An ultra-wideband dual-ridged TEM horn antenna

Abstract

The application relates to the technical field of antennas, in particular to an ultra-wideband double-ridge TEM horn antenna, which comprises a feed coaxial, a water-drop-shaped metal barrier, a zigzag double-ridge structure, an elliptical gradually-changing inner wall, a two-stage elliptical gradually-changing inner wall, an E-plane metal wall, an aperture-plane metal frame, a dielectric lens, a feed-end supporting dielectric block and a supporting frame; the feed coaxial, the water-drop-shaped metal barrier and the E-plane metal wall are sequentially connected; the zigzag double-ridge structure and the two-stage elliptical gradually-changing inner wall are arranged in the E-plane metal wall; the aperture-plane metal frame is located at the end of the E-plane metal wall; the dielectric lens is fixed in the aperture-plane metal frame; the feed-end supporting dielectric block is located at the end of the feed end; and the supporting frame is connected with the E-plane metal wall. The zigzag double-ridge structure is gradually opened by segmented straight lines; the supporting frame is used for fixing the metal components and ensuring the rigidity of the overall structure; the supporting frame is designed with through holes, so that the coaxial cable can pass through the through holes. The test proves that the antenna has a wide bandwidth and good radiation characteristics.

Description

Technical Field

[0001] This invention relates to the field of antenna technology, and specifically to an ultra-wideband dual-ridge TEM horn antenna. Background Technology

[0002] Ultra-wideband (UWB) technology, as one of the key technologies in modern wireless communication, radar detection, and electromagnetic testing, has an extremely wide spectrum bandwidth and has been widely used in UWB wireless communication, through-wall radar, electromagnetic compatibility testing, electromagnetic pulse radiation sources, and microwave imaging systems.

[0003] In antenna design, horn antennas are widely used due to their simple structure, high gain, and good radiation directivity. Among them, the double-ridged TEM horn antenna improves the high-frequency radiation characteristics of traditional TEM antennas in terms of ultra-wideband performance by introducing a double-ridged structure into the traditional TEM horn antenna. The double-ridged structure allows the antenna to maintain good impedance matching in the low-frequency band while maintaining quasi-TEM mode transmission in the high-frequency band, reducing high-order mode excitation, and achieving excellent ultra-wideband radiation characteristics.

[0004] However, existing double-ridged horn antennas still have some technical problems: in extremely wide bandwidths (such as 2-100 GHz), impedance matching is often difficult in the low-frequency band due to the small distance between the ridges, resulting in a high standing wave ratio; the gain in the low-frequency band is relatively low, mainly due to the uneven phase distribution of the aperture field, leading to low far-field synthesis efficiency; in the high-frequency band, problems such as main lobe splitting, concavity, sidelobe enlargement, and pattern asymmetry are prone to occur, affecting radiation characteristics and system detection accuracy. Traditional feeding methods are difficult to achieve full-band matching and feeding balance in the ultra-wideband range, and aperture edge diffraction and surface wave propagation also affect radiation performance. Summary of the Invention

[0005] The purpose of this invention is to provide an ultra-wideband dual-ridge TEM horn antenna, which aims to solve the technical problems of existing ultra-wideband dual-ridge horn antennas in the 2-100GHz frequency band, such as difficulty in low-frequency matching, low low-frequency gain, and unstable high-frequency radiation pattern.

[0006] To achieve the above objectives, the present invention provides an ultra-wideband dual-ridge TEM horn antenna, comprising a feeding coaxial cable, a teardrop-shaped metal balun, a zigzag dual-ridge structure, an elliptical gradient inner wall, a secondary elliptical gradient inner wall, an E-plane metal wall, an aperture surface metal frame, a dielectric lens, a supporting dielectric block at the feeding point, and a supporting frame, wherein the feeding coaxial cable, the teardrop-shaped metal balun, and the E-plane metal wall are connected sequentially;

[0007] The teardrop-shaped metal balun includes an upper part and a lower part, the upper part being a grounding portion and the lower part being a feed point connection portion; the inner conductor of the feed coaxial cable is connected to the lower part, and the outer conductor is connected to the upper part;

[0008] The zigzag double-ridge structure is composed of two symmetrical ridge plates. The two sides of the ridge plates are respectively connected to the elliptical gradient inner wall and the secondary elliptical gradient inner wall. The front end of the zigzag double-ridge structure is coaxially connected to the power supply through the teardrop-shaped metal balun.

[0009] The E-side metal wall is located outside the elliptical gradient inner wall and the secondary elliptical gradient inner wall, with one end connected to the aperture surface metal frame and the other end connected to the support frame.

[0010] The aperture-face metal frame is located at the end of the E-face metal wall, and the dielectric lens is fixed inside the aperture-face metal frame;

[0011] The power supply support medium block is located behind the power supply coaxial line and is connected to the support frame;

[0012] The support frame includes a metal plate, a hollow metal frame, and a support structure. The metal plate is disposed on the end face of the hollow metal frame and is positioned opposite to the medium lens. The support structure is fixedly connected to the metal wall on the E-side.

[0013] Preferably, the elliptical gradient inner wall is located in the region from the feed end to the aperture inside the antenna, and the secondary elliptical gradient inner wall is located after the elliptical gradient inner wall, in the region close to the antenna aperture surface. The outlines of both are gradually changing according to an elliptical function, but the curvature of the gradient is different.

[0014] Preferably, the characteristic impedance Z(y) of the teardrop-shaped metal balun is determined by the parallel two-conductor transmission line model, and its expression is as follows:

[0015]

[0016] Where h(y) is the distance between the two conductor plates in the teardrop-shaped metal balun, W(y) is the width of the conductor plate, and y is the position coordinate along the antenna axis.

[0017] Preferably, the zigzag double-ridge structure is composed of multiple straight segments connected sequentially, and the whole structure gradually opens up in a zigzag shape, with the distance between the ridges and the ridge width varying linearly along the antenna axis in segments.

[0018] Preferably, the dielectric lens includes a low-frequency convex lens dielectric lens and a high-frequency guiding dielectric lens. The interior of the dielectric lens is completely filled with a dielectric material, which is cross-linked polystyrene with a dielectric constant of 2.5.

[0019] Preferably, the ultra-wideband dual-ridge TEM horn antenna operates at a frequency of 2GHz-100GHz and has overall dimensions of 0.226λ1×0.238λ1×0.243λ1, where λ1 is the wavelength corresponding to the operating frequency of 2GHz.

[0020] This invention provides an ultra-wideband dual-ridge TEM horn antenna, comprising a coaxial feed, a teardrop-shaped metal balun, a zigzag double-ridge structure, an elliptical gradient inner wall, a second-order elliptical gradient inner wall, an E-plane metal wall, an aperture-plane metal frame, a dielectric lens, a supporting dielectric block at the feed point, and a support frame. The coaxial feed, teardrop-shaped metal balun, and E-plane metal wall are connected sequentially. The zigzag double-ridge structure and the two-order elliptical gradient inner wall are disposed within the E-plane metal wall. The aperture-plane metal frame is located at the end of the E-plane metal wall. The dielectric lens is fixed inside the aperture-plane metal frame. The supporting dielectric block at the feed point is located at the end of the feed point. The support frame is connected to the E-plane metal wall. The teardrop-shaped metal balun is further divided into upper and lower parts. The inner conductor of the coaxial feed structure is connected to the lower feed point, and the outer conductor is connected to the upper grounding part. The zigzag double-ridge structure opens outwards by segmented straight gradients. The support frame fixes all metal components and ensures the overall structural rigidity. The support frame is designed with through holes to facilitate the passage of coaxial cables. Verification shows that this invention provides an antenna with a wide bandwidth and good radiation characteristics. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the overall structure of the ultra-wideband dual-ridge TEM horn antenna according to a specific embodiment of the present invention.

[0023] Figure 2 This is a side view of the antenna according to a specific embodiment of the present invention.

[0024] Figure 3 This is a top view of the antenna according to a specific embodiment of the present invention.

[0025] Figure 4 This is a front view of the antenna according to a specific embodiment of the present invention.

[0026] Figure 5 This is a schematic diagram of the teardrop-shaped metal balun structure described in an embodiment of the present invention.

[0027] Figure 6 This is a VSWR simulation result diagram of the ultra-wideband dual-ridge TEM horn antenna described in an embodiment of the present invention;

[0028] Figure 7 This is a simulation result of the gain curve of the ultra-wideband dual-ridge TEM horn antenna described in an embodiment of the present invention;

[0029] Figure 8 This is a simulated radiation pattern (E-plane) of the ultra-wideband dual-ridge TEM horn antenna described in an embodiment of the present invention.

[0030] Figure 9 This is a simulated radiation pattern (H-plane) of the ultra-wideband dual-ridge TEM horn antenna described in this embodiment of the invention.

[0031] 1-Coaxial power supply, 2-Teardrop-shaped metal balun, 201-Upper part, 202-Lower part, 3-Folded double ridge structure, 4-Elliptical gradient inner wall, 5-Secondary elliptical gradient inner wall, 6-E-surface metal wall, 7-Aperture surface metal frame, 8-Dielectric lens, 801-Low-frequency convex lens dielectric lens, 802-High-frequency guiding dielectric lens, 9-Power supply support dielectric block, 10-Support frame, 1001-Metal plate, 1002-Hollow metal frame, 1003-Support structure. Detailed Implementation

[0032] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0033] This invention provides an ultra-wideband dual-ridge TEM horn antenna, comprising a feeding coaxial cable, a teardrop-shaped metal balun, a zigzag dual-ridge structure, an elliptical gradient inner wall, a secondary elliptical gradient inner wall, an E-plane metal wall, an aperture-plane metal frame, a dielectric lens, a supporting dielectric block at the feeding point, and a supporting frame, wherein the feeding coaxial cable, the teardrop-shaped metal balun, and the E-plane metal wall are connected sequentially.

[0034] The teardrop-shaped metal balun includes an upper part and a lower part, the upper part being a grounding portion and the lower part being a feed point connection portion; the inner conductor of the feed coaxial cable is connected to the lower part, and the outer conductor is connected to the upper part;

[0035] The zigzag double-ridge structure is composed of two symmetrical ridge plates. The two sides of the ridge plates are respectively connected to the elliptical gradient inner wall and the secondary elliptical gradient inner wall. The front end of the zigzag double-ridge structure is coaxially connected to the power supply through the teardrop-shaped metal balun.

[0036] The E-side metal wall is located outside the elliptical gradient inner wall and the secondary elliptical gradient inner wall, with one end connected to the aperture surface metal frame and the other end connected to the support frame.

[0037] The aperture-face metal frame is located at the end of the E-face metal wall, and the dielectric lens is fixed inside the aperture-face metal frame;

[0038] The power supply support medium block is located behind the power supply coaxial line and is connected to the support frame;

[0039] The support frame includes a metal plate, a hollow metal frame, and a support structure. The metal plate is disposed on the end face of the hollow metal frame and is positioned opposite to the medium lens. The support structure is fixedly connected to the metal wall on the E-side.

[0040] The ultra-wideband dual-ridge TEM horn antenna of this invention comprises a pair of gradually expanding ridges formed by a zigzag double-ridge structure. A teardrop-shaped metal balun is used to connect to the ridges to achieve impedance conversion and broadband matching. In use, electromagnetic signals are fed to the antenna via a coaxial feed and radiated outwards through the zigzag double-ridge structure. By setting elliptical and second-order elliptical gradually expanding inner walls to alter the low-frequency impedance and phase distribution, the low-frequency bandwidth of the antenna can be extended and the low-frequency gain improved. A dielectric lens guides the outward radiation of electromagnetic waves, improving the antenna's high-frequency radiation pattern and correcting the antenna aperture phase error, thereby increasing the antenna gain.

[0041] The ultra-wideband double-ridged TEM horn antenna described in this invention can be used in ultra-wideband communication and radar systems. It achieves ultra-wideband feed balance through a teardrop-shaped metal balun, achieves continuous impedance transition through a zigzag double-ridged structure, improves low-frequency matching and gain through a bi-stage elliptical gradient inner wall, and improves high-frequency radiation pattern through a dielectric lens.

[0042] For details, please refer to Figures 1 to 9This embodiment provides an ultra-wideband dual-ridge TEM horn antenna, including a coaxial feed (1), a teardrop-shaped metal balun (2), a zigzag dual-ridge structure (3), an elliptical gradient inner wall (4), a secondary elliptical gradient inner wall (5), an E-plane metal wall (6), an aperture surface metal frame (7), a dielectric lens (8), a dielectric block supporting the feed (9), and a support frame (10). The teardrop-shaped metal balun (2) includes an upper part (201) and a lower part (202). The upper part (201) is teardrop-shaped, and the lower part (202) is a matching teardrop shape. The distance between the upper part (201) and the lower part (202) gradually changes along the axial direction. The zigzag dual-ridge structure (3) consists of two symmetrical ridge plates, which are connected sequentially by multiple straight segments to form a zigzag outline. The front end is connected to the teardrop-shaped metal balun (2), and the two sides are connected to the elliptical gradient inner wall (4) and the secondary elliptical gradient inner wall (5). The elliptical gradient inner wall (4) is located in the region from the feed end to the aperture, and its outline gradually changes according to an elliptical function. The secondary elliptical gradient inner wall (5) is located behind the elliptical gradient inner wall (4) and near the aperture surface, and its outline gradually changes according to an elliptical function, and its gradient curvature is different from that of the elliptical gradient inner wall (4). The E-plane metal wall (6) is located outside the elliptical gradient inner wall (4) and the secondary elliptical gradient inner wall (5). The aperture surface metal frame (7) is located at the end of the E-plane metal wall (6), and the dielectric lens (8) is fixed inside the aperture surface metal frame (7). The dielectric lens (8) includes a low-frequency convex lens dielectric lens (801) and a high-frequency guiding dielectric lens (802). The feed-supporting dielectric block (9) is located behind the feed coaxial (1). The support frame (10) includes a metal plate (1001), a hollow metal frame (1002), and a support structure (1003), which is fixed to the metal wall (6) on the E side.

[0043] In this embodiment, the antenna has a height of 235mm, a length of 365mm, and a width of 294mm.

[0044] The upper part (201) of the teardrop-shaped metal balun (2) has a maximum width of 3 mm, a length of 10 mm, and a feed end ridge distance of 0.35 mm.

[0045] The zigzag double ridge structure (3) consists of 7 straight segments. The first segment is 33mm long and the distance between the ridge ends is 1.2mm. The second segment is 9mm long and the distance between the ridge ends is 2.6mm. The third segment is 95mm long and the distance between the ridge ends is 29mm. The fourth segment is 90mm long and the distance between the ridge ends is 65mm. The fifth segment is 78mm long and the distance between the ridge ends is 114mm. The sixth segment is 7mm long and the distance between the ridge ends is 149mm. The seventh segment is 3.7mm long and the distance between the ridge ends is 198mm. The thickness of the ridge plate is 2mm.

[0046] The major axis of the elliptical gradient inner wall (4) is 253 mm and the minor axis is 130 mm. The major axis of the secondary elliptical gradient inner wall (5) is 35 mm and the minor axis is 31.5 mm.

[0047] The thickness of the metal wall (6) on side E is 2mm.

[0048] The thickness of the metal frame (7) is 2mm.

[0049] In the dielectric lens (8), the low-frequency convex lens dielectric lens (801) has a center thickness of 45mm and an edge thickness of 20mm, and the high-frequency guiding dielectric lens (802) has a maximum diameter of 5mm and a length of 150mm. The lens material is cross-linked polystyrene with a dielectric constant of 2.5.

[0050] The power supply support medium block (9) has a size of 26mm×12mm×6mm and is made of cross-linked polystyrene.

[0051] The metal plate (1001) of the support frame (10) is 2mm thick, and the hollow metal frame (1002) is provided with weight reduction holes.

[0052] As attached Figure 6 As shown in the attached figure, the VSWR simulation results of the ultra-wideband dual-ridge TEM horn antenna described in this embodiment are given. It can be seen from the figure that the VSWR is less than 2.5 in the 2GHz-100GHz frequency band, meeting the antenna VSWR requirements. Figure 7 As shown in the attached figure, the gain simulation results of the ultra-wideband dual-ridge TEM horn antenna described in this embodiment are given. It can be seen from the figure that within the 2GHz-100GHz frequency band, the antenna gain is greater than 6dBi at 2GHz, greater than 12dBi at 10GHz, and greater than 20dBi at 100GHz. Figure 5 As shown, attached Figure 8 The simulated radiation pattern (E-plane) of the ultra-wideband dual-ridge TEM horn antenna described in this embodiment is given, with appendix. Figure 9 The simulated radiation pattern (H-plane) of the ultra-wideband dual-ridge TEM horn antenna described in this embodiment is given. Figure 8 and 9 As can be seen from this, the ultra-wideband dual-ridge TEM horn antenna described in this embodiment has good directional radiation characteristics and line-of-sight symmetry across the entire frequency band, and no serious beam splitting or deflection occurs.

[0053] The overall size of the ultra-wideband dual-ridge TEM horn antenna in this embodiment is 0.226λ1×0.238λ1×0.243λ1 (λ1 refers to the wavelength corresponding to the lowest operating frequency of 2GHz). It has a small overall size, high gain, and a bandwidth of 2GHz-100GHz. It has good ultra-wideband characteristics and good directional radiation characteristics, which can meet the requirements of ultra-wideband communication and radar systems for antennas.

[0054] In summary, compared with the prior art, the present invention has the following beneficial effects:

[0055] Excellent low-frequency impedance matching: By setting an elliptical gradient inner wall (4), the outline of which gradually changes according to the elliptical function, a smooth transition from low impedance at the feed end to high impedance in free space is achieved, which significantly improves the impedance matching in the 2-10GHz low-frequency band and reduces the voltage standing wave ratio.

[0056] Significantly improved low-frequency gain: By setting a secondary elliptical gradient inner wall (5) in the middle and rear region and adopting an elliptical gradient curvature different from that of the first stage, the phase distribution of the low-frequency electromagnetic wave in the aperture surface is effectively optimized while maintaining impedance matching, so that the aperture field tends to be in phase, thereby improving the low-frequency gain.

[0057] Stable high-frequency radiation characteristics: The dielectric lens (8) includes a low-frequency convex lens dielectric lens (801) and a high-frequency guiding dielectric lens (802), which performs phase compensation on the wavefront of the entire frequency band, effectively suppressing beam splitting and main lobe skew at the high-frequency end, so that the radiation pattern in the 2-100GHz full frequency band maintains good line-of-sight symmetry.

[0058] Wideband coverage capability: The synergistic effect of the teardrop-shaped metal balun (2), the zigzag double ridge structure (3) and the double-level elliptical gradient inner wall enables the antenna to operate stably in 2-100GHz (50:1 bandwidth) to meet the requirements of ultra-wideband systems.

[0059] The above description discloses only one preferred embodiment of the present invention, and should not be construed as limiting the scope of the present invention. Those skilled in the art will understand that all or part of the processes of the above embodiments can be implemented, and equivalent changes made in accordance with the claims of the present invention are still within the scope of the invention.

Claims

1. An ultra-wideband dual-ridge TEM horn antenna, characterized in that, It includes a feeding coaxial cable, a teardrop-shaped metal balun, a zigzag double-ridge structure, an elliptical gradient inner wall, a secondary elliptical gradient inner wall, an E-plane metal wall, an aperture surface metal frame, a dielectric lens, a supporting dielectric block at the feeding point, and a supporting frame. The feeding coaxial cable, the teardrop-shaped metal balun, and the E-plane metal wall are connected in sequence. The teardrop-shaped metal balun includes an upper part and a lower part, the upper part being a grounding portion and the lower part being a feed point connection portion; the inner conductor of the feed coaxial cable is connected to the lower part, and the outer conductor is connected to the upper part; The zigzag double-ridge structure is composed of two symmetrical ridge plates. The two sides of the ridge plates are respectively connected to the elliptical gradient inner wall and the secondary elliptical gradient inner wall. The front end of the zigzag double-ridge structure is coaxially connected to the power supply through the teardrop-shaped metal balun. The E-surface metal wall is located outside the elliptical gradient inner wall and the secondary elliptical gradient inner wall, with one end connected to the aperture surface metal frame and the other end connected to the support frame. The aperture-face metal frame is located at the end of the E-face metal wall, and the dielectric lens is fixed inside the aperture-face metal frame. The power supply support medium block is located behind the power supply coaxial line and is connected to the support frame; The support frame includes a metal plate, a hollow metal frame, and a support structure. The metal plate is disposed on the end face of the hollow metal frame and is positioned opposite to the medium lens. The support structure is fixedly connected to the metal wall on the E-side.

2. The ultra-wideband dual-ridge TEM horn antenna as described in claim 1, characterized in that, The elliptical gradient inner wall is located in the region from the feed end to the aperture inside the antenna. The secondary elliptical gradient inner wall is located after the elliptical gradient inner wall and in the region close to the antenna aperture surface. The outlines of both are gradually changing according to an elliptical function, but the curvature of the gradient is different.

3. The ultra-wideband dual-ridge TEM horn antenna as described in claim 2, characterized in that, The characteristic impedance Z(y) of the teardrop-shaped metal balun is determined by the parallel two-conductor transmission line model, and its expression is as follows: Where h(y) is the distance between the two conductor plates in the teardrop-shaped metal balun, W(y) is the width of the conductor plate, and y is the position coordinate along the antenna axis.

4. The ultra-wideband dual-ridge TEM horn antenna as described in claim 3, characterized in that, The zigzag double-ridge structure is composed of multiple straight segments connected sequentially, and the whole structure gradually expands in a zigzag shape. The distance between the ridges and the ridge width change in a piecewise linear manner along the antenna axis.

5. The ultra-wideband dual-ridge TEM horn antenna as described in claim 4, characterized in that, The dielectric lens includes a low-frequency convex lens dielectric lens and a high-frequency guiding dielectric lens. The interior of the dielectric lens is completely filled with a dielectric material, which is cross-linked polystyrene with a dielectric constant of 2.

5.

6. The ultra-wideband dual-ridge TEM horn antenna as described in claim 5, characterized in that, The ultra-wideband dual-ridge TEM horn antenna operates at a frequency of 2GHz-100GHz and has overall dimensions of 0.226λ1×0.238λ1×0.243λ1, where λ1 is the wavelength corresponding to the operating frequency of 2GHz.

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