WO2023162869A1

WO2023162869A1 - Impedance converter

Info

Publication number: WO2023162869A1
Application number: PCT/JP2023/005627
Authority: WO
Inventors: 幹男福井; 伸司高野; 高史夘野
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2022-02-25
Filing date: 2023-02-17
Publication date: 2023-08-31

Abstract

An impedance converter (1) comprises a cavity (2), an input port (3), an output port (4), and an adjustment mechanism (5). The cavity (2) has an internal space (20) that is electromagnetically sealed. The input port (3) is provided to the cavity (2) for input of radio waves into the internal space (20). The output port (4) is provided to the cavity (2) for output of radio waves from the internal space (20). The adjustment mechanism (5) has a stub (6) that is made of metal and that is disposed in the internal space (20). The adjustment mechanism (5) adjusts the position of the stub (6) between the input port (3) and the output port (4) and the length of the stub (6) inserted in the internal space (20).

Description

impedance converter

The present disclosure relates to impedance converters.

Patent Document 1 discloses an automatic matching device that responds to changes in microwave frequencies. The automatic matching device described in Patent Document 1 is configured as part of a waveguide connecting a microwave power source and a load, and includes a directional coupler, three stubs, and a controller.

By adjusting the insertion length of the three stubs, it is possible to change the reflection coefficient at the reference point on the load side set for the load in the waveguide. That is, the three stubs function as impedance modifiers.

JP 2018-32974 A

In the impedance changing means described in Patent Document 1, the reflected impedance is changed by changing the insertion length of the three stubs. Since the insertion length of the three stubs and the change in the actual impedance have no regularity, it is necessary to search for the conditions of the three stubs to obtain the desired impedance by trial and error.

An object of the present disclosure is to provide an impedance converter that can perform impedance conversion with a simple operation.

An impedance converter of one aspect of the present disclosure includes a cavity, an input port, an output port, and an adjustment mechanism.

The cavity has an electromagnetically sealed internal space. An input antenna is provided in the cavity for inputting radio waves into the internal space of the cavity. An output port is provided in the cavity for outputting radio waves from the internal space of the cavity.

The adjustment mechanism has a metal stub arranged within the internal space of the cavity. An adjustment mechanism adjusts the position of the stub between the input port and the output port and the insertion length of the stub. The stub insertion length is the effective length of the stub inserted into the internal space of the cavity.

According to the aspect of the present disclosure, impedance conversion can be performed with a simple operation.

FIG. 1 is a perspective view from above showing the appearance of an impedance converter according to an embodiment of the present disclosure. FIG. 2 is a perspective view from below showing the appearance of the impedance converter according to the embodiment. FIG. 3 is a plan view of the impedance converter according to the embodiment. 4 is a cross-sectional view taken along line 4--4 of FIG. 3. FIG. FIG. 5 is an exploded perspective view of the impedance converter according to the embodiment. 6 is a cross-sectional view taken from below along line 6--6 of FIG. 4; FIG. FIG. 7 is an exploded perspective view of the adjustment mechanism of the impedance converter according to the embodiment. FIG. 8 is an enlarged cross-sectional view of the periphery of the electrical connection portion of the impedance converter according to the embodiment. FIG. 9 is a plan view showing the first position of the stub in the impedance converter according to the embodiment. 10 is a cross-sectional view along line 10-10 of FIG. 9. FIG. FIG. 11 is a plan view showing the second position of the stub in the impedance converter according to the embodiment. 12 is a cross-sectional view taken along line 12-12 of FIG. 11. FIG. FIG. 13 is a cross-sectional view showing the third position of the stub in the impedance converter according to the embodiment. FIG. 14 is a cross-sectional view showing the fourth position of the stub in the impedance converter according to the embodiment. FIG. 15 is a Smith chart showing a first example of impedance change by the impedance converter according to the embodiment. FIG. 16 is a Smith chart showing a second example of impedance change by the impedance converter according to the embodiment. FIG. 17 is a Smith chart showing a third example of impedance change by the impedance converter according to the embodiment.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings as appropriate. However, detailed descriptions of known matters and redundant descriptions of substantially the same configurations may be omitted.

[composition]
1 to 6 show configuration examples of an impedance converter 1 according to the present embodiment. FIG. 1 is a perspective view from above showing the appearance of the impedance converter 1. FIG. FIG. 2 is a perspective view from below showing the appearance of the impedance converter 1. As shown in FIG. FIG. 3 is a plan view of the impedance converter 1. FIG. 4 is a cross-sectional view taken along line 4--4 of FIG. 3. FIG. FIG. 5 is an exploded perspective view of the impedance converter 1. FIG. 6 is a cross-sectional view taken from below along line 6--6 of FIG. 4; FIG.

　As shown in FIGS. 1 to 5, the impedance converter 1 includes a cavity 2, an input port 3, an output port 4, and an adjustment mechanism 5.

The cavity 2 has an internal space 20 that is electromagnetically sealed. The cavity 2 is made of metal such as aluminum, but the material is not particularly limited. Cavity 2 has a cuboid shape.

As shown in FIG. 4, the cavity 2 has a first wall 21 and a second wall 22 perpendicular to the first axis C1. The first wall portion 21 and the second wall portion 22 have the same rectangular plate shape. The cavity 2 has a third wall 23 and a fourth wall 24 perpendicular to the second axis C2. The third wall portion 23 and the fourth wall portion 24 have the same rectangular plate shape.

As shown in FIGS. 1 and 2, the cavity 2 has a fifth wall 25 and a sixth wall 26 perpendicular to the third axis C3. The fifth wall portion 25 and the sixth wall portion 26 have the same rectangular plate shape.

Note that, as shown in FIGS. 1 and 2, the first axis is the vertical axis. As shown in FIGS. 3 and 4, the second axis C2 is the horizontal axis of the cavity 2 orthogonal to the first axis C1. As shown in FIGS. 1 to 4, the third axis C3 is the depth direction axis of the cavity 2 orthogonal to both the first axis C1 and the second axis C2.

In this embodiment, the cavity 2 has the largest dimension along the second axis C2, the second largest dimension along the third axis C3 and the smallest dimension along the first axis C1. have

As shown in FIGS. 1 to 6, the cavity 2 has mounting

holes

27a and 27b provided in the first wall portion 21, and openings . The input port 3, the output port 4 and the adjustment mechanism 5 are attached to the mounting hole 27a, the mounting hole 27b and the opening 28, respectively. That is, the input port 3 , the output port 4 and the adjustment mechanism 5 are arranged on the first wall portion 21 .

The internal space 20 of the cavity 2 is surrounded by the first to sixth walls 21 to 26 and electromagnetically sealed. The cavity 2 has mounting

holes

27a and 27b and an opening 28, and although the internal space 20 of the cavity 2 is not spatially sealed, it may be regarded as electromagnetically sealed.

As shown in FIGS. 5 and 6, the first wall portion 21 of the cavity 2 has a first surface 21a and a second surface 21b. The first surface 21 a is the front surface of the first wall portion 21 , and the second surface 21 b is the rear surface of the first wall portion 21 facing the internal space 20 .

The first wall portion 21 has recesses 211a and 211b, a base portion 212, and a bank portion 213 provided on the first surface 21a. The recessed portion 211 a is arranged near the end of the first wall portion 21 that contacts the third wall portion 23 . The recessed portion 211 b is arranged near the end of the first wall portion 21 that contacts the fourth wall portion 24 . The recesses 211a, 211b are aligned along the second axis C2 of the cavity 2. As shown in FIG. The concave portions 211a and 211b have, for example, a rectangular shape.

A mounting hole 27a is formed in the bottom of the recess 211a, and a mounting hole 27b is formed in the bottom of the recess 211b. The base portion 212 supports the adjustment mechanism 5 . The adjusting mechanism 5 is installed on the base portion 212 . The base portion 212 is arranged near the end portion of the first wall portion 21 that contacts the sixth wall portion 26 . The base portion 212 has a rectangular plate-like shape extending along the second axis C<b>2 of the cavity 2 .

The bank portion 213 is a peripheral portion of the opening 28 of the cavity 2, which is arranged on the first wall portion 21 between the mounting

holes

27a and 27b. The bank portion 213 has a rectangular shape extending along the second axis C2 of the cavity 2 .

As shown in FIGS. 4 and 6, the first wall portion 21 of the cavity 2 has a recess 214 provided on the second surface 21b on the second wall portion 22 side.

As shown in FIG. 6, the recess 214 is arranged on the second surface 21b of the first wall portion 21 between the mounting

holes

27a and 27b. The recess 214 is a groove extending along the second axis C2 of the cavity 2 . The recess 214 has an oval shape when viewed along the first axis C1. The recessed portion 214 corresponds to the internal space of the bank portion 213 .

An opening 28 is formed at the bottom of the recess 214 . The opening 28 is a slit-shaped through hole extending along the second axis C2 of the cavity 2 . The opening 28 is arranged between the mounting hole 27a and the mounting hole 27b. An opening 28 is thus arranged in the first wall 21 between the input port 3 and the output port 4 .

The input port 3 is provided in the cavity 2 for inputting radio waves into the internal space 20 . As shown in FIGS. 4 and 5, the input port 3 is provided with an input antenna 31 and a connector 32 . When the input port 3 receives a high-frequency signal from the outside via the connector 32 , radio waves corresponding to the high-frequency signal are input to the internal space 20 via the input antenna 31 .

The input antenna 31 is arranged within the internal space 20 of the cavity 2 . The input antenna 31 has a round bar shape. The input antenna 31 is made of copper, for example. The input antenna 31 has a tip portion 31a and a trunk portion 31b. The diameter of the tip portion 31a is larger than that of the body portion 31b.

The input antenna 31 is arranged so that no discharge occurs between the tip 31 a of the input antenna 31 and the cavity 2 . Specifically, the distance between the tip portion 31a of the input antenna 31 and each of the second wall portion 22, the third wall portion 23, the fifth wall portion 25 and the sixth wall portion 26 of the cavity 2 is equal to the tip portion 31a and each wall portion.

The connector 32 is arranged outside the internal space 20 of the cavity 2 and used to electrically connect the impedance converter 1 to external equipment. For example, connector 32 is a coaxial connector connectable to a coaxial cable. The connector 32 includes a rod-shaped inner conductor 32a, a cylindrical outer conductor 32b surrounding the inner conductor 32a, and an insulator 32c arranged between the inner conductor 32a and the outer conductor 32b.

As shown in FIG. 4, the input port 3 is attached to the cavity 2 through the attachment hole 27a. The connector 32 connects the input antenna 31 to the internal conductor 32a through the mounting hole 27a, and is fixed in the recess 211a of the first surface 21a of the first wall 21. As shown in FIG. A trunk portion 31 b of the input antenna 31 is connected to an internal conductor 32 a of the connector 32 .

The output port 4 is provided in the cavity 2 to output radio waves from the internal space 20 . As shown in FIGS. 4 and 5, the output port 4 is provided with an output antenna 41 and a connector 42 . At the output port 4 , when the radio wave input to the internal space 20 is received by the output antenna 41 , the power of the high frequency signal corresponding to the received radio wave is output from the connector 42 .

The output antenna 41 is arranged within the internal space 20 of the cavity 2 . The output antenna 41 has a round bar shape. The output antenna 41 is made of copper, for example. The output antenna 41 has a tip portion 41a and a trunk portion 41b. The diameter of the tip portion 41a is larger than that of the body portion 41b.

The output antenna 41 is arranged so that no discharge occurs between the tip 41 a of the output antenna 41 and the cavity 2 . More specifically, the distance between the tip portion 41a of the output antenna 41 and each of the second wall portion 22, the fourth wall portion 24, the fifth wall portion 25 and the sixth wall portion 26 of the cavity 2 is It is set so that discharge does not occur between each wall.

The connector 42 is arranged outside the internal space 20 of the cavity 2 and used to electrically connect the impedance converter 1 to external equipment. For example, connector 42 is a coaxial connector connectable to a coaxial cable. The connector 42 includes a rod-shaped inner conductor 42a, a cylindrical outer conductor 42b surrounding the inner conductor 42a, and an insulator 42c arranged between the inner conductor 42a and the outer conductor 42b.

As shown in FIG. 4, the output port 4 is attached to the cavity 2 through the attachment hole 27b. The connector 42 connects the output antenna 41 to the inner conductor 42a through the mounting hole 27b and is fixed in the recess 211b of the first surface 21a of the first wall 21. As shown in FIG. A trunk portion 41 b of the output antenna 41 is connected to an internal conductor 42 a of the connector 42 .

As shown in FIGS. 4 and 5, the input antenna 31 of the input port 3 has the same shape as the output antenna 41 of the output port 4. More specifically, tip 31 a of input antenna 31 has the same diameter and length as tip 41 a of output antenna 41 . Body 31 b of input antenna 31 has the same diameter and length as body 41 b of output antenna 41 .

As shown in FIG. 3, the input port 3 and the output port 4 are aligned in the direction of the second axis C2 of the cavity 2 (horizontal direction in FIG. 3) when viewed along the first axis C1 of the cavity 2. A straight line L1 passing through the input port 3 and the output port 4 corresponds to the centerline of the cavity 2 in the direction of the third axis C3 (vertical direction in FIG. 3) when viewed along the first axis C1 of the cavity 2 . In FIG. 3, the cavity 2 is symmetrical with respect to a straight line L1 passing through the input port 3 and the output port 4 when viewed along the first axis C1.

The input port 3 is closer to the third wall 23 than the output port 4. That is, output port 4 is closer to fourth wall 24 than input port 3 . As shown in FIG. 4, the distance D11 between the input port 3 and the third wall 23 is equal to the distance D12 between the output port 4 and the fourth wall 24 .

In the impedance converter 1 , high-frequency signal power is input to the connector 32 of the input port 3 . A radio wave corresponding to the power input to the input port 3 is radiated from the input antenna 31 into the internal space 20 of the cavity 2 . At the output port 4 , when the radio waves radiated into the internal space 20 are received by the output antenna 41 , power of the high-frequency signal corresponding to the received radio waves is output from the connector 42 .

The adjustment mechanism 5 adjusts the impedance between the input port 3 and the output port 4. The adjustment mechanism 5 has a stub 6 . How the stub 6 is arranged in the internal space 20 of the cavity 2 affects the propagation of radio waves from the input port 3 to the output port 4 .

That is, the position of the stub 6 adjusts the impedance between the input port 3 and the output port 4. The adjustment mechanism 5 can individually adjust the position of the stub 6 between the input port 3 and the output port 4 and the insertion length of the stub 6 . The insertion length is the effective length of the portion of the stub 6 inserted into the internal space 20 of the cavity 2 . The effective length is the length of the portion of the stub 6 that affects the impedance.

Specifically, the insertion length of the stub 6 is the distance between the tip of the stub 6 and the second surface 21b of the first wall portion 21 in the direction of the first axis C1. The insertion length is zero when the tip of the stub 6 does not protrude from the second surface 21b. That is, the insertion length of the stub 6 is the effective length of the portion of the stub 6 inserted into the internal space 20 of the cavity 2 .

7 is an exploded perspective view of the adjustment mechanism 5. FIG. The adjustment mechanism 5 includes a stub 6 , a position adjustment mechanism 71 , an insertion length adjustment mechanism 72 , a support 73 and an electrical connector 8 .

The stub 6 is made of metal such as aluminum, but the material is not particularly limited. The stub 6 in FIG. 7 has a rod-like shape. The stub 6 has a leading end 6a, a trailing end 6b and an intermediate portion 6c between the leading end 6a and the trailing end 6b.

The tip 6a has a disk-like shape with rounded corners. Due to this shape, the electric field strength in the vicinity of the tip 6a can be reduced, and the discharge between the tip 6a and the cavity 2 can be reduced.

The rear end portion 6b and the intermediate portion 6c have a flat plate shape. The width of the intermediate portion 6c, ie the dimension in the direction of the second axis, is smaller than that of the rear end portion 6b. The dimension of the tip 6a of the stub 6 in the direction of the third axis C3 is greater than that of the opening 28 along the third axis C3. Therefore, the tip portion 6a cannot pass through the opening 28. As shown in FIG. The dimensions of the rear end portion 6b and the intermediate portion 6c of the stub 6 in the direction of the third axis C3 are smaller than that of the opening 28 and can pass through the opening 28. As shown in FIG.

The stub 6 passes through the opening 28 as shown in FIG. That is, the leading end portion 6a and the trailing end portion 6b of the stub 6 are arranged inside and outside the internal space 20, respectively. The tip 6 a of the stub 6 can be accommodated in the recess 214 of the cavity 2 . In particular, the recess 214 has a depth capable of accommodating the tip portion 6a of the stub 6, that is, a dimension in the direction of the first axis C1. Therefore, the tip portion 6 a of the stub 6 does not protrude outside the recess 214 .

As shown in FIGS. 3 and 7, the position adjustment mechanism 71 holds the stub 6 movably within the opening 28 along the second axis C2. The position adjustment mechanism 71 has a movable portion 711 and a fixed portion 712 . The stub 6 is attached to the movable portion 711 in the position adjusting mechanism 71 . The fixed portion 712 is fixed to the cavity 2 such that the longitudinal direction of the fixed portion 712 is along the second axis C2, and holds the movable portion 711 movably along the second axis C2.

The fixed part 712 has a base 712a, a rail 712b, and a screw 712c. The base 712a has a rectangular plate shape. The base 712 a is attached to the platform 212 of the cavity 2 .

The rail 712b is used to move the movable portion 711 along the longitudinal direction of the fixed portion 712, that is, along the second axis C2. The rail 712b extends in the longitudinal direction of the fixed portion 712, that is, along the second axis C2. Rail 712b is attached to base 712a. The rail 712b has a shape whose width increases toward its tip. As a result, the movable portion 711 is coupled to the fixed portion 712 so as not to come off.

The screw 712c moves the movable part 711 with respect to the fixed part 712 along the second axis C2. The screw 712c has a rotation axis along the second axis C2 and is rotatable about the rotation axis. The movable portion 711 has a cuboid shape.

The movable part 711 has a rail groove 711a with which the rail 712b of the fixed part 712 is engaged. A thread groove is formed in the rail groove 711a to mesh with the thread groove of the screw 712c. The movable portion 711 has a mounting surface 711b provided on the side opposite to the rail groove 711a. The stub 6 is indirectly attached to the attachment surface 711 b via the support 73 and the insertion length adjustment mechanism 72 .

In the position adjustment mechanism 71, when the screw 712c of the fixed portion 712 is rotated around the rotation axis of the screw 712c, the rotational motion of the screw 712c is converted into linear motion along the second axis C2, and the movable portion 711 moves along the rail 712b. It moves up along the second axis C2.

The insertion length adjusting mechanism 72 holds the stub 6 movably along the first axis C1. The insertion length adjusting mechanism 72 has a movable portion 721 and a fixed portion 722 . The stub 6 is attached to the movable portion 721 in the insertion length adjusting mechanism 72 . The fixed part 722 is fixed to the cavity 2 such that the longitudinal direction of the fixed part 722 is along the first axis C1, and holds the movable part 721 movably along the first axis C1.

The fixed part 722 has a base 722a, a rail groove 722b, and a screw 722c. The base 722a has a rectangular plate shape. The base 722 a is attached to the attachment surface 711 b of the movable portion 711 of the position adjustment mechanism 71 via the support 73 .

The rail groove 722b is used to move the movable portion 721 along the longitudinal direction of the fixed portion 722, that is, along the first axis C1. The rail groove 722b extends along the first axis C1. The rail groove 722b is formed on one surface of the base 722a.

The screw 722c moves the movable part 721 with respect to the fixed part 722 along the first axis C1. The screw 722c has a rotation axis along the second axis C2 and is rotatable about the rotation axis. The movable portion 721 has a cuboid shape.

The movable portion 721 has rails 721 a that engage with rail grooves 722 b of the fixed portion 722 . The rail 721a has a shape whose width increases toward its tip. As a result, the movable portion 721 is coupled to the fixed portion 722 so as not to come off.

In the insertion length adjusting mechanism 72, when the screw 722c of the fixed part 722 is rotated around the rotation axis of the screw 722c, the rotational motion of the screw 722c is converted into linear motion along the first axis C1, and the movable part 721 moves along the rail. 721a along the first axis C1.

The support 73 is a member for attaching the insertion length adjusting mechanism 72 and the electrical connection portion 8 to the movable portion 711 of the position adjusting mechanism 71 . The support 73 has a fixing portion 73a, a first support 73b, a second support 73c, and a pair of connecting portions 73d.

The fixed portion 73a is fixed to the mounting surface 711b of the movable portion 711 of the position adjustment mechanism 71. The first support 73b has a plate-like shape extending from the fixing portion 73a in parallel with the first axis C1. A fixing portion 722 of the insertion length adjusting mechanism 72 is attached to the first support 73b. The second support 73c is fixed to the fixed portion 73a by a pair of connecting portions 73d so as to face the bank portion 213 of the cavity 2 in the direction of the first axis C1.

The fixed part 73a has a through hole 731 facing the opening 28 of the cavity 2 in the direction of the first axis C1. The dimension of the through hole 731 in the direction of the second axis C2 or the third axis C3 is smaller than that of the leading end portion 6a and the rear end portion 6b of the stub 6, but larger than that of the intermediate portion 6c. FIG. 8 is an enlarged cross-sectional view of the periphery of the electrical connection portion 8. As shown in FIG. As shown in FIG. 8, a concave portion 732 for accommodating the electrical connection portion 8 is formed in the cavity 2 side surface of the second support 73c.

The electrical connection portion 8 electrically connects the stub 6 to the cavity 2 . The stub 6 is arranged to pass through the opening 28 and functions as an antenna for outputting part of the radio wave input from the input antenna 31 to the internal space 20 to the outside from the internal space 20 of the cavity 2 . By electrically connecting the stub 6 to the cavity 2 , the electrical connection portion 8 can prevent the stub 6 from functioning as an antenna and prevent power leakage through the stub 6 .

As shown in FIGS. 7 and 8, the electrical connection portion 8 has a pair of first conductive members 81, a second conductive member 82, and a pair of urging members 83. As shown in FIGS.

Each of the pair of first conductive members 81 is arranged outside the internal space 20 of the cavity 2 . The pair of first conductive members 81 are arranged to sandwich the stub 6 in the direction of the third axis C3 (horizontal direction in FIG. 8) and elastically contact the stub 6 in the direction of the third axis C3. Each of the pair of first conductive members 81 is a leaf spring.

The insertion length adjusting mechanism 72 can move the stub 6 along the first axis C1 while stably making electrical contact with the pair of first conductive members 81 .

The second conductive member 82 is arranged outside the internal space 20 of the cavity 2 and electrically connects the first conductive member 81 to the embankment 213 , that is, the peripheral portion of the opening 28 of the cavity 2 . The second conductive member 82 has a rectangular box shape. The second conductive member 82 has a through hole 82a through which the stub 6 passes.

The second conductive member 82 accommodates a pair of first conductive members 81 that are arranged to sandwich the stub 6 and contact the stub 6 . Thereby, the second conductive member 82 is electrically connected to the pair of first conductive members 81 while keeping the pair of first conductive members 81 elastically in contact with the stub 6 . Since the second conductive member 82 is in contact with the bank portion 213 , the pair of first conductive members 81 are electrically connected to the peripheral portion of the opening 28 of the cavity 2 via the second conductive member 82 .

A pair of biasing members 83 bias the second conductive member 82 toward the cavity 2 , so that the second conductive member 82 elastically contacts the bank portion 213 of the cavity 2 . The pair of biasing members 83 are, for example, coil springs. The position adjusting mechanism 71 can move the stub 6 along the second axis C2 while the biasing member 83 keeps the second conductive member 82 stably in electrical contact with the cavity 2 .

Thus, the electrical connection 8 electrically connects the stub 6 to the cavity 2 . As a result, power leakage through the stub 6 can be prevented.

As described above, in the adjustment mechanism 5 , the fixed portion 712 of the position adjustment mechanism 71 is directly fixed to the cavity 2 . The fixed portion 722 of the insertion length adjusting mechanism 72 is fixed to the movable portion 711 of the position adjusting mechanism 71 via the support 73 . The stub 6 is fixed to the movable portion 721 of the insertion length adjusting mechanism 72 .

The position adjusting mechanism 71 allows the stub 6, the insertion length adjusting mechanism 72, and the support 73 to move together with the movable portion 711 along the second axis C2. The insertion length adjusting mechanism 72 allows the stub 6 to move along the first axis C1 together with the movable portion 721 .

[motion]
The operation of the impedance converter 1 will be described.

The impedance converter 1 uses the adjustment mechanism 5 to adjust the impedance. The adjustment mechanism 5 can individually adjust the position of the stub 6 between the input port 3 and the output port 4 and the insertion length of the stub 6 .

The position adjustment mechanism 71 adjusts the position of the stub 6 between the input port 3 and the output port 4. In the position adjustment mechanism 71, when the screw 712c of the fixed portion 712 is rotated around the rotation axis of the screw 712c, the rotational motion of the screw 712c is converted into linear motion along the second axis C2, and the movable portion 711 moves along the rail 712b. It moves up along the second axis C2. The stub 6 can be moved toward either the input port 3 or the output port 4 depending on the direction of rotation of the screw 712c.

9 is a plan view showing the first position of the stub 6 in the impedance converter 1. FIG. 10 is a cross-sectional view along line 10-10 of FIG. 9. FIG. As shown in FIGS. 9 and 10, in FIGS. 9 and 10, the stub 6 is arranged at the input port 3 side end of the opening 28 extending along the second axis C2. That is, the first position is the position closest to the input port 3 in the movable range of the stub 6 along the second axis C2.

11 is a plan view showing the second position of the stub 6 in the impedance converter 1. FIG. 12 is a cross-sectional view taken along line 12-12 of FIG. 11. FIG. 11 and 12, the stub 6 is arranged at the output port 4 side end of the opening 28 extending along the second axis C2. That is, the second position is the position closest to the output port 4 within the movable range of the stub 6 along the second axis C2.

Thus, the position adjustment mechanism 71 can set the position of the stub 6 to any position within the movable range of the stub 6 along the second axis C2.

The insertion length adjustment mechanism 72 adjusts the insertion length of the stub 6. In the insertion length adjusting mechanism 72, when the screw 722c of the fixed portion 722 is rotated, the rotational motion of the screw 722c is converted into linear motion along the first axis C1, and the movable portion 721 moves along the rail 721a along the first axis C1. move along. Depending on the direction of rotation of the screw 722c, the stub 6 can be moved either in the direction of increasing or decreasing the insertion length.

13 is a cross-sectional view showing the third position of the stub 6 in the impedance converter 1. FIG. As shown in FIG. 13, at the third position, the insertion length of the stub 6 is the maximum value in the movable range of the stub 6 along the first axis C1. When the stub 6 is placed at the third position, the rear end 6b of the stub 6 contacts the edge of the through hole 731 of the second support 73c of the support 73, restricting the movement of the stub 6 in the direction of increasing the insertion length. be.

14 is a cross-sectional view showing the fourth position of the stub 6 in the impedance converter 1. FIG. As shown in FIG. 14, at the fourth position, the insertion length of the stub 6 is the minimum value in the movable range of the stub 6 along the first axis C1. When the stub 6 is arranged at the fourth position, the tip 6a of the stub 6 is accommodated in the recess 214 of the cavity 2 and does not protrude into the internal space 20. As shown in FIG. In this case, the insertion length of stub 6 is substantially zero.

That is, by hiding the stub 6 in the recess 214 by the insertion length adjustment mechanism 72, the impedance between the input port 3 and the output port 4 can be set to a value equivalent to that without the stub 6.

The dimension of the opening 28 in the direction of the third axis C3 is smaller than that of the tip 6a of the stub 6. Therefore, the tip 6a of the stub 6 contacts the bottom of the recess 214, and the movement of the stub 6 in the direction in which the insertion length is reduced is restricted. That is, the insertion length adjustment mechanism 72 can set the position of the stub 6 to any position within the movable range of the stub 6 along the first axis C1.

[evaluation]
The inventors used a network analyzer to evaluate the S parameter (Scattering parameter) in order to evaluate the change in impedance of the impedance converter 1 . In this evaluation, the inventors connected a 50Ω terminating resistor to the output port 4 and used the reflection coefficient (S ₁₁ ) of the input port 3 in the evaluation of the S-parameters.

FIG. 15 is a Smith chart showing a first example of impedance change by the impedance converter 1. FIG. A Smith chart is a circular chart that shows complex impedance used in the design of impedance matching. The center of the Smith chart corresponds to impedance matching. The perimeter of the Smith chart corresponds to 100% reflection.

The Smith chart expresses impedance by the length of a line segment from the center to an arbitrary point on the chart and the angle formed by the line segment and a straight line extending leftward from the center. The length of the line segment corresponds to the magnitude of the reflection coefficient and the angle of the line segment corresponds to the phase of the reflection coefficient.

　Impedance includes a resistance component and a reactance component. The magnitude of the reflection coefficient is related to the resistive component of the impedance, and the phase of the reflection coefficient is related to the reactive component of the impedance.

In the first example, the insertion length of the stub 6 was changed. That is, the insertion length adjusting mechanism 72 moves the stub 6 along the first axis C1. As the insertion length increased, the impedance changed as indicated by arrow A1 in FIG. From FIG. 15, it can be seen that the change in the insertion length of the stub 6 greatly affects the resistance component of the impedance.

FIG. 16 is a Smith chart showing a second example of impedance change by the impedance converter 1. FIG. In the second example, the position of stub 6 between input port 3 and output port 4 was changed. That is, the position adjusting mechanism 71 moves the stub 6 along the second axis C2.

When the stub 6 was moved within the opening 28 from the end on the input port 3 side toward the end on the output port 4 side, the impedance changed as indicated by arrow A2 in FIG. From FIG. 16, it can be seen that a change in the position of the stub 6 between the input port 3 and the output port 4 greatly affects the reactance component of the impedance.

FIG. 17 is a Smith chart showing a third example of impedance change by the impedance converter 1. FIG. As in the first example, the insertion length of the stub 6 was changed, and each time the insertion length was changed, the position of the stub 6 between the input port 3 and the output port 4 was changed as in the second example.

Each of the arrows A31, A32, A33, A34, A35 in FIG. 17 indicates changes in impedance according to the position of the stub 6 between the input port 3 and the output port 4 at the corresponding insertion length. The insertion length increases in the order of arrow A31, arrows A32, A33, A34, and A35.

With reference to FIGS. 15 to 17, the inventors confirmed that the impedance can be adjusted by the position of the stub 6 between the input port 3 and the output port 4 and the insertion length of the stub 6.

Specifically, the position of the stub 6 between the input port 3 and the output port 4 can adjust the reactance component of the impedance. The resistance component of impedance can be adjusted by the insertion length of the stub 6 . That is, the stub 6 can individually adjust the resistance component and the reactance component of the impedance.

The inventors have tried various designs in the impedance converter 1, and confirmed that it is possible to change the magnitude of the reflection coefficient from 0% to 98% in the frequency band of 2400 MHz to 2500 MHz. . The inventors also confirmed that it is possible to change the phase of the reflection coefficient from 0° to 360° in the same frequency band. Furthermore, the inventors have confirmed that the reflection loss can be suppressed to 0.4% to 1%.

As explained in detail above, the impedance converter 1 adjusts the reactance component of the impedance (the phase of the reflection coefficient) at the position of the stub 6 between the input port 3 and the output port 4, and the insertion length of the stub 6 The resistive component of impedance (magnitude of reflection coefficient) can be adjusted.

According to the present embodiment, unlike Patent Document 1, there is no need for trial and error with respect to the three stubs and changes in reflected impedance. The impedance can be easily adjusted using the correlation between the stub 6 and the resistance component (magnitude of reflection coefficient) and reactance component (phase of reflection coefficient) of the impedance.

Furthermore, according to this embodiment, it is possible to make the device more compact than a conventionally known EH tuner that requires two plungers perpendicular to the axial direction of the waveguide.

[Modification]
The present disclosure is not limited to the above embodiments. The above-described embodiments can be modified in various ways according to design and the like, as long as the objects of the present disclosure can be achieved. Modifications of the above embodiment are listed below. Modifications described below can be applied in combination as appropriate.

In one modification, the shape of the cavity 2 is not limited. The dimensions of the cavity 2 in the directions of the first axis C1, the second axis C2, and the third axis C3 are appropriately set in consideration of the arrangement of the input port and the output port, the frequency of the high-frequency signal input to the input port, and the like. be. All dimensions of the cavity 2 in the directions of the first axis C1, the second axis C2 and the third axis C3 are related to efficiency (power loss) and frequency characteristics.

For example, in order to determine the dimensions of each of the first axis C1, the second axis C2 and the third axis C3 of the cavity 2, first, the dimension along the first axis C1 and the dimension in the direction of the second axis C2 are arbitrarily selected. to optimize the dimension in the direction of the third axis C3. Next, the dimension in the direction of the first axis C1 is not changed, but the dimension in the direction of the second axis C2 is changed to optimize the dimension in the direction of the third axis C3.

Thereby, the optimum combination of the dimension in the direction of the second axis C2 and the dimension in the direction of the third axis C3 is searched for the dimension in the direction of the first axis C1 at that time. The dimension in the direction of the first axis C1 is changed to search for the optimum combination of the dimension in the direction of the second axis C2 and the dimension in the direction of the third axis C3. This searches for the optimal combination of the three dimensions.

In one modification, the cavity 2 is not limited to a rectangular parallelepiped shape. The cavity 2 may have a circular or polygonal box-like shape. The dimensions of the cavity 2 may be appropriately set in consideration of the arrangement of the input port and the output port, the frequency of the high frequency signal input to the input port, etc., as described above.

In one modification, the shapes of the input antenna 31 of the input port 3 and the shape of the output antenna 41 of the output port 4 are not limited to those described in the above embodiment. In a modified example, the shapes of the connectors 32, 42 of the input port 3 and the output port 4 are not limited to those described in the above embodiment.

The input port 3 may be a waveguide input section that is an opening provided in the cavity 2 for inputting radio waves into the internal space 20 . In this case, the input port 3 can directly input radio waves into the internal space 20 .

The output port 4 may be a waveguide output section that is an opening provided in the cavity 2 for outputting radio waves from the internal space 20 . In this case, the output port 4 can directly output radio waves from the internal space 20 .

In one modification, the configuration of cavity 2, input port 3 and output port 4 (eg, relative shapes and positional relationships, etc.) may differ from those described in the above embodiments. The input port 3 and the output port 4 do not necessarily have to be arranged on the first wall portion 21 . The input port 3 may be arranged on the first wall 21 or the second wall 22 and the output port 4 may be arranged on the first wall 21 or the second wall 22 .

When viewed along the first axis C1, the input port 3 and the output port 4 do not necessarily have to line up along the second axis C2. When viewed along the first axis C1, the cavity 2 does not have to be symmetrical with respect to a straight line passing through the input port 3 and the output port 4. The distance D11 between the input port 3 and the third wall 23 may be different from the distance D12 between the output port 4 and the fourth wall 24 .

In one modification, the adjustment mechanism 5 may not necessarily be able to individually adjust the position of the stub 6 between the input port 3 and the output port 4 and the insertion length of the stub 6. That is, the adjustment mechanism 5 may be configured to simultaneously adjust the position of the stub 6 between the input port 3 and the output port 4 and the insertion length of the stub 6 .

In a modified example, the fixed portion 722 of the insertion length adjustment mechanism 72 may be fixed to the cavity 2 and the position adjustment mechanism 71 may be fixed to the movable portion 721 of the insertion length adjustment mechanism 72.

In a modified example, the shapes of the position adjustment mechanism 71 and the insertion length adjustment mechanism 72 may be changed as appropriate as long as the stub 6 can be moved in a desired direction.

In one modified example, the adjustable range of the position of the stub 6 between the input port 3 and the output port 4 may be appropriately set according to the performance required of the impedance converter 1. The same applies to the adjustable range of the insertion length of the stub 6 .

In one variant, the cavity 2 may not have the recess 214 . That is, the stub 6 may not be able to hide the stub 6 within the recess 214 .

In one modification, the adjustment mechanism 5 may not have the electrical connection 8. For example, electrical connection 8 may be omitted if leakage of power through stub 6 has little adverse effect.

[Aspect and effect]
As described in detail above, the present disclosure includes the following aspects. In the following aspects, reference numerals are given in parentheses to clarify the correspondence with the above embodiments.

An impedance converter (1) according to the first aspect of the present disclosure comprises a cavity (2), an input port (3), an output port (4) and an adjustment mechanism (5).

The cavity (2) has an electromagnetically sealed internal space (20). An input port (3) is provided in the cavity (2) for inputting radio waves into the internal space (20) of the cavity (2). An output port (4) is provided in the cavity (2) for outputting radio waves from the internal space (20) of the cavity (2).

The adjustment mechanism (5) has a metal stub (6) arranged within the interior space (20) of the cavity (2). An adjustment mechanism (5) adjusts the position of the stub (6) between the input port (3) and the output port (4) and the insertion length of the stub (6). The insertion length of the stub (6) is the effective length of the portion of the stub (6) inserted into the interior space (20) of the cavity (2). According to this aspect, impedance conversion can be performed with a simple operation.

In the impedance converter (1) according to the second aspect, in addition to the first aspect, the adjustment mechanism (5) adjusts the position of the stub (6) between the input port (3) and the output port (4) and , and the insertion length of the stub (6) into the internal space (20) of the cavity (2) are individually adjusted. According to this aspect, impedance conversion can be performed more easily.

In the impedance converter (1) according to the third aspect, in addition to the first or second aspect, the cavity (2) has a first wall (21) and a second wall (21) orthogonal to the first axis C1 (22).

The input port (3) is arranged on the first wall (21) or the second wall (22). The output port (4) is located on the first wall (21) or the second wall (22). When viewed along the first axis C1, the input port (3) and the output port (4) are aligned along a second axis C2 orthogonal to the first axis C1. According to this aspect, power loss can be reduced.

In the impedance converter (1) according to the fourth aspect, in addition to the third aspect, the cavity (2) is provided in the first wall (21) between the input port (3) and the output port (4). It has an aperture (28) provided. The stub (6) passes through the opening (28) so that the leading end (6a) and the trailing end (6b) of the stub (6) are positioned inside and outside the internal space (20), respectively. According to this aspect, impedance conversion can be performed with a simple operation.

In the impedance converter (1) according to the fifth aspect, in addition to the fourth aspect, the opening (28) of the cavity (2) extends along the second axis C2. The adjustment mechanism (5) includes a positioning mechanism (71) that holds the stub (6) movably within the opening (28) of the cavity (2) along the second axis C2.

The position adjustment mechanism (71) has a movable part (711) and a fixed part (712). A stub (6) is attached to the movable part (711). The fixed part (712) is fixed to the cavity (2) so that the longitudinal direction of the fixed part (712) is along the second axis C2, and the movable part (711) of the position adjustment mechanism (71) is aligned with the second axis C2. movably held along. According to this aspect, impedance conversion can be performed with a simple operation.

In the impedance converter (1) according to the sixth aspect, in addition to the fourth or fifth aspect, the adjustment mechanism (5) is an insert holding the stub (6) movably along the first axis C1. Includes a length adjustment mechanism (72). The insertion length adjusting mechanism (72) has a movable portion (721) and a fixed portion (722).

A stub (6) is attached to the movable part (721) of the insertion length adjusting mechanism (72). The fixed part (722) of the insertion length adjustment mechanism (72) is fixed to the cavity (2) so that the longitudinal direction is along the first axis C1, and the movable part (721) of the insertion length adjustment mechanism (72) is moved to the first position. It is held movably along the axis C1. According to this aspect, impedance conversion can be performed with a simple operation.

In the impedance converter (1) according to the seventh aspect, in addition to the sixth aspect, the cavity (2) has a surface (second surface) of the first wall (21) on the second wall (22) side 21b) with a recess (214) provided therein. The opening (28) of the cavity (2) is formed at the bottom of the recess (214) of the cavity (2). The recess (214) of the cavity (2) has a depth capable of accommodating the tip (6a) of the stub (6). According to this aspect, by hiding the stub (6) in the recess (214) of the cavity (2), the impedance between the input port (3) and the output port (4) is reduced to that without the stub (6). Can be set to equivalent values.

In the impedance converter (1) according to the eighth aspect, in addition to any one of the fourth to seventh aspects, the adjustment mechanism (5) electrically connects the stub (6) to the cavity (2) It further has a connecting electrical connection (8). According to this aspect, power leakage through the stub (6) can be prevented.

In the impedance converter (1) according to the ninth aspect, in addition to the eighth aspect, the electrical connection part (8) includes a first conductive member (81) and a second conductive member (82) .

A first conductive member (81) is positioned outside the interior space (20) of the cavity (2) and is directed to the stub (6) in the direction of a third axis C3 orthogonal to both the first axis C1 and the second axis C2. elastic contact. A second conductive member (82) is positioned outside the interior space (20) of the cavity (2) and electrically connects the first conductive member (81) to the peripheral portion of the opening (28) of the cavity (2). . According to this aspect, power leakage through the stub (6) can be prevented.

In the impedance converter (1) according to the tenth aspect, in addition to any one of the fourth to ninth aspects, when viewed along the first axis C1, the cavity (2) has an input port ( 3) and is symmetrical about a straight line (L1) through the output port (4). According to this aspect, power loss can be further reduced.

In the impedance converter (1) according to the eleventh aspect, in addition to any one of the fourth to tenth aspects, the cavity (2) has a third wall (23) orthogonal to the second axis C2 and a fourth wall (24).

The input port (3) is closer to the third wall (23) than the output port (4). The distance (D11) between the input port (3) and the third wall (23) is equal to the distance (D12) between the output port (4) and the fourth wall (24). According to this aspect, power loss can be further reduced.

In the impedance converter (1) according to the twelfth aspect, in addition to any one of the fourth to eleventh aspects, the input port (3) and the output port (4) are the first It is located on the wall (21). According to this aspect, power loss can be further reduced.

In the impedance converter (1) according to the thirteenth aspect, in addition to any one of the first to twelfth aspects, the input port (3) is arranged within the internal space (20) of the cavity (2) It has an input antenna (31) that is The output port (4) has an output antenna (41) located in the interior space (20) of the cavity (2). According to this aspect, a high frequency signal can be transmitted.

In the impedance converter (1) according to the 14th aspect, in addition to the 13th aspect, the input antenna (31) has the same shape as the output antenna (41). According to this aspect, power loss can be further reduced.

In the impedance converter (1) according to the fifteenth aspect, in addition to the thirteenth or fourteenth aspect, the input antenna (31) is provided between the tip (31a) of the input antenna (31) and the cavity (2). They are arranged so that no discharge occurs between them. The output antenna (41) is arranged so that no discharge occurs between the tip (41a) of the output antenna (41) and the cavity (2). According to this aspect, it is possible to reduce the occurrence of discharge between the input antenna (31) and the output antenna (41) and the cavity (2).

The present disclosure is particularly applicable to impedance converters for high frequencies.

1 Impedance Converter 2 Cavity 20 Interior Space 21 First Wall 21a First Surface 21b Second Surface 211a, 211b Recess 212 Base 213 Bank 214 Recess 22 Second Wall 23 Third Wall 24 Fourth Wall 25 Wall 26 Wall

27a Mounting hole

27b Mounting hole 28 Opening 3 Input port 31 Input antenna 31a Tip 31b Body 32 Connector 32a Internal conductor 32b External conductor 32c Insulator 4 Output port 41 Output antenna 41a Tip 41b Body 42 Connector 42a inner conductor 42b outer conductor 42c insulator 5 adjustment mechanism 6 stub 6a front end 6b rear end 6c intermediate portion 71 position adjustment mechanism 711 movable portion 711a rail groove 711b mounting surface 712 fixed portion 712a base 712b rail 712c screw 72 insertion length adjustment Mechanism 721 Movable Part 721a Rail 722 Fixed Part 722a Base 722b Rail Groove 722c Screw 73 Support 73a Fixed Part 73b First Support 73c Second Support 73d Connecting Part 731 Through Hole 732 Recess 8 Electrical Connection Part 81 First Conductive Member 82 Second Conductive Member 82a Through hole 83 Biasing member

Claims

a cavity having an electromagnetically sealed internal space;
an input port provided in the cavity and configured to input radio waves into the internal space;
an output port provided in the cavity and configured to output radio waves from the internal space;
a metal stub positioned within the interior space of the cavity, the position of the stub between the input port and the output port and the portion of the stub inserted into the interior space of the cavity; an adjustment mechanism configured to adjust the effective length and the insertion length;
comprising
impedance converter.
wherein the adjustment mechanism is configured to individually adjust the position of the stub between the input port and the output port and the insertion length of the stub;
2. The impedance converter of claim 1.
the cavity has a first wall and a second wall orthogonal to a first axis;
the input port is disposed on the first wall or the second wall;
the output port is located on the first wall or the second wall;
when viewed along the first axis, the input port and the output port are aligned along a second axis orthogonal to the first axis;
3. The impedance converter according to claim 1 or 2.
the cavity has an opening in the first wall between the input port and the output port;
the stub penetrates the opening of the cavity and the leading end and the trailing end of the stub are arranged inside and outside the internal space, respectively;
4. Impedance converter according to claim 3.
the opening of the cavity extends along the second axis;
the adjustment mechanism includes a position adjustment mechanism that holds the stub movably along the second axis within the opening of the cavity;
The position adjustment mechanism is
a movable portion to which the stub is attached;
a fixed portion fixed to the cavity and holding the movable portion of the position adjustment mechanism movably along the direction of the second axis;
having
5. Impedance converter according to claim 4.
the adjustment mechanism includes an insertion length adjustment mechanism that holds the stub movably along the first axis;
The insertion length adjustment mechanism is
a movable portion to which the stub is attached;
a fixed portion fixed to the cavity and holding the movable portion of the insertion length adjusting mechanism movably along the first axis;
having
6. An impedance converter according to claim 4 or 5.
The cavity has a recess provided in the surface of the first wall on the second wall side,
The opening is formed at the bottom of the recess,
The recess has a depth that can accommodate the tip of the stub,
7. Impedance converter according to claim 6.
The adjustment mechanism further comprises an electrical connection that electrically connects the stub to the cavity.
The impedance converter according to any one of claims 4-7.
The electrical connection is
a first conductive member disposed outside the interior space of the cavity and resiliently contacting the stub in the direction of a third axis orthogonal to both the first axis and the second axis;
a second conductive member disposed outside the internal space of the cavity and electrically connecting the first conductive member to a peripheral portion of the opening of the cavity;
including,
9. Impedance transformer according to claim 8.
When viewed along the first axis, the cavity is symmetrical about a line passing through the input port and the output port.
The impedance converter according to any one of claims 4-9.
the cavity has a third wall and a fourth wall perpendicular to the second axis;
the input port is closer to the third wall than the output port;
the distance between the input port and the third wall is equal to the distance between the output port and the fourth wall;
The impedance converter according to any one of claims 4-10.
the input port and the output port are located on the first wall;
The impedance converter according to any one of claims 4-11.
the input port has an input antenna disposed within the interior space;
the output port has an output antenna positioned within the interior space;
The impedance converter according to any one of claims 1-12.
the input antenna has the same shape as the output antenna;
14. Impedance transformer according to claim 13.
the input antenna is arranged so that no discharge occurs between the tip of the input antenna and the cavity;
The output antenna is arranged so that no discharge occurs between the tip of the output antenna and the cavity.
15. Impedance transformer according to claim 13 or 14.