High-gain miniaturized biconical antenna based on rectangular dielectric prism

Abstract

The invention discloses a high-gain miniaturized biconical antenna based on a rectangular dielectric prism, which belongs to the technical field of radar antennae and structurally comprises a dielectric prism, a biconical antenna upper radiation arm, a biconical antenna lower radiation arm and a metal circular truncated cone positioned on one side, close to the biconical antenna lower radiation arm, of the biconical antenna upper radiation arm, the metal cylinder is positioned between the biconical antenna lower radiation arm and the metal circular truncated cone; the metal connecting rod is positioned in the biconical antenna lower radiation arm and is connected with the metal cylinder; according to the high-gain miniaturized biconical antenna based on the rectangular medium prism, the defect that the size is too large due to the fact that a metal reflecting plate is adopted by an existing biconical antenna can be avoided, miniaturization can be achieved, the gain of the biconical antenna can be improved, and the high-gain miniaturized biconical antenna can be widely applied to radar antennas and has good application prospects.

Description

Technical Field

[0001] The present invention relates to the field of radar antennas, and relates to a high-gain miniaturized biconical antenna based on a rectangular dielectric prism. Background Art

[0002] As a common ultra-wideband antenna, the biconical antenna has been widely used in wireless communication, SAR radar imaging, biomedicine, and wireless spectrum detection. The biconical antenna consists of two coaxial conical conductors with opposite vertices, and is connected to a coaxial cable or other feeder through a feeding point at the vertex. The opening angle and height of the cone directly affect the input impedance and bandwidth of the antenna, and its working principle is based on the broadband expansion of a symmetrical dipole. The gradually changing geometric shape of the conical structure enables the current distribution to present a smooth transition along the axial direction, thereby reducing the impedance mutation caused by frequency changes. When the operating frequency changes, the effective electrical length of the antenna is adjusted accordingly, enabling it to maintain an approximately constant radiation resistance within multiple octaves. The core characteristics of the biconical antenna stem from its geometric symmetry and gradually changing conductor profile, enabling stable impedance matching and radiation characteristics within a wide frequency band.

[0003] Due to its omnidirectional radiation characteristics and open structure, it is inherently difficult for a biconical antenna to achieve high gain. However, the electromagnetic waves radiated downward can be reflected into the upper half space by using the mirror principle, compressing the beam width in the vertical plane and enhancing the directivity in the horizontal plane. Usually, a metal reflector with a diameter greater than half of the operating wavelength and a quarter-wavelength spacing from the bottom of the biconical antenna is introduced at the bottom of the biconical antenna to achieve phase superposition of the radiation field of the biconical antenna. The introduction of the metal reflector can increase the gain of the biconical antenna by 1-3 dB, but the overall height of the antenna increases by about 50%, and the operating frequency band becomes narrower. The biconical antenna can be limitedly improved in gain through structural optimization, but it is difficult to meet the requirements of modern high-frequency and high-integration scenarios due to physical principles. Summary of the Invention

[0004] In order to overcome the disadvantages of low gain and large overall size of the biconical antenna in the prior art, the present invention provides a high-gain miniaturized biconical antenna based on a rectangular dielectric prism. The present invention removes the metal reflector structure for improving the gain of the biconical antenna in the conventional method, and loads a rectangular dielectric prism above the biconical antenna, and realizes beam focusing to improve the antenna gain by regulating the phase of the electromagnetic waves radiated by the antenna.

[0005] To simultaneously achieve the objectives of high gain and miniaturization of the biconical antenna, the present invention adopts the following technical solution: a high-gain miniaturized biconical antenna based on a rectangular dielectric prism, with a dielectric prism composed of rectangular dielectric units loaded above the antenna, including a dielectric prism and a biconical antenna distributed from top to bottom; The dielectric prism is composed of several dielectric prism units. A dielectric prism special-shaped structure is provided at the position where the bottom of the dielectric prism contacts the biconical antenna. The dielectric prism special-shaped structure is obtained by performing a difference set operation on the biconical antenna and the dielectric prism through Boolean operation. The dielectric prism special-shaped structure enables the dielectric prism to closely adhere to the upper part of the biconical antenna; The biconical antenna includes an upper radiation arm of the biconical antenna, a lower radiation arm of the biconical antenna, a second metal frustum located on the side of the upper radiation arm of the biconical antenna close to the lower radiation arm of the biconical antenna, a third metal cylinder located between the lower radiation arm of the biconical antenna and the second metal frustum, and a metal connecting rod located inside the lower radiation arm of the biconical antenna and connected to the third metal cylinder.

[0006] As a further improvement of the present invention, the dielectric prism is composed of 35 dielectric prism units arranged in 5 columns and 7 rows. The dielectric prism unit is made by digging a first cylinder with the same height as the rectangular dielectric block inside the rectangular dielectric block. The material of the dielectric prism unit is set as FR-4.

[0007] As a further improvement of the present invention, the dielectric prism units in the dielectric prism have different heights respectively. By controlling the height difference of each dielectric prism unit, the propagation path length of the electromagnetic wave passing through the dielectric prism is changed, and the phase of the electromagnetic wave at different positions is adjusted.

[0008] As a further improvement of the present invention, the upper radiation arm and the lower radiation arm of the biconical antenna are mirror-symmetrical with respect to the y0z plane, and are both formed by superposing a second metal cylinder and a first metal frustum with the x-axis as the axis and cutting along the x0y plane as the section.

[0009] As a further improvement of the present invention, the second metal cylinder and the first metal frustum are hollow structures with metal walls. A first metal plate is provided on the x0y plane of the section of the second metal cylinder, and a second metal plate is provided on the x0y plane of the section of the first metal frustum.

[0010] As a further improvement of the present invention, on the upper radiation arm and the lower radiation arm of the biconical antenna, a sine metal groove with an inclination angle of θ with the z-axis is provided at one end of the upper radiation arm of the biconical antenna and far from the lower radiation arm of the biconical antenna, and a chamfer is provided at the edge of the sine metal groove.

[0011] As a further improvement of the present invention, the fourth metal cylinder inside the metal connecting rod is connected to the third metal cylinder, the third metal cylinder is connected to the upper plane of the second metal frustum, and the lower plane of the second metal frustum is connected to the upper plane of the first metal frustum of the upper radiation arm of the biconical antenna; the second hollow metal tube outside the metal connecting rod is connected to the upper plane of the first metal frustum of the lower radiation arm of the biconical antenna.

[0012] As a further improvement of the present invention, the metal connecting rod adopts a three-layer structure. The inner layer is a fourth metal cylinder with the same caliber as the third metal cylinder. The middle layer is a first hollow cylindrical tube that wraps the fourth metal cylinder. The material of the first hollow cylindrical tube is set as FR-4. The outer layer is a second hollow metal cylindrical tube that wraps the first hollow cylindrical tube. The metal connecting rod is placed inside the lower radiation arm of the biconical antenna and penetrates through the upper plane of the first metal frustum of the lower radiation arm of the biconical antenna. By adjusting the distance between the metal connecting rod and the x0y plane of the cross-section of the lower radiation arm of the biconical antenna, the operating frequency band of the biconical antenna can be changed.

[0013] The above-mentioned high-gain miniaturized biconical antenna based on a rectangular dielectric prism is characterized in that: (1) The metal reflector of the conventional biconical antenna is removed, reducing the physical size of the biconical antenna; (2) Compared with the conventional biconical antenna, the loaded rectangular dielectric prism has stronger beam focusing ability; (3) The inside of the radiation arm of the biconical antenna is a hollow structure, reducing the overall weight of the biconical antenna; (4) A sinusoidal metal slot is provided at the end of the radiation arm of the biconical antenna, expanding the operating frequency band width of the biconical antenna.

[0014] The beneficial effects of the present invention are as follows: The high-gain miniaturized biconical antenna based on a rectangular dielectric prism provided by the present invention can meet the miniaturization of the biconical antenna while improving the gain of the biconical antenna compared with the existing technology. Description of the Drawings

[0015] Figure 1 It is the overall structure diagram of the high-gain miniaturized biconical antenna based on a rectangular dielectric prism of the present invention; Figure 2 It is the three-dimensional structure schematic diagram of the dielectric prism provided in the embodiment of the present invention; Figure 3 It is the three-dimensional structure schematic diagram of the dielectric prism unit provided in the embodiment of the present invention; Figure 4 It is the front view structural cross-section diagram of the biconical antenna in the embodiment of the present invention; Figure 5 It is the side view structural cross-section diagram of the biconical antenna in the embodiment of the present invention; Figure 6 It is the structural schematic diagram at the center feed point of the biconical antenna in the embodiment of the present invention; Figure 7 It is the three-dimensional structure schematic diagram of the metal connecting rod in the embodiment of the present invention; Figure 8 It is the distribution schematic diagram of the dielectric prism units in the embodiment of the present invention; Figure 9This is the S11 graph of the biconical antenna loaded with a rectangular dielectric prism in the embodiments of the present invention compared with the biconical antenna without the loaded rectangular dielectric prism when operating at 24 - 34 GHz. Here, S11 is the return loss when the electromagnetic wave is incident from port 1 and received by port 1. ant1 is the S11 of the biconical antenna without the loaded rectangular dielectric prism, and ant2 is the S11 of the biconical antenna loaded with the rectangular dielectric prism. Figure 10 This is the gain graph of the biconical antenna loaded with a rectangular dielectric prism in the embodiments of the present invention compared with the biconical antenna without the loaded rectangular dielectric prism when operating at 31 GHz. In the graph, Realized Gain is the gain, Theta is the angle, ant1 is the gain of the biconical antenna without the loaded rectangular dielectric prism, and ant2 is the gain of the biconical antenna loaded with the rectangular dielectric prism. Specific embodiments

[0016] The embodiments of the present invention provide a biconical antenna loaded with a rectangular dielectric prism. It should be noted that relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. The structure includes: Combined with Figure 1 , a dielectric prism composed of rectangular dielectric units is loaded above the antenna, and the distribution from top to bottom includes dielectric prism 1 and biconical antenna 2; Dielectric prism 1: Combined with Figure 2 , Figure 3 , Figure 8 , the dielectric prism 1 is vertically arranged with 35 dielectric prism units 3 at the bottom in the x0y plane, with 5 columns and 7 rows. The side length m1 of the rectangular dielectric block 5 of the dielectric prism unit 3 is 4 mm, the radius o1 of the first cylinder 4 dug in the middle of the rectangular dielectric block (5) is 2 mm, the material of the dielectric prism unit 3 is FR - 4. At the contact between the bottom of the dielectric prism 1 and the biconical antenna 2, there is a dielectric prism special-shaped structure 6, which is obtained by performing a difference operation between the biconical antenna 2 and the dielectric prism 1, and the dielectric prism special-shaped structure 6 makes the dielectric prism 1 closely fit above the biconical antenna 2.

[0017] Biconical antenna 2: Combined with Figure 4 , the biconical antenna 2 includes an upper radiation arm 7 of the biconical antenna, a lower radiation arm 8 of the biconical antenna, a second metal frustum 18 on the side of the upper radiation arm 7 of the biconical antenna close to the lower radiation arm 8, a third metal cylinder 17 between the lower radiation arm 8 of the biconical antenna and the second metal frustum 18, and a metal connecting rod 13 inside the lower radiation arm 8 of the biconical antenna and connected to the third metal cylinder 17.

[0018] Combined with Figure 4 and Figure 5 , the upper radiation arm 7 of the biconical antenna and the lower radiation arm 8 of the biconical antenna are mirror symmetric with the inner side of the upper plane of the first metal frustum 10. The upper radiation arm 7 of the biconical antenna is composed of the first metal frustum 10 with an inclination angle angle2 = 3° with the z-axis and the second metal cylinder 9. The first metal frustum 10 is an elliptical frustum with a major axis a2 = 6 mm and a minor axis b2 = 3 mm on the upper plane and a major axis a1 = 80 mm and a minor axis b1 = 40 mm on the lower plane, and a height of h3 = h1 - a1×tan(angle = 11°) - h2, where h1 = 43 mm and h2 = 20 mm. The second metal cylinder 9 is a cylinder with an upper and lower plane of an ellipse with a major axis a1 = 80 mm and a minor axis b1 = 40 mm and a height of h1 - h3, and is sectioned with the center of the major axis. A first metal plate 12 with a length of 6 mm and a second metal plate 19 for its transition function are provided at the section. The second metal cylinder 9 is a hollow structure with an inner wall thickness of 2 mm. A sine metal groove 11 with an inclination angle angle = 11° with the z-axis is provided at the end of the second metal cylinder 9. The edge of the sine metal groove 11 is chamfered and its sine function curve is x = cos(0.1×π×t), z = t, where the parameter t represents the position of the point on the curve on the curve.

[0019] Combined with Figure 6 , the second metal frustum 18 is composed of a frustum with a circle with o2 = 0.5 mm on the upper plane, a semi-ellipse with a major axis a2 = 6 mm and a minor axis b2 = 3 mm on the lower plane, and a height hk = 4 mm. The length of hk has a great influence on the matching performance of the biconical antenna 2. The third metal cylinder 17 is composed of a cylinder with o2 = 0.5 mm on the upper and lower planes and a height hin = 0.5 mm. The length of hin has a great influence on the feeding of the biconical antenna 2. The smaller hin is, the higher the electric field strength is, which may limit the power capacity of the antenna. A larger gap can reduce the breakdown risk, but impedance matching needs to be weighed.

[0020] Combined with Figure 7 , the metal connecting rod 13 is a three-layer structure. The inner layer is the fourth metal cylinder 14, which is composed of a metal cylinder with a radius o2 = 0.5 mm and a height lf = 30 mm. The middle layer is the first hollow cylinder tube 15, which is composed of a hollow cylinder tube with an inner diameter o2 = 0.5 mm, an outer diameter o3 = 1.493 mm, and a height lf = 30 mm. The material of the first hollow cylinder tube 15 is FR-4. The outer layer is the second hollow metal cylinder tube 16, which is composed of a metal hollow cylinder tube with an inner diameter o3 = 1.493 mm and an outer diameter o4 = 1.6 mm and a height lf = 30 mm.

[0021] Combined with Figure 4, the inner fourth metal cylinder 14 of the metal connecting rod 13 is connected to the third metal cylinder 17, the third metal cylinder 17 is connected to the upper plane of the second metal frustum 18, and the lower plane of the second metal frustum 18 is connected to the upper plane of the first metal frustum 10 of the upper radiation arm 7 of the biconical antenna; the outer second hollow metal tube 16 of the metal connecting rod 13 is connected to the upper plane of the first metal frustum 10 of the lower radiation arm 8 of the biconical antenna.

[0022] Further, in combination with Figure 8 , the heights of the dielectric prism units 3 in the dielectric prism 1 are different. By controlling the height differences of each dielectric prism unit 3, the propagation path length of electromagnetic waves passing through the dielectric prism 1 is changed, so as to accurately adjust the phase of electromagnetic waves at different positions. The height of each dielectric prism unit 3 from left to right and from top to bottom is nij, where i is the row number and j is the column number: n11 = 28mm, n12 = 41mm, n13 = 41mm, n14 = 41mm, n15 = 28mm; n21 = 22mm, n22 = 31mm, n23 = 32mm, n24 = 31mm, n25 = 22mm; n31 = 39mm, n32 = 3mm, n33 = 3mm, n34 = 3mm, n35 = 39mm; n41 = 40mm, n42 = 2mm, n43 = 2mm, n44 = 2mm, n45 = 40mm; n51 = 39mm, n52 = 3mm, n53 = 3mm, n54 = 3mm, n55 = 39mm; n61 = 32mm, n62 = 31mm, n63 = 32mm, n64 = 31mm, n65 = 32mm; n71 = 28mm, n72 = 41mm, n73 = 41mm, n74 = 41mm, n75 = 28mm.

[0023] In this embodiment, the S11 of the biconical antenna loaded with the rectangular dielectric prism and the S11 of the biconical antenna without loading the rectangular dielectric prism are as Figure 9 shown, where ant1 is the S11 of the biconical antenna without loading the rectangular dielectric prism, and ant2 is the S11 of the biconical antenna after loading the rectangular dielectric prism; in this embodiment, the loading of the rectangular dielectric prism will improve the matching performance of the biconical antenna, and increase its bandwidth by about 25%.

[0024] The gain of the biconical antenna after loading the rectangular dielectric prism and the biconical antenna without loading the rectangular dielectric prism at 31 GHz is as Figure 10As shown, where ant1 is the gain of the biconical antenna without loading the rectangular dielectric prism, and ant2 is the gain of the biconical antenna after loading the rectangular dielectric prism; without loading the rectangular dielectric prism, the maximum gain of the biconical antenna at 31 GHz is 7.72 dBi; after loading the rectangular dielectric prism, the maximum gain of the biconical antenna at 31 GHz is 15.6 dBi; in this embodiment, the loading of the rectangular dielectric prism will focus the radiation beam of the biconical antenna, increasing its gain by 7.88 dBi, approximately 102%.

[0025] In this embodiment, the loading of the rectangular dielectric prism, while meeting the miniaturization of the size of the biconical antenna, improves its bandwidth and maximum radiation gain.

[0026] The above content is a further detailed description of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is only limited to these descriptions. For those of ordinary skill in the technical field to which the present invention pertains, without departing from the concept of the present invention, several simple deductions or substitutions can be made, and all should be regarded as belonging to the protection scope of the present invention.

Claims

1. A high-gain miniaturized biconical antenna based on a rectangular dielectric prism, characterized in that A dielectric prism composed of rectangular dielectric units is loaded above the antenna, and the distribution from top to bottom includes a dielectric prism (1) and a biconical antenna (2). The dielectric prism (1) is composed of several dielectric prism units (3). A dielectric prism special-shaped structure (6) is provided at the position where the bottom of the dielectric prism (1) contacts the biconical antenna (2). The dielectric prism special-shaped structure (6) is obtained by performing a Boolean subtraction operation on the biconical antenna (2) and the dielectric prism (1), and the dielectric prism special-shaped structure (6) makes the dielectric prism (1) closely fit above the biconical antenna (2). The biconical antenna (2) includes an upper radiation arm (7) of the biconical antenna, a lower radiation arm (8) of the biconical antenna, a second metal frustum (18) located on the side of the upper radiation arm (7) of the biconical antenna close to the lower radiation arm (8) of the biconical antenna, a third metal cylinder (17) located between the lower radiation arm (8) of the biconical antenna and the second metal frustum (18), and a metal connecting rod (13) located inside the lower radiation arm (8) of the biconical antenna and connected to the third metal cylinder (17).

2. The high-gain miniaturized bicone antenna based on a rectangular dielectric prism according to claim 1, characterized in that The dielectric prism (1) is composed of 35 dielectric prism units (3) arranged in 5 columns and 7 rows. The dielectric prism unit (3) is made by digging a first cylinder (4) with the same height as the rectangular dielectric block (5) inside the rectangular dielectric block (5), and the material of the dielectric prism unit (3) is set as FR-4.

3. The high-gain miniaturized biconical antenna based on a rectangular dielectric prism according to claim 1, characterized in that, Each dielectric prism unit (3) in the dielectric prism (1) has a different height. By controlling the height difference of each dielectric prism unit (3), the propagation path length of the electromagnetic wave passing through the dielectric prism (1) is changed, and the phase of the electromagnetic wave at different positions is adjusted.

4. The high-gain miniaturized bicone antenna based on a rectangular dielectric prism according to claim 1, wherein, The upper radiation arm (7) of the biconical antenna and the lower radiation arm (8) of the biconical antenna are mirror-symmetrical with respect to the y0z plane, and are both formed by stacking a second metal cylinder (9) and a first metal frustum (10) with the x-axis as the axis and cutting with the x0y plane as the section.

5. The high-gain miniaturized bicone antenna based on a rectangular dielectric prism according to claim 1, wherein The second metal cylinder (9) and the first metal frustum (10) are hollow structures with metal walls. A first metal plate (12) is provided on the x0y plane of the section of the second metal cylinder (9), and a second metal plate (19) is provided on the x0y plane of the section of the first metal frustum (10).

6. The high-gain miniaturized bicone antenna based on a rectangular dielectric prism according to claim 1, wherein For the upper radiation arm (7) of the biconical antenna and the lower radiation arm (8) of the biconical antenna, a sine metal slot (11) with an inclination angle of θ with the z-axis is provided at one end of the upper radiation arm (7) of the biconical antenna and far from the lower radiation arm (8) of the biconical antenna, and a chamfer is provided at the edge of the sine metal slot (11).

7. The high-gain miniaturized bicone antenna based on a rectangular dielectric prism according to claim 1, wherein The fourth metal cylinder (14) inside the metal connecting rod (13) is connected to the third metal cylinder (17). The third metal cylinder (17) is connected to the upper plane of the second metal frustum (18), and the lower plane of the second metal frustum (18) is connected to the upper plane of the first metal frustum (10) of the upper radiation arm (7) of the biconical antenna; the second hollow metal tube (16) outside the metal connecting rod (13) is connected to the upper plane of the first metal frustum (10) of the lower radiation arm (8) of the biconical antenna.

8. The high-gain miniaturized bicone antenna based on a rectangular dielectric prism according to claim 1, wherein The metal connecting rod (13) adopts a three-layer structure. The inner layer is a fourth metal cylinder (14) with the same diameter as the third metal cylinder (17). The middle layer is a first hollow cylindrical tube (15) that wraps the fourth metal cylinder (14). The material of the first hollow cylindrical tube (15) is set as FR-4. The outer layer is a second hollow metal cylindrical tube (16) that wraps the first hollow cylindrical tube (15). The metal connecting rod (13) is placed inside the lower radiation arm (8) of the biconical antenna and penetrates the upper plane of the first metal frustum (10) of the lower radiation arm (8) of the biconical antenna. By adjusting the distance of the metal connecting rod (13) from the x0y plane of the cross-section of the lower radiation arm (8) of the biconical antenna, the operating frequency band of the biconical antenna (2) can be changed.

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