Waveguide tube converter

Abstract

The invention provides a waveguide converter. A plurality of pairs of ground vias disposed so as to face each other across a slit in a plan view may include at least one pair of first ground vias located in a first distance range from the center of the second opening in a direction in which the slit extends in the plan view, and at least one pair of second ground vias located in a second distance range from the center of the second opening in the plan view. The at least one pair of second ground vias is located in a second distance range farther than the first distance range. A minimum distance between via walls of the at least one pair of first ground vias may be wider than a minimum distance between via walls of the at least one pair of second ground vias. A signal of a first frequency band may be transmitted in the transmission line in a first resonant mode, and a signal of a second frequency band different from the first frequency band is transmitted in the transmission line in a second resonant mode different from the first resonant mode.

Description

[0001] The contents of the following patent applications are incorporated herein by reference:

[0002] Application No. 2024-041995 filed in Japan on March 18, 2024. Technical Field

[0003] The present invention relates to a waveguide converter. Background Art

[0004] Patent Document 1 discloses a waveguide converter comprising a waveguide, a patch conductor, a ground conductor, and a port. Patent Document 2 discloses a waveguide converter in which the conductor patches have protrusions on their short sides near both ends of their long sides. Patent Document 3 discloses a short-circuit metal layer having cutouts for arranging a stripline, with the short-circuit metal layer and the stripline arranged at a predetermined distance on a dielectric substrate.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2011-055377

[0008] Patent Document 2: Japanese Patent Application Laid-Open No. 2013-172251

[0009] Patent Document 3: Japanese Patent Application Laid-Open No. 2000-244212 Summary of the Invention

[0010] Problems to be solved by the invention

[0011] In the waveguide converter as described above, a wide-band frequency characteristic can be obtained while suppressing the height of the waveguide.

[0012] Means for solving problems

[0013] A waveguide converter according to one embodiment of the present invention may include: a substrate; and a waveguide disposed on a first surface of the substrate and having a cavity. The substrate may include a dielectric layer. The substrate may include a first ground conductor layer disposed on the waveguide side of the dielectric layer and having a second opening and a slit, the second opening facing the first opening at one end of the cavity of the waveguide, the slit extending from the second opening along the first surface. The substrate may include a transmission line disposed within the slit and extending along the first surface and the slit without contacting the first ground conductor layer. The substrate may include a conductor patch disposed within the second opening without contacting the first ground conductor layer. The substrate may include a connection line disposed along the first surface, within the second opening and the slit, connecting the transmission line to the conductor patch. The substrate may include a second ground conductor layer disposed on the side of the dielectric layer opposite the first ground conductor layer. The substrate may include a plurality of ground vias, arranged along the edges of the second opening and the slit, respectively, when viewed from above, electrically connecting the first and second ground conductor layers. The plurality of ground vias may include a plurality of pairs of ground vias arranged opposite each other across the slit when viewed from above. The plurality of pairs of ground vias may include at least one pair of first ground vias and at least one pair of second ground vias, the at least one pair of first ground vias being located within a first distance range from the center of the second opening in the direction in which the slit extends when viewed from above, and the at least one pair of second ground vias being located within a second distance range farther from the center of the second opening than the first distance range. The minimum distance between the via walls of the at least one pair of first ground vias may be greater than the minimum distance between the via walls of the at least one pair of second ground vias. Signals in a first frequency band may be transmitted through the transmission line in a first resonance mode, and signals in a second frequency band different from the first frequency band may be transmitted through the transmission line in a second resonance mode different from the first resonance mode.

[0014] In the waveguide converter, the first distance range may be a distance range from the center of the second opening along the direction in which the slit extends in a plan view to a distance greater than at least 0.55 times the wavelength of a signal transmitted through the transmission line. The minimum distance between the guide hole walls of the at least one pair of first ground guide holes may be a distance corresponding to a wavelength between 0.5 and 0.6 times the wavelength of the signal.

[0015] In any of the waveguide converters, the first distance range may be a distance range from the center of the second opening along the direction in which the slit extends in a plan view to a distance longer than a distance corresponding to at least 0.65 times the wavelength of the signal.

[0016] In any of the waveguide converters, the characteristic impedance of the connection line may be different from the characteristic impedance of the transmission line.

[0017] In any of the waveguide converters, the characteristic impedance of the connection line may be a value between the characteristic impedance of the transmission line and the impedance of the conductor patch.

[0018] In any of the waveguide converters, the width of the connection line may be different from the width of the transmission line.

[0019] In any of the waveguide converters, the width of the connection line may be narrower than the width of the transmission line.

[0020] In any of the waveguide converters, the substrate may further include a pair of passive elements disposed in the second opening so as to face each other with the conductor patch interposed therebetween in a direction intersecting the direction in which the transmission line extends.

[0021] In any of the waveguide converters, the conductor patch may be in a fan-shaped shape with a center angle ranging from 30 degrees to 160 degrees when viewed from above.

[0022] In any of the waveguide converters, the relative dielectric constant of the dielectric layer may be a value between 2 and 4.

[0023] In any of the waveguide converters, the thickness of the dielectric layer may be between 0.025 mm and 0.5 mm.

[0024] In any of the waveguide converters, the first distance range may be a distance range from the center of the second opening along the direction in which the slit extends to a distance equivalent to twice the wavelength of a signal transmitted in the transmission line.

[0025] In the waveguide converter, the substrate may further include at least one third conductor layer and other dielectric layers that are arranged on the side of the second ground conductor layer opposite to the dielectric layer and are alternately stacked.

[0026] The above summary of the invention does not list all the features of the present invention, and subcombinations of these feature groups may also constitute inventions. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1This is a diagram showing an example of a perspective view of the appearance of the waveguide converter according to the first embodiment.

[0028] Figure 2 This is a plan view of the waveguide converter according to the first embodiment as viewed from the first ground conductor layer side of the substrate.

[0029] Figure 3 yes Figure 1 AA line section view.

[0030] Figure 4 It is a diagram showing simulation results of the transmission amount and reflection amount of the waveguide converter according to the first embodiment.

[0031] Figure 5 It is a top view of a substrate included in a waveguide converter of a comparative example.

[0032] Figure 6 It is a diagram showing simulation results of the transmission amount and reflection amount of the waveguide converter of the comparative example.

[0033] Figure 7 Yes Figure 4 Graph of the electric field distribution on the substrate at frequency f0.

[0034] Figure 8 Yes Figure 4 Graph of the electric field distribution on the substrate at a frequency of 1.05f0.

[0035] Figure 9 This is a graph showing the dependence of the bandwidth of a return loss of 15 dB on the minimum distance Wr and the first distance range Lr.

[0036] Figure 10 This is a graph showing the dependence of the bandwidth of a return loss of 10 dB on the minimum distance Wr and the first distance range Lr.

[0037] Figure 11 This is a plan view of the waveguide converter according to the second embodiment as viewed from the first ground conductor layer side of the substrate.

[0038] Figure 12 This is a plan view of the waveguide converter according to the third embodiment as viewed from the first ground conductor layer side of the substrate.

[0039] Description of labels

[0040] 10 waveguide converters

[0041] 20, 20A, 20B substrate

[0042] 22 dielectric layer

[0043] 24 first ground conductor layer

[0044] 25 second opening

[0045] 26 Second ground conductor layer

[0046] 27 slits

[0047] 30 waveguide

[0048] 32 Hollow

[0049] 33 first opening

[0050] 34 cutout

[0051] 40 transmission lines

[0052] 42, 48 conductor patches

[0053] 44 connection lines

[0054] 46 passive components

[0055] 50, 52, 54, 56, 58 grounding vias

[0056] 100 waveguide converter

[0057] 200 substrates

[0058] Wr minimum distance

[0059] Lr first distance range DETAILED DESCRIPTION

[0060] The present invention will be described below by way of embodiments of the invention, but the following embodiments do not limit the invention as defined in the claims. Furthermore, not all combinations of features described in the embodiments are necessarily essential to the solution provided by the invention.

[0061] In devices with antennas and transceiver circuits operating at high frequencies, such as those in the millimeter-wave band, used in automotive radar and wireless communications, installing a waveguide at the connection between the transmitting / receiving circuit and the antenna can reduce wiring losses and reduce device size. Waveguide converters are sometimes used as these connections to convert power transmitted by the waveguide into power transmitted by transmission lines on a substrate.

[0062] Regarding such waveguide converters, for example, Patent Document 1 discloses a basic structure in which a microstrip line on a substrate is connected to a waveguide from the signal line side. Patent Document 2 also discloses improving frequency characteristics by adding a protrusion to a patch. Furthermore, Patent Document 3 discloses a structure that achieves broadband operation by connecting a ground conductor forming a microstrip line on a substrate to a waveguide from the side of the surface.

[0063] The waveguide converter described in Patent Document 1 has a simple structure, is thin, and has a single resonance point. Therefore, in principle, the frequency band is narrow, making it difficult to achieve the wideband frequency characteristics of 5% or more required for recent millimeter-wave radars.

[0064] The waveguide converter described in Patent Document 2 improves frequency characteristics by adding protrusions to both sides of a conductor patch in the structure described in Patent Document 1. However, the improvement is limited and the high-precision patterning required to add the tiny protrusions to the conductor patch increases costs.

[0065] The waveguide converter described in patent document 3 can achieve broadband frequency characteristics by adding a short-circuit waveguide tube portion with a length of one-quarter of the wavelength. However, since the height of the short-circuit waveguide tube portion is about 1mm to 2mm, it is difficult to achieve thinning. In addition, due to the large deviation caused by the processing accuracy of the short-circuit waveguide tube portion, it is not suitable for mass production. In addition, due to the relationship of arranging a waveguide tube on the side opposite to the signal line surface of the transmission line, when using a multi-layer substrate, it is necessary to utilize expensive substrate materials with low dielectric constant and low dielectric loss tangent in all layers, thus becoming a high-cost structure.

[0066] Therefore, the waveguide converter of this embodiment achieves wide-band frequency characteristics while suppressing the height of the waveguide.

[0067] Figure 1 An example of an external perspective view of the waveguide converter 10 according to the first embodiment is shown. Figure 2 This is a plan view of the substrate 20 included in the waveguide converter 10 as viewed from the first ground conductor layer 24 side. Figure 3 yes Figure 1 AA line section view. Figure 1 In FIG. 1 , the direction along the long side of the conductor patch 42 is defined as the X axis, the direction along the short side of the conductor patch 42 is defined as the Y axis, and the direction in which the cavity 32 of the waveguide 30 extends is defined as the Z axis.

[0068] The waveguide converter 10 includes a substrate 20 and a waveguide tube 30. The waveguide tube 30 is disposed on the first surface 20a side of the substrate 20. The waveguide tube 30 includes a square cylindrical cavity 32 surrounded by a conductive wall. The cavity 32 extends in a direction intersecting the first surface 20a. The cavity 32 can extend in a Z-axis direction perpendicular to the first surface 20a. The waveguide tube 30 includes a first opening 33 at one end of the cavity 32. The first opening 33 is formed by a cross section of the cavity 32 in a direction perpendicular to the signal transmission direction. An antenna for radiating and receiving high-frequency signals such as microwaves or millimeter waves can be connected to the other end of the cavity 32.

[0069] The waveguide 30 can be made of an aluminum alloy. Alternatively, the waveguide 30 may be made of other waveguide conductors, such as brass plated with gold or resin plated with a conductor. Furthermore, the cross-sectional shape of the cavity 32 of the waveguide 30, i.e., the shape of the first opening 33, can be rectangular, such as a square or rectangle. For example, the first opening 33 can have a long side of 3.099 mm and a short side of 1.549 mm, as per the WG-12 standard for the 79 GHz band.

[0070] The substrate 20 includes a dielectric layer 22, a first grounding conductor layer 24, and a second grounding conductor layer 26. The first grounding conductor layer 24 is disposed on the waveguide 30 side of the dielectric layer 22 and includes a second opening 25 opposite the first opening 33 of the waveguide 30 and a slit 27 extending from the second opening 25 along the first surface 20a. The slit 27 extends in a direction intersecting the longitudinal direction of the second opening 25. The slit 27 can extend perpendicularly to the X-axis, which is the longitudinal direction of the second opening 25, and in the Y-axis, which is the direction along the first surface 20a. The second opening 25 can have a shape that conforms to the first opening 33 of the waveguide 30 and can be smaller than the first opening 33. The center of the first opening 33 of the waveguide 30 and the center of the second opening 25 of the waveguide 30 coincide with each other when viewed from above.

[0071] The second grounding conductor layer 26 is arranged on the side of the dielectric layer 22 opposite to the first grounding conductor layer 24. The relative dielectric constant of the dielectric layer 22 can be a value between 2 and 4, for example, 3.1. The thickness of the dielectric layer 22 can be, for example, not less than 0.025 mm and not more than 0.5 mm. The substrate 20 can be composed of an organic substrate or an inorganic substrate, which has two or more conductor layers composed of copper and having a thickness of not less than 1 μm, including the first grounding conductor layer 24 and the second grounding conductor layer 26. The substrate 20 may also have at least one third conductor layer and other dielectric layers arranged alternately on the side of the second grounding conductor layer 26 opposite to the dielectric layer 22. In other words, the substrate 20 can be composed of a multilayer structure in which conductor layers and other dielectric layers are alternately arranged in addition to the first grounding conductor layer 24 and the second grounding conductor layer 26.

[0072] The substrate 20 further includes a transmission line 40, a conductor patch 42, and a connection line 44. The transmission line 40 is disposed within the slit 27 and extends along the first surface 20a and the slit 27 without contacting the first ground conductor layer 24. The conductor patch 42 is disposed within the second opening 25 without contacting the first ground conductor layer 24. The connection line 44 is disposed within the second opening 25 and the slit 27 along the first surface 20a, connecting the transmission line 40 and the conductor patch 42.

[0073] The shape of the conductor patch 42 is consistent with the TE01 mode of the waveguide 30 and is a rectangle or square with its short side approximately half the wavelength of the signal transmitted in the transmission line 40. The characteristic impedance of the connection line 44 may be different from that of the transmission line 40. The characteristic impedance of the connection line 44 may be a value between the characteristic impedance of the transmission line 40 and the impedance of the conductor patch 42. The width of the connection line 44 may be different from that of the transmission line 40. The width of the connection line 44 may be narrower than that of the transmission line 40.

[0074] Furthermore, the connection line 44 may not be used depending on the characteristic impedance of the transmission line 40. That is, the characteristic impedance of the connection line 44 may be the same as that of the transmission line 40. That is, the width of the connection line 44 may be the same as that of the transmission line 40.

[0075] The first ground conductor layer 24 can be formed by cutting a ground conductor plate along the transmission line 40, the conductor patch 42, and the connection line 44. The second ground conductor layer 26 can be formed of a conductor that sufficiently covers the entire surface of the substrate 20 or the width of the transmission line 40, the conductor patch 42, and the connection line 44 in a plan view.

[0076] To prevent the transmission line 40 and the connecting line 44 from contacting the waveguide 30 at the interface between the waveguide 30 and the substrate 20, thereby preventing electrical coupling between the transmission line 40 and the connecting line 44 and the waveguide 30, the waveguide 30 includes a notch 34 that communicates with the cavity 32. The height of the notch 34 can be 0.5 mm or greater, and the width of the notch 34 can be 0.9 mm or greater. The notch 34 can be formed by removing a portion of the conductor wall of the waveguide 30.

[0077] The substrate 20 further includes a plurality of ground vias 50. The plurality of ground vias 50 are formed of a conductor and are arranged along the edges of the second opening 25 and the slit 27 when viewed from above, electrically connecting the first ground conductor layer 24 and the second ground conductor layer 26. The plurality of ground vias 50 are arranged so as to surround the portion of the transmission line 40, the conductor patch 42, and the connection line 44 that are at the same potential.

[0078] The plurality of ground vias 50 include a plurality of pairs of ground vias 52 disposed opposite each other across the slit 27 in a plan view. The plurality of pairs of ground vias 52 include a plurality of pairs of first ground vias 54 and a plurality of pairs of second ground vias 56. The plurality of pairs of first ground vias 54 are located within a first distance range Lr from the center of the second opening 25 along the direction in which the slit 27 extends in a plan view, while the plurality of pairs of second ground vias 56 are located within a second distance range Ls that is further away from the first distance range Lr. The plurality of pairs of ground vias 52 only need to include at least one pair of first ground vias 54 and at least one pair of second ground vias 56.

[0079] The minimum distance Wr between the via walls of the pair of first ground vias 54 is greater than the minimum distance Ws between the via walls of the pair of second ground vias 56. With this configuration, signals in the first frequency band propagate through the transmission line 40 in a first resonance mode, such as the TE01 mode, while signals in a second frequency band, which differs from the first frequency band, propagate through the transmission line 40 in a second resonance mode, such as a higher-order mode, which differs from the first resonance mode.

[0080] The first distance range Lr may be a distance range from the center of the second opening 25 along the direction in which the slit 27 extends in a plan view to a distance greater than at least 0.55 wavelengths of the wavelength of the signal transmitted through the transmission line 40. Alternatively, the first distance range Lr may be a distance range from the center of the second opening 25 along the direction in which the slit 27 extends in a plan view to a distance greater than at least 0.65 wavelengths of the wavelength of the signal. The first distance range Lr may be a distance range from the center of the second opening 25 along the direction in which the slit 27 extends to a distance greater than twice the wavelength of the wavelength of the signal transmitted through the transmission line 40. By setting the first distance range Lr to a distance greater than twice the wavelength, substrate area space can be reduced.

[0081] The minimum distance Wr between the via walls of the pair of first ground vias 54 may be a distance corresponding to a wavelength between 0.5 times and 0.6 times the wavelength of the signal.

[0082] By arranging the pair of ground vias 54 and the pair of second ground vias 56 in the above-described arrangement, in addition to the TM01 mode, which is the first resonant mode in the substrate 20 excited by the conductor patch 42, a higher-order mode, which is the second resonant mode, is generated in a frequency band different from the TM01 mode, which is the first resonant mode. This reduces reflection loss and insertion loss.

[0083] The minimum distance Wr between the via walls of the pair of first ground vias 54 can be, for example, 0.57 times the wavelength of the signal on the substrate 20 (e.g., 1.23 mm in the 79 GHz band). Furthermore, the first distance range Lr of the pair of first ground vias 54 arranged at the minimum distance Wr is maintained from the center of the first opening 33 of the waveguide 30 connected to the substrate 20, i.e., the center of the second opening 25, along the short-side direction of the second opening 25 (the direction in which the slit 27 extends) to 0.8 times the wavelength of the signal (e.g., 1.73 mm in the 79 GHz band). This allows the waveguide converter 10 to be controlled to form a resonator that forms a high-order mode.

[0084] Figure 4 An example of frequency characteristics of the transmission amount and reflection amount of the waveguide converter 10 according to the first embodiment is shown based on a simulation. Figure 5This is a top view of a substrate 200 included in a waveguide converter according to a comparative example. In the comparative example, the minimum distance between the guide hole walls of a pair of ground guide holes 58 disposed opposite each other with the slit 27 interposed therebetween does not meet the requirements of the waveguide converter 10 according to the first embodiment. For example, the minimum distance between the guide hole walls of the pair of ground guide holes 58 disposed opposite each other with the slit 27 interposed therebetween is the same for all of them. Figure 6 An example of frequency characteristics of the transmission amount and reflection amount of the waveguide converter 100 according to the comparative example is shown based on simulation.

[0085] like Figure 6 As shown, the comparative example waveguide converter 100 can maintain a bandwidth of approximately 2% at a reflection level of 15 dB. In contrast, the waveguide converter 10 according to the first embodiment can maintain a bandwidth of 8% or more at a reflection level of 15 dB. In other words, the waveguide converter 10 can achieve wider-bandwidth frequency characteristics than the waveguide converter 100.

[0086] Figure 7 express Figure 4 The electric field distribution on the substrate 20 at the frequency f0 in FIG. Figure 8 express Figure 4 The electric field distribution on the substrate 20 at a frequency of 1.05f0 in FIG. The waveguide converter 10 of the first embodiment forms a high-order mode on the substrate 20, and the resonance point of the high-order mode contributes to widening the frequency band.

[0087] Figure 9 A graph showing the dependence of the bandwidth of a return loss of 15 dB on the minimum distance Wr and the first distance range Lr. Figure 10 A graph showing the dependence of the bandwidth of the return loss of 10 dB on the minimum distance Wr and the first distance range Lr. Figure 9 and Figure 10 The results shown show that the minimum distance Wr between the via walls of the ground via 54 is a compromise between the allowable return loss and the required bandwidth, and therefore an optimal value can be selected according to the application used.

[0088] For example, to ensure at least 2% of the bandwidth when the reflection amount is 15 dB, the minimum distance Wr between the via walls of the pair of first ground vias 54 is preferably a distance corresponding to a wavelength between 0.5 and 0.6 times the wavelength of the signal transmitted through the transmission line 40. Furthermore, the first distance range Lr is preferably a distance range extending to a distance longer than at least 0.55 or at least 0.65 times the wavelength.

[0089] Similarly, for example, to ensure 8% or more of the bandwidth when the reflection amount is 10 dB, the minimum distance Wr between the via walls of the pair of first ground vias 54 is preferably a distance corresponding to a wavelength between 0.5 and 0.6 times the wavelength of the signal transmitted through the transmission line 40. Furthermore, the first distance range Lr is preferably a distance range extending to a distance longer than at least 0.55 or at least 0.65 times the wavelength.

[0090] Figure 11 This is a top view of a substrate 20A included in a waveguide converter according to the second embodiment. Unlike the substrate 20 of the first embodiment, the substrate 20A includes a pair of passive elements 46 disposed within the second opening 25, facing each other with a conductor patch 42 interposed therebetween in a direction intersecting the direction in which the transmission line 40 extends (the X-axis direction). By utilizing the pair of passive elements 46 to add a subresonant point, the frequency bandwidth can be further widened.

[0091] Figure 12 This is a top view of a substrate 20B included in a waveguide converter according to the third embodiment. Unlike the substrate 20 of the first embodiment, substrate 20B includes a sector-shaped conductor patch 48 with a central angle between 30 and 160 degrees when viewed from above. By replacing the conductor patch with a sector-shaped probe, a further widened frequency band can be achieved.

[0092] According to the waveguide converter of each embodiment, even in a structure where a signal line side connecting waveguide is not required to add an expensive short-circuit waveguide that hinders thinning, wideband frequency characteristics can be achieved with low loss and low cost.

[0093] like Figure 6 As shown in FIG. 1 , in the structure of the comparative example, only the TM01 mode resonance point is present as the resonance point, so the bandwidth where the return loss is 15 dB is approximately 2%. On the other hand, when the structure of each embodiment is applied, as shown in FIG. Figure 4 As shown in the figure, two resonance points can be generated at similar frequencies, which can improve the bandwidth of the return loss of 15dB to about 8% at most. Figure 7 In addition to the TM01 mode in the substrate also present in the structure of the comparative example, the additional resonance point is also formed by Figure 8 The resonant portion within substrate 20 formed by ground vias 50 and 52 (54 and 56) as shown generates a high-order mode. This creates two resonant points within the frequency band, achieving wideband, low-loss characteristics. By adopting the structures of each embodiment, low-loss power conversion between the waveguide and transmission line is possible across a wide frequency band, even in a configuration where the waveguide is connected to the signal line side.

[0094] In this embodiment, a wide bandwidth is achieved by generating two resonance points by adding a resonant structure based on the guide hole wall. However, the present invention is not limited to wide bandwidth based on the two resonance points described above. In addition to the resonator structure based on the guide hole wall of this embodiment, further wide bandwidth can be achieved by adding one or more resonance points by adding a resonant structure based on the guide hole wall similar to that of this embodiment, which has resonance points at other frequencies, or by adding other types of resonators.

[0095] While the present invention has been described above using embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It is apparent to those skilled in the art that various modifications or improvements can be made to the above embodiments. As can be seen from the claims, embodiments incorporating such modifications or improvements are also within the technical scope of the present invention.

[0096] (Other possible items)

[0097] (Item 1)

[0098] A waveguide converter comprising:

[0099] substrate;

[0100] a waveguide disposed on the first surface side of the substrate and having a hollow portion, the hollow portion extending along a first direction intersecting the first surface;

[0101] The substrate comprises:

[0102] dielectric layer;

[0103] a first ground conductor layer disposed on the waveguide tube side of the dielectric layer and having a second opening and a slit, the second opening being opposite to the first opening at one end of the hollow portion of the waveguide tube, and the slit extending in a third direction intersecting the second direction, which is the longitudinal direction of the second opening;

[0104] a transmission line disposed in the slot and extending along the first surface and the slot without contacting the first ground conductor layer;

[0105] a conductor patch disposed in the second opening so as not to contact the first ground conductor layer;

[0106] a connecting line, disposed along the first surface and within the second opening and the slit, connecting the transmission line to the conductor patch;

[0107] a second grounding conductor layer disposed on a side of the dielectric layer opposite to the first grounding conductor layer; and

[0108] A plurality of ground vias are arranged along the edges of the second opening and the slit in a plan view, electrically connecting the first ground conductor layer and the second ground conductor layer.

[0109] The plurality of ground vias include a plurality of pairs of ground vias that are arranged opposite to each other with the slit interposed therebetween in a plan view.

[0110] The plurality of pairs of grounding guide holes include at least one pair of first grounding guide holes and at least one pair of second grounding guide holes, wherein the at least one pair of first grounding guide holes are located in a first distance range from the center of the second opening along the direction in which the slit extends in a plan view, and the at least one pair of second grounding guide holes are located in a second distance range farther from the center of the second opening than the first distance range.

[0111] The minimum distance between the guide hole walls of the at least one pair of first ground guide holes is wider than the minimum distance between the guide hole walls of the at least one pair of second ground guide holes.

[0112] A signal of a first frequency band is transmitted in the transmission line in a first resonance mode, and a signal of a second frequency band different from the first frequency band is transmitted in the transmission line in a second resonance mode different from the first resonance mode.

[0113] (Item 2)

[0114] The waveguide converter according to item 1, wherein:

[0115] The first distance range is a distance range from the center of the second opening along the direction in which the slit extends in a plan view to a distance longer than a distance corresponding to at least 0.55 times the wavelength of the signal transmitted in the transmission line.

[0116] The minimum distance between the via walls of the at least one pair of first ground vias is at least a distance corresponding to a wavelength between 0.5 times and 0.6 times the wavelength of the signal.

[0117] (Item 3)

[0118] The waveguide converter according to item 2, wherein:

[0119] The first distance range is a distance range from the center of the second opening along the direction in which the slit extends in a plan view to a distance longer than a distance corresponding to at least 0.65 times the wavelength of the signal.

[0120] (Item 4)

[0121] The waveguide converter according to item 1, wherein:

[0122] The characteristic impedance of the connection line is different from the characteristic impedance of the transmission line.

[0123] (Item 5)

[0124] The waveguide converter according to item 4, wherein:

[0125] The characteristic impedance of the connection line is a value between the characteristic impedance of the transmission line and the impedance of the conductor patch.

[0126] (Item 6)

[0127] The waveguide converter according to item 1, wherein:

[0128] The width of the connection line is different from the width of the transmission line.

[0129] (Item 7)

[0130] The waveguide converter according to item 6, wherein:

[0131] The width of the connection line is narrower than the width of the transmission line.

[0132] (Item 8)

[0133] The waveguide converter according to item 1, wherein:

[0134] The substrate further includes a pair of passive elements that are arranged in the second opening so as to face each other with the conductor patch interposed therebetween in a direction intersecting the direction in which the transmission line extends.

[0135] (Item 9)

[0136] The waveguide converter according to item 1, wherein:

[0137] The conductor patch is in a fan-shaped shape with a central angle ranging from 30 degrees to 160 degrees when viewed from above.

[0138] (Item 10)

[0139] The waveguide converter according to item 1, wherein:

[0140] The relative dielectric constant of the dielectric layer is a value between 2 and 4.

[0141] (Item 11)

[0142] The waveguide converter according to item 1, wherein:

[0143] The thickness of the dielectric layer is between 0.025 mm and 0.5 mm.

[0144] (Item 12)

[0145] The waveguide converter according to item 2 or 3, wherein:

[0146] The first distance range is a distance range from the center of the second opening to a distance corresponding to twice the wavelength of a signal transmitted through the transmission line along the direction in which the slit extends.

[0147] (Item 13)

[0148] The waveguide converter according to item 1, wherein:

[0149] The substrate further includes at least one third conductor layer and other dielectric layers that are arranged on the side of the second ground conductor layer opposite to the dielectric layer and are alternately stacked.

[0150] It should be noted that the order in which actions, processes, steps, and stages, etc., of the apparatuses, systems, programs, and methods described in the claims, specifications, and drawings may be performed in any order, unless otherwise expressly indicated as "before," "prior to," or the like, and the output of an earlier process is not used in a later process. Even if the action flow in the claims, specifications, and drawings is described using phrases such as "first" or "next," for convenience, it does not necessarily mean that the actions must be performed in that order.

Claims

1. A waveguide converter comprising: substrate; a waveguide disposed on the first surface side of the substrate and having a hollow portion, the hollow portion extending along a first direction intersecting the first surface; The substrate comprises: dielectric layer; a first ground conductor layer disposed on the waveguide tube side of the dielectric layer and having a second opening and a slit, the second opening being opposite to the first opening at one end of the hollow portion of the waveguide tube, and the slit extending in a third direction intersecting the second direction, which is the longitudinal direction of the second opening; a transmission line disposed in the slot and extending along the first surface and the slot without contacting the first ground conductor layer; a conductor patch disposed in the second opening so as not to contact the first ground conductor layer; a connecting line, disposed along the first surface and within the second opening and the slit, connecting the transmission line to the conductor patch; a second grounding conductor layer disposed on a side of the dielectric layer opposite to the first grounding conductor layer; as well as A plurality of ground vias are arranged along the edges of the second opening and the slit in a plan view, electrically connecting the first ground conductor layer and the second ground conductor layer. The plurality of ground vias include a plurality of pairs of ground vias that are arranged opposite to each other with the slit interposed therebetween in a plan view. The plurality of pairs of grounding guide holes include at least one pair of first grounding guide holes and at least one pair of second grounding guide holes, wherein the at least one pair of first grounding guide holes are located in a first distance range from the center of the second opening along the direction in which the slit extends in a plan view, and the at least one pair of second grounding guide holes are located in a second distance range farther from the center of the second opening than the first distance range. The minimum distance between the guide hole walls of the at least one pair of first ground guide holes is wider than the minimum distance between the guide hole walls of the at least one pair of second ground guide holes. A signal of a first frequency band is transmitted in the transmission line in a first resonance mode, and a signal of a second frequency band different from the first frequency band is transmitted in the transmission line in a second resonance mode different from the first resonance mode.

2. The waveguide converter according to claim 1, wherein The first distance range is a distance range from the center of the second opening along the direction in which the slit extends in a plan view to a distance longer than a distance corresponding to at least 0.55 times the wavelength of the signal transmitted in the transmission line. The minimum distance between the via walls of the at least one pair of first ground vias is a distance corresponding to a wavelength between 0.5 times and 0.6 times the wavelength of the signal.

3. The waveguide converter according to claim 2, wherein: The first distance range is a distance range from the center of the second opening along the direction in which the slit extends in a plan view to a distance longer than a distance corresponding to at least 0.65 times the wavelength of the signal.

4. The waveguide converter according to claim 1, wherein The characteristic impedance of the connection line is different from the characteristic impedance of the transmission line.

5. The waveguide converter according to claim 4, wherein The characteristic impedance of the connection line is a value between the characteristic impedance of the transmission line and the impedance of the conductor patch. The waveguide converter according to claim 1 , wherein: The width of the connection line is different from the width of the transmission line.

7. The waveguide converter according to claim 6, wherein: The width of the connection line is narrower than the width of the transmission line.

8. The waveguide converter according to claim 1, wherein The substrate further includes a pair of passive elements that are arranged in the second opening so as to face each other with the conductor patch interposed therebetween in a direction intersecting the direction in which the transmission line extends.

9. The waveguide converter according to claim 1, wherein: The conductor patch is in a fan-shaped shape with a central angle ranging from 30 degrees to 160 degrees when viewed from above.

10. The waveguide converter according to claim 1, wherein The relative dielectric constant of the dielectric layer is a value between 2 and 4.

11. The waveguide converter according to claim 1, wherein: The thickness of the dielectric layer is between 0.025 mm and 0.5 mm.

12. The waveguide converter according to claim 2, wherein: The first distance range is a distance range from the center of the second opening to a distance corresponding to twice the wavelength of a signal transmitted through the transmission line along the direction in which the slit extends.

13. The waveguide converter according to claim 3, wherein: The first distance range is a distance range from the center of the second opening to a distance corresponding to twice the wavelength of a signal transmitted through the transmission line along the direction in which the slit extends.

14. The waveguide converter according to claim 1, wherein The substrate further includes at least one third conductor layer and other dielectric layers that are arranged on the side of the second ground conductor layer opposite to the dielectric layer and are alternately stacked.

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