An ultra-wideband double-ridged horn antenna with ridge end loading

Abstract

The present application proposes an ultra-wideband double-ridge horn antenna with ridge end loading, which is composed of a rectangular open ridge waveguide, a symmetrical double-ridge structure, a terminal annular closed ring, a closed ring support and a coaxial feeding structure. The first end of the rectangular open ridge waveguide is closed and the second end has an opening; the outer ridge line of the symmetrical double-ridge structure is a straight line, and the inner ridge line is composed of two functional curves; the symmetrical double-ridge structure has ridge end loading; the terminal annular closed ring constructs an annular structure at the end of the ridge as the outermost opening of the horn antenna; the closed ring support is in the shape of an open support rod, which is installed on the open waveguide to support the terminal annular closed ring; the coaxial feeding structure is electrically connected to the double-ridge structure through a through hole on the side wall of the open waveguide. The present application improves the gain drop problem of the ultra-wideband double-ridge horn antenna caused by the cracking of the high-frequency radiation pattern, improves the gain stability of the antenna, and solves the problem of high low-frequency voltage standing wave ratio.

Description

Technical Field

[0001] The invention relates to an antenna, in particular to an ultra-wideband double-ridge horn antenna with ridge end loading. Background Art

[0002] With the rapid development of information technology, various information transmission technologies have emerged, which have a profound impact on social progress and people's lives. In the entire communication system, wireless communication systems occupy an important position due to their advantages such as low cost and mobility. With the increase in the number of users, the amount of information has increased sharply, and higher requirements have been placed on the resource allocation of wireless communication. In order to avoid communication interference caused by channel congestion, system broadbandization has become the most urgent issue in the development of wireless communication. Only by achieving system-level broadbandization can the data transmission rate be effectively and accurately improved, the integration of wireless communication services can be achieved on a large scale, and the requirements of modern wireless communication can be met in a real sense. To this end, technicians have developed various corresponding services. Ultra-Wide Band technology defines broadbandization by definition, and with its significant characteristics such as ultra-large spatial capacity, ultra-high transmission efficiency and ultra-low power loss, it has developed rapidly in a variety of short-distance high-speed wireless communication systems such as wireless local area networks (WLANs) and wireless personal networks (WPANs). The development of military communications tends to be broadband, integrated, digital and intelligent, so the application prospects of ultra-wideband communication technology in military communications are considerable. To date, ultra-wideband technology has also been deeply studied in civilian use and is widely used in radar, wireless communication systems, precise positioning, electronic countermeasures and other fields.

[0003] Ultra-wideband technology is mainly developing in the direction of narrow pulses, high directivity, high peak power and high repetition frequency. Traditionally, ultra-wideband antennas are defined as: the impedance characteristics and directional characteristics of the antenna can remain unchanged or slightly change within a very wide working frequency band, and the ratio of the highest working frequency to the lowest working frequency in this working frequency band is 10:1, or even greater. In recent years, ultra-wideband antennas have been widely used in electromagnetic compatibility (EMC) testing, ground penetrating radar, spread spectrum and broadband communications, and pulse radar. At the same time, ultra-wideband technology also involves medicine, such as for detecting human cancer cells, targeted medical robots, etc. These applications are of very practical and urgent significance. At the same time, there are still many problems to be solved in ultra-wideband antennas, including antenna structural design, bandwidth broadening, loss, etc. Among them, the double-ridged horn antenna, as the front end of the ultra-wideband communication system, needs to meet higher indicators, that is, it needs to ensure large bandwidth and high efficiency.

[0004] The ridge curve of a conventional double-ridged horn is generally an exponential function curve. This type of double-ridged horn will have a gain drop problem due to the cracking of the main lobe of the radiation pattern at high frequencies, i.e., 12GHz and above, and a high peak in the low-frequency voltage standing wave ratio. In order to meet the requirements of the double-ridged horn antenna to adapt to a wide frequency band, it is necessary to eliminate the gain drop problem due to the cracking of the main lobe of the radiation pattern in the high frequency band and the high peak in the low-frequency voltage standing wave ratio. Summary of the invention

[0005] The technical problem to be solved by the present application is to overcome the deficiencies in the above-mentioned prior art and to provide a double-ridged horn antenna with ridge end loading, which aims to improve the antenna bandwidth, avoid the gain drop problem caused by the cracking of the main lobe of the radiation pattern in the high frequency band and the problem of a high peak in the low-frequency voltage standing wave ratio.

[0006] In order to solve the above technical problems, the double-ridge horn curve with ridge end loading proposed in the present application includes a rectangular open ridge waveguide, a symmetrical double-ridge structure, a terminal annular closed loop, a closed loop support, and a coaxial feeding structure. The rectangular open ridge waveguide is a rectangular parallelepiped as a whole, with a closed first end and an opening at the second end; there are two symmetrical ridges in the middle of the rectangular open ridge waveguide, and a through hole with a step is opened on the side wall of the mounting ridge of the rectangular open ridge waveguide and the corresponding ridge, and the diameter of the first step of the through hole is greater than the diameter of the second step of the through hole. The symmetrical double-ridge structure includes two symmetrical ridge plates, the outer ridge line of each ridge plate is a straight line, and the inner ridge line is composed of two function curves, that is, the upper and lower sections of the inner ridge line are respectively composed of an exponential function curve and an elliptical function curve. There is a ridge end loading section on each of the two symmetrical ridge plates of the symmetrical double-ridge structure, and the shape of the ridge end loading is determined by a third-order Bessel function curve. The terminal annular closed loop constructs an annular structure at the end of the ridge as the outermost opening of the horn antenna. The closed loop support is in the shape of an open strut, which is installed on the rectangular open ridge waveguide to support the terminal annular closed loop. The coaxial feeding structure is electrically connected to another ridge board through a through hole on a side wall of a rectangular open ridge waveguide.

[0007] The above-mentioned ultra-wideband double-ridge horn antenna with ridge end loading integrates a symmetrical double-ridge structure, ridge end loading, an end annular closed loop, and a coaxial feeding structure on the basis of a rectangular ridge waveguide antenna, thereby avoiding the gain drop problem caused by the main lobe cracking of the high-frequency radiation pattern, thereby improving the gain stability within the antenna working frequency band, and at the same time avoiding the high peak of the low-frequency voltage standing wave ratio, thereby improving the working bandwidth of the antenna. Among them, the rectangular ridge waveguide can effectively reduce the main mode cutoff frequency of the waveguide, thereby achieving a longer working bandwidth than the waveguide of the same size. The ridge line in the symmetrical double-ridge structure is composed of two function curves: the section close to the rectangular open ridge waveguide adopts a traditional exponential function curve with a linear term, and the section connected to the annular closed loop adopts an elliptical function curve. On the one hand, such a ridge curve has the advantages of the traditional exponential function ridge curve to improve the bandwidth of the double-ridged horn antenna. On the other hand, the elliptical function curve connected to the annular closed circle has the characteristics of smooth changes and the highest point of the curve is higher than the mouth of the double-ridged horn, which makes the impedance matching effect better than the exponential function curve, thereby avoiding the gain drop problem caused by the main lobe cracking of the high-frequency radiation pattern, thereby improving the stability of the gain within the band. The two symmetrical ridge plates of the symmetrical double-ridge structure have a ridge end loading, and its shape is determined by the third-order Bessel function. The ridge end loading can effectively avoid the problem of spikes in the low-frequency voltage standing wave, thereby reducing the low-frequency voltage standing wave ratio. The stepped through hole on a ridge plate is used as the outer wall of the coaxial feeding structure for feeding, so that an impedance transformation section is added between the antenna and the 50-ohm coaxial line, which helps to improve the low-frequency electrical performance of the double-ridged horn antenna.

[0008] Furthermore, the ridge in the rectangular open ridge waveguide is stepped in the vertical direction, and the width of the ridge near the first end of the rectangular open ridge waveguide is smaller than the width of the ridge near the second end. This is beneficial to improving the low-frequency typical performance of the double-ridge horn antenna, while leaving operating space for welding the core wire of the coaxial feed structure and the ridge plate.

[0009] Furthermore, the length of the side wall of the rectangular open ridge waveguide with the ridge installed is greater than the length of the side wall without the ridge installed, which can prevent the distance between the symmetrical double ridge structures from being too large, thereby affecting the high frequency performance of the antenna.

[0010] Furthermore, the function expression of the inner ridge line of the symmetrical double-ridge structure close to the rectangular open waveguide on the YOZ plane is as follows:

[0011]

[0012] Among them, z is the z-axis coordinate of the point on the ridge line, and its value range is Wherein h1 is the height of the rectangular open ridge waveguide, h2 is the vertical distance from the opening end of the rectangular open ridge waveguide to the opening end of the horn, K1, K2, and K3 are parameters for determining the shape of the ridge line of this section. This is an exponential function with a linear term. Using this function curve in the part connected to the impedance transformation section is beneficial to maintaining the advantage of large bandwidth of the traditional double-ridged horn antenna.

[0013] Furthermore, the function expression of the inner ridge line of the symmetrical double ridge close to the end annular closed circle on the YOZ plane is as follows:

[0014]

[0015] Where φ is the angle swept by the inner ridge line in the YOZ plane, ranging from the angle between the outer ridge line and the Y axis φ1 to 180°, and the parameter a is defined by the following formula:

[0016]

[0017] in

[0018] The parameter b is defined by:

[0019]

[0020] Where φ1 is the angle between the outer ridge line and the Y axis. By adjusting the value of φ, the shape of the ridge curve can be adjusted, making the ridge curve change more gently at the opening of the double-ridge horn antenna, thereby avoiding the gain drop problem caused by the main lobe cracking of the high-frequency radiation pattern and improving the stability of the in-band gain.

[0021] Furthermore, both ridge plates of the symmetrical double-ridge structure have a ridge end loading section, whose shape is determined by a third-order Bessel function curve. The function expression of this curve on the YOZ plane is:

[0022] y=(1-α) 3 ×y1+3×α×(1-α) 2 ×y2+3×α 2 ×(1-t)×y3+α 3 ×y4

[0023] z=(1-α) 3 ×z1+3×h×(1-α) 2 ×z2+3×α 2 ×(1-t)×z3+α 3 ×z4

[0024] Among them, the value range of parameter α is 0<α<1, the starting point of the inner ridge line is point A, and the coordinates are (z1, y1); the end point of the inner ridge line is point D, and the coordinates are (z4, y4); two points B and C are selected on the inner ridge line, the coordinates of point B are (z2, y2), and the coordinates of point C are (z3, y3). The shape of the ridge end loading curve is adjusted by adjusting the position parameters of points B and C. Ridge end loading can effectively avoid the problem of spikes in low-frequency voltage standing waves, thereby reducing the low-frequency voltage standing wave ratio.

[0025] Furthermore, the top of the symmetrical double-ridge structure is higher than the annular closed circle at the end, which can increase the length of the ridge curve, making the impedance change at the opening of the double-ridge horn antenna more gentle, thereby improving the impedance matching of the double-ridge horn antenna.

[0026] Furthermore, the closed loop support is in the shape of an open support rod, which is installed at the upper end of the rectangular open ridge waveguide to support the terminal annular closed loop. This can suppress the high-order modes of the double-ridge horn antenna and improve its high-frequency electrical performance.

[0027] Furthermore, the side wall of the rectangular open ridge waveguide and the through hole on the ridge serve as the outer wall of the coaxial feeding structure, and the core wire of the coaxial feeding structure is formed by a metal needle extending from the RF connector. The connection between the ridge and the side wall of the rectangular open ridge waveguide is equivalent to grounding, and the metal needle is connected to another ridge for feeding.

[0028] Furthermore, the characteristic impedance of a section of the coaxial feeding structure close to the RF connector is 50 ohms, and the section close to the other ridge plate is an impedance transformation section, whose characteristic impedance is not 50 ohms. Adding an impedance transformation section to the coaxial feeding section can improve the impedance matching of the antenna and enhance the low-frequency electrical performance of the antenna.

[0029] The technical achievements of this application are reflected in the following aspects:

[0030] First, the inner ridge line of the symmetrical double-ridge structure is composed of two function curves, namely, the section connected to the rectangular open ridge waveguide adopts the traditional exponential function with linear terms, and the section connected to the annular closed circle adopts an elliptical function. The shape of the inner ridge line is changed by adjusting the parameters of the two functions in an associated manner, making the impedance transformation of the antenna smoother, thereby avoiding the gain drop problem caused by the cracking of the main lobe of the high-frequency radiation pattern and improving the stability of the in-band gain.

[0031] Second, both ridge plates of the symmetrical double-ridge structure have a ridge end loading section, whose shape is determined by the third-order Bessel function curve. By adjusting the parameters of the third-order Bessel function curve, the low-frequency impedance transformation is smoother, which can effectively avoid the problem of peaks in the low-frequency voltage standing wave ratio, thereby reducing the low-frequency voltage standing wave ratio of the antenna.

[0032] Third, the top of the symmetrical double-ridge structure is higher than the closed loop at the end, which can increase the length of the ridge curve, thereby making the impedance transformation at the opening of the double-ridge horn antenna smoother and improving the impedance matching of the double-ridge horn antenna.

[0033] Fourth, the closed loop support is in the shape of an open support rod, which can suppress the generation of high-order modes of the double-ridged horn antenna and improve the impedance matching at high frequencies.

[0034] Fifth, the characteristic impedance of the section of the coaxial feeding structure close to the RF connector is 50 ohms, and the section close to the other ridge plate is an impedance transformation section, whose characteristic impedance is not 50 ohms. Adding an impedance transformation section to the coaxial feeding section can improve the impedance matching of the antenna and enhance the low-frequency electrical performance of the antenna.

[0035] The simulation results show that the double-ridged horn antenna provided in the present application has a voltage standing wave ratio of less than 2 in the 0.8-16 GHz frequency band and a gain between 4 and 18 dBi, which avoids the gain drop problem caused by the main lobe splitting of the high-frequency radiation pattern and improves the stability of the in-band gain. At the same time, by increasing the ridge end loading, the problem of peaks in the low-frequency voltage standing wave ratio can be effectively avoided, thereby reducing the low-frequency voltage standing wave ratio. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic structural diagram of an ultra-wideband double-ridged horn antenna with ridge end loading according to the present invention;

[0037] Figure 1a It is a plan view of the ultra-wideband double-ridged horn antenna with ridge end loading in the YOZ plane of the present invention;

[0038] Figure 2 It is a schematic diagram of a separate structure of a rectangular open ridge waveguide with an ultra-wideband double-ridge horn antenna with ridge end loading according to the present invention;

[0039] Figure 3a It is a schematic diagram of a symmetrical double-ridge structure of an ultra-wideband double-ridge horn antenna with ridge end loading of the present invention;

[0040] Figure 3b It is a structural schematic diagram of a single ridge plate of an ultra-wideband double-ridge horn antenna with ridge end loading according to the present invention;

[0041] Figure 4 It is a schematic diagram of the end closing ring and the supporting structure of the ultra-wideband double-ridge horn antenna with ridge end loading of the present invention;

[0042] Figure 5 It is a schematic diagram of the coaxial feeding structure of the ultra-wideband double-ridged horn antenna with ridge end loading of the present invention;

[0043] Figure 6The voltage standing wave ratio curve of the ultra-wideband double-ridged horn antenna with ridge end loading and the voltage standing wave ratio curve of the horn antenna without ridge end loading of the present invention;

[0044] Figure 7 The frequency gain curve of the ultra-wideband double-ridged horn antenna with ridge end loading of the present invention;

[0045] Figure 8a This is a typical E-plane radiation pattern of the ultra-wideband double-ridged horn antenna with ridge end loading of the present invention.

[0046] Figure 8b 1 is a typical H-plane radiation pattern of the ultra-wideband double-ridged horn antenna with ridge end loading of the present invention.

[0047] Explanation of the reference numerals in the figure: 1 is a rectangular open ridge waveguide; 2 is a symmetrical double ridge structure; 3 is an end annular closed ring; 4 is a closed ring support; 5 is a coaxial feeding structure; 1-1 is the first end of the rectangular open ridge waveguide; 1-2 is the second end of the rectangular open ridge waveguide; 1-3 is the first ridge of the rectangular open ridge waveguide; 1-4 is the second ridge of the rectangular open ridge waveguide; 2-1 is the first ridge of the symmetrical double ridge structure; 2-2 is the second ridge of the symmetrical double ridge structure; 2-3 is the ridge end loading on the first ridge of the symmetrical double ridge structure; 2-4 is the ridge end loading on the second ridge of the symmetrical double ridge structure; 2-1-1 is the outer ridge line of the first ridge of the symmetrical double ridge structure; 2-1-2 is the outer ridge line of the first ridge of the symmetrical double ridge structure ; 2-2-1 is the outer ridge line of the second ridge of the symmetrical double-ridge structure; 2-2-2 is the inner ridge line of the second ridge of the symmetrical double-ridge structure; 2-1-2-1 is the portion defined by the exponential function on the curve transformation segment; 2-1-2-2 is the portion defined by the elliptic function on the curve transformation segment; 4-1 is the first support rod of the closed loop support; 4-2 is the second support rod of the closed loop support; 4-3 is the third support rod of the closed loop support; 4-4 is the fourth support rod of the closed loop support; 5-1 is the core wire of the coaxial feeding structure; 5-2 is the cavity of the coaxial feeding structure; 5-2-1 is the 50Ω segment of the coaxial feeding structure; 5-2-2 is the impedance transformation segment of the coaxial feeding structure. DETAILED DESCRIPTION

[0048] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific implementation described herein is only used to explain the present invention and is not intended to limit the present invention.

[0049] See also Figures 1 to 5 The present application provides an ultra-wideband double-ridge horn antenna with ridge end loading, including a rectangular open ridge waveguide 1, a symmetrical double-ridge structure 2, an end annular closed ring 3, a closed ring support 4 and a coaxial feeding structure 5.

[0050] The rectangular open ridge waveguide 1 is a rectangular waveguide structure as a whole, wherein the first end 1-1 thereof is closed and the second end 1-2 thereof has an opening, such as Figure 2 The long side wall of the rectangular open ridge waveguide 1 is provided with two symmetrical ridges 1-3 and 1-4, which are stepped in the vertical direction, and the width of the ridges near the first end 1-1 of the rectangular open ridge waveguide 1 is smaller than the width of the ridges near the second end 1-2, as shown in FIG. Figure 5 In this embodiment, the cavity height h1 of the rectangular open ridge waveguide 1 is 38 mm, the length of the cavity cross section is 68 mm, the width is 51 mm, the side wall thickness is 2 mm, the thickness of the stepped ridges 1-3 and 1-4 is 6.8 mm, the height of a section near the first end 1-1 is 14.5 mm, the width is 17.2 mm, and the height of a section near the second end 1-2 is 22.6 mm, and the width is 22.8 mm.

[0051] See also Figure 3a and Figure 3b The symmetrical double-ridge structure 2 includes two symmetrical ridge plates 2-1 and 2-2. Taking one of the ridge plates 2-1 as an example, it includes an outer ridge line 2-1-1 and an inner ridge line 2-1-2. Figure 3a The inner ridge line 2-1-2 consists of two segments, 2-1-2-1 and 2-1-2-2, of which the 2-1-2-1 segment is defined by an exponential function and the 2-1-2-2 segment is defined by an elliptic function. 2-3 is the ridge end loading, and its shape is defined by a third-order Bessel function.

[0052] Furthermore, the function expression of a section 2-1-2-1 of the inner ridge line close to the rectangular open ridge waveguide 1 on the YOZ plane is:

[0053]

[0054] Among them, z is the z-axis coordinate of the point on the inner ridge line 2-1-2, and the value range is h2 is the vertical distance from the opening end of the rectangular open ridge waveguide to the opening end of the horn, and K1, K2, and K3 are parameters for determining the shape of the ridge line. In this embodiment, h2 is 160 mm, l1 is 25 mm, K1 is 0.75, K2 is 0.0011, and K3 is 1*exp(-6).

[0055] Furthermore, the function expression of the section 2-1-2-2 of the inner ridge line close to the end annular closed circle 4 on the YOZ plane is:

[0056]

[0057] Where a is the angle swept by the curve in the YOZ plane, ranging from the angle between the outer ridge line 2-2-1 and the Y axis φ1 to 180°, and the parameter a is defined by the following formula:

[0058]

[0059] in

[0060] The parameter b is defined by:

[0061]

[0062] In this embodiment, φ1 is 76°. The shape of the ridge curve section can be adjusted by adjusting the φ value, so that the ridge curve changes more gently at the opening of the double-ridged horn antenna, thereby avoiding the gain drop problem caused by the cracking of the high-frequency radiation pattern.

[0063] Furthermore, the two ridge plates of the symmetrical double-ridge structure each have a ridge end loading 2-3, 2-4, whose shape is determined by a third-order Bessel function curve, and its function expression on the YOZ plane is:

[0064] y=(1-α) 3 ×y1+3×α×(1-α) 2 ×y2+3×α 2 ×(1-t)×y3+α 3 ×y4

[0065] z=(1-α) 3 ×z1+3×α×(1-α) 2 ×z2+3×α 2 ×(1-t)×z3+α 3 ×z4

[0066] The range of parameter α is 0<α<1. The starting point of the inner ridge line is point A, with coordinates (y1, z1); the end point of the inner ridge line is point D, with coordinates (y4, z4); two points B and C are selected on the inner ridge line, with the coordinates of point B being (y2, z2) and point C being (y3, z3). In this embodiment, the coordinates of point A are (0, 0.68), the coordinates of point B are (10, 20), the coordinates of point C are (45, 166), and the coordinates of point D are (66.7, 155.5). At the same time, the thickness of the ridge end is 3 mm. Figure 3b Ridge-end loading can make the low-frequency impedance transformation of the antenna smoother, thereby avoiding the problem of high peaks in the low-frequency voltage standing wave ratio and reducing the low-frequency voltage standing wave ratio.

[0067] For further information, see Figure 1a The top of the symmetrical double-ridge structure 2 is higher than the end closed circle 3, which can increase the length of the ridge curve, making the impedance change at the opening of the double-ridge horn antenna smoother, thereby improving the impedance matching of the double-ridge horn antenna.

[0068] For further information, see Figure 4 The closed loop support 4 is in the shape of an open support rod, and is composed of four open support rods 4-1, 4-2, 4-3, and 4-4. It is installed at the upper end of the rectangular open ridge waveguide 1 to support the terminal annular closed loop, which can suppress the high-order modes of the double-ridge horn antenna and improve its high-frequency electrical performance.

[0069] For further information, see Figure 5 The side wall of the rectangular open ridge waveguide 1 and the stepped through hole 5-2 on the ridge 1-3 are the outer wall of the coaxial feeding structure 5, and 5-1 is the core wire of the coaxial feeding structure 5. A section of the coaxial feeding structure 5 close to the RF connector is a 50Ω section 5-2-1, and a section close to another ridge plate is an impedance transformation section 5-2-2. Adding the impedance transformation section 5-2-2 can improve the impedance matching of the antenna and enhance the low-frequency electrical performance of the antenna.

[0070] See also Figure 6 This is the voltage standing wave ratio curve of the double-ridged horn antenna. The working frequency band of the embodiment of the present application is 0.8 GHz to 16 GHz. In this frequency band, the voltage standing wave ratio of the antenna is less than 2, and the relative working bandwidth of the antenna is 1:20. Compared with the antenna without ridge end loading, the voltage standing wave ratio of the low frequency 0.8-1.5 GHz of the antenna with ridge end loading is significantly improved.

[0071] See also Figure 7 , This is the frequency-gain curve of the double-ridged horn antenna. The working frequency band of the embodiment of the present application is 0.8GHz to 16GHz. In this frequency band, the minimum gain of the antenna is 4dBi, and the maximum gain of the antenna is 18dBi. The gain changes smoothly in the entire frequency band, and there is no gain drop problem caused by the cracking of the high-frequency radiation pattern.

[0072] See also Figure 8a , This is a typical E-plane radiation pattern of the double-ridged horn antenna. This is the E-plane radiation pattern of the embodiment of the present application at 0.8 GHz, 8 GHz and 16 GHz, and the radiation pattern has no cracks.

[0073] See also Figure 8b , This is a typical H-plane radiation pattern of a double-ridged horn antenna. This is an H-plane radiation pattern of an embodiment of the present application at 0.8 GHz, 8 GHz and 16 GHz, and the radiation pattern has no cracks.

[0074] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should all be included in the protection scope of the present application.

Claims

1. An ultra-wideband double-ridged horn antenna with ridge end loading, characterized in that: It includes a rectangular open ridge waveguide, a symmetrical double ridge structure, an end annular closed ring, a closed ring support and a coaxial feeding structure; The rectangular open ridge waveguide is in the shape of a rectangular parallelepiped as a whole, with a first end closed and a second end having an opening; there are two symmetrical ridges in the middle of the rectangular open ridge waveguide, and a through hole with steps is opened on the side wall of the mounting ridge of the rectangular open ridge waveguide and the corresponding ridge, and the diameter of the first step of the through hole on the ridge is greater than the diameter of the second step of the through hole on the ridge, wherein the first step is the part of the through hole close to the side wall of the mounting ridge, and the second step is the part of the through hole away from the side wall of the mounting ridge; The symmetrical double-ridge structure includes two symmetrical ridge plates, the outer ridge line of each ridge plate is a straight line, the inner ridge line is a ridge curve composed of two functions, the section connected to the rectangular open ridge waveguide is an exponential function with a linear term, and the section connected to the end annular closed circle is an elliptical function; The two symmetrical ridge plates of the symmetrical double-ridge structure each have a ridge end loading, and the shape of the ridge end loading is determined by a third-order Bessel function curve; The terminal annular closed ring forms an annular structure at the end of the ridge, serving as the outermost opening of the horn antenna; The closed ring support is in the shape of an open support rod, and is installed on the rectangular open ridge waveguide to support the end annular closed ring; The coaxial feeding structure is electrically connected to another ridge board through the stepped through holes on the side walls of the rectangular open ridge waveguide. The side walls of the rectangular open ridge waveguide and the through holes on the ridge serve as the outer walls of the coaxial feeding structure. The core wire of the coaxial feeding structure is composed of metal needles extending from the RF connector.

2. The ultra-wideband double-ridged horn antenna with ridge end loading according to claim 1, characterized in that: The ridge in the rectangular open ridge waveguide is stepped in the vertical direction, and the width of the ridge near the first end of the rectangular open ridge waveguide is smaller than the width of the ridge near the second end.

3. The ultra-wideband double-ridged horn antenna with ridge end loading according to claim 1, characterized in that: The length of the rectangular open ridge waveguide cavity cross section is greater than the width of the cavity cross section, wherein the rectangular open ridge waveguide cavity cross section refers to the cross section perpendicular to the opening direction of the ridge waveguide cavity, and the dimension of the rectangular open ridge waveguide cavity cross section perpendicular to the coaxial feeding structure is the length, and the dimension parallel to the coaxial feeding structure is the width.

4. The ultra-wideband double-ridged horn antenna with ridge end loading according to claim 1, characterized in that: The curve change section of the inner ridge line of the symmetrical double ridge close to the rectangular open waveguide is an exponential function curve, and its function expression in the YOZ section of the spatial rectangular coordinate system is: and=K1e K2z +K3z Among them, z is the z-axis coordinate of the point on the ridge line, and its value range is Wherein h1 is the height of the rectangular open ridge waveguide, h2 is the vertical distance from the opening end of the rectangular open ridge waveguide to the opening end of the horn, and K1, K2, and K3 are parameters for determining the shape of the ridge line.

5. The ultra-wideband double-ridged horn antenna with ridge end loading according to claim 1, characterized in that: Both ridge plates of the symmetrical double-ridge structure have a ridge end loading section, whose shape is determined by the third-order Bessel function. The function expression of this curve on the YOZ plane is: y=(1-a) 3 ×y1+3×α×(1-α) 2 ×y2+3×α 2 ×(1-t)×y3+α 3 ×y4 z=(1-a) 3 ×z1+3×α×(1-α) 2 ×z2+3×α 2 ×(1-t)×z3+α 3 ×z4 Among them, the value range of parameter α is 0<α<1, the starting point of the curve change segment of the inner ridge line is point A, and the coordinates are (y1, z1); the end point of the inner ridge line is point D, and the coordinates are (y4, z4); then two points B and C are selected in the YOZ plane, the coordinates of point B are (y2, z2), and the coordinates of point C are (y3, z3), and the shape of the ridge end loading is adjusted by adjusting the position parameters of points B and C.

6. The ultra-wideband double-ridged horn antenna with ridge end loading according to claim 1, characterized in that: The top of the symmetrical double-ridge structure is higher than the end annular closed circle.

7. The ultra-wideband double-ridged horn antenna with ridge end loading according to claim 1, characterized in that: The characteristic impedance of a section of the coaxial feeding structure close to the radio frequency connector is 50 ohms, and the section close to the other spine plate is an impedance transformation section, and its characteristic impedance is not 50 ohms.

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