Conversion circuit

Abstract

This provides a conversion circuit that can be easily constructed. [Solution] The conversion circuit comprises a waveguide and a grounding pattern connected to the transmission line, the electrical length of which corresponds to one-quarter wavelength of the signal propagating along the transmission line from the portion of the substrate overlapping the waveguide.

Description

Technical Field

[0001] The present disclosure relates to a conversion circuit.

Background Art

[0002] In base station equipment, phased array antennas with multiple antennas installed on a substrate are often used. When using coaxial connectors to connect multiple antennas and transceiver circuits, the work of tightening the connectors is time-consuming and the number of components increases. Therefore, waveguide tubes that enable connectorless may be used. When a waveguide tube is used, a conversion circuit that converts a signal propagating on a microstrip line into a signal propagating on the waveguide tube is used. Patent Document 1 discloses a technology related to a conversion circuit that enables connection between a microstrip line and a waveguide tube.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a conversion circuit that enables connection between a microstrip line and a waveguide tube related to Patent Document 1, a technology that can simply configure the conversion circuit is required.

[0005] One of the objectives of each aspect of the present disclosure is to provide a conversion circuit that can solve the above problems.

Means for Solving the Problems

[0006] According to one aspect of the present disclosure, the conversion circuit comprises a waveguide and a grounding pattern connected to the transmission line, the length of which corresponds to one-quarter wavelength of the signal propagating along the transmission line as an electrical length from the portion of the substrate overlapping the waveguide. [Effects of the Invention]

[0007] According to each aspect of this disclosure, a conversion circuit that can be easily configured can be provided. [Brief explanation of the drawing]

[0008] [Figure 1] The first figure shows an example of the configuration of a conversion circuit according to some embodiments of the present disclosure. [Figure 2] This figure shows an example of the substrate configuration according to some embodiments of the present disclosure. [Figure 3] This figure shows an example of the waveguide configuration according to some embodiments of the present disclosure. [Figure 4] The second figure shows an example of the configuration of a conversion circuit according to some embodiments of the present disclosure. [Figure 5] This figure shows an example of the processing flow of a conversion circuit according to some embodiments of the present disclosure. [Figure 6] The first figure shows an example of the configuration of a comparative conversion circuit according to some embodiments of the present disclosure. [Figure 7] This figure shows an example of the configuration of a comparative substrate according to some embodiments of the present disclosure. [Figure 8] The second figure shows an example of the configuration of a comparative conversion circuit according to some embodiments of the present disclosure. [Figure 9] The first figure shows an example of the configuration of a conversion circuit according to some embodiments of the present disclosure. [Figure 10] The second figure shows an example of the configuration of a conversion circuit according to some embodiments of the present disclosure. [Figure 11] This is a third figure showing an example of the configuration of a conversion circuit according to some embodiments of the present disclosure. [Figure 12]This figure shows an example of the configuration of a conversion circuit according to some embodiments of the present disclosure. [Modes for carrying out the invention]

[0009] The embodiments will be described in detail below with reference to the drawings. <Embodiment> (Configuration of the conversion circuit) A conversion circuit 1 according to an embodiment of the present disclosure will be described with reference to the drawings. The conversion circuit 1 is a circuit that converts a signal propagating through a microstrip line into a signal propagating through a waveguide. Figure 1 is a first diagram showing an example of the configuration of the conversion circuit 1 according to some embodiments of the present disclosure. Figure 2 is a diagram showing an example of the configuration of a substrate 10 according to some embodiments of the present disclosure. Figure 3 is a diagram showing an example of the configuration of a waveguide 20 according to some embodiments of the present disclosure. Figure 4 is a second diagram showing an example of the configuration of the conversion circuit 1 according to some embodiments of the present disclosure.

[0010] The conversion circuit 1 comprises a substrate 10 and a waveguide 20, as shown in Figure 1. For the sake of explanation, the x, y, and z axes are set in a Cartesian coordinate system in three-dimensional space, as shown in Figure 1.

[0011] The substrate 10 is a plate parallel to the xy plane. Here, the surface of the substrate 10 in the positive direction of the z axis is referred to as the front surface, and the surface of the substrate 10 in the negative direction of the z axis is referred to as the back surface. An insulator exists between the front and back surfaces of the substrate 10. The back surface of the substrate 10 is a ground surface composed of a conductor. As shown in Figure 2, the front surface of the substrate 10 includes a microstrip line 101 (an example of a transmission line), a connection part 102, a first conductor part 103, a second conductor part 104, and a plurality of through holes 105. Figure 2 also shows a connection part con on the surface of the substrate 10, indicating the location where it is connected to the waveguide 20.

[0012] As shown in Fig. 2, the end of the microstrip line 101 in the positive x-axis direction is connected to the end of the connection part 102 in the negative x-axis direction. Also, as shown in Fig. 2, the end of the connection part 102 in the positive x-axis direction is connected to the end of the first conductor part 103 in the negative x-axis direction. Further, as shown in Fig. 2, the end of the first conductor part 103 in the positive x-axis direction is connected to a part of the outer shape of the second conductor part 104 surrounding the connection part con that faces the through hole 105 and does not correspond to the connection part con. Also, the second conductor part 104 is connected to the ground on the back surface of the substrate 10 through a plurality of through holes 105.

[0013] For convenience of explanation, the conductor parts of the microstrip line 101, the connection part 102, the first conductor part 103, and the second conductor part 104 have been described separately. However, in actual manufacturing, the microstrip line 101, the connection part 102, the first conductor part 103, and the second conductor part 104 may be integrally manufactured.

[0014] The length X of the first conductor part 103 in the x-axis direction is, as the electrical length, a length corresponding to one-fourth of the wavelength of the signal propagating through the microstrip line 101. Also, the length Y of the first conductor part 103 in the y-axis direction is a length corresponding to the dimensions of the waveguide 20 described later.

[0015] The waveguide 20 is, for example, a ridge waveguide. As shown in FIGS. 1 and 3, when looking down from the positive direction of the z-axis with the positive direction of the x-axis facing left and the positive direction of the y-axis facing down, the waveguide 20 has a U-shape. The waveguide 20 is composed of conductors along the U-shaped outer contour. That is, as shown in FIG. 3, the waveguide 20 includes flat plates A, B, C, D, E, F, G, and H. Each of the flat plates A, B, C, D, E, F, G, and H is a conductor. Note that the flat plates A, C, E, and G are flat plates parallel to the yz plane. Also, the flat plates B, D, F, and H are flat plates parallel to the zx plane. There is no conductor parallel to the xy plane. Further, in the flat plate G near the connection part between the microstrip line 101 and the connection part 102, there is a notch for connecting the space on the microstrip line 101 and the space in the waveguide 20.

[0016] The lengths of the flat plates B and D in the x-axis direction are the same as the length X of the first conductor part 103 in the x-axis direction described above. That is, the lengths of the flat plates B and D in the x-axis direction are, as the electrical length, lengths corresponding to one-fourth of the wavelength of the signal propagating through the microstrip line 101. Also, the length of the flat plate C in the y-axis direction is a length Y corresponding to the frequency of the signal propagating through the microstrip line 101. That is, the lengths of the flat plates B and D of the waveguide 20 in the x-axis direction are designed to be lengths that are one-fourth of the wavelength of the signal propagating through the microstrip line 101 as the electrical length. Also, the length of the flat plate C of the waveguide 20 in the y-axis direction is designed to be a length corresponding to the frequency of the signal propagating through the microstrip line 101.

[0017] For the convenience of explanation, the conductor parts of each of the flat plates A, B, C, D, E, F, G, and H have been described separately. However, in actual manufacturing, the flat plates A, B, C, D, E, F, G, and H may be manufactured integrally.

[0018] Figure 4 shows the conversion circuit 1 when the positive x-axis is oriented downwards, the positive z-axis is oriented to the left, and the view is from the positive y-axis to the negative y-axis. As described above, the waveguide 20 is connected to the surface of the substrate 10 by a connector con. Therefore, as shown in Figure 4, the waveguide 20 exists only on the surface side of the substrate 10.

[0019] As mentioned above, one example of a conductor is metal. Furthermore, the connection between the substrate 10 and the waveguide 20 may be by direct contact (i.e., direct connection). Alternatively, the connection between the substrate 10 and the waveguide 20 may use a conductive gasket or the like.

[0020] (Processing performed by conversion circuit 1) Figure 5 is a diagram showing an example of the processing flow of a conversion circuit 1 according to some embodiments of the present disclosure. Next, the processing performed by the conversion circuit 1 will be described with reference to Figure 5. The conversion circuit 1 divides the signal propagating through the microstrip line 101 into a first signal that proceeds to the waveguide 20 and a second signal that proceeds to the first conductor section 103 via the connection section 102 (step S1). The first conductor section 103 converts the second signal into a waveguide mode signal (step S2). The length X in the x-axis direction of the first conductor section 103 is, as an electrical length, equivalent to one-quarter wavelength of the signal propagating through the microstrip line 101. Therefore, the grounded end (i.e., the through-hole 105 which is ground) of the second conductor section 104 located at the connection point with the first conductor section 103 reflects the waveguide mode signal (step S3). The signal reflected at this grounded end proceeds to the waveguide 20 side. The signal reflected at this grounded end is in phase with the first signal. Therefore, the waveguide 20 propagates a signal which is a combination of the first signal and the waveguide mode signal reflected at the ground end (step S4).

[0021] In the above description of the conversion circuit 1, its operation was explained as converting the signal entering from the microstrip line 101 and outputting it to the waveguide 20. However, the conversion circuit 1 can also convert the signal entering from the waveguide 20 and output it to the microstrip line 101. In other words, the conversion circuit 1 enables bidirectional signal conversion between the microstrip line 101 and the waveguide 20.

[0022] (advantage) The conversion circuit 1 according to the embodiment of the present disclosure has been described above. The conversion circuit 1 comprises a waveguide 20 and a first conductor portion 103 (an example of a grounding pattern) connected to the microstrip line 101, with an electrical length corresponding to one-quarter wavelength of the signal propagating through the microstrip line 101 from the portion of the substrate 10 overlapping with the waveguide 20.

[0023] Here, the comparative conversion circuit 900 will be described. Figure 6 is a first diagram showing an example of the configuration of the comparative conversion circuit 900 according to some embodiments of the present disclosure. Figure 7 is a diagram showing an example of the configuration of the comparative substrate 901 according to some embodiments of the present disclosure. Figure 8 is a second diagram showing an example of the configuration of the comparative conversion circuit 900 according to some embodiments of the present disclosure.

[0024] As shown in Figure 6, the conversion circuit 900 comprises a substrate 901 and a waveguide 902. Unlike waveguide 20, waveguide 902 is a waveguide whose outer shape (i.e., all four sides) is surrounded by a conductor. As shown in Figure 7, substrate 901 comprises an insulator 901a, a microstrip line 901b, a first conductor section 901c, a second conductor section 901d, and through-holes 901e. As can be seen from Figure 7, substrate 901 of conversion circuit 900 does not have a configuration corresponding to the first conductor section 103 of substrate 10. Instead, as shown in Figures 6 and 8, conversion circuit 900 has a waveguide 902 portion on the back side of substrate 901 that corresponds to one-quarter wavelength of the signal. This quarter-wavelength portion of waveguide 902 causes the signal propagating from the microstrip line 901b in the positive z-axis direction of waveguide 902 and the signal propagating from the microstrip line 901b in the negative z-axis direction of waveguide 902, reflected at the negative z-axis end of waveguide 902, and propagating in the positive z-axis direction of waveguide 902 to be in phase. Then, the signal propagating from the microstrip line 901b in the positive z-axis direction of waveguide 902 and the signal reflected at the negative z-axis end of waveguide 902 and propagating in the positive z-axis direction of waveguide 902 are combined and propagate in the positive z-axis direction of waveguide 902. In other words, in the conversion circuit 900, it is necessary to process the substrate 901 in order to allow waveguide 902 to penetrate to the back surface of substrate 901.

[0025] Next, the comparative conversion circuit described in Patent Document 1 will be explained. The conversion circuit described in Patent Document 1 uses a ribbon or the like to connect the ridge waveguide and the substrate.

[0026] Therefore, the conversion circuit 1 can simplify the processing of the substrate 10 compared to the substrate 901 of the conversion circuit 900 under comparison. In other words, the conversion circuit 1 can be constructed more simply than the conversion circuit 900 under comparison. Furthermore, if the waveguide 20 is a ridge waveguide, it can be made smaller compared to a waveguide in which the outer shape (i.e., all four sides) of the waveguide 902 is surrounded by a conductor. Also, since the conversion circuit described in Patent Document 1 requires the use of a ribbon or the like for connecting the ridge waveguide and the substrate, the conversion circuit 1 can be constructed more simply than the conversion circuit described in Patent Document 1.

[0027] (Modified examples of the embodiment) A modified example of the embodiment of this disclosure, the conversion circuit 1, is a conversion circuit that includes a stripline 101a, described later, in which a transmission line corresponding to the microstrip line 101 of the conversion circuit 1 according to the embodiment of this disclosure is incorporated as an inner layer. In the modified example of the embodiment of this disclosure, the connection between the stripline 101a and the waveguide 20, described later, may be made using a non-through-hole. Furthermore, in the modified example of the embodiment of this disclosure, the notch present in the conversion circuit 1 according to the embodiment of this disclosure is unnecessary.

[0028] Figure 9 is a first diagram showing an example of the configuration of a conversion circuit 1 according to some embodiments of the present disclosure. Figure 10 is a second diagram showing an example of the configuration of a conversion circuit 1 according to some embodiments of the present disclosure. Figure 11 is a third diagram showing an example of the configuration of a conversion circuit 1 according to some embodiments of the present disclosure.

[0029] A modified example of the embodiment of this disclosure, the conversion circuit 1, comprises a substrate 10 and a waveguide 20, as shown in Figure 9. The substrate 10 is a plate parallel to the xy plane. Here, the surface of the substrate 10 in the positive direction of the z axis is considered the front surface, and the surface of the substrate 10 in the negative direction of the z axis is considered the back surface. As shown in Figure 9, the substrate 10 has a layer 10a on its front surface. Layer 10a is ground. The substrate 10 also has a layer 10c on its back surface. Layer 10c is ground. The substrate 10 also has a layer 10b between layers 10a and 10c. Layer 10b includes ground and a stripline 101a. An insulator exists as a dielectric layer between layers 10a and 10b, and between layers 10b and 10c.

[0030] Layer 10a includes a ground and a number of through-holes 105, as shown in part (a) of Figure 10. Part (a) of Figure 10 also shows a connection point con, which indicates the location where it is connected to the waveguide 20.

[0031] Layer 10b includes a ground, a stripline 101a, a connector 102, and a number of through-holes, as shown in part (b) of Figure 10. Layer 10c includes a ground and a number of through-holes 105, as shown in part (c) of Figure 10. The grounds of layers 10a, 10b, and 10c are connected to each other via the through-holes 105.

[0032] The positive x-axis end of the stripline 101a is connected to the negative x-axis end of the connector 102, as shown in part (b) of Figure 10. The positive x-axis end of the connector 102 is connected to a conductor (i.e., the conductor corresponding to the first conductor 103 in Figure 2) that exists between the connector and the ground and has a length of X in the x-axis direction and a length of Y in the y-axis direction, as shown in part (b) of Figure 10. The length X in the x-axis direction corresponds to one-quarter wavelength of the signal propagating through the stripline 101a as an electrical length. The length Y in the y-axis direction corresponds to the dimensions of the waveguide 20.

[0033] Waveguide 20 is, for example, a ridge waveguide. Waveguide 20, as shown in Figure 11, has a U-shape when viewed from the positive z-axis to the negative z-axis, with the positive x-axis pointing to the left and the positive y-axis pointing downwards. Waveguide 20 is composed of conductors that follow the outer shape of the U-shape. That is, as shown in Figure 11, waveguide 20 comprises flat plates A, B, C, D, E, F, Gg, and H. Each of flat plates A, B, C, D, E, F, Gg, and H is a conductor. Flat plates A, C, E, and Gg are parallel to the yz-plane. Flat plates B, D, F, and H are parallel to the zx-plane. There are no conductors parallel to the xy-plane. Furthermore, unlike the flat plate G near the connection point between the microstrip line 101 and the connection point 102, the flat plate Gg near the connection point between the stripline 101a and the ground of layer 10a does not require a notch.

[0034] (advantage) The above describes a conversion circuit 1 according to a modified embodiment of the present disclosure. The above-described conversion circuit 1 enables bidirectional signal conversion between the stripline 101a and the waveguide 20, even when a stripline 101a different from the microstrip line 101 is provided, similar to the conversion circuit 1 according to the embodiment of the present disclosure. In the conversion circuit 1 according to a modified embodiment of the present disclosure, the flat plate Gg near the connection portion between the stripline 101a and the ground of layer 10a does not require a notch, unlike the flat plate G near the connection portion between the microstrip line 101 and the connection portion 102.

[0035] Figure 12 shows an example of the configuration of a conversion circuit 1 according to some embodiments of the present disclosure. As shown in Figure 12, the conversion circuit 1 comprises a waveguide 701 and a grounding pattern 702. The grounding pattern 702 has an electrical length corresponding to one-quarter wavelength of the signal propagating through the microstrip line from the portion of the substrate that overlaps with the waveguide 701, and is connected to the microstrip line.

[0036] Waveguide 701 can be realized, for example, using the functions of waveguide 20 shown in Figure 1. Grounding pattern 702 can be realized, for example, using the functions of first conductor section 103 shown in Figure 2.

[0037] Several embodiments of the conversion circuit 1 of this disclosure have been described above. This conversion circuit 1 makes it possible to realize a conversion circuit with a simple configuration.

[0038] In addition, the order of processing in the embodiments of this disclosure may be changed, as long as appropriate processing is performed.

[0039] While several embodiments of this disclosure have been described, these embodiments are illustrative and do not limit the scope of the disclosure. These embodiments may be modified in various ways, without departing from the gist of the disclosure.

[0040] Furthermore, some or all of the above embodiments may also be described as follows, but are not limited to these.

[0041] (Note 1) Waveguide and From the portion of the substrate overlapping the waveguide, the electrical length corresponds to one-quarter wavelength of the signal propagating through the microstrip line, and a grounding pattern connected to the microstrip line, A conversion circuit equipped with this.

[0042] (Note 2) The waveguide is a ridge waveguide. The conversion circuit described in Appendix 1.

[0043] (Note 3) The waveguide is, Extending in a direction perpendicular to the plane including the microstrip line, and propagating signals in the said perpendicular direction, The conversion circuit described in Appendix 1 or Appendix 2.

[0044] (Note 4) The first surface of the substrate includes a connection portion with the waveguide, and a conductor is connected to the ground, which is the back surface of the first surface, through a plurality of through holes on the outer circumference of the connection portion. A conversion circuit described in any one of the appendices 1 to 3, comprising the above.

[0045] (Note 5) A conversion circuit comprising a waveguide and a ground pattern connected to the microstrip line, the electrical length of which corresponds to one-quarter wavelength of the signal propagating through the microstrip line from the portion of the substrate overlapping the waveguide, The signal propagating along the microstrip line is divided into a first signal that proceeds to the waveguide and a second signal that proceeds to the ground pattern, and the signal obtained by combining the first signal and the signal reflected at the end of the ground pattern is propagated through the waveguide. A processing method that includes the following.

[0046] (Note 6) The waveguide is a ridge waveguide. The processing method described in Appendix 5.

[0047] (Note 7) The waveguide is, Extending in a direction perpendicular to the plane containing the microstrip line, and propagating signals in the said perpendicular direction, The processing method described in Appendix 5 or Appendix 6, including the above.

[0048] (Note 8) The aforementioned conversion circuit The first surface of the substrate includes a connection portion with the waveguide, and a conductor is connected to the ground, which is the back surface of the first surface, through a plurality of through holes on the outer circumference of the connection portion. Equipped with, The signal propagating along the microstrip line is divided into a first signal that proceeds to the waveguide and a second signal that proceeds to the ground pattern, and the signal obtained by combining the first signal and the signal reflected at the end of the ground pattern is propagated through the waveguide. The processing method described in any one of the appendices 5 to 7, including the above. [Explanation of Symbols]

[0049] 1. Conversion circuit 10... Circuit board 20...Waveguide 101...Microstrip Tracks 101a... Stripline 102...Connection part 103...First Conductor Section 104...Second conductor section 105... Through-hole 900...Conversion circuit 901... Circuit board 902...Waveguide 901a...Insulator 901b...Microstrip track 901c...First conductor section 901d...Second conductor section 901e... Through-hole con...connection part A, B, C, D, E, F, G, Gg, H...flat plate

Claims

1. Waveguide and From the portion of the substrate overlapping the waveguide, the electrical length corresponds to one-quarter wavelength of the signal propagating through the transmission line, and the grounding pattern connected to the transmission line, A conversion circuit equipped with this.

2. The waveguide is a ridge waveguide. The conversion circuit according to claim 1.

3. The waveguide is, Extending in a direction perpendicular to the plane including the transmission line, and propagating signals in the aforementioned vertical direction, The conversion circuit according to claim 1.

4. The aforementioned transmission line is a microstrip line, The first surface of the substrate includes a connection portion with the waveguide, and a conductor is connected to the ground, which is the back surface of the first surface, through a plurality of through holes on the outer circumference of the connection portion. The conversion circuit according to claim 1, comprising:

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