric. The waveguide manufacturing method according to claim 7 or 8 , wherein the waveguide substrate having a planar shape corresponding to a function to be added as an analog circuit component is manufactured by processing the hard dielectric. The waveguide manufacturing method according to any one of claims 7 to 9 , wherein a metal plating layer by metal plating is formed as the metal coating layer on the surface of the waveguide base. The waveguide manufacturing method according to claim 10 , wherein a copper plating layer is formed by copper plating as the metal plating layer. A base layer is formed on the surface of the waveguide base for the purpose of improving adhesion between the metal plating layer and the waveguide base, and then the metal plating is formed on the surface of the base layer. The waveguide manufacturing method according to claim 10 or 11 . The waveguide according to any one of claims 1 to 6 is embedded in a groove provided on the surface of the circuit board or inside the circuit board, or is surface-mounted on the surface of the circuit board. A waveguide mounting structure characterized by A step of embedding and mounting the waveguide according to any one of claims 1 to 6 in a groove provided on a surface of a circuit board, or a step of embedding and mounting the waveguide inside the circuit substrate, or the conductor A waveguide mounting method comprising a step of surface mounting a waveguide on a surface of the circuit board.   A high-frequency communication module comprising an analog front end constituted by the waveguide mounting structure according to claim 13.

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