Extension mast

Abstract

To provide an extension mast that is adopted to a use in an environment with a restriction such as lunar, can be housed compactly and developed, and is configured as an antenna integrated type.SOLUTION: An extension mast 200 at least comprises: a top board 2; a bottom board 1; a plurality of elastic vertical beams 3 connecting the top board 2 and the bottom board 1; add a wiring 70 which is connected to the top board 2 via a hole part 4 provided to the bottom board 1 to energize to each elastic vertical beam 3 between the top board 2 and bottom board 1 to contract it in a coli shape, and which releases the energization and stretches each elastic vertical beam 3 linearly. A first part 9d of the wiring 70 on the bottom board side is constituted by a cable 9 in order to be connected to an antenna element as an antenna integrated type.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to an extendable mast, and particularly to an extendable mast configured as an antenna integrated type.

Background Art

[0002] Examples of existing technologies of masts (spar) with antennas that are commonly and generally known in daily life include Non-Patent Document 1, Patent Document 1, etc.

[0003] The hydraulic telescopic mast disclosed in Non-Patent Document 1, etc. can be used, for example, by installing it on a mobile station base station vehicle, changing the amount of oil sent from a hydraulic tank to extend and retract the pole (mast), and attaching an antenna to the tip of the extended and retracted pole. The wire-type telescopic mast disclosed in Patent Document 1, etc. is extended and retracted by pushing and pulling a wire passed through a pole with an electric motor and is generally used as an antenna for automobiles, etc.

[0004] Also, as an existing technology that can be used for antenna deployment in a spacecraft system, there is an extendable boom disclosed in Non-Patent Document 2, etc. There are known a self-extending method in which an elastic boom with a membrane structure is wound and stored and the boom is extended by simply releasing the elastic energy, and a method in which the force of a drive motor is also borrowed for boom extension.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

[0006] [Non-Patent Document 1] Telescopic pole system for radio wave measurement, 2021, (Yuasa Koki Co., Ltd.), [Retrieved September 15, 2023], Internet<URL:http: / / www.yuasakk.co.jp / pole / mast04.html> [Non-Patent Document 2] Hiroshi Furuya; Kei Sakamoto. Space deployment structure consisting of an extendable boom and membrane. Journal of the Japan Society for Aeronautical and Space Sciences, 2016, 64.11: 322-326. [Overview of the project] [Problems that the invention aims to solve]

[0007] However, conventional technology could not address the need to compactly house and deploy antenna masts for use on the lunar surface.

[0008] The need for antenna-equipped masts for lunar use arises from the following reasons: To establish 5G and other mobile phone coverage areas on the lunar surface for lunar resource development, it is necessary to attach antennas to masts tens of meters in height and install them on the lunar surface. To reduce the amount of work to be done on the lunar surface, where the working environment is worse than on Earth, it is desirable to attach the antennas and cables to the masts on Earth beforehand and then transport them to the moon. Spacecraft have limited space for equipment, so the antenna-equipped masts need to be compactly housed. Furthermore, the antenna-equipped masts need to be deployable with simple operations after arriving on the lunar surface.

[0009] In contrast, everyday antenna masts such as those described in Non-Patent Document 1 and Patent Document 1 require drive systems such as hydraulic systems and motor systems. If these were to be used as antenna masts for lunar use in their original form, extra space would be needed to accommodate these drive systems, sacrificing compactness, making them unsuitable for lunar use after being transported by a spacecraft. The extendable boom described in Non-Patent Document 2 may be suitable for deployment in a planar manner, but it is not necessarily suitable for efficiently deploying in a straight line as a mast of several tens of meters.

[0010] Furthermore, for antenna-equipped masts used on the lunar surface, the space required for mounting the antenna must be kept as compact as possible, but conventional technology could not address this issue.

[0011] Furthermore, while there are prior art examples such as Patent Documents 2-6, which describe extendable masts that can be deployed in a straight line, these extendable masts are general-purpose products, and no disclosures have been made regarding how to minimize the space required for attaching the antenna to the extendable mast.

[0012] In view of the problems of the conventional technology described above, the present invention aims to provide an extendable mast that can be compactly housed and deployed, and is configured as an integrated antenna, suitable for use in restrictive environments such as the lunar surface. [Means for solving the problem]

[0013] To achieve the above objective, the present invention provides an extendable mast comprising at least a top plate, a bottom plate, a plurality of elastic vertical beams connecting the top plate and the bottom plate, and a pull cord connected to the top plate through a hole provided in the bottom plate, which biases the elastic vertical beams between the top plate and the bottom plate to contract them into a coil shape, and releases the bias to extend the elastic vertical beams in a straight line, characterized in that the first portion of the pull cord on the bottom plate side is composed of a cable for connecting to an antenna element, thereby being configured as an integrated antenna type.

Advantages of the Invention

[0014] According to the present invention, by making the cable connected to the antenna element play the role of the guy wire of the extension mast, the extension mast can be configured as an antenna integrated type that can be compactly accommodated and deployed and is suitable for use in a restricted environment.

Brief Description of the Drawings

[0015] [Figure 1] It is a diagram showing the main structure and deployment mode of an existing extension mast. [Figure 2] It is a front view of a cross beam. [Figure 3] It is an explanatory diagram of how to provide diagonal cables. [Figure 4] It is a configuration diagram of an extension mast according to an embodiment. [Figure 5] It is a diagram showing the structure of an antenna element. [Figure 6] As an example of an extension mast provided with a plurality of antenna elements, it is a diagram showing an example of a two-frequency two-branch configuration. [Figure 7] As an example of an extension mast provided with a plurality of antenna elements, it is a diagram showing an example of a one-frequency four-branch configuration.

Embodiments for Carrying Out the Invention

[0016] In an embodiment of the present invention, as a base structure for enabling the antenna to be compactly accommodated and deployed, an extension mast (coilable extension mast) disclosed in Patent Documents 2 to 6 and the like and available for purchase from the applicant (Nippon Aircraft Co., Ltd.) can be used.

[0017] For illustrative purposes, the base extendable mast will be referred to as the existing extendable mast 100. In the embodiment of the present invention, the existing extendable mast 100 is used as the structure for deployment, and an antenna-integrated extendable mast 200 (abbreviated as extendable mast 200) can be used, which is an additional design that integrates an antenna into the existing extendable mast 100. Below, as a prerequisite for explaining the extendable mast 200 according to the embodiment of the present invention, the existing extendable mast 100 as existing technology will be described.

[0018] Furthermore, the basic configuration of the existing extendable mast 100 is disclosed in Patent Document 2, and while that basic configuration has three longitudinal beams, an example of configuring it with five or more is disclosed in Patent Document 3. In addition, an example of adding a spring member or spring for forced uprighting during the initial stages of deployment to the basic configuration is disclosed in Patent Document 5. In addition, an example of adding a spring material to reduce deformation of the transverse beams to the basic configuration is disclosed in Patent Document 5. In addition, an example of improving the transverse beams to the basic configuration is disclosed in Patent Document 6.

[0019] As the existing extendable mast 100, only the basic configuration of Patent Document 2 (including modified examples and conventional examples) may be used, or a configuration in which all or part of the design of Patent Documents 3 to 6 has been modified from the said basic configuration may be used.

[0020] Figure 1 shows the main structure and deployment modes of the existing extendable mast 100, with the deployment state shown as states C1, C2, and C3. For the existing extendable mast 100, state C1 shows the contracted state (fully folded state), state C2 shows the state in the middle of extension, and state C3 shows the extended state (fully extended state). The existing extendable mast 100 has a structure in which a circular base plate 1 and a top plate 2 are connected by multiple (for example, three) elastic vertical beams 3 made of elastic material such as fiber-reinforced resin, which act as extension columns.

[0021] The base plate 1 has a hole 4 in its center through which a pull cord 7 passes, allowing the pull cord 7 to move up and down. The pull cord 7 is fixed from the inside to the center of the top plate 2 through the hole 4. By pulling the pull cord 7 by hand or by some pull cord winding mechanism in the contraction direction D2 from the top plate 2 towards the base plate 1, a force is applied to the top plate 2 toward the base plate 1, causing the elastic vertical beam 3 of the existing extendable mast 100 to deform from a straight extended state into a coil shape, thereby allowing the existing extendable mast 100 to contract as shown in states C3→C2→C1. Conversely, when the pull cord 7 is released in the contracted state C1 (releasing the point where it was pulled and held), the existing extendable mast 100 can autonomously extend in the extension direction D1 as shown in states C1→C2→C3, solely by the elastic energy stored in the elastic vertical beam 3, etc. (without requiring any other driving force such as a motor).

[0022] In other words, when a tensile force is applied by the tensioning cable 7, the elastic longitudinal beam 3 is biased, and the existing extendable mast 100 contracts as shown in states C3 → C2 → C1. When the tensile force from the tensioning cable 7 is released, the biasing force on the elastic longitudinal beam 3 is also released, and the existing extendable mast 100 extends as shown in states C1 → C2 → C3. (Regarding the extendable mast 200 according to the embodiment of this application, when contracted, the tensioning cable 7 is fixed with a fastener (not shown), and when extending on the lunar surface, part of the power used to open the door housing the extendable mast 200 may be used to release the fastener. Alternatively, some kind of tensioning cable 7 winding mechanism using a motor (which may not be dedicated to winding the tensioning cable 7 but may also serve other purposes) may be used to extend on the lunar surface.)

[0023] Furthermore, as in Patent Document 2, instead of fixing the pull cord 7 to the center of the top plate 2, a hole (not shown) may be provided at the center of the top plate 2, the pull cord 7 may be passed through this hole, and then connected to the oblique cord (described later) formed at the top, thereby enabling smoother contraction and extension. In this configuration as well, the pull cord 7 is in contact with the top plate 2, and although the top plate 2 and the pull cord 7 are not fixed, they are mechanically connected, so the action of pulling the top plate 2 remains the same.

[0024] Furthermore, since the existing extendable mast 100 can be deformed in various ways, as described in Patent Documents 2 to 6, for example, there may be elastic members other than the elastic vertical beam 3 that are used to bias / release the biasing force by the tension cord 7 when the existing extendable mast 100 is contracted / extended. However, at least the elastic vertical beam 3 is subject to biasing / release by the tension cord 7.

[0025] As a structure that is directly or indirectly subject to biasing / release of bias by the pull rope 7 (depending on the deformation of the elastic longitudinal beam 3 by the pull rope 7), the existing extendable mast 100 is equipped with a transverse beam 5 (described later), and may also be equipped with a spring member or spring mechanism (not shown) disclosed in Patent Document 5 to improve the initial extendability when extending from state C1 to C2 to C3, or a spring material (not shown) disclosed in Patent Document 5, which has the effect of reducing the deformation of the transverse beam 5, may be provided on the "inclined rope" described later.

[0026] Multiple elastic crossbeams 5 are provided on the three elastic vertical beams 3 at regular intervals in the extension direction when extended, and are fixed to the elastic vertical beams 3. Figure 2 is a front view of the crossbeam 5, and the crossbeam 5 is fixed to the elastic vertical beams 3 at the tips of three straight sections 5b that are arranged radially from the center at an angle of 120° to each other. A hole 5a is formed at the center where the three straight sections 5b are connected, through which a pull rope 7 is passed, and through which the pull rope 7 is passed (through the crossbeam 5). By providing the crossbeam 5, it is possible to stably contract / extend the existing extension mast 100.

[0027] The existing extension mast 100 may also be provided with diagonal cables (diagonal strings) stretched in an X shape to connect pairs of vertical beams 3,3 for each vertically adjacent crossbeam 5,5 (not shown in Figure 1, etc., for the sake of simplifying the drawings) as a configuration to stabilize its contraction / extension. Diagonal cables are also disclosed in Patent Document 2, etc. Figure 3 is an explanatory diagram of how to install the diagonal cables, and the vertically adjacent crossbeams 5,5 are shown as upper crossbeam 5u and lower crossbeam 5d, distinguishing them as upper and lower. The tip parts ua, ub, uc of the upper crossbeam 5u and the tip parts da, db, dc of the lower crossbeam 5d indicate the points where they are fixed to the vertical beams 3 (not shown, but distinguished as 3a, 3b, 3c). In this case, for example, for adjacent vertical beams 3b, 3c, diagonal cables can be installed between points ub, dc and between points uc, db so as to cross in an X shape between the upper crossbeam 5u and the lower crossbeam 5d. The inclined cables only need to be fixed to the longitudinal beam 3 or the transverse beam 5 at the locations ub,dc and uc,db where they are installed.

[0028] The above describes an embodiment of the (antenna-integrated) extendable mast 200 of the present invention, based on the existing extendable mast 100. Figure 4 is a configuration diagram of the extendable mast 200 according to one embodiment, showing the configuration in the extended state, which corresponds to state C3 of the existing extendable mast 100. The extendable mast 200 is identical to the existing extendable mast 100, except that the pull rope 7 in the existing extendable mast 100 has been replaced with a pull rope 70 for the antenna. Therefore, the same reference numerals are used for the same structural components in the extendable mast 200 as in the existing extendable mast 100 (this includes the base plate 1, top plate 2, elastic longitudinal beam 3 and transverse beam 5, and also for diagonal cables not shown).

[0029] The antenna guide cable 70 comprises an upper guide section 7u fixed from the inside to the center of the top plate 2, an antenna element 80 provided on one elastic vertical beam 3, and a coaxial cable 9 (shown as a thick black line in the figure) for power supply connected to the antenna element 80. (However, a portion of the coaxial cable 9 is configured not to be subjected to tensile stress as a guide cable, as will be described later.) The upper guide section 7u is configured as a separate, independent guide section (string) from the coaxial cable 9. The coaxial cable 9 is fixed to the upper guide section 7u by being tied to it at an upper location n close to the top plate 2. The coaxial cable 9 is distinguished by calling the part above location n the upper cable section 9u and the part below location u the lower cable section 9d.

[0030] The upper cable portion 9u has an antenna element 8 at its tip, which is on the opposite side of location n, and this antenna element 8 is formed on one elastic vertical beam 3.

[0031] In this embodiment, the role of the pull rope 7 of the existing extendable mast 100 is played by the upper cable portion 7u and the lower cable portion 9d which is fixed to the upper cable portion 7u at point n. In other words, the conventional pull rope 7 (the portion furthest from the top plate 2) is realized not by a dedicated pull rope, but by using the lower cable portion 9d of a coaxial cable 9 which can also be used as a pull rope, thereby allowing the coaxial cable 9 to play the role of the pull rope 7. This is the embodiment of the present invention.

[0032] Here, the upper cable portion 9u to which the antenna element 8 is connected is designed with sufficient length to ensure that the upper cable portion 9u remains flexible even when the upper cable portion 7u and lower cable portion 9d, which act as a "pull cord (conventional pull cord 7)", are pulled, so that no tensile force acts on the connection point of the antenna element 8. Alternatively, the upper cable portion 9u may be installed on one of the three straight sections 5b of the crossbeam 5 as described in Figure 2, either in a flexible state or without bending (for example, by attaching the upper cable portion 9u to the surface of the straight section 5b to integrate it). Since the crossbeam 5 is made of an elastic material but is made of a material that is stiffer than the coaxial cable 9, tensile stress can be prevented from being applied to the upper cable portion 9u, or its application can be significantly reduced (i.e., the effect of stress can be eliminated, or if it cannot be eliminated, it can be mitigated to some extent).

[0033] In the example shown in Figure 4, there are no crossbeams 5 (which can be provided at roughly equal intervals in the vertical direction along the elastic vertical beam 3) above location n, and it appears as if the antenna element 8 is installed near the highest point in the height direction of the top plate 2 of the extended mast 200 in the extended state. However, the height at which the antenna element 8 is placed on the extended mast 200 in the extended state can be any height on the elastic vertical beam 3. That is, one or more crossbeams 5 may be arranged along the upper cable section 7u. For example, if 20 crossbeams 5 appear in the height direction on the extended mast 200 in the extended state, the antenna element 8 may be placed at the 10th height position in the middle, and "location n" may be formed at this location. The upper cable section 7u may then be formed in the range above location n where 10 crossbeams 5 appear.

[0034] The same applies to the examples in Figures 6 and 7 described later; the number of crossbeams 5 shown is merely illustrative, and the height of the location where the antenna elements 8 are placed can be arbitrary.

[0035] Figure 5 shows an example of the structure of an antenna element 8. The antenna element 8 can be manufactured as a thin metal film covering the surface of the elastic vertical beam 3, which is made of resin or the like, by plating (metal plating) the surface of the elastic vertical beam 3. For example, as a λ / 4 wavelength dipole antenna, the antenna element 8 can be constructed by covering the outer circumference of the elastic vertical beam 3 with the plated portion for equal lengths in the vertical direction, forming an upper plated portion 8u and a lower plated portion 8d, respectively, and connecting them to the coaxial cable 9. In the example in Figure 5, the cross-sectional shape of the elastic vertical beam 3 is circular, but even if the cross-section is a different shape, such as a square or triangle, the antenna element 8 can be constructed in the same way by covering two places with plated portions for equal lengths in the vertical direction. The number of antenna elements 8 will vary depending on the type of antenna (dipole or monopole, etc.). A balun, matching circuit, conversion circuit, etc. may also be connected between the antenna element 8 and the coaxial cable 9. The antenna composed of the antenna elements 8 may be configured for transmission, reception, or combined transmission and reception.

[0036] As an example of development from the embodiment shown in Figure 4, an extendable mast 200 may be used to provide multiple antenna elements 8, as shown in Figures 6 and 7.

[0037] The example in Figure 6 uses antenna elements of different frequencies plated at different positions to enable a multi-frequency configuration, and also uses two different feed cables 91 and 92 to support multi-branch (multi-antenna) configurations. The first feed cable 91 connects to the first antenna element 81u of the first frequency and the second antenna element of the second frequency via the first demultiplexer d1. 81m This is divided into two parts, enabling multi-frequency operation. Similarly, the second power supply cable 91 is connected to the first antenna element of the first frequency via the second demultiplexer d2. 82m It is divided into a second antenna element 82d for the second frequency, thereby realizing multi-frequency operation. The antenna lead rope 70 consists of the upper lead rope section 7u, these cables 91, 92, and the antenna element 81u, 81m ,82u, 82mThus, similar to the example in Figure 4, a portion of the cables 91 and 92 is configured not to be subjected to tensile stress as a pull rope, as will be described later.

[0038] Here, since the first and second demultiplexers d1 and d2 are used, as shown in Figure 6, antenna elements of different frequencies can be placed at different positions (in the vertical direction of the elastic vertical beam 3). For example, via the first demultiplexer d1, the first antenna element 81u of the first frequency is connected to the second antenna element of the second frequency. 81m It is positioned higher than the first antenna element 82u of the first frequency via the second demultiplexer d2, and the second antenna element of the second frequency 82m They are positioned at a higher level than [the specified position]. Furthermore, for antenna elements of the same frequency, their heights may or may not be aligned. The example shows two first antenna elements 81u and 82u of the first frequency not at the same height, while the example shows two antenna elements 81m and 82m of the second frequency being at the same height.

[0039] In the example in Figure 6, the wiring near the four antenna elements 81u, 81m, 82u, and 82m is configured as cable sections 91u, 91m, 92u, and 92m, respectively. Similar to the case of the upper cable section 9u in Figure 4, the cable should be bent and connected to the elastic vertical beam 3 or placed on the horizontal beam 5 so that no tensile stress is applied when the pull cord is pulled. Furthermore, the antenna element 81u, which is the highest of the four antenna elements 81u, 81m, 82u, and 82m, should be designated as a section to form location n, similar to that in Figure 4, and the section above location n should be configured as an upper pull cord section 7u (as a separate cord from the cable of this application). Below location n, the first feed cable 91 and the 22 feed cable should be bundled together and tied to each other, etc., to form a configuration corresponding to the lower cable section 9d in Figure 4, so that it functions as a single pull cord.

[0040] Thus, in the example in Figure 6, as in the example in Figure 4, the upper cable section 7u and, at locations below point n, the first power supply cable 91 and the second power supply cable 92 (if both cables exist at that height) can be bundled together by tying them to each other, and this configuration can serve the role of the conventional pull cable 7. (For example, at the height of the location immediately below point n, only the first power supply cable 91 exists, so it is not necessary to tie it together with the second power supply cable 92.)

[0041] The four antenna elements 81u, 81m, 82u, and 82m can each be constructed by plating the elastic longitudinal beam 3, similar to the antenna element 8 described in Figure 5.

[0042] The example in Figure 6 above was a 2-frequency, 2-branch configuration. Similarly, Figure 7 shows an example of a 1-frequency, 4-branch configuration. Here, four different feed cables 93, 94, 95, and 96 are provided as the four branches, and antenna elements 83, 84, 85, and 86 of the same frequency are provided to each. Here, antenna element 83, 85 They are at the same height, and the antenna element is at a different height. 84 Although 83, 84, 85, and 86 are arranged at the same height, the height of the location where each antenna element 83, 84, 85, and 86 is placed can be arbitrary. The antenna lead rope 70 consists of the upper lead rope section 7u, these cables 93, 94, 95, and 96, and the antenna elements 83, 84, 85, and 86. Similar to the example in Figure 4, a portion of the cables 93, 94, 95, and 96 is configured not to be subjected to tensile stress as a lead rope, as will be described later.

[0043] Furthermore, the wiring near each antenna element 83, 84, 85, 86 is configured as cable sections 93u, 94u, 95u, and 96u, respectively. Similar to the case of the upper cable section 9u in Figure 4, these can be bent and connected to the elastic vertical beam 3 or placed on the horizontal beam 5 so as not to be subjected to tensile stress when the cable is pulled. Also, similar to the examples in Figures 4 and 6, a point n is formed at the highest position among the cable sections 93u, 94u, 95u, and 96u of the nearby wiring, and the area above point n is configured as the upper cable section 7u. At point n, the corresponding cable can be fixed to the upper cable section 7u. (In the example in Figure 7, the power supply cable 93, 95 (It is fixed to the upper cable portion 7u at the same location n.)

[0044] Below point n, all of the power supply cables 93, 94, 95, and 96 present at each height are bundled together by tying them to each other so that they function as a single pull rope. The bundled section (corresponding to the lower cable section 9d in Figure 4) and the upper cable section 7u can then perform the role of the conventional pull rope 7.

[0045] As explained above, in the extendable mast 200 of this embodiment, the antenna element configuration is not limited to one frequency and one branch as shown in Figure 4, but can also be configured as two frequencies and two branches as shown in Figure 6, or one frequency and four branches as shown in Figure 7. Similarly, for any natural numbers n, m ≥ 1, the extendable mast 200 of this embodiment can be realized with an n frequency and m branch configuration.

[0046] As described above, according to the embodiment of the present invention, the side furthest from the top plate 2 is configured with a power supply cable that connects to the antenna element, and this power supply cable takes on the role of the power supply cable 7. As a result, the extendable mast 200 can be constructed by integrating the antenna with the structure of the existing extendable mast 100. This allows the extendable mast 200, as a mast with an antenna, to be compactly housed and deployed, thus saving space for installation on a spacecraft.

[0047] For example, it is conceivable to place the antenna elements on the top plate 2 of the existing extendable mast 100, but the extendable mast 200 of this embodiment does not employ such a configuration. Instead, as explained in Figure 5, the antenna elements are made compact by plating the outer surface of the elastic vertical beam 3, without significantly altering the shape of the elastic vertical beam 3 itself. Therefore, the space on the top plate 2 can be used to install other sensor devices, etc., in addition to the antenna, allowing for efficient use of space while saving space to be mounted on the spacecraft.

[0048] Embodiments of the present invention can contribute to lunar resource development and other activities, thereby contributing to Goal 9 of the United Nations-led Sustainable Development Goals (SDGs): "Build resilient infrastructure, promote sustainable industrialization and expand innovation." [Explanation of symbols]

[0049] 100...Existing extendable mast, 200...(Antenna integrated) extendable mast, 1...Bottom plate, 2...Top plate, 3...Elastic vertical beam, 4...Hole, 5...Cross beam, 7...Takeaway cable, 70...Takeaway cable for antenna, 7u...Upper cable section, 80...Antenna element, 9...Coaxial cable (feed cable), n...Location, 9u...Upper cable section, 9d...Lower cable section, 8u...Upper plated section, 8d...Lower plated section, wu,wd...Wiring

Claims

1. An extendable mast comprising at least a top plate, a bottom plate, a plurality of elastic vertical beams connecting the top plate and the bottom plate, and a pull cord connected to the top plate through a hole provided in the bottom plate, which biases the elastic vertical beams between the top plate and the bottom plate, causing them to contract into a coil shape, and releasing the biasing force to extend the elastic vertical beams in a straight line, The first portion of the aforementioned pull rope on the bottom plate side is composed of a cable for connecting to the antenna element, thus it is configured as an integrated antenna type. An extendable mast characterized in that, apart from the first portion of the aforementioned pull rope, the second portion connected to the top plate is not configured as the cable.

2. An extendable mast comprising at least a top plate, a bottom plate, a plurality of elastic vertical beams connecting the top plate and the bottom plate, and a pull cord connected to the top plate through a hole provided in the bottom plate, which biases the elastic vertical beams between the top plate and the bottom plate, causing them to contract into a coil shape, and releasing the biasing force to extend the elastic vertical beams in a straight line, The first portion of the aforementioned pull rope on the bottom plate side is composed of a cable for connecting to the antenna element, thus it is configured as an integrated antenna type. The extension mast is characterized in that the antenna element is formed by plating the surface of the elastic longitudinal beam.

3. An extendable mast comprising at least a top plate, a bottom plate, a plurality of elastic vertical beams connecting the top plate and the bottom plate, and a pull cord connected to the top plate through a hole provided in the bottom plate, which biases the elastic vertical beams between the top plate and the bottom plate, causing them to contract into a coil shape, and releasing the biasing force to extend the elastic vertical beams in a straight line, The first portion of the aforementioned pull rope on the bottom plate side is composed of a cable for connecting to the antenna element, thus it is configured as an integrated antenna type. An extendable mast characterized in that at least one demultiplexer is provided in the middle of the cable, so that the antenna elements exist for multiple different frequencies.

4. An extendable mast comprising at least a top plate, a bottom plate, a plurality of elastic vertical beams connecting the top plate and the bottom plate, and a pull cord connected to the top plate through a hole provided in the bottom plate, which biases the elastic vertical beams between the top plate and the bottom plate, causing them to contract into a coil shape, and releasing the biasing force to extend the elastic vertical beams in a straight line, The first portion of the aforementioned pull rope on the bottom plate side is composed of a cable for connecting to the antenna element, thus it is configured as an integrated antenna type. The extension mast is characterized in that the cable is made up of multiple cables bundled together, and each of the multiple cables has an antenna to which it is connected.

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