Waveguide device, waveguide system, and radar device

Abstract

To provide a waveguide device capable of reducing the number of operations of a pressurizing device.SOLUTION: According to an embodiment, a waveguide device includes a hollow waveguide and a sheet. The waveguide is provided to be able to guide radio waves between the antenna device and the transmitter, the receiver, or the transceiver. Dry air is supplied to the waveguide from a pressurizing device. The sheet partitions the waveguide between the transmitter, the receiver, or the transceiver and the antenna device. The sheet allows dry air to pass to the antenna device side while the pressure of the dry air on the transmitter, receiver, or transceiver side is higher than the pressure of the dry air on the antenna device side due to the partitioning of the sheet within the waveguide. The pressure of the dry air on the antenna device side is equal to or higher than the atmospheric pressure.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD OF THE INVENTION Embodiments of the present invention relate to a waveguide device, a waveguide system, and a radar device. [Background technology]

[0002] By uniformly pressurizing the inside of the waveguide from the transmitter to the antenna device with dry air, the spatial insulation distance is extended and corrosion inside the waveguide is prevented. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 7-39716 [Patent Document 2] Japanese Patent Application Laid-Open No. 2001-127508 [Patent Document 3] Japanese Patent Application Publication No. 5-29807 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a waveguide device, a waveguide system, and a radar device that can reduce the number of operations of a pressurizing device. [Means for solving the problem]

[0005] According to an embodiment, the waveguide device includes a hollow waveguide and a sheet. The waveguide is configured to guide radio waves between a transmitter, a receiver, or a transceiver, and an antenna device. Dry air is supplied to the waveguide from a pressure device. The sheet partitions the inside of the waveguide between the transmitter, the receiver, or the transceiver, and the antenna device. The sheet partitions the inside of the waveguide, allowing the dry air to pass toward the antenna device while maintaining a higher pressure of the dry air on the transmitter, receiver, or transceiver side than the pressure of the dry air on the antenna device side. The pressure of the dry air on the antenna device side is equal to or higher than atmospheric pressure. [Brief explanation of the drawings]

[0006] [Figure 1] 1 is a schematic block diagram showing a radar device according to a first embodiment. [Figure 2] 2 is a schematic vertical cross-sectional view showing a connection portion of a waveguide in the radar device shown in FIG. 1. [Figure 3] FIG. 3 is an enlarged view of the position indicated by the symbol III in FIG. 2. [Figure 4] FIG. 2 is a schematic block diagram showing a first modified example of the radar device shown in FIG. [Figure 5] FIG. 2 is a schematic block diagram showing a second modified example of the radar device shown in FIG. [Figure 6] FIG. 10 is a schematic block diagram showing a radar device according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0007] A radar device 10 according to an embodiment will be described with reference to the drawings.

[0008] (First embodiment) A radar device 10 according to a first embodiment will be described with reference to FIGS. 1 to 3. FIG.

[0009] Fig. 1 is a schematic block diagram showing a radar device 10 according to this embodiment. Fig. 2 is a schematic vertical cross-sectional view showing a connection portion between a first waveguide body 42a and a second waveguide body 42b of a waveguide 42 of the radar device 10 shown in Fig. 1. Fig. 3 is an enlarged view of the position indicated by reference symbol III in Fig. 2.

[0010] 1, a radar device 10 according to this embodiment includes an antenna device 12, a waveguide system 14, and a transmitter 16. An example of the radar device 10 is a weather radar device.

[0011] The antenna device 12 comprises a support (base) 22, a rotation device 24 provided on the support 22 and rotating around an axis of rotation that is, for example, vertical to the support 22, and an antenna 26 supported on the rotation device 24.

[0012] Support unit 22 is fixed to, for example, the ground or a floor. Rotation device 24 rotates, for example, around a vertical rotation axis, and includes rotary joint 24a that guides radio waves guided through waveguide 42 (described below) to antenna 26. Rotary joint 24a is rotated via a gear (not shown) provided in a drive motor (not shown). Antenna 26 is rotatably supported by rotary joint 24a and can rotate around the rotation axis at, for example, an appropriate rotation speed.

[0013] The structure for guiding radio waves between the waveguide 42 and the antenna 26 within the rotating device 24 is not limited to the rotary joint 24a itself, but various cables and the like placed within and / or outside the rotary joint 24a can be used.

[0014] The antenna 26 according to this embodiment is capable of transmitting (emitting) radio waves into the air. Currently, it is becoming common for antennas 26 used in weather radars, for example, to be solid-state radars that utilize semiconductors rather than klystron-based antennas (klystron radars). For this reason, in this embodiment, a solid-state radar that utilizes semiconductors is used as the antenna 26. Solid-state radars operate with less power than conventional klystron-based antennas (klystron radars). It has also been found that dielectric breakdown does not occur in most parts of the waveguide 42 and the antenna device 12, even with a spatial insulation distance at atmospheric pressure.

[0015] The waveguide system 14 includes a waveguide device 32, a humidity sensor 34, a pressure device 36, and a control unit 38.

[0016] The waveguide device 32 includes a hollow waveguide 42 that is capable of guiding radio waves, and a sheet 44 that is provided within the waveguide 42 .

[0017] The waveguide 42 is formed in a tubular shape such as a circular or rectangular tube so that air does not enter or leave between its inside and outside. The waveguide 42 guides radio waves from the transmitter 16 toward the antenna 26 of the antenna device 12, and dry air is supplied from the pressure device 36 through the transmitter. The waveguide 42 is made of aluminum, copper, or another metal material.

[0018] The waveguide 42 includes a first waveguide body 42a and a second waveguide body 42b. The first waveguide body 42a faces the transmitter 16 and the pressure applying device 36. The second waveguide body 42b faces the antenna device 12. The end 43a of the first waveguide body 42a and the end 43b of the second waveguide body 42b are connected to each other and cooperate to sandwich the sheet 44. The waveguide 42 is formed so that radio waves pass through the connection between the ends 43a, 43b of the first waveguide body 42a and the second waveguide body 42b. In other words, radio waves pass through the connection between the first waveguide body 42a and the second waveguide body 42b.

[0019] The ends 43a, 43b of the first waveguide body 42a and the second waveguide body 42b are preferably formed as flanges that protrude radially outward. An O-ring 46 serving as a seal is sandwiched and fixed between the ends 43a, 43b by a bolt 45a, a nut 45b, and a washer 45c. The O-ring 46 prevents liquids and gases from flowing from the outside to the inside of the waveguide 42 and vice versa through the gap between the ends 43a, 43b.

[0020] Within support portion 22 of antenna device 12 or within rotation device 24, rotary joint 24a rotates while being sealed against the end of second waveguide body 42b opposite end 43b. The dry air within waveguide 42 and rotary joint 24a of rotation device 24 has a higher pressure than the atmosphere outside waveguide 42 and rotary joint 24a of rotation device 24. This prevents air from entering waveguide 42 and rotary joint 24a of rotation device 24 from the outside.

[0021] The first waveguide body 42a and the second waveguide body 42b may each have a structure in which a plurality of waveguide bodies are connected.

[0022] The sheet 44 is provided inside the waveguide 42 between the transmitter 16 and the antenna device 12. The sheet 44 is formed from a film-like material having minute holes (porous holes) that allow dry air to pass through. Preferably, the sheet 44 is made of a material that has low radio wave absorption and allows radio waves to pass through easily. The film-like material that forms the sheet 44 is preferably made from, for example, a polyester film, a PTFE sheet, or the like.

[0023] The sheet 44 divides the inside of the waveguide 42 between the transmitter 16 and the antenna device 12. In this embodiment, the sheet 44 is sandwiched between the end 43a of the first waveguide body 42a and the end 43b of the second waveguide body 42b. The sheet 44 creates a pressure difference in the dry air within the waveguide 42, allowing the dry air to pass toward the antenna device 12. The sheet 44 divides the inside of the waveguide 42, allowing the dry air to pass toward the antenna device 12 while making the pressure of the dry air on the transmitter 16 side higher than the pressure of the dry air on the antenna device 12 side. Therefore, within the waveguide 42, the pressure on the transmitter 16 or pressurizing device 36 side of the sheet 44 is higher, and the pressure on the antenna device 12 side is lower. Within the waveguide 42, the pressure on the antenna device 12 side of the sheet 44 is the same as or higher than atmospheric pressure.

[0024] The sheet 44 may allow water vapor to pass between the first waveguide body 42a and the second waveguide body 42b, or may block the passage of water vapor.

[0025] The humidity sensor 34 is preferably arranged in each area defined by the sheet 44, for example.

[0026] The humidity sensor 34 may be located, for example, on the transmitter 16 and pressure device 36 side of the sheet 44, and not on the antenna device 12 side. Alternatively, the humidity sensor 34 may be located, for example, on the antenna device 12 side, and not on the transmitter 16 and pressure device 36 side of the sheet 44. Therefore, one or more humidity sensors 34 may be located anywhere within the waveguide 42 between the transmitter 16 and the antenna device 12.

[0027] In practice, the humidity sensor 34 is fixed in the first waveguide body 42a and the second waveguide body 42b, respectively. In this case, it is preferable that the humidity sensor 34 is shielded from radio waves so that signals transmitted to and received from the control unit 38 are not affected by the radio waves guiding through the waveguide 42 or do not affect the radio waves guiding through the waveguide.

[0028] Preferably, two thresholds are set for each humidity sensor 34. The first threshold is the humidity threshold at which the pressure device 36 starts to operate. The second threshold is the humidity threshold at which the pressure device 36 stops operating.

[0029] The pressurizing device 36 is used as a device for obtaining dry air by removing water vapor from moist air. Furthermore, the pressurizing device 36 supplies dry air into the waveguide 42 when the humidity detected by one or more humidity sensors 34 reaches a predetermined humidity (first threshold) (when the humidity increases to the predetermined humidity). The trigger for operating the pressurizing device 36 to supply dry air into the waveguide 42 may be immediately after any one humidity sensor 34 reaches the predetermined humidity, or may be immediately after multiple humidity sensors 34 reach the predetermined humidity.

[0030] Furthermore, the pressure device 36 is stopped from operating when, for example, any of the humidity sensors 34 detects that the humidity has dropped to a second threshold value.

[0031] There may be one or more transmitters 16. When there is one transmitter 16, for example, it operates to transmit horizontally polarized waves from antenna 26 as radio waves that pass through waveguide 42 and rotary joint 24a of rotation device 24. Transmitter 16 may, for example, be a combination of a transmitter for horizontally polarized waves and a transmitter for vertically polarized waves. That is, in this case, there are multiple transmitters 16. In this case, transmitter 16 may alternately or simultaneously transmit horizontally polarized waves and vertically polarized waves from antenna 26 as radio waves that pass through waveguide 42 and rotary joint 24a of rotation device 24.

[0032] The control unit 38 controls the humidity sensor 34 and the pressurizing device 36 of the waveguide system 14. The control unit 38 may be connected to them by wire or wirelessly. The humidity sensor 34 and the control unit 38 may be connected by providing a through-hole in the waveguide 42, for example, to prevent interference with the propagation of radio waves through the waveguide 42, or may be connected through the inside of the waveguide 42 and the inside of the transmitter 16.

[0033] The operation of the radar device 10 according to this embodiment will be described below.

[0034] The radar device 10 continues to operate the transmitter 16 while rotating the rotary joint 24a of the rotation device 24 and the antenna 26 about the axis of rotation at an appropriate rotation speed relative to the support part 22. The transmitter 16 continues to guide radio waves to the antenna 26 via the first waveguide body 42a and the second waveguide body 42b of the waveguide 42 and the rotary joint 24a of the rotation device 24, and continues to transmit radio waves from the antenna 26 into the air.

[0035] The control unit 38 controls the humidity sensor 34 disposed inside the waveguide 42 to measure the humidity of the air inside the waveguide 42 at appropriate time intervals. When the control unit 38 detects that the humidity of at least one of the one or more humidity sensors 34 has reached or exceeded a predetermined threshold, the control unit 38 activates the pressure device 36. The control unit 38 causes the pressure device 36 to send dry air at a pressure P higher than atmospheric pressure into the first waveguide body 42a of the waveguide 42. In this embodiment, the dry air supplied from the pressure device 36 is supplied to the sheet 44 side through the transmitter 16 located on the path of the first waveguide body 42a, thereby pressurizing the sheet 44. The presence of the sheet 44 inside the waveguide 42 causes the pressure inside the waveguide 42 (first waveguide body 42a) on the pressure device 36 side (including the transmitter 16) of the sheet 44 to be higher than that on the antenna device 12 side.

[0036] The dry air that has passed through the minute porous holes in the sheet 44 also fills the second waveguide body 42b on the antenna device 12 side of the waveguide 42. The dry air also fills the rotary joint 24a of the rotating device 24 through the end portion 43c of the second waveguide body 42b of the waveguide 42.

[0037] At this time, the pressures before and after the sheet 44 inside the waveguide 42 are balanced. For example, let the air pressure inside the first waveguide body 42a be P, and the air pressure inside the second waveguide body 42b be P0. At this time, this can be expressed as P = P0 + ΔP, where ΔP is the pressure loss caused by the sheet 44.

[0038] That is, the pressurizing device 36 pressurizes the sheet 44 with the pressure P from the inside of the first waveguide body 42a (the side of the pressurizing device 36), and due to the pressure loss ΔP by the sheet 44, a pressure P0 < P is obtained inside the second waveguide body 42b (the side of the antenna device 12). Note that the pressure P0 is greater than the atmospheric pressure.

[0039] At this time, the inside of the transmitter 16 is also pressurized to the pressure P by the pressurizing device 36. Therefore, when the control unit 38 drives the pressurizing device 36 based on the detection data of the humidity sensor 34, the pressurized dry air is supplied toward the sheet 44 of the waveguide device 32 and also supplied toward the transmitter 16. For this reason, the radar device 10 keeps the air pressure inside the transmitter 16 high, preventing dielectric breakdown of the air inside the transmitter 16 and preventing corona discharge from occurring.

[0040] Then, the control unit 38 operates the pressurizing device 36 until the humidity sensor 34 on the antenna device 12 side with respect to the sheet 44, which is, for example, on the side far from the pressurizing device 36, becomes below a predetermined humidity, and after it becomes below the predetermined humidity, stops the operation of the pressurizing device 36.

[0041] Alternatively, the control unit 38 may operate the pressurizing device 36 until the humidity sensor 34 on the transmitter 16 side with respect to the sheet 44, which is, for example, on the side close to the pressurizing device 36, becomes below a predetermined humidity, and after it becomes below the predetermined humidity, stop the operation of the pressurizing device 36. For example, it is assumed that the humidity of the second threshold value of the humidity sensor 34 on the transmitter 16 side with respect to the sheet 44, which is on the side close to the pressurizing device 36, drops to the second humidity earlier than the humidity of the second threshold value of the humidity sensor 34 on the antenna device 12 side with respect to the sheet 44, which is on the side far from the pressurizing device 36. For this reason, the control unit 38 may set the humidity of the second threshold value of the humidity sensor 34 on the transmitter 16 side with respect to the sheet 44 to be lower than the humidity of the second threshold value of the humidity sensor 34 on the antenna device 12 side with respect to the sheet 44. In this case, when the control unit 38 detects that the humidity has dropped to the second threshold value with any one of the humidity sensors 34, it stops the operation of the pressurizing device 36.

[0042] Although a difference in pressure occurs between the regions partitioned by the sheet 44, the pressurizing device 36 pressurizes the entire interior of the waveguide 42 with dry air. Therefore, the humidity inside the waveguide 42 is maintained at or below a predetermined humidity level, preventing corrosion inside the waveguide 42.

[0043] Within support portion 22 of antenna device 12 or within rotation device 24, rotary joint 24a rotates while being sealed against end 43c of second waveguide body 42b opposite end 43b. Furthermore, the dry air within waveguide 42 and rotary joint 24a of rotation device 24 is maintained at a higher pressure than the atmosphere outside waveguide 42 and rotary joint 24a of rotation device 24. This prevents air from entering waveguide 42 and rotary joint 24a of rotation device 24 from the outside.

[0044] Due to the sheet 44, the internal pressure P0 within the second waveguide body 42b of the waveguide 42 and within the rotary joint 24a of the rotating device 24 is lower than the internal pressure P within the first waveguide body 42a, and is also lower than in the past, when the pressure within the waveguide was uniform P.

[0045] Here, conventionally, an antenna device using a klystron that transmits large amounts of power has been used, and therefore pressurization has been required to maintain the pressure of the dry air at an appropriate pressure P in order to ensure a sufficient spatial insulation distance. In this situation, it has been difficult to maintain the airtightness of waveguide 42 (between end 43c of second waveguide body 42b and rotary joint 24a) in rotating device 24, which moves relative to support part 22, for a long period of time, and airtightness leakage has frequently occurred.

[0046] As described above, in this embodiment, so-called solid-state radar that utilizes semiconductors is used as the antenna 26. Solid-state radar operates with less power than conventional radar that utilizes klystrons, and it is known that no dielectric breakdown occurs in most parts of the waveguide 42 and the antenna device 12, even at spatial insulation distances at atmospheric pressure.

[0047] Therefore, when using the antenna device 12 according to this embodiment, almost no attention needs to be paid to ensuring the space insulation distance within the antenna device 12. For this reason, as long as the dry state within the second waveguide body 42b can be maintained, almost no attention needs to be paid to keeping the pressure of the dry air within the second waveguide body 42b at an appropriate pressure higher than the atmospheric pressure. Therefore, the airtightness of the relative rotation part between the end 43c of the second waveguide body 42b of the waveguide 42 within the rotating device 24 and the rotary joint 24a may be lower than when using the conventional antenna device 12 utilizing a klystron, and airtightness leakage of the degree that has been a problem so far will not become a problem either. For this reason, while maintaining the humidity within the second waveguide body 42b at a low humidity, the pressurization using the pressurizing device 36 into the second waveguide body 42b may be at a pressure P0 < P, and the number of operating times of the pressurizing device 36 can be reduced. For this reason, the pressurizing device 36 can be made to have a longer lifespan.

[0048] Therefore, according to this embodiment, it is possible to provide a waveguide device 32, a waveguide system 14, and a radar device 10 capable of reducing the number of operating times of the pressurizing device 3

[0049] (First Modified Example) The radar device 10 according to this embodiment has been described with an example of using a transmitter 16. Instead of the transmitter 16, as shown in FIG. 4, a receiver 16a may be arranged and used. When arranging the receiver 16a as shown in FIG. 4 instead of the transmitter 16, the antenna 26 can receive radio waves from the air. In FIG. 4, illustration of the control unit 38 and the like is omitted.

[0050] (Second Modified Example) Also, as shown in FIG. 5, instead of the transmitter 16, a transceiver 16b may be arranged and used. The transceiver 16b can be used by switching between a mode of transmitting radio waves using the waveguide 42 and a mode of receiving radio waves using the waveguide 42, for example. In this case, the antenna 26 can transmit radio waves into the air and / or receive radio waves from the air according to the mode. In FIG. 5, illustration of the control unit 38 and the like is omitted.

[0051] Therefore, the hollow waveguide 42 can guide radio waves between the transmitter 16, the receiver 16a, or the transceiver 16b and the antenna device 12, and dry air is supplied to the waveguide 42 from the pressurizing device 36 through the transmitter 16, the receiver 16a, or the transceiver 16b. The pressurizing device 36 is provided at a position in the waveguide 42 away from the antenna device 12, and supplies dry air through the waveguide 42 to the transmitter 16, the receiver 16a, or the transceiver 16b.

[0052] The waveguide 42 also includes a first waveguide body 42a on the transmitter 16, receiver 16a, or transceiver 16b side, and a second waveguide body 42b on the antenna device 12 side, which has an end 43b connected to the end 43a of the first waveguide body 42a and cooperates with the end 43a of the first waveguide body 42a to sandwich the sheet 44.

[0053] The radar device 10 is also preferably configured in this manner.

[0054] (Second embodiment) A radar device 10 according to the second embodiment will be described with reference to Fig. 6. This embodiment is a modified example of the first embodiment, and the same components as those described in the first embodiment or components having the same functions are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0055] As shown in FIG. 6, in this embodiment, the arrangement of the transmitter 16 and the pressure device 36 is different from that of the radar device 10 shown in FIG.

[0056] In the example shown in FIG. 6, a first waveguide body 42a of a waveguide 42 extending from the transmitter 16 to the antenna device 12 side branches off and is connected to a pressure device .

[0057] Even with this configuration, when the control unit 38 drives the pressurizing device 36 based on humidity detection data from the humidity sensor 34, pressurized dry air is supplied toward the sheet 44 inside the waveguide 42 of the waveguide device 32 and also toward the transmitter 16. As a result, the radar device 10 maintains a high air pressure inside the transmitter 16, preventing dielectric breakdown of the air inside the transmitter 16 and preventing corona discharge.

[0058] In this embodiment, while maintaining the humidity inside the waveguide 42, the pressurization of the second waveguide body 42b in the waveguide 42 using the pressurizing device 36 can be performed such that the air pressure P0 inside the second waveguide body 42b is less than the air pressure P inside the first waveguide body 42a. Thus, the radar device 10 according to this embodiment can also reduce the number of operations of the pressurizing device 36. This allows the life of the pressurizing device 36 to be extended.

[0059] Therefore, according to this embodiment, it is possible to provide the waveguide device 32, the waveguide system 14, and the radar device 10 that can reduce the number of operations of the pressurizing device 36.

[0060] According to at least one of the embodiments described above, it is possible to provide the waveguide device 32, the waveguide system 14, and the radar device 10 that can reduce the number of operations of the pressurizing device 36.

[0061] The present invention is not limited to the above-described embodiments, and various modifications can be made in the implementation stage without departing from the spirit of the invention. Furthermore, the embodiments may be implemented in appropriate combinations, in which case the combined effects can be obtained. Furthermore, the above-described embodiments include various inventions, and various inventions can be extracted by combining selected elements from the disclosed elements. For example, if the problem can be solved and the desired effect can be obtained even if some elements are deleted from all elements shown in the embodiments, the configuration from which these elements are deleted can be extracted as an invention. [Explanation of symbols]

[0062] 10...Radar device, 12...Antenna device, 14...Waveguide system, 16...Transmitter, 16a...Receiver, 16b...Transceiver, 22...Support part, 24...Rotating device, 24a...Rotary joint, 26...Antenna, 32...Waveguide device, 34...Humidity sensor, 36...Pressurizing device, 38...Control part, 42...Waveguide, 42a...First waveguide body, 42b...Second waveguide body, 43a, 43b, 43c...End part, 44...Seat, 45a...Bolt, 45b...Nut, 45c...Washer, 46...O-ring.

Claims

1. a hollow waveguide capable of guiding radio waves between a transmitter, a receiver, or a transceiver and an antenna device, and into which dry air is supplied from a pressurizing device; a sheet that partitions the inside of the waveguide between the transmitter, the receiver, or the transceiver and the antenna device, and allows the dry air to pass to the antenna device side while making the pressure of the dry air on the transmitter, the receiver, or the transceiver side higher than the pressure of the dry air on the antenna device side, which is equal to or higher than atmospheric pressure, by the partition within the waveguide; A waveguide device comprising:

2. The sheet is formed of a film-like member having minute porous holes that allow the dry air to pass through.

10. The waveguide device of claim 1.

3. The waveguide is a first waveguide body on the transmitter, the receiver, or the transceiver side; a second waveguide body on the antenna device side, the second waveguide body being connected to an end of the first waveguide body and having an end that cooperates with the end of the first waveguide body to sandwich the sheet; Equipped with a connection portion between the first waveguide body and the second waveguide body that allows radio waves to pass through; 10. The waveguide device of claim 1.

4. The waveguide device according to claim 1 , wherein the dry air is supplied to the waveguide from the pressurizing device through the transmitter, the receiver, or the transceiver.

5. A waveguide device according to any one of claims 1 to 4; A control unit; a humidity sensor provided in the waveguide, controlled by the control unit, and configured to detect humidity within the waveguide; a pressure device that is provided in the waveguide at a position away from the antenna device, is controlled by the control unit, and supplies the dry air into the waveguide based on the humidity detected by the humidity sensor; A waveguide system comprising:

6. A waveguide device according to any one of claims 1 to 4; the antenna device including an antenna capable of transmitting and / or receiving radio waves, and a rotation device that can guide the radio waves to the antenna through the waveguide and / or is connected so as to be able to guide the radio waves from the antenna to the waveguide, and that rotatably supports the antenna; the transmitter, the receiver, or the transceiver; a pressure applying device provided in the waveguide at a position away from the antenna device, the pressure applying device supplying the dry air to the transmitter, the receiver, or the transceiver through the waveguide; A radar device comprising:

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