A double-ridged horn antenna

Abstract

The present invention proposes a double-ridged horn antenna, comprising a feeding waveguide; a horn outer wall, which is two parallel pairs of outer walls, and forms an open waveguide structure with the feeding waveguide; a double-ridged horn, comprising a horn upper ridge and a horn lower ridge, wherein the horn upper ridge and the horn lower ridge are respectively fixed on the inner walls of the two opposite sides of the horn outer wall and connected to the feeding waveguide; a feeding probe, one end of which is inserted into a through hole reserved for the feeding waveguide and connected to the feeding waveguide, and matched with the impedance of the feeding waveguide. The double-ridged horn antenna proposed by the present invention can change the cutoff frequency and out-of-band suppression of the double-ridged horn antenna by adjusting the size of the horn outer wall, so as to meet different out-of-band suppression requirements.

Description

Technical Field

[0001] The present invention relates to the field of antenna technology, and in particular to a double-ridged horn antenna. Background Art

[0002] Under information conditions, large weapon combat platforms are densely loaded with electronic equipment and have an extremely wide electromagnetic spectrum, making the electromagnetic environment complex and the electromagnetic compatibility problem prominent. Especially for radars with similar frequencies, the spatial coupling between radars is strong, and coupling interference will occur between them, resulting in radar performance degradation or even malfunction. In order to solve the electromagnetic compatibility problem between radar systems, the phased array radar antenna is required to have strong out-of-band suppression characteristics while ensuring wide-band operation.

[0003] According to the analysis of the transmission mechanism of the radar receiving state, the methods of suppressing out-of-band interference can be summarized into two categories: one is to add a filter or filtering circuit at the back end of the antenna to directly filter out the out-band interference signal; the other is to add a frequency selection structure at the front end of the antenna and use the spatial filtering characteristics of the frequency selection structure to filter out the out-band interference signal.

[0004] The double-ridged horn antenna is widely used in the design of phased array radar antennas because it has the advantages of smaller size, wider impedance bandwidth, higher gain and more stable directivity than ordinary horn antennas in the same frequency band. However, because it does not have filtering function, it is easy to interfere with other radars with similar frequencies to the combat platform.

[0005] According to the above method of suppressing out-of-band interference, the double-ridged horn antenna can achieve filtering function through the following three technical approaches:

[0006] Method 1: Add a cavity filter to the feeder line between the antenna and the T / R component. The antenna is connected to the input port of the cavity filter, and the output port of the cavity filter is connected to the T / R component. When an out-of-band interference signal passes through the antenna, it is first filtered out by the cavity filter and then enters the front end of the T / R component to ensure that the radar is not interfered by the out-of-band signal.

[0007] Method 2: Integrate an LC filter circuit when designing the low-noise amplifier chip of the T / R component. Place the LC filter circuit before the low-noise amplifier. When an out-of-band interference signal enters the front end of the T / R component through the antenna, a certain suppression effect can be achieved.

[0008] Method 3: Use a frequency-selective radome instead of a conventional radome. Through special design of the frequency-selective radome, good wave transmission characteristics for signals within the working band can be achieved, while it has a strong suppression effect on out-of-band interference signals.

[0009] Method 1 is to add a cavity filter to the feeder line between the antenna and the T / R assembly. However, due to the large size of the cavity filter, the double-ridged horn antenna will lose its small size advantage.

[0010] The second method is to integrate the LC filter circuit when designing the low-noise amplifier chip of the T / R component, which will introduce a large insertion loss. In addition, since the low-noise amplifier chip adopts the GaAs process, the filter out-of-band suppression capability under this process is very limited. In addition, whether it is a cavity filter or an LC filter circuit, on the one hand, it will cause the noise coefficient to deteriorate. On the other hand, for large active phased arrays with hundreds, thousands or even tens of thousands of antenna units, it will cause a significant increase in the development cost of the phased array.

[0011] When method three is used, a frequency-selective radome is used instead of a conventional radome. The antenna loss will increase dramatically during wide-angle scanning, which will cause the antenna array scanning performance to deteriorate, the wide-angle scanning capability of the phased array to be weakened, and the advantage of the phased array in large-angle scanning will be lost.

[0012] It can be seen that in the prior art, the double-ridged horn antenna itself does not have a filtering function, and if an external component is used in the existing manner to enable it to have a filtering function, it will bring more technical problems. Summary of the invention

[0013] The technical problem to be solved by the present invention is that the current double-ridged horn antenna itself does not have a filtering function. In view of this, the present invention provides a double-ridged horn antenna that can achieve a filtering function.

[0014] The technical solution adopted by the present invention is that the double-ridged horn antenna includes: a feeding waveguide; a horn outer wall, which is two parallel outer walls and forms an open waveguide structure with the feeding waveguide; a double-ridged horn, including a horn upper ridge and a horn lower ridge, the horn upper ridge and the horn lower ridge are respectively fixed on the inner walls of two opposite sides of the horn outer wall, and connected to the feeding waveguide; a feeding probe, one end of which is inserted into a through hole reserved in the feeding waveguide and connected to the feeding waveguide, and matches the impedance of the feeding waveguide.

[0015] In one embodiment, the outer wall of the speaker includes two relatively parallel wide sides and two narrow sides, wherein the thickness of the wide sides is greater than the thickness of the narrow sides; the upper ridge of the speaker and the lower ridge of the speaker are respectively fixed on the inner walls of the two wide sides.

[0016] In one embodiment, the feeding waveguide and the double-ridge antenna have the same length in a direction parallel to the broadside.

[0017] In one embodiment, the feeding waveguide includes: a waveguide upper ridge, connected to the horn upper ridge; a waveguide lower ridge, connected to the horn lower ridge and having a gap between the waveguide upper ridge and the waveguide lower ridge; a short-circuit plate; arranged on the waveguide upper ridge and on a side of the waveguide lower ridge away from the double-ridge antenna, having a gap between the waveguide lower ridge and the waveguide lower ridge, and having a through hole corresponding to the waveguide lower ridge.

[0018] In one embodiment, the feeding probe includes: an inner conductor, an outer conductor and an insulating layer; the outer conductor is surrounded by a portion of the inner conductor and connected to the short-circuit plate; another portion of the inner conductor without the outer conductor is surrounded by the insulating layer, the inner conductor and the insulating layer pass through the short-circuit plate through the through hole and are inserted into the waveguide lower ridge, and the inner conductor is not connected to the waveguide lower ridge.

[0019] In one embodiment, the upper speaker ridge and the lower speaker ridge are asymmetrical structures.

[0020] In one embodiment, the upper horn ridge includes a four-step structure, and the lower horn ridge includes a two-step structure.

[0021] In one embodiment, the feeding probe is a coaxial probe with an impedance of 50Ω.

[0022] In one embodiment, the material used for the double-ridged horn and the horn outer wall includes aluminum.

[0023] In one embodiment, the operating frequency band of the double-ridged horn antenna is Ku band.

[0024] By adopting the above technical solution, the present invention has at least the following advantages:

[0025] The double-ridged horn antenna of the present invention integrates the radiation function and the filtering function, realizing a highly integrated, miniaturized, and low-loss design. By designing the relevant parameters of the feed waveguide and the double-ridged horn, the operating frequency band can be adjusted and the radiation characteristics can be changed; by adjusting the height and wide side size of the horn outer wall, different out-of-band suppression requirements can be met. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic diagram of the structure of a double-ridged horn antenna according to an embodiment of the present invention;

[0027] Figure 2 is a schematic diagram of the cross-sectional structure of a double-ridged horn antenna according to an embodiment of the present invention;

[0028] Figure 3 is a schematic diagram of a cross-sectional structure of another double-ridged horn antenna according to an embodiment of the present invention;

[0029] Figure 4 is a schematic diagram of the bottom cross-sectional structure of a double-ridged horn antenna according to an embodiment of the present invention;

[0030] Figure 5 It is a schematic diagram of the voltage standing wave ratio simulation result of the double-ridged horn antenna according to an embodiment of the present invention;

[0031] Figure 6 It is a schematic diagram of the transmission coefficient simulation results of the double-ridged horn antenna according to an embodiment of the present invention;

[0032] Figure 7 It is a schematic diagram of the simulation results of the E-plane (Phi=90) / H-plane (Phi=0) radiation pattern of the double-ridged horn antenna of an embodiment of the present invention at a low frequency;

[0033] Figure 8 It is a schematic diagram of the simulation results of the E-plane (Phi=90) / H-plane (Phi=0) radiation pattern of the double-ridged horn antenna of an embodiment of the present invention at the mid-frequency point;

[0034] Fig. 9 It is a schematic diagram of the simulation results of the E-plane (Phi=90) / H-plane (Phi=0) radiation pattern of the double-ridged horn antenna of an embodiment of the present invention at high frequencies.

[0035] Reference numerals:

[0036] Feeding probe 1, inner conductor 11, outer conductor 12, insulating layer 13;

[0037] Feed waveguide 2, waveguide upper ridge 21, waveguide lower ridge 22, short-circuit plate 23;

[0038] Double-ridged speaker 3, upper speaker ridge 31, lower speaker ridge 32;

[0039] Speaker outer wall 4. DETAILED DESCRIPTION

[0040] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined purpose, the present invention is described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0041] The first embodiment of the present invention introduces a double-ridged horn antenna. Figure 1 As shown, the apparatus comprises the following components: a feeding probe 1, a feeding waveguide 2, a double-ridged horn 3, and a horn outer wall 4.

[0042] In this embodiment, the operating frequency band of the double-ridged horn antenna may be the Ku band.

[0043] In this embodiment, the speaker outer wall 4 has two pairs of solid metal wall structures that are parallel to each other and have a certain thickness, and the cross section is rectangular. Further, the material of the speaker outer wall 4 can be aluminum; the thickness of the speaker outer wall 4 can be different, specifically, it has two parallel wide sides and two parallel narrow sides, wherein the thickness of the wide side is greater than that of the narrow side, and the thickness of the two wide sides can usually be the same, and similarly, the thickness of the two narrow sides can usually be the same.

[0044] In this embodiment, the double-ridge speaker 3 is arranged on the inner walls of the two wide sides of the speaker outer wall 4. Specifically, the double-ridge speaker 3 includes an upper speaker ridge 31 and a lower speaker ridge 32, which are respectively arranged on the inner walls of the two wide sides of the speaker outer wall 4.

[0045] In this embodiment, the feeding waveguide 2 and the double-ridged horn 3 have the same length in a direction parallel to the wide side and are connected to each other. Specifically, the feeding waveguide 2 includes a waveguide upper ridge 21 and a waveguide lower ridge 22. The waveguide upper ridge 21 is connected to the horn upper ridge 31 of the double-ridged horn 3, and the waveguide lower ridge 22 is connected to the horn lower ridge 32. Further, the feeding waveguide 2 also includes a short-circuit plate 23, which is arranged on a side of the waveguide upper ridge 21 and the waveguide lower ridge 22 away from the double-ridged horn 3, with a gap between the waveguide lower ridge 22 and the waveguide lower ridge 22, and has a through hole corresponding to the waveguide lower ridge 22.

[0046] In this embodiment, the horn outer wall 4 and the feeding waveguide 2 form an open waveguide structure, that is, the structure formed by the horn outer wall 3 and the feeding waveguide 2 is a hollow structure, so that the double-ridged horn antenna adds a filtering function with a low-frequency cutoff characteristic to the original radiation function. The out-of-band suppression degree can be changed by adjusting the height of the horn outer wall 4; the length of the inner wall of the wide side of the horn outer wall 4 (i.e. Figure 4 By adjusting the length a) in the figure, the cutoff frequency of the double-ridged horn antenna can be changed to meet different out-of-band suppression requirements.

[0047] In this embodiment, the feeding probe 1 can be a coaxial probe with an impedance of 50Ω, and can include: an inner conductor 11, an outer conductor 12 and an insulating layer 13; the outer conductor 12 surrounds a portion of the inner conductor 11 and is connected to a short-circuit plate 23; another portion of the inner conductor 11 without the outer conductor 12 is surrounded by an insulating layer 13, the inner conductor 11 and the insulating layer 13 pass through the short-circuit plate 23 through a through hole and are inserted into the waveguide lower ridge 22, and the inner conductor 11 is not connected to the waveguide lower ridge 22.

[0048] In this embodiment, the dual-ridged speaker 3 can be an asymmetric structure and can be implemented with stepped steps. For example, the upper ridge of the speaker can have a 4-step structure, and the lower ridge of the speaker can have a 2-step structure. The height of each step and the number of steps can be designed independently. Through the asymmetric structural design as described above, the working bandwidth of the dual-ridged speaker 3 can be broadened.

[0049] The second embodiment of the present invention is based on the above embodiment and combined with the attached Figures 1 to 9 An application example of the present invention is introduced.

[0050] In this embodiment, the operating frequency band of the double-ridged horn antenna is the Ku band. Figure 1 As shown, it includes a feeding probe 1, a feeding waveguide 2, a double-ridged horn 3 and a horn outer wall 4. The two pairs of horn outer walls 4 of the double-ridged horn antenna are parallel to each other and form an open waveguide structure with the feeding waveguide 2. The double-ridged horn 3 is fixed on the inner side of the two wide sides of the horn outer wall 4. The inner conductor 11 of the feeding probe 1 is wrapped with an insulating layer 13, passes through the through hole reserved in the feeding waveguide 2, and is coupled and fed to the double-ridged horn 3. The feeding waveguide 2, the double-ridged horn and the horn outer wall 4 are all made of aluminum plates. The overall size of the antenna is 14.5mm×14.5mm×35mm (x×y×z, where x is the direction parallel to the wide side, y is the direction perpendicular to the wide side, and z is the height direction of the double-ridged horn antenna).

[0051] refer to Figures 2 to 4 . In this embodiment, the characteristic impedance of the feeding probe 1 is 50Ω, the diameter of the inner conductor 11 is r11, the diameter of the outer conductor 13 is r13, the diameter of the insulating dielectric sleeve 12 is r12, the material can be polytetrafluoroethylene, and the dielectric constant can be 2.1. The feeding waveguide 2 is a double-ridged waveguide, comprising a waveguide upper ridge 21, a waveguide lower ridge 22 and a short-circuit plate 23. The double-ridged horn 3 is divided into a horn upper ridge 31 and a horn lower ridge 32, wherein the horn upper ridge 31 is composed of four steps, and the horn lower ridge 32 is composed of two steps. The ridge width of the feeding waveguide 2 and the double-ridged horn 3 is w3. The inner cross-sectional size of the horn outer wall 4 is a×b. In this embodiment, the dimensions of each structure are marked as shown in Figure 3 and Figure 4 The optimized structural parameters are given in Table 1.

[0052] Table 1 Antenna structural parameters (unit: mm)

[0053] variable l211 l212 l22 l311 l312 l313 l314 l321 Numeric 3.84 4.15 4.2 4.75 2.47 2.07 0.86 2.45 variable h211 h23 h22 h311 h312 h313 h314 h321 Numeric 0.4 1.4 2.2 2.3 3.2 3.2 2.8 5.5 variable l322 h322 w3 r11 r12 r13 a b Numeric 0.75 6 3.34 0.38 0.8 1.3 13.3 9.5

[0054] refer to Figure 5 , Figure 5 The voltage standing wave ratio simulation result of the double-ridged horn antenna provided by the present invention is shown in FIG. Figure 5It can be seen from the figure that the voltage standing wave ratio of the double-ridged horn antenna of the present invention is less than 2 in the entire working frequency band, indicating that the present invention has good broadband impedance matching characteristics.

[0055] refer to Figure 6 , Figure 6 The transmission coefficient simulation results of the double-ridged horn antenna provided by the present invention are as follows. Figure 6 It can be seen that the in-band loss of the double-ridged horn antenna provided by the present invention is less than 0.5 dB, the suppression at 1 GHz out of the band is 11 dB, and the suppression at 2 GHz out of the band is 20 dB.

[0056] Figures 7 to 9 The simulation results of the E-plane (Phi=90) / H-plane (Phi=0) radiation pattern of the double-ridged horn antenna provided by the present invention at low, medium and high frequencies. It can be seen from the figure that the radiation pattern of the double-ridged horn antenna provided by the present invention is stable in the entire working frequency band, and there is no problem of lobed radiation pattern.

[0057] Compared with the prior art, the present invention has at least the following advantages:

[0058] 1) The present invention integrates the radiation function and the filtering function into one, achieving a highly integrated, miniaturized, and low-loss design. By designing the relevant parameters of the feeding waveguide and the double-ridged horn, the operating frequency band can be adjusted and the radiation characteristics can be changed; by adjusting the height and wide side size of the horn outer wall, different out-of-band suppression requirements can be met. The radiation function and the filtering function are integrated into the antenna to achieve a highly integrated design; no additional cavity filter is introduced to achieve a miniaturized design; no additional filtering circuit is introduced or a frequency-selective antenna cover is designed to achieve a low-loss design.

[0059] 2) The present invention adopts an integrated processing method to achieve low-cost design. The broadband double-ridged horn antenna with filtering function designed by the present invention adopts the existing mature high-precision machining processes such as electric spark and wire cutting for integrated processing. The processing technology is conventional and does not add additional complex processes. Compared with adding filters or filtering circuits or frequency-selective antenna covers, it is conducive to reducing costs.

[0060] Through the description of the specific implementation methods, a deeper and more specific understanding of the technical means and effects adopted by the present invention to achieve the predetermined purpose should be obtained. However, the accompanying drawings are only for reference and illustration purposes and are not intended to limit the present invention.

Claims

1. A double-ridged horn antenna, characterized in that: include: Feed waveguide; The outer walls of the horn are two parallel outer walls, which together with the feeding waveguide form an open waveguide structure; A double-ridged horn, comprising an upper horn ridge and a lower horn ridge, wherein the upper horn ridge and the lower horn ridge are respectively fixed to inner walls of two opposite sides of the outer wall of the horn and connected to the feeding waveguide; A feeding probe, one end of which is inserted into a through hole reserved in the feeding waveguide and connected to the feeding waveguide, and matched with the impedance of the feeding waveguide; Wherein, the outer wall of the speaker includes two relatively parallel wide sides and two narrow sides, wherein the thickness of the wide sides is greater than the thickness of the narrow sides; The upper ridge of the speaker and the lower ridge of the speaker are respectively fixed on the inner walls of the two wide sides; The structure formed by the outer wall of the horn and the feeding waveguide is a hollow structure, so that the double-ridged horn antenna adds a filtering function with a low-frequency cutoff characteristic to the original radiation function; Among them, methods to meet different out-of-band suppression requirements include: By adjusting the height of the speaker outer wall, different out-of-band suppression requirements can be met; or, By adjusting the length of the inner wall of the wide side of the outer wall of the horn, the cutoff frequency of the double-ridged horn antenna is changed to meet different out-of-band suppression requirements.

2. The double-ridged horn antenna according to claim 1, characterized in that: The feeding waveguide and the double-ridged horn have the same length in a direction parallel to the wide side.

3. The double-ridged horn antenna according to claim 1, characterized in that: The feeding waveguide comprises: A waveguide upper ridge connected to the horn upper ridge; A waveguide lower ridge is connected to the horn lower ridge and has a gap with the waveguide upper ridge; A short-circuit plate is arranged on the waveguide upper ridge and the side of the waveguide lower ridge away from the double-ridge horn, with a gap between the waveguide lower ridge and the short-circuit plate, and a through hole correspondingly connected to the waveguide lower ridge is provided on the short-circuit plate.

4. The double-ridged horn antenna according to claim 3, characterized in that: The feeding probe comprises: an inner conductor, an outer conductor and an insulating layer; The outer conductor surrounds a portion of the inner conductor and is connected to the short-circuit plate; The inner conductor is surrounded by the insulating layer without another part of the outer conductor on the outside, the inner conductor and the insulating layer pass through the short-circuit plate through the through hole and are inserted into the waveguide lower ridge, and the inner conductor is not connected to the waveguide lower ridge.

5. The double-ridged horn antenna according to claim 1, characterized in that: The upper speaker ridge and the lower speaker ridge are asymmetrical structures.

6. The double-ridged horn antenna according to claim 5, characterized in that: The upper ridge of the speaker includes a four-step structure, and the lower ridge of the speaker includes a two-step structure.

7. The double-ridged horn antenna according to claim 1, characterized in that: The feeding probe is a coaxial probe with an impedance of 50Ω.

8. The double-ridged horn antenna according to claim 1, characterized in that: The material used for the double-ridge speaker and the outer wall of the speaker includes aluminum.

9. The double-ridged horn antenna according to claim 1, characterized in that: The operating frequency band of the double-ridged horn antenna is the Ku band.

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