Small wideband antenna
The small broadband antenna design with a loop-shaped feed plate and dogbone slots addresses the challenge of compact size and wide frequency operation, achieving stable performance and cost reduction by using a conductive housing.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- NEC PLATFROMS LTD
- Filing Date
- 2023-12-26
- Publication Date
- 2026-05-11
AI Technical Summary
Existing antennas are difficult to realize in a compact size while operating in a wide frequency band, and they often require expensive and less environmentally resistant materials like FRP for protection.
A small broadband antenna design featuring a ground plate, power supply plate, and a housing with a loop-shaped feed plate and dogbone slots, covered by a conductive housing, which allows for stable operation and reduced size.
The antenna achieves a wide frequency band operation in a compact size, reduces interference, and lowers material costs by using a conductive housing and minimizing the use of FRP, suitable for embedding in buildings and vehicles.
Smart Images
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Abstract
Description
[Technical Field]
[0001] This disclosure relates to a small, broadband antenna, and more particularly to a small, broadband antenna that can be realized in a compact size and used in a wide frequency band. [Background technology]
[0002] Small, wideband antennas are a crucial technology because they can be embedded in building ceilings as mobile communication base station antennas, or mounted on aircraft fuselages to minimize air resistance. Patch antennas, monopole antennas, or dipole antennas are used for mobile communication base station antennas and aircraft-mounted antennas. These antennas are covered with a radome, a dielectric material, to protect them from wind, rain, snow, hail, etc. The radome is made of FRP (Fiber Reinforced Plastics), which is more expensive than metal materials in terms of both material and molding, and also has inferior environmental resistance. Therefore, there is a desire to miniaturize the antenna and the radome that covers it. Furthermore, with the explosive increase in demand for mobile communications, various frequencies are being used for mobile communications, and there is a need to realize antennas that can handle wideband.
[0003] Patent Document 1 describes an antenna device comprising a ground plate, a linear feeding element, and two mushroom cells, wherein the linear feeding element is a linear conductor element arranged parallel to the ground plate with its end connected to a feeding circuit, and each mushroom cell has a mushroom structure combining an opposing conductor plate parallel to the ground plate and a short-circuit portion that electrically connects the center of the opposing conductor plate to the ground plate, and each mushroom cell is arranged in a line along the linear feeding element. Patent Document 1 does not disclose a compact, broadband antenna that can be realized in a small size and used in a wide frequency band.
[0004] Patent Document 2 describes a slot antenna comprising: a first conductive member having a first conductive surface; a second conductive member having a second conductive surface facing the first conductive surface; a waveguide member located between the first and second conductive members, having a stripe-shaped conductive waveguide facing the first conductive surface, and extending in a first direction along the first conductive surface; and artificial magnetic conductors located on both sides of the waveguide member between the first and second conductive members, wherein the first conductive member has a slot, and the slot is a composite slot having a pair of vertical portions and a horizontal portion connecting the pair of vertical portions, the horizontal portion facing the waveguide and intersecting the first direction. Patent Document 2 does not disclose an antenna using a loop-shaped feed plate. Furthermore, Patent Document 2 does not disclose a compact, broadband antenna that can be realized in a small size and used in a wide frequency band. [Prior art documents] [Patent Documents]
[0005] [Patent Document 1] International Publication No. 2022 / 202623 [Patent Document 2] Special Publication No. 2018-511951 [Overview of the Initiative] [Problems that the invention aims to solve]
[0006] As described above, the technologies described in Patent Documents 1 and 2 make it difficult to realize a compact, wideband antenna that can be used in a wide frequency band, and there has been a demand for such an antenna.
[0007] The purpose of this disclosure is to provide a compact, wideband antenna that solves the problems described above. [Means for solving the problem]
[0008] The small broadband antenna relating to this disclosure is A ground plate having ground surfaces parallel to the X and Y directions, A power supply plate provided on the ground surface, A power supply unit is provided between the ground plate and the power supply plate, and supplies a high-frequency signal to the power supply plate, A housing that covers the ground surface, the power supply unit, and the power supply plate, The upper plate of the housing on the ground surface, and a slot provided in the upper plate facing the ground surface, Equipped with, The aforementioned power supply board is A first portion connected to the power supply unit and extending in the Z direction, A second portion extending in the opposite direction to the X direction from the end of the first portion extending in the Z direction, It has a third portion that extends in the opposite direction to the Z direction from the end of the second portion that extends in the opposite direction to the X direction and connects to the ground plate, The aforementioned slot is A single line slot extending in the Y direction, or A dog horn slot extending in the X direction, splitting into two branches along its extension, one branch extending in the X direction and the other extending in the Y direction, and further splitting into two branches at the end of the Y direction, one branch extending in the X direction and the other extending in the opposite direction to the X direction. When viewed from the Z direction, a part of the doghorn slot and a part of the power supply plate overlap, The ground plate, the power supply plate, and the housing are composed of conductors. [Effects of the Invention]
[0009] According to this disclosure, it is possible to provide a small, broadband antenna that can be realized in a compact size and used in a wide frequency band. [Brief explanation of the drawing]
[0010] [Figure 1A] This is a perspective view illustrating a small, broadband antenna related to this disclosure. [Figure 1B] This is a perspective view illustrating an example of a power supply method for a small, broadband antenna related to this disclosure. [Figure 2A] Perspective view illustrating the small broadband antenna according to the present disclosure. [Figure 2B] Perspective view illustrating the small broadband antenna according to the present disclosure, with a perspective view of the power supply board portion. [Figure 2C] Plan view illustrating the small broadband antenna according to the present disclosure. [Figure 2D] Cross-sectional view taken along line segment A1 - A2 shown in FIG. 2C. [Figure 3] Schematic view illustrating the shape of the slot of the small broadband antenna according to the present disclosure. [Figure 4] Perspective view illustrating the power supply board of the small broadband antenna according to the present disclosure. [Figure 5] Perspective view illustrating the small broadband antenna according to the present disclosure. [Figure 6] Perspective view illustrating the small broadband antenna according to the present disclosure. [Figure 7] Graph illustrating the matching characteristics of the small broadband antenna according to the present disclosure. [Figure 8] Graph illustrating the radiation pattern of the small broadband antenna according to the present disclosure.
Embodiments for Carrying Out the Invention
[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each drawing, the same or corresponding elements are denoted by the same reference numerals, and redundant explanations will be omitted as necessary for clarity of explanation.
[0012] [Embodiment 1] [Configuration] FIG. 1A is a perspective view illustrating the small broadband antenna according to the present disclosure. FIG. 1B is a perspective view illustrating the power supply method of the small broadband antenna according to the present disclosure. In Figures 1A and 1B, the upward direction is defined as the Z direction, and the directions perpendicular to the Z direction are defined as the X and Y directions. The Y direction is also perpendicular to the X direction. The X direction is sometimes referred to as the first direction, the Y direction as the second direction, and the Z direction as the third direction. XYZ coordinates will be used in subsequent drawings as needed. In Figure 1B, only the ground plate, feed plate, and coaxial cable (corresponding to the feed point) are shown for ease of understanding.
[0013] As shown in Figure 1A, the compact broadband antenna 11 according to this disclosure comprises a ground plate 111, a feed plate 112, a feed section 113, a housing 114, and a slot 115. The ground plate 111, the feed plate 112, and the housing 114 are composed of conductors.
[0014] The ground plate 111 has ground surfaces 111s1 parallel to the X and Y directions.
[0015] The feed plate 112 is provided on the ground plane 111s1. The feed plate 112 has a first part 1121, a second part 1122, and a third part 1123. The first part 1121 is connected to the feed section 113 and extends in the Z direction. The second part 1122 extends in the opposite direction to the X direction from the end of the Z-direction extension of the first part 1121. The third part 1123 extends in the opposite direction to the Z direction from the end of the X-direction extension of the second part 1122 and is connected (grounded) to the ground plate 111. When viewed from the Y direction, the feed plate has a loop shape (U-shape), so the feed plate is sometimes referred to as a loop element or loop antenna.
[0016] The power supply unit 113 is provided between the ground plate 111 and the power supply plate 112, and supplies a high-frequency signal to the power supply plate 112. As shown in Figure 1B, the power supply unit 113 supplies a high-frequency signal to the power supply plate 112, for example, by a coaxial cable 113. Specifically, the power supply unit 113 is made up of a coaxial cable. The power supply unit 113 has a core wire 1131 and an outer conductor 1132 of the coaxial cable, with the core wire 1131 connected to the power supply plate 112 and the outer conductor 1132 connected (grounded) to the ground plate 111.
[0017] The housing 114 covers the ground surface 111s1, the power supply unit 113, and the power supply plate 112. The plate of the housing 114 in the Z direction is referred to as the top plate 1141.
[0018] Slot 115 is provided in the top panel 1141 on the ground surface 111s1 of the housing 114. The top panel 1141 faces the ground surface 111s1. The first surface (not shown) of the top panel 1141 includes a flat or curved surface. Slot 115 is an elongated cutout provided in the top panel 1141. The top panel 1141 is part of the housing 114. Slot 115 is a single-line slot extending in the Y direction, or a doghorn slot. A doghorn slot extends in the X direction, then splits into two branches, one extending in the X direction and the other in the Y direction, and then splits again, one extending in the X direction and the other in the opposite direction of the X direction. When viewed from the Z direction, the shape of a doghorn slot is that of the capital letter H. The height (length) of the housing 114 in the Z direction is greater than the height of the first part 1121 and the third part 1123 in the Z direction, so the second part 1122 does not come into contact with the top panel 1141.
[0019] When the small wideband antenna 11 is viewed from the Z direction, a portion of the doghorn slot and a portion or all of the feed plate 112 overlap, or they do not overlap but are in close proximity. In other words, the doghorn slot and the feed plate 112 are located in close proximity. The relative position of the feed plate 112 and the slot 115, i.e., the relative distance in the X, Y, and Z directions, is determined based on the impedance characteristics at the feed point. Specifically, the relative position of the feed plate 112 and the slot 115 is determined so that the return loss at the feed point is sufficiently low. In Embodiment 1, it is determined to be -14.0 dB or less. It is known that when a dogbone slot is used as the slot, the frequency bandwidth is wider than that of a single-line slot.
[0020] <Operation> The operation of the small, wideband antenna 11 will be explained. As shown in Figure 1A, a power supply unit 113, located between the power supply plate 112 and the ground plate 111, supplies a high-frequency signal to the power supply plate 112. Here, the third portion 1123 (the tip of which) of the power supply plate 112 is grounded to the ground plate 111 (electrically connected to ground). The high-frequency signal supplied (excited) from the power supply unit 113 to the power supply point in the center of the first portion 1121 of the power supply plate 112 causes current to flow from that power supply point (one side of the power supply unit 113) to the power supply plate 112, that is, current flows from the first portion 1121 to the second portion 1122, and then to the third portion 1123, and returns to the other side of the power supply unit 113 via the ground plane 111s1 from the underside of the third portion 1123. The high-frequency signal from the power supply unit 113 flows in a loop through the power supply plate 112, so the power supply plate 112 and the ground plane 111s1 act as a loop antenna. The electric field generated by this loop antenna is electromagnetically coupled in the area where the slot 115 is in close proximity, and is radiated outwards as radio waves from the slot 115.
[0021] During operation, the feed plate 112 has a plate-like loop shape, which provides broadband characteristics. In addition, by providing dogbone slots instead of single-line slots on the top plate 1141 of the housing 114, it operates as an antenna with a wider bandwidth than one with single-line slots.
[0022] Figure 2A is a perspective view illustrating a compact, broadband antenna according to this disclosure. Figure 2B is a perspective view illustrating a small broadband antenna according to this disclosure, showing a transparent view of the feed plate. Figure 2C is a plan view illustrating a small, broadband antenna according to this disclosure. Figure 2D is a cross-sectional view taken along the line segment A1-A2 shown in Figure 2C.
[0023] Figures 2A to 2D show typical dimensions of a small, wideband antenna. For example, in Figures 2A and 2B, the length of the housing 114 in the X direction is recommended to be 0.4 to 0.5 times the wavelength of the high-frequency signal, so a typical value of 0.45λ is shown. O The following was written. However, λ Ois the wavelength of the high-frequency signal radiated from the antenna. Similarly, since the recommended value for the length of the housing 114 in the Y direction is 0.4 to 0.5 times the wavelength of the high-frequency signal, a representative value is 0.45λ O is described. Also, since the recommended value for the length of the housing 114 in the Z direction is 0.12 to 0.14 times the wavelength of the high-frequency signal, a representative value is 0.13λ O is described.
[0024] In FIG. 2C, the length of the power supply plate 112 in the Y direction is 0.07λ as a representative value O is described. The width of the dogbone slot is 0.019λ O or 0.026λ O is described. The length of the dogbone slot in the Y direction is 0.29λ O is described. The length of the dogbone slot in the X direction is 0.18λ O is described. In FIG. 2D, since the recommended value for the length of the second portion 1122 of the power supply plate 112 in the X direction is 0.12 to 0.14 times the wavelength of the high-frequency signal, a representative value is 0.13λ O is described. Since the recommended value for the length of the third portion 1123 of the power supply plate 112 in the Z direction is 0.09 to 0.11 times the wavelength of the high-frequency signal, a representative value is 0.10λ O is described. A predetermined distance or more is provided between the power supply plate 112 and the housing 114 (upper panel 1141) so that they do not contact each other.
[0025] The small broadband antenna 11 according to the present disclosure operates the power supply plate 112 as a loop antenna and radiates a high-frequency signal to the outside from the slot 115 electromagnetically coupled to the power supply plate 112. And, the small broadband antenna 11 can realize a wide bandwidth by using a dogbone slot as the slot. Also, the size of the small broadband antenna 11 is 0.45λ O ×0.45λ O ×0.13λ O and can be realized in a small size.
[0026] As a result, according to the present disclosure, it is possible to provide a small broadband antenna that can be realized in a small size and can be used in a wide frequency band.
[0027] Furthermore, in the small wideband antenna 11, the slot 115 is fed by a feed plate (loop antenna) 112, and the ground plane 111s1, the feed section 113, and the feed plate 112 are covered by a housing 114 made of a conductor. This structure reduces interference from the surroundings, allowing the antenna to operate stably.
[0028] Furthermore, the compact broadband antenna 11 is small and has a structure in which the ground plane 111s1, feed section 113, and feed plate 112 are covered by a conductive housing 114, allowing it to be embedded in the ceiling of a building. This means that, in cases where the presence of an antenna is not to be noticeable for design reasons, the compact broadband antenna 11 can be installed on the ceiling or wall of an indoor building and used as an antenna for a mobile base station. Also, because the compact broadband antenna 11 is small and has a housing-covered structure, it can be embedded in the fuselage of a car or aircraft. This reduces the air resistance of moving objects such as cars and aircraft that are moving at high speeds.
[0029] Figure 3 is a schematic diagram illustrating the shape of the slot of the compact broadband antenna according to this disclosure. Figure 3 shows various slot shapes when viewed from the Z direction. Figures 3(a) to 3(c) show doghorn slots, and Figures 3(d) to 3(f) show single-line slots.
[0030] In Figure 1A, etc., the slot shape is shown as a doghorn slot as in Figure 3(a), but it is not limited to this.
[0031] In this disclosure, in addition to the doghorn slot shown in Figure 3(a), doghorn slots as shown in Figures 3(b) and 3(c) may also be used. The doghorn slot shown in Figure 3(b) differs from the doghorn slot shown in Figure 3(a) in that the ends of the slot are formed in a curve (circle). The doghorn slot shown in Figure 3(c) differs from the doghorn slot shown in Figure 3(a) in that the ends of the slot form a circle, and the diameter of the circle is larger than the width of the doghorn slot.
[0032] Furthermore, in this disclosure, in addition to the dockhorn slot shown in Figure 3(a), a single-line slot as shown in Figures 3(d) to 3(f) may also be used. The dockhorn slot shown in Figure 3(e) differs from the dockhorn slot shown in Figure 3(d) in that the end of the slot is formed by a curve (circle). The dockhorn slot shown in Figure 3(f) differs from the dockhorn slot shown in Figure 3(d) in that the end of the slot forms a circle, and the diameter of the circle is larger than the width of the dockhorn slot. It is known that a small broadband antenna using a dockhorn slot has a wider bandwidth than a small broadband antenna using a single-line slot.
[0033] Figure 4 is a perspective view illustrating an example of a feed plate for a small, broadband antenna according to this disclosure. Figure 4 shows various shapes of power supply plates.
[0034] In Figure 1A, etc., the shape of the power supply plate is shown as shown in Figure 4(a), but it is not limited to this shape.
[0035] In this disclosure, in addition to the power supply plate shown in Figure 4(a), power supply plates as shown in Figures 4(b) to 4(g) may also be used. The power supply plates shown in Figures 4(b) and 4(c) differ from the power supply plate shown in Figure 4(a) in that the length of the first portion 1121 of the power supply plate in the Y direction decreases as you move in the opposite direction of the Z direction.
[0036] Furthermore, the power supply plates shown in Figures 4(d) and 4(e) differ from the power supply plate shown in Figure 4(a) in that the maximum length in the Y direction of the second portion 1122 of the power supply plate is greater than the maximum length in the Y direction of the first portion 1121, and the maximum length in the Y direction of the second portion 1122 of the power supply plate is greater than the maximum length in the Y direction of the third portion 1123.
[0037] The power supply plate shown in Figure 4(f) has a recessed shape in part of the second portion 1122 of the power supply plate. Also, the shape of the power supply plate as viewed from the Y direction, as shown in Figure 4(g), is curved or arc-shaped.
[0038] [Embodiment 2] Figure 5 is a perspective view illustrating a small, broadband antenna according to this disclosure.
[0039] As shown in Figure 5, the compact broadband antenna 21 according to this disclosure differs from the compact broadband antenna 11 according to this disclosure in that it further includes a radome 116. The radome 116 is a cover made of dielectric material that covers the slot 115. The dielectric material used for the radome 116 is made of fiber-reinforced plastic (FRP). Other materials that may be used for the radome 116 include polycarbonate, ABS resin, AES material, and Teflon. For simplicity, tape-like forms of the above materials may be used.
[0040] The radome 116 covers the slot 115, protecting the inside of the antenna from wind, rain, snow, and hail. This prevents malfunction of the small wideband antenna 11. In Figure 5, the radome 116 is located on the outside of the housing 114, but this is not the only option. The radome 116 may also be located on the inside of the housing 114.
[0041] Furthermore, when covering patch antennas, monopole antennas, and dipole antennas used as base station antennas for mobile communications or aircraft-mounted antennas with a radome, the cost is high because the entire antenna is covered with the radome. On the other hand, in the case of the small wideband antenna 21 according to this disclosure, only the portion of the slot 115 is covered with the radome 116, so the cost can be significantly reduced compared to the former case.
[0042] Furthermore, in this disclosure, since the portion covered by the radome 116 is the radiating element portion (i.e., the slot 115), the portion covered with FRP, etc., is very small, and since the covered portion is flat, the radome 116 can be realized at a low cost. In addition, because the portion (range) covered by the radome 116 is small, the amount of FRP required is small, so strong environmental resistance (robustness) can be obtained.
[0043] [Modified version of Embodiment 2] Figure 6 is a perspective view illustrating a small, broadband antenna according to this disclosure.
[0044] As shown in Figure 6, the modified compact broadband antenna 21a differs from the compact broadband antenna 21 according to this disclosure in that it is equipped with a radome 116a that is larger in size. The compact broadband antenna 21a can reduce costs compared to the case in which the entire antenna is covered with a radome.
[0045] <Simulation Results> Figure 7 is a graph illustrating the matching characteristics of the compact broadband antenna according to this disclosure. In Figure 7, the horizontal axis represents frequency, and the vertical axis represents return loss (|S11|).
[0046] Figure 7 shows the matching characteristics of the antenna calculated using the antenna dimensions shown in Figures 2A to 2D. In this case, the external dimensions of the antenna are 0.45λ. O ×0.45λ O ×0.13λ O That is the case.
[0047] As shown in Figure 7, the return loss is -14.0 dB or less (equivalent to VSWR < 1.5) in the range of 1.8 GHz to 2.0 GHz, indicating good matching characteristics. The frequency band of 1.8 GHz to 2.0 GHz corresponds to a relative bandwidth of 10.5%. Note that return loss and |S11| are synonymous terms.
[0048] Here, most antennas in the world are resonant, and commonly used patch antennas have a relative bandwidth of 1-2%. Antennas with a relative bandwidth exceeding 10% are described as "broadbanding," etc. Therefore, the small broadband antenna 11 according to this disclosure achieves a relative bandwidth of 10.5%, and can therefore be called broadband.
[0049] Figure 8 is a graph illustrating the radiation pattern of the small broadband antenna according to this disclosure. The solid line shows the radiation pattern in the φ=0 degree plane, i.e., the XZ plane, and the dashed line shows the radiation pattern in the φ=90 degree plane, i.e., the YZ plane. Both radiation patterns are broad, with a peak in the Z-axis direction.
[0050] Figure 8 shows the radiation pattern characteristics of the antenna calculated using the antenna dimensions shown in Figures 2A to 2D. As shown in Figure 8, the compact broadband antenna 11 according to this disclosure can obtain uniform and broad, good directivity characteristics at a frequency of 1.9 GHz.
[0051] <Features> The features of the compact, broadband antenna described herein are as follows. The compact broadband antenna according to this disclosure is fed to a slot by a plate-shaped loop element placed below the slot. In other words, the compact broadband antenna has a structure in which the feeding plate located below the slot (in the Z direction) is a type of loop antenna that feeds the slot.
[0052] <Effects> The effects of the compact, broadband antenna described herein are shown below. i) It is a small antenna in terms of its external dimensions. ii) It is an antenna with broadband characteristics. iii) It is a directional antenna. iv) An antenna that can be used without performance degradation even when embedded in metal walls or other surfaces. v) It is a low-cost antenna with high environmental resistance. vi) Since the antenna itself is enclosed in a conductive housing, there is no leakage of radio waves to the surroundings. As a result, when antennas are arranged in an array, the amount of interference between adjacent antennas is reduced, and the design of the antenna array is simplified.
[0053] This disclosure is not limited to the embodiments described above, and may be modified as appropriate without departing from its spirit.
[0054] Some or all of the above embodiments may also be described as follows, but are not limited to the following: (Note 1) A ground plate having ground surfaces parallel to the X and Y directions, A power supply plate provided on the ground surface, A power supply unit is provided between the ground plate and the power supply plate, and supplies a high-frequency signal to the power supply plate, A housing that covers the ground surface, the power supply unit, and the power supply plate, The upper plate of the housing on the ground surface, and a slot provided in the upper plate facing the ground surface, Equipped with, The aforementioned power supply board is A first portion connected to the power supply unit and extending in the Z direction, A second portion extending in the opposite direction to the X direction from the end of the first portion extending in the Z direction, It has a third portion that extends in the opposite direction to the Z direction from the end of the second portion that extends in the opposite direction to the X direction and connects to the ground plate, The aforementioned slot is A single line slot extending in the Y direction, or A dog horn slot extending in the X direction, splitting into two branches along its extension, one branch extending in the X direction and the other extending in the Y direction, and further splitting into two branches at the end of the Y direction, one branch extending in the X direction and the other extending in the opposite direction to the X direction. When viewed from the Z direction, a part of the doghorn slot and a part of the power supply plate overlap, The ground plate, the power supply plate, and the housing are composed of conductors. A small, wideband antenna. (Note 2) The length of the first portion of the power supply plate in the Y direction decreases as you move in the opposite direction to the Z direction. A small, wideband antenna as described in Appendix 1. (Note 3) The maximum length of the second portion of the power supply plate in the Y direction is greater than the maximum length of the first portion in the Y direction. The maximum length of the second portion of the power supply plate in the Y direction is greater than the maximum length of the third portion in the Y direction. A small, wideband antenna as described in Appendix 1. (Note 4) The power supply plate has a shape in which a part of the second portion of the power supply plate is recessed. A small, wideband antenna as described in Appendix 1. (Note 5) The shape of the power supply plate as viewed from the Y direction is an arc shape. A small, wideband antenna as described in Appendix 1. (Note 6) The system further comprises a radome made of a dielectric material that covers the aforementioned slot. A small, wideband antenna as described in Appendix 1. (Note 7) The dielectric of the radome is formed from fiber-reinforced plastics (FRP). A small, wideband antenna as described in Appendix 6. (Note 8) The aforementioned power supply unit is The core wire connected to the power supply plate, Having an external conductor connected to the ground plate, A small, wideband antenna as described in Appendix 1. (Note 9) The shape of the doghorn slot is H-shaped when viewed from the Z direction. A small, wideband antenna as described in Appendix 1. (Note 10) The length of the housing in the X direction is 0.4 to 0.5 times the wavelength of the high-frequency signal. The length of the housing in the Y direction is 0.4 to 0.5 times the wavelength of the high-frequency signal. The length of the housing in the Z direction is 0.12 to 0.14 times the wavelength of the high-frequency signal. The length of the second portion of the power supply plate in the X direction is 0.12 to 0.14 times the wavelength of the high-frequency signal. The length of the third portion of the power supply plate in the Z direction is 0.09 to 0.11 times the wavelength of the high-frequency signal. A small, wideband antenna as described in Appendix 1. (Note 11) The first surface of the top plate includes a flat or curved surface. A small, wideband antenna as described in Appendix 1. [Explanation of Symbols]
[0055] 11, 21... Small wideband antenna 111...Groundboard 111s1... Ground surface 112...Power supply board 1121…First part 1122…Second part 1123...Third part 113... Power supply unit, coaxial cable 1131... Core wire 1132...Outer conductor 114... Cabinet 1141…Top plate 115... Slot 116, 116a... radome
Claims
1. A ground plate having ground surfaces parallel to the X and Y directions, A power supply plate provided on the ground surface, A power supply unit is provided between the ground plate and the power supply plate, and supplies a high-frequency signal to the power supply plate, A housing that covers the ground surface, the power supply unit, and the power supply plate, The upper plate of the housing on the ground surface, and a slot provided in the upper plate facing the ground surface, Equipped with, The aforementioned power supply board is A first portion connected to the power supply unit and extending in the Z direction, A second portion extending in the opposite direction to the X direction from the end of the first portion that extends in the Z direction, It has a third portion that extends in the opposite direction to the Z direction from the end of the second portion that extends in the opposite direction to the X direction and connects to the ground plate, The aforementioned slot is A single line slot extending in the Y direction, or A dog horn slot extending in the X direction, splitting into two branches along its extension, one branch extending in the X direction and the other extending in the Y direction, and further splitting into two branches at the end of the Y direction, one branch extending in the X direction and the other extending in the opposite direction to the X direction. When viewed from the Z direction, a part of the doghorn slot and a part of the power supply plate overlap, The ground plate, the power supply plate, and the housing are composed of conductors. A small, wideband antenna.
2. The length of the first portion of the power supply plate in the Y direction decreases as you move in the opposite direction to the Z direction. A compact, wideband antenna according to claim 1.
3. The maximum length of the second portion of the power supply plate in the Y direction is greater than the maximum length of the first portion in the Y direction. The maximum length of the second portion of the power supply plate in the Y direction is greater than the maximum length of the third portion in the Y direction. A compact, wideband antenna according to claim 1.
4. The power supply plate has a recessed shape in part of the second portion of the power supply plate. A compact, wideband antenna according to claim 1.
5. The shape of the power supply plate as viewed from the Y direction is an arc shape. A compact, wideband antenna according to claim 1.
6. The system further comprises a radome made of a dielectric material that covers the aforementioned slot. A compact, wideband antenna according to claim 1.
7. The dielectric of the radome is formed from fiber-reinforced plastics (FRP). The compact broadband antenna according to claim 6.
8. The aforementioned power supply unit is The core wire connected to the power supply plate, Having an external conductor connected to the ground plate, A compact, wideband antenna according to claim 1.
9. The shape of the doghorn slot is H-shaped when viewed from the Z direction. A compact, wideband antenna according to claim 1.
10. The length of the housing in the X direction is 0.4 to 0.5 times the wavelength of the high-frequency signal. The length of the housing in the Y direction is 0.4 to 0.5 times the wavelength of the high-frequency signal. The length of the housing in the Z direction is 0.12 to 0.14 times the wavelength of the high-frequency signal. The length of the second portion of the power supply plate in the X direction is 0.12 to 0.14 times the wavelength of the high-frequency signal. The length of the third portion of the power supply plate in the Z direction is 0.09 to 0.11 times the wavelength of the high-frequency signal. A compact, wideband antenna according to claim 1.