A broadband beam miniaturized SIW horn antenna

Abstract

A broadband beam miniaturized SIW horn antenna, including a first dielectric plate, the inside upper surface of the first dielectric plate is embedded with an additional radiation structure, the lower side of the first dielectric plate is distributed with a SIW-H plane horn antenna with a ridge structure, the upper and lower surfaces of the horn opening end of the SIW-H plane horn antenna with a ridge structure are attached with a parasitic patch, and the lower surface of the SIW-H plane horn antenna with a ridge structure is attached with a first metal rectangular patch; the present application introduces a parasitic patch and an additional radiation structure on the basis of the initial horn antenna structure, thereby introducing the radiation mode of the equivalent half-wave oscillator unit and array, causing the alternation of the antenna radiation mode, thereby changing the input impedance of the antenna, realizing the expansion of the low-frequency working bandwidth and the improvement of the impedance matching ability of the middle and high frequencies, and at the same time, the pattern of the equivalent half-wave oscillator and the pattern of the initial horn antenna are superimposed, realizing the expansion of the antenna wave width.

Description

Technical Field

[0001] This invention belongs to the field of antenna technology, specifically relating to a miniaturized SIW horn antenna with a wide bandwidth beam. Background Technology

[0002] With the rapid development of modern technology, society needs wider bandwidth and easier-to-install or portable devices to transmit the explosive growth of information. Substrate integrated waveguide technology has gained significant practical value due to its low profile and ease of integration. Currently, horn antennas, as end-fire antennas, are widely used in communication, remote sensing, and other fields due to their simple structure and high power capacity. However, their large size limits their further development. When designing horn antennas using substrate integrated waveguide technology, not only can the advantages of traditional horn antennas be retained, but the antenna can also be miniaturized. However, when using thin dielectric substrates in the 6-18 GHz frequency band, the mismatch between the horn aperture and free space leads to a narrow impedance bandwidth. In addition, the inherent characteristics of horn antennas cause their half-power radiation bandwidth to decrease as the antenna frequency increases. Therefore, how to achieve wide bandwidth, miniaturization, and wide beamwidth performance while maintaining good radiation performance of horn antennas is of great research value.

[0003] In response to this, the prior art, patent application CN109742547A entitled "Low Profile Ultra-Wideband H-plane Horn Antenna Based on SIW and Its Fabrication Method", discloses an ultra-wideband design method. This method extends the single-mode operating bandwidth by introducing a stepped ridge structure, realizes the broadband transition of the electromagnetic field from SMA to the ridge waveguide through an inverted conical probe and an arc-shaped short-circuit cavity, and smooths the convexity of the horn aperture and free space by extending an arc-shaped patch and an arc-shaped dielectric plate at the horn opening, thus realizing a broadband H-plane horn antenna with a stable radiation pattern.

[0004] To extend the bandwidth of SIW horn antennas, existing technologies include: adding a ridge structure to the horn antenna, changing the profile of a traditional H-plane horn to a hyperelliptical taper, introducing an extended dielectric plate that can act as an impedance transformer in front of the horn aperture, and loading air vias or printed transition structures with varying diameters on the extended dielectric plate. However, all of these technologies result in an increase in antenna size and a decrease in half-power radiation beamwidth. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, the present invention aims to provide a miniaturized SIW horn antenna with a wide bandwidth beam. By introducing parasitic patches and additional radiating structures on the basis of the initial horn antenna structure, the radiation modes of the equivalent half-wave dipole element and array are introduced, causing the antenna radiation mode to change. This changes the input impedance of the antenna, thereby widening the low-frequency operating bandwidth and improving the impedance matching capability in the mid-to-high frequency range. At the same time, by superimposing the radiation pattern of the equivalent half-wave dipole and the radiation pattern of the initial horn antenna, the antenna bandwidth is widened.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A miniaturized SIW horn antenna with wide bandwidth beamwidth includes a first dielectric substrate 3, the first dielectric substrate 3 having an additional radiating structure 2, a ridged SIW-H surface horn antenna 7 distributed directly below the first dielectric substrate 3, parasitic patches 1 attached to the upper and lower surfaces of the horn opening end of the ridged SIW-H surface horn antenna 7, and a first metal rectangular patch 113 attached to the lower surface of the ridged SIW-H surface horn antenna 7.

[0007] The additional radiation structure 2 includes a second metal patch 23 attached to the upper surface of the first dielectric plate 3, and a third straight portion 21 and a fourth straight portion 22 are embedded directly below the second metal patch 23.

[0008] The SIW-H surface horn antenna 7 with a ridge structure includes a dielectric substrate 15 laid parallel to the ground. The dielectric substrate 15 includes an upper short-circuit surface layer 51, a second dielectric substrate 5, and a lower short-circuit surface layer 52 that are arranged in parallel and overlapping manner from top to bottom in the vertical direction. The upper short-circuit surface layer 51 and the lower short-circuit surface layer 52 extend along the length of the second dielectric plate 5 from the starting direction of the second dielectric plate 5. The second dielectric plate 5 is in close contact with the upper short-circuit surface layer 51 and the lower short-circuit surface layer 52, respectively. The length and width of the upper short-circuit surface layer 51 and the lower short-circuit surface layer 52 are equal.

[0009] The parasitic patch 1 consists of a printed dipole patch 11 and a semi-elliptical metal patch 12 that are attached to the upper and lower surfaces of the SIW-H surface horn antenna 7 with a ridge structure. The printed dipole patch 11 and the semi-elliptical metal patch 12 are distributed at a certain horizontal distance.

[0010] The third straight section 21 and the fourth straight section 22 are composed of a number of third metal through holes 24 arranged in a straight line at a certain distance from each other. The extension direction of each third metal through hole 24 is perpendicular to the ground, and each third metal through hole 24 penetrates the second dielectric plate 5.

[0011] The medium plate 15 is inlaid with a groove-shaped ridge structure 73 on the second medium plate 5. The ridge structure 73 is symmetrically provided with a first side wall portion 71 and a second side wall portion 72, as well as a first straight portion 911 and a second straight portion 912 on both sides. The extension direction is parallel to the axis center line of the ridge structure 73. The starting end of the ridge structure 73 is connected to the conversion portion 13.

[0012] The ridge structure 73 includes a first step 711, a second step 712, and a third step 713 located on the upper surface of the second medium plate 5 and connected in a stepped manner. The extension direction of the center line of the ridge structure is parallel to the ground. The height and width of the first step 711, the second step 712, and the third step 713 decrease in a stepped manner. The conversion section 13 includes a curved short-circuit plate 131 located at one end of the ridge structure 73 and a coaxial inner core 8. The coaxial inner core 8 is connected to the end of the first step 711 away from the second step 712. The extension direction of the coaxial inner core 8 is perpendicular to the ground and penetrates the second dielectric plate 5. A plurality of second metal through holes 9 provided on the second dielectric plate 5 are arranged equidistantly around the coaxial inner core 8 to form a curved short-circuit plate 131 with a semi-circular arm. The extension direction of the second metal through holes 9 is perpendicular to the ground, and all the second metal through holes 9 penetrate the second dielectric plate 5. The first straight section 911, the second straight section 912, the first side wall section 71 and the second side wall section 72 are each composed of a plurality of first metal through holes 4 arranged at equal intervals on the second medium plate 5. The extension direction of the first metal through holes 4 is perpendicular to the ground, and each first metal through hole 4 penetrates the second medium plate 5. The first sidewall portion 71 and the second sidewall portion 72 are first arranged in a trumpet-shaped opening, then in a straight line, and finally in a trumpet-shaped opening with the same opening angle. The two ends of the curved short-circuit plate 131 with a semi-circular arm are respectively connected to one end of the first straight section 911 and the second straight section 912. The other end of the first straight section 911 is connected to one end of the first sidewall section 71 near the ridge structure 73. The other end of the second straight section 912 is connected to one end of the second sidewall section 72 near the ridge structure 73. The other ends of the first sidewall section 71 and the second sidewall section 72 are respectively connected to a fourth metal through hole 10 located at the termination position of the upper short-circuit surface layer 51. The extension direction of the fourth metal through hole 10 is perpendicular to the ground. Each fourth metal through hole 10 penetrates the second dielectric plate 5.

[0013] The printed dipole patch 11 includes an upper printed dipole patch 111 located on the upper surface of the extended second dielectric plate 5 and a lower printed dipole patch 112 located on the lower surface of the extended second dielectric plate 5. The upper printed dipole patch 111 and the lower printed dipole patch 112 are both distributed along the extension direction of the second dielectric plate 5 and are arranged in a mirror antisymmetric manner about the horizontal central axis of the second dielectric plate 5. A first metal rectangular patch 113 is printed between the lower printed dipole patch 112 and the lower short-circuit surface layer 52 of the second dielectric plate 5. The semi-elliptical metal patch 12 includes an upper semi-elliptical metal patch layer 121 distributed on the same layer as the upper printed dipole patch 111, and a lower semi-elliptical metal patch layer 122 distributed on the same layer as the lower printed dipole patch 112. The upper semi-elliptical metal patch layer 121 and the lower semi-elliptical metal patch layer 122 are symmetrically distributed about the horizontal central axis of the second dielectric plate 5.

[0014] The upper printed dipole patch 111 includes a first horizontal upper arm 1111 and a first inclined upper arm 1112; the lower printed dipole patch 112 includes a first horizontal lower arm 1121 and a first inclined lower arm 1122. The width of the first horizontal upper arm 1111 and the first horizontal lower arm 1121 first narrows and then remains constant as they are distributed forward along the extending direction of the second medium plate 5. The first inclined upper arm 1112 and the first inclined lower arm 1122 are angularly distributed with the first horizontal upper arm 1111 and the first horizontal lower arm 1121, respectively, and their widths increase gradually along the direction of the angle. The upper semi-elliptical metal patch layer 121 includes a second inclined upper arm 1211 and a third inclined upper arm 1212 symmetrically distributed along the extension direction of the second dielectric plate 5, and the inclination direction of the third inclined upper arm 1212 is parallel to the first inclined upper arm 1112. The lower semi-elliptical metal patch layer 122 includes a second inclined lower arm 1221 and a third inclined lower arm 1222 symmetrically distributed along the extension direction of the second dielectric plate 5, and the inclination direction of the second inclined lower arm 1221 is parallel to the first inclined lower arm 1122.

[0015] The second inclined upper arm 1211, the third inclined upper arm 1212, the second inclined lower arm 1221 and the third inclined lower arm 1222 each include four unit semi-elliptical metal patches 6, which are arranged in two rows with a distance between them, in the form of three and one.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention, by loading a parasitic patch 1 and an additional radiating structure 2, alters the antenna's radiation mode at low and high frequencies, thereby changing the antenna's input impedance and expanding its low-frequency operating bandwidth while improving its mid-to-high frequency matching capability. Compared to the final bandwidth and size of the antenna in the existing technology "SSIW-based low-profile ultra-wideband H-plane horn antenna and its fabrication method," this invention achieves a wider bandwidth while being smaller in size and exhibiting more effective miniaturization.

[0017] 2. By introducing the parasitic patch 1, the present invention achieves a stable radiation pattern. Compared with the existing technology "low profile ultra-wideband H-plane horn antenna based on SIW and its manufacturing method" which uses an arc transition to achieve a stable radiation pattern, the present invention does not have the problem of upward bias in the E-plane radiation pattern throughout the entire frequency band, and the H-plane radiation pattern is also very stable, resulting in better end-fire radiation effect.

[0018] 3. By introducing an additional radiating structure 2, the present invention achieves a wider beamwidth for the antenna radiation pattern. Compared with the final 3dB beamwidth of the antenna in the prior art “low profile ultra-wideband H-plane horn antenna based on SIW and its manufacturing method”, the present invention has a wider beamwidth.

[0019] In summary, by introducing parasitic patch 1, when the antenna operates at low frequencies, the parasitic patch 1 can be equivalent to a half-wave dipole element. By introducing additional radiating structure 2, when the antenna operates at mid-to-high frequencies, the additional radiating structure 2 can be equivalent to a half-wave dipole array distributed in a 2*2 pattern. Therefore, it is equivalent to introducing a half-wave dipole radiating structure into the initial antenna. The introduction of this radiating structure causes the antenna's radiation mode to change, thereby altering the impedance of the entire operating frequency band and achieving bandwidth expansion and miniaturization. Furthermore, based on the principle of pattern superposition, the radiation pattern of the introduced radiating structure and the radiation pattern of the initial antenna are combined, thus achieving bandwidth broadening of the SIW horn antenna. Ultimately, the antenna achieves a size of only 1.22 × 0.74 × 0.21 (… )( With the free space wavelength at the center frequency as the standard, the antenna achieves a third harmonic operating bandwidth (6.33-18.36 GHz) and a 120° E-plane / 70° H-plane beamwidth. The antenna proposed in this invention has the advantages of miniaturization, wide beamwidth, wide bandwidth, and end-fire capability. Attached Figure Description

[0020] Figure 1 This is an anatomical diagram of the miniaturized SIW horn antenna with wide bandwidth beamwidth according to the present invention.

[0021] Figure 2 This is a top view of the miniaturized SIW horn antenna with wide bandwidth beamwidth according to the present invention.

[0022] Figure 3 This is a cross-sectional view of the miniaturized SIW horn antenna with wide bandwidth beam of the present invention.

[0023] Figure 4 is a top view and a cross-sectional view of the conversion section 13 of the miniaturized SIW horn antenna with wide bandwidth beam of the present invention, wherein Figure 4(a) is a top view of the antenna conversion section 13 of the present invention, and Figure 4(b) is a cross-sectional view of the antenna conversion section 13 of the present invention.

[0024] Figure 5 shows a perspective view and a bottom view of the miniaturized SIW horn antenna with wide bandwidth beam of the present invention, wherein Figure 5(a) is a perspective view of the antenna of the present invention and Figure 5(b) is a bottom view of the antenna of the present invention.

[0025] Figure 6 This is a comparison diagram of the antenna standing wave ratio and input impedance before and after the parasitic patch 1 is loaded according to the present invention.

[0026] Figure 7 This is a schematic diagram of the surface equivalent current distribution of the additional radiation structure 2 of the present invention.

[0027] Figure 8 This is a comparison diagram of the antenna standing wave ratio and input impedance before and after the addition of the additional radiation structure 2 in this invention.

[0028] Figure 9 is a schematic diagram of the superposition of radiation patterns of the present invention. Figure 9(a) is a schematic diagram of the superposition process of radiation patterns on the H plane of the present invention, and Figure 9(b) is a schematic diagram of the superposition process of radiation patterns on the E plane of the present invention.

[0029] Figure 10 A comparison diagram of antenna gain, E-plane beamwidth, and H-plane beamwidth before and after loading the additional radiation structure 2 of this invention.

[0030] Among them, 1. Parasitic patch; 2. Additional radiating structure; 21. Third straight section; 22. Fourth straight section; 23. Second metal patch; 24. Third metal via; 3. First dielectric substrate; 4. First metal via; 5. Second dielectric substrate; 51. Upper short-circuit surface layer; 52. Lower short-circuit surface layer; 6. Unit semi-elliptical metal patch; 7. SIW-H surface horn antenna with ridge structure; 71. First sidewall; 72. Second sidewall; 73. Ridge structure; 711. First stepped section; 712. Second stepped section; 713. Third stepped section; 8. Coaxial inner core; 9. Second metal via; 911. First straight section; 912. Second straight section; 10. Fourth metal 11. Through-hole; 11. Printed dipole patch; 111. Upper printed dipole patch; 112. Lower printed dipole patch; 1111. First horizontal upper arm; 1112. First inclined upper arm; 112. Lower printed dipole patch; 1121. First horizontal lower arm; 1122. First inclined lower arm; 12. Semi-elliptical metal patch; 121. Upper semi-elliptical metal patch layer; 122. Lower semi-elliptical metal patch layer; 1211. Second inclined upper arm; 1212. Third inclined upper arm; 1221. Second inclined lower arm; 1222. Third inclined lower arm; 113. First rectangular metal patch; 13. Transition section; 131. Curved shorting board; 15. Dielectric board. Detailed Implementation

[0031] To better understand the technical content of the present invention, specific embodiments are described below in conjunction with the accompanying drawings.

[0032] Example 1 like Figure 1 As shown, a miniaturized SIW horn antenna with a wide bandwidth beam includes a first dielectric substrate 3. An additional radiating structure 2 is embedded in the upper surface of the first dielectric substrate 3. A ridged SIW-H horn antenna 7 is distributed directly below the first dielectric substrate 3. The first dielectric substrate 3 and the ridged SIW-H horn antenna 7 have the same length and width and are stacked together by studs. Parasitic patches 1 are attached to the upper and lower surfaces of the horn opening end of the ridged SIW-H horn antenna 7, and a first metal rectangular patch 113 is attached to the lower surface of the ridged SIW-H horn antenna 7.

[0033] The first dielectric plate 3 is located directly above the ridged SIW-H surface horn antenna 7 and parallel to the ground. Both plates have equal length and width, and the vertical spacing is 0. The parasitic patch 1 is attached to the upper and lower surfaces of the second dielectric plate 5 at the horn opening end of the ridged SIW-H surface horn antenna 7. The additional radiating structure 2 is embedded and attached to the inner upper surface of the first dielectric plate 3. The first metal rectangular patch 113 is located on the lower surface of the second dielectric plate 5 at the horn opening end of the ridged SIW-H surface horn antenna 7 and is connected to the parasitic patch 1.

[0034] The second dielectric plate 5 has the same length and width as the first dielectric plate 3.

[0035] The length of the first metal rectangular patch 113 is the width of the ridged SIW-H surface horn antenna 7.

[0036] In a further embodiment, the second dielectric substrate 5 has dimensions of 18.3*30*4 mm. The first dielectric substrate 3, manufactured using the F4B process with a dielectric constant of 2.65, has dimensions of 18.3*30*1 mm. It is made of FR4_epoxy with a dielectric constant of 4.4.

[0037] like Figure 2 As shown, the additional radiation structure 2 includes a second metal patch 23 attached to the upper surface of the first dielectric plate 3, and a third straight portion 21 and a fourth straight portion 22 are embedded directly below the second metal patch 23. The midpoint of the width of the second metal patch 23 coincides with the midpoint of the distance between the third straight portion 21 and the fourth straight portion 22.

[0038] The third straight section 21 and the fourth straight section 22 are composed of several third metal through holes 24 arranged in a straight line at a certain distance from each other. The extension direction of each third metal through hole 24 is perpendicular to the ground, and each third metal through hole 24 penetrates the second dielectric plate 5. The third metal through holes 24 are arranged at equal intervals.

[0039] The length of the second metal patch 23 is the width of the second dielectric plate 5.

[0040] The second dielectric plate 3 has an extended dielectric portion relative to the short-circuit surface, that is, the length of the second dielectric plate 3 is longer than the length of the upper short-circuit surface layer 51.

[0041] The line connecting the midpoint of the distance between the third straight section 21 and the fourth straight section 22 and the midpoint of the termination position line of the upper short-circuit surface layer 51 of the second dielectric plate 5 is perpendicular to the horizontal ground.

[0042] like Figure 2 , Figure 3As shown, the SIW-H surface horn antenna 7 with a ridge structure includes a dielectric substrate 15 laid parallel to the ground. The dielectric substrate 15 includes an upper short-circuit surface layer 51, a second dielectric substrate 5, and a lower short-circuit surface layer 52 that are arranged in parallel and overlapping manner from top to bottom in the vertical direction. The upper short-circuit surface layer 51 and the lower short-circuit surface layer 52 extend along the length of the second dielectric plate 5 from the starting direction of the second dielectric plate 5. The second dielectric plate 5 is in close contact with the upper short-circuit surface layer 51 and the lower short-circuit surface layer 52, respectively. The length and width of the upper short-circuit surface layer 51 and the lower short-circuit surface layer 52 are equal.

[0043] The medium plate 15 is inlaid with a ridge structure 73 that can be regarded as a groove shape inside the second medium plate 5. The ridge structure 73 has a first side wall portion 71 and a second side wall portion 72, as well as a first straight portion 911 and a second straight portion 912 symmetrically arranged on both sides. The extension direction is parallel to the axis center line of the ridge structure 73. The starting end of the ridge structure 73 is connected to the inner core 8 of the coaxial line of the conversion part 13.

[0044] The groove-shaped ridge structure 73 includes a first step 711, a second step 712, and a third step 713 connected in a stepped manner. The extension direction of the center line of the axial part is parallel to the ground. The height and width of the first step 711, the second step 712, and the third step 713 decrease in a stepped manner.

[0045] As shown in Figure 4, the conversion part 13 includes a curved short-circuit plate 131 located at one end of the ridge structure 73 and a coaxial inner core 8 penetrating through the second dielectric plate 5. The coaxial inner core 8 is connected to the end of the first step 711 away from the second step 712. The extension direction of the coaxial inner core 8 is perpendicular to the ground and penetrates through the second dielectric plate 5. A plurality of second metal through holes 9 disposed on the second dielectric plate 5 are arranged at equal intervals around the inner core 8 of the coaxial axis to form a curved short circuit board 131 with a semi-circular arm. The center of the curved short circuit board 131 is the inner core 8 of the coaxial axis. The extension direction of the second metal through holes 9 is perpendicular to the ground. All the second metal through holes 9 penetrate the second dielectric plate 5. The first straight section 911, the second straight section 912, the first side wall section 71 and the second side wall section 72 are each composed of a plurality of first metal through holes 4 arranged at equal intervals on the second medium plate 5. The extension direction of the first metal through holes 4 is perpendicular to the ground, and each first metal through hole 4 penetrates the second medium plate 5. The first sidewall portion 71 and the second sidewall portion 72 are first arranged in a trumpet-shaped opening, then in a straight line, and finally in a trumpet-shaped opening with the same opening angle. The two ends of the curved short-circuit plate 131 with a semi-circular arm are respectively connected to one end of the first straight section 911 and the second straight section 912. The other end of the first straight section 911 is connected to one end of the first sidewall section 71 near the ridge structure 73. The other end of the second straight section 912 is connected to one end of the second sidewall section 72 near the ridge structure 73. The other ends of the first sidewall section 71 and the second sidewall section 72 are respectively connected to a fourth metal through hole 10 located at the termination position of the upper short-circuit surface layer 51, but not exceeding the termination position. The extension direction of the two fourth metal through holes 10 is perpendicular to the ground. Both fourth metal through holes 10 penetrate the second dielectric plate 5.

[0046] As shown in Figure 5, the parasitic patch 1 is loaded on the end of the third step 713 away from the second step 712. The parasitic patch 1 is composed of a printed dipole patch 11 and a semi-elliptical metal patch 12 that are closely attached to the upper and lower surfaces of the SIW-H surface horn antenna 7 with a ridge structure. The printed dipole patch 11 and the semi-elliptical metal patch 12 are distributed at a certain horizontal distance.

[0047] The printed dipole patch 11 includes an upper printed dipole patch 111 located on the upper surface of the extended second dielectric substrate 5 and a lower printed dipole patch 112 located on the lower surface of the extended second dielectric substrate 5. The upper printed dipole patch 111 and the lower printed dipole patch 112 are both distributed along the extension direction of the second dielectric substrate 5 and are arranged in a mirror antisymmetric manner about the horizontal central axis of the second dielectric substrate 5. A first metal rectangular patch 113 is printed between the lower printed dipole patch 112 and the lower short-circuit surface layer 52 of the second dielectric substrate 5. The first metal rectangular patch 113 serves as a transition structure and is connected to both the lower short-circuit surface layer 52 and the lower printed dipole patch 112. The length of the first metal rectangular patch 113 is the width of the antenna.

[0048] The semi-elliptical metal patch 12 includes an upper semi-elliptical metal patch layer 121 distributed on the same layer as the upper printed dipole patch 111, and a lower semi-elliptical metal patch layer 122 distributed on the same layer as the lower printed dipole patch 112. The upper semi-elliptical metal patch layer 121 and the lower semi-elliptical metal patch layer 122 are symmetrically distributed about the horizontal central axis of the second dielectric plate 5.

[0049] The upper printed dipole patch 111 includes a first horizontal upper arm 1111 and a first inclined upper arm 1112; the lower printed dipole patch 112 includes a first horizontal lower arm 1121 and a first inclined lower arm 1122. The width of the first horizontal upper arm 1111 and the first horizontal lower arm 1121 first narrows and then remains constant as they are distributed forward along the extending direction of the second medium plate 5. The first inclined upper arm 1112 and the first inclined lower arm 1122 are distributed at a specific angle to the first horizontal upper arm 1111 and the first horizontal lower arm 1121, respectively, and their widths increase gradually along the extension direction of the specific angle. The upper semi-elliptical metal patch layer 121 includes a second inclined upper arm 1211 and a third inclined upper arm 1212 symmetrically distributed along the extension direction of the second dielectric plate 5, and the inclination direction of the third inclined upper arm 1212 is parallel to the first inclined upper arm 1112. The lower semi-elliptical metal patch layer 122 includes a second inclined lower arm 1221 and a third inclined lower arm 1222 symmetrically distributed along the extension direction of the second dielectric plate 5, and the inclination direction of the second inclined lower arm 1221 is parallel to the first inclined lower arm 1122. The second inclined upper arm 1211, the third inclined upper arm 1212, the second inclined lower arm 1221 and the third inclined lower arm 1222 each include four unit semi-elliptical metal patches 6, which are arranged in two rows in a certain distance with three and one respectively.

[0050] This invention introduces a radiating structure of a half-wave dipole element by loading a parasitic patch 1. When the parasitic patch 1 is excited by energy at the horn aperture, it will start to radiate energy outward. Thus, within the operating frequency band, the radiation mode of the antenna is changed from radiation by the equivalent magnetic flux element (i.e., the horn aperture) alone to joint radiation by the equivalent magnetic flux element and the half-wave dipole element. The introduction of this radiating structure will change the impedance distribution of the antenna at low frequencies, thereby widening the low-frequency bandwidth.

[0051] The additional radiating structure 2 of this invention, when the antenna operates in the mid-to-high frequency band, can be equivalently represented as two half-wave dipole binary linear arrays with equal amplitude, opposite phase, and horizontally placed along the x-axis, such as... Figure 7 As shown in the current distribution diagram, the antenna's radiation mode changes from radiation solely from the equivalent magnetic flux element (i.e., the horn aperture) to combined radiation from the equivalent magnetic flux element and the half-wave dipole array. This change in radiation structure causes a change in the antenna's resonant resistance at the mid-to-high frequency range. Therefore, by appropriately adjusting the dimensions of the additional radiation structure, the antenna's impedance at mid-to-high frequencies can be altered, improving its mid-to-high frequency matching capability and achieving broadband operation. Simultaneously, the equivalent half-wave dipole array is placed 5mm above the ground (approximately s*). Where 0.3 ≤ s ≤ 0.5, The antenna is positioned on a horizontal plane (where the waveguide wavelength corresponds to the mid-to-high frequency range). Therefore, firstly, based on the mirror principle, the two-element linear array of the half-wave dipole is transformed into a 2*2 planar array. Secondly, the normalized planar two-element pattern function is obtained according to the pattern product theorem. Finally, as shown in Figure 9, the E-plane and H-plane wavelengths of the antenna are significantly broadened.

[0052] Based on the aforementioned structure, this invention provides a method for miniaturizing the wide bandwidth beam of a SIW horn antenna. The method includes: using SIW technology to simultaneously load a ridge structure 73, a parasitic patch 1 structure, and an additional radiating structure 2 to fabricate the aforementioned miniaturized wide bandwidth beam SIW horn antenna.

[0053] This invention employs SIW technology to simultaneously load a ridge structure 73, a parasitic patch 1 structure, and an additional radiating structure 2 to fabricate the aforementioned wide-bandwidth beam miniaturized SIW horn antenna. Through these technologies, a wide-bandwidth beam miniaturized antenna is fabricated, exhibiting a smaller size, wider bandwidth, and wider beamwidth compared to existing antennas.

[0054] Example 2 Combination Figure 1 Figure 5 illustrates the fabrication of a miniaturized SIW horn antenna with a wide bandwidth beamwidth. Specific parameters are as follows: =18.3mm, =4.1mm, =3.1mm, =2.1mm, =2.19mm, =4mm, =1.6mm, L=30mm, =1mm, =5.6mm, =3.8mm, =1mm, =9.1mm, =1.8mm, =0.4mm, =0.6mm, =1.3mm, =2.3mm, =1.2mm, =5mm, =2.9mm, =2.5mm, =1.9mm, =4mm, =10.5mm.

[0055] Combination Figures 6-10 As can be seen, this invention can solve the key problem of miniaturization of SIW horn antennas, ensuring that the average antenna gain remains basically unchanged while having the characteristics of ultra-wideband, wide beam and stable radiation pattern.

[0056] like Figure 6As shown, it can be seen that by introducing the unit radiation structure of the half-wave dipole, the parasitic patch 1 significantly reduces the real and imaginary parts of the antenna impedance at low frequencies, making the real part at low frequencies closer to 50 Ω and the imaginary part at low frequencies closer to 0 Ω. This means that the present invention achieves good matching in the low-frequency band.

[0057] like Figure 7 As shown, when the antenna operates in the mid-to-high frequency band, the added radiation structure 2 can be equivalent to two half-wave dipole binary linear arrays with equal amplitude, opposite phase, and placed horizontally along the x-axis.

[0058] like Figure 8 As shown, it can be seen that the added radiation structure 2 can reduce the real part of the antenna impedance at mid-to-high frequencies, making the real part of the mid-to-high frequency impedance closer to 50 Ω, and the imaginary part of the mid-to-high frequency impedance closer to 0 Ω. This means that the present invention achieves good matching in the mid-to-high frequency band.

[0059] As shown in Figure 9, it can be seen that by using the principle of pattern superposition, the beamwidths of both the E-plane and H-plane will be broadened after loading the additional radiation structure 2.

[0060] like Figure 10 As shown, it can be seen that the added additional radiation structure 2 achieves significantly broadened E-plane and H-plane beamwidths while slightly sacrificing the high-frequency end-fire gain of the antenna. The average E-plane beamwidth is 123° and the average H-plane beamwidth is 70°.

[0061] The loading structure proposed in this invention consists of two parts: a parasitic patch 1 and an additional radiating structure 2. On one hand, the objective of this invention can still be achieved even when the unit shape, unit size, number of units per row, and unit spacing of the semi-elliptical metal patch 12 in the parasitic patch 1 are specifically modified. On the other hand, the objective of this invention can also be achieved when the radius and spacing of the third metal through-hole 24 in the additional radiating structure 2 are specifically modified.

[0062] In recent years, SIW technology has been used to design H-plane horns, enabling the transformation of traditional horns from non-planar structures to planar structures and making antenna miniaturization possible. However, due to the mismatch between the SIW substrate and the air, the designed antenna suffers from narrow bandwidth. The loading structure (parasitic patch 1 and additional radiating structure 2) proposed in this invention can effectively extend the antenna bandwidth to about three harmonics, while achieving excellent characteristics of antenna miniaturization and wide beamwidth. This allows it to achieve wide-angle radiation over a wide bandwidth when conformally mounted on an aircraft.

[0063] In this disclosure, various aspects of the invention are described with reference to the accompanying drawings, in which numerous illustrative embodiments are shown. The embodiments of this disclosure are not necessarily defined to include all aspects of the invention. It should be understood that the various concepts and embodiments described above can be implemented in any of many ways, because the concepts and embodiments disclosed herein are not limited to any particular implementation. Furthermore, some aspects of the invention disclosed may be used alone or in any suitable combination with other aspects of the invention disclosed.

[0064] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention shall be determined by the claims.

Claims

1. A miniaturized SIW horn antenna with wide bandwidth beamwidth, comprising a first dielectric substrate (3), characterized in that: The first dielectric substrate (3) has an additional radiating structure (2), and a ridged SIW-H surface horn antenna (7) is distributed directly below the first dielectric substrate (3). Parasitic patches (1) are attached to the upper and lower surfaces of the horn opening end of the ridged SIW-H surface horn antenna (7), and a first metal rectangular patch (113) is attached to the lower surface of the ridged SIW-H surface horn antenna (7). The additional radiation structure (2) includes a second metal patch (23) attached to the upper surface of the first dielectric plate (3), and a third straight portion (21) and a fourth straight portion (22) are embedded directly below the second metal patch (23). The parasitic patch (1) consists of a printed dipole patch (11) and a semi-elliptical metal patch (12) attached to the upper and lower surfaces of the horn opening end of the SIW-H surface horn antenna (7) with a ridge structure. The printed dipole patch (11) and the semi-elliptical metal patch (12) are distributed at a horizontal distance from each other. The third straight section (21) and the fourth straight section (22) are composed of several third metal through holes (24) arranged in a straight line at a certain distance from each other. The extension direction of each third metal through hole (24) is perpendicular to the ground, and each third metal through hole (24) penetrates the second medium plate (5).

2. The miniaturized SIW horn antenna with wide bandwidth beamwidth according to claim 1, characterized in that: The SIW-H surface horn antenna (7) with a ridge structure includes a dielectric plate (15) laid parallel to the ground. The dielectric plate (15) includes an upper short-circuit surface layer (51), a second dielectric plate (5), and a lower short-circuit surface layer (52) that are arranged in parallel and overlapping manner from top to bottom in the vertical direction. The upper short-circuit surface layer (51) and the lower short-circuit surface layer (52) extend along the length of the second dielectric plate (5) from the starting direction of the second dielectric plate (5). The second dielectric plate (5) is in close contact with the upper short-circuit surface layer (51) and the lower short-circuit surface layer (52), respectively. The length and width of the upper short-circuit surface layer (51) and the lower short-circuit surface layer (52) are equal.

3. The miniaturized SIW horn antenna with wide bandwidth beamwidth according to claim 2, characterized in that: The medium plate (15) has a groove-shaped ridge structure (73) embedded inside and on the second medium plate (5). The ridge structure (73) has a first side wall portion (71) and a second side wall portion (72) symmetrically arranged on both sides, as well as a first straight portion (911) and a second straight portion (912). The extension direction is parallel to the axis center line of the ridge structure (73). The starting end of the ridge structure (73) is connected to the conversion portion (13).

4. A miniaturized SIW horn antenna with wide bandwidth beamwidth according to claim 3, characterized in that: The ridge structure (73) includes a first step (711), a second step (712) and a third step (713) located on the upper surface of the second medium plate (5) and connected in a stepped manner. The extension direction of the center line of the axis is parallel to the ground. The height and width of the first step (711), the second step (712) and the third step (713) decrease in a stepped manner. The conversion section (13) includes a curved short circuit plate (131) located at one end of the ridge structure (73) and a coaxial inner core (8). The coaxial inner core (8) is connected to the end of the first step section (711) away from the second step section (712). The extension direction of the coaxial inner core (8) is perpendicular to the ground and penetrates the second dielectric plate (5). A plurality of second metal through holes (9) provided on the second dielectric plate (5) are arranged equidistantly around the coaxial inner core (8) to form a curved short circuit plate (131) with a semi-circular arm. The extension direction of the second metal through holes (9) is perpendicular to the ground, and all the second metal through holes (9) penetrate the second dielectric plate (5). The first straight section (911), the second straight section (912), the first sidewall section (71) and the second sidewall section (72) are each composed of a plurality of first metal through holes (4) arranged at equal intervals on the second medium plate (5). The extension direction of the first metal through holes (4) is perpendicular to the ground, and each first metal through hole (4) penetrates the second medium plate (5). The first sidewall portion (71) and the second sidewall portion (72) are first arranged in a trumpet-shaped angle, then in a straight line, and finally in a trumpet-shaped angle with the same opening angle. The two ends of the curved short-circuit plate (131) with a semi-circular arm are respectively connected to one end of the first straight section (911) and the second straight section (912). The other end of the first straight section (911) is connected to one end of the first side wall section (71) near the ridge structure (73). The other end of the second straight section (912) is connected to one end of the second side wall section (72) near the ridge structure (73). The other ends of the first side wall section (71) and the second side wall section (72) are respectively connected to a fourth metal through hole (10) located at the end position of the upper short-circuit surface layer (51). The extension direction of the fourth metal through hole (10) is perpendicular to the ground. Each fourth metal through hole (10) penetrates the second dielectric plate (5).

5. A miniaturized SIW horn antenna with wide bandwidth beamwidth according to claim 1, characterized in that: The printed dipole patch (11) includes an upper printed dipole patch (111) located on the upper surface of the extended second dielectric plate (5) and a lower printed dipole patch (112) located on the lower surface of the extended second dielectric plate (5). The upper printed dipole patch (111) and the lower printed dipole patch (112) are both distributed along the extension direction of the second dielectric plate (5) and are arranged in a mirror antisymmetric manner about the horizontal central axis of the second dielectric plate (5). A first metal rectangular patch (113) is printed between the lower printed dipole patch (112) and the lower short-circuit surface layer (52) of the second dielectric plate (5). The semi-elliptical metal patch (12) includes an upper semi-elliptical metal patch layer (121) distributed on the same layer as the upper printed dipole patch (111), and a lower semi-elliptical metal patch layer (122) distributed on the same layer as the lower printed dipole patch (112). The upper semi-elliptical metal patch layer (121) and the lower semi-elliptical metal patch layer (122) are symmetrically distributed about the horizontal central axis of the second dielectric plate (5).

6. A miniaturized SIW horn antenna with wide bandwidth beamwidth according to claim 5, characterized in that: The upper printed dipole patch (111) includes a first horizontal upper arm (1111) and a first inclined upper arm (1112); the lower printed dipole patch (112) includes a first horizontal lower arm (1121) and a first inclined lower arm (1122). The width of the first horizontal upper arm (1111) and the first horizontal lower arm (1121) first narrows and then remains unchanged when they are distributed forward along the extension direction of the second medium plate (5); The first inclined upper arm (1112) and the first inclined lower arm (1122) are angularly distributed with the first horizontal upper arm (1111) and the first horizontal lower arm (1121), respectively, and their widths increase gradually along the direction of the angle. The upper semi-elliptical metal patch layer (121) includes a second inclined upper arm (1211) and a third inclined upper arm (1212) symmetrically distributed along the extension direction of the second dielectric plate (5), and the inclination direction of the third inclined upper arm (1212) is parallel to the first inclined upper arm (1112). The lower semi-elliptical metal patch layer (122) includes a second inclined lower arm (1221) and a third inclined lower arm (1222) symmetrically distributed along the extension direction of the second dielectric plate (5), and the inclination direction of the second inclined lower arm (1221) is parallel to the first inclined lower arm (1122).

7. A miniaturized SIW horn antenna with wide bandwidth beamwidth according to claim 6, characterized in that: The second inclined upper arm (1211), the third inclined upper arm (1212), the second inclined lower arm (1221) and the third inclined lower arm (1222) each include four unit semi-elliptical metal patches (6), which are arranged in two rows in a distance of three and one respectively.

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