CN108270077B - Waveguide slot array anti-jamming antenna - Google Patents

Abstract

The invention provides a waveguide slot array anti-jamming antenna, comprising a metal waveguide (1) and a metal diaphragm, the metal waveguide (1) is provided with a cavity, and the inner space of the cavity forms a storage space, The metal diaphragm is installed in the storage space; a plurality of metal diaphragms are arranged sequentially along the extending direction of the metal waveguide (1), and the plurality of metal diaphragms include a first metal diaphragm (2) and a second metal diaphragm ( 3), the first metal diaphragm (2) and the second metal diaphragm (3) are arranged in sequence; the metal waveguide (1) is provided with a radiation gap, and the internal space of the radiation gap communicates with the storage space. The invention integrates the filtering characteristics of the waveguide slow-wave structure into the waveguide slot array antenna, so that it has good radiation characteristics in the working frequency band and adjacent high-frequency interference suppression characteristics on the basis of almost unchanged space volume, without additional equipment, and reduces System anti-jamming design is difficult, reducing the amount of equipment required.

Description

Waveguide slot array anti-jamming antenna

technical field

The invention relates to the field of microwave technology, in particular to a waveguide slot array anti-jamming antenna, in particular to a waveguide slot array anti-jamming antenna loaded with a capacitive diaphragm.

Background technique

With the continuous development of wireless communication technology, the electromagnetic spectrum has been fully utilized and greatly expanded, but it has also become increasingly tense and crowded. Today, there are more and more electronic devices working at various frequencies, and electromagnetic interference in different frequency bands is ubiquitous; and on narrow platforms such as vehicles, ships, airplanes and satellites, the mutual interference of various electronic devices is particularly serious. Typical The best example is the receiving antenna of a small platform in satellite communication, which is severely interfered by the transmitting antenna. Therefore, electromagnetic compatibility issues such as interference and anti-interference need to be considered when designing electronic systems.

To solve the problem of electromagnetic compatibility between electronic systems, the common method is to add filters. This method is simple and effective, but it leads to an increase in the amount of equipment in the system. Especially in some large phased array antennas, a large number of filters are required Filter thousands of antennas. In addition, the additional filter increases the feeder loss, which has a great influence on the system index.

The frequency-selective broadband waveguide slot antenna array provided by the patent document CN10557040B adopts the idea of integrating the waveguide filter and the antenna feed waveguide, and introduces the filtering function into the feed power divider, so that the antenna has the ability to work with frequency selectivity. However, in this invention, the antenna and the filter are still physically independent, and the two occupy different spaces, and the antenna itself does not have good filtering performance. At the same time, this method is only applicable to the slot waveguide antenna with the straight waveguide section of the waveguide power divider. For the single-layer waveguide slot antenna without the straight waveguide section of the waveguide power divider, there is no room for an integrated filter.

The patent document CN107146943A provides a slotted metamaterial waveguide slot antenna and its design method, which proposes a method of integrated design of filtering structure and antenna space, and can achieve interference suppression for specified frequency bands. However, this method arranges a large number of metal columns at the bottom of the metal waveguide, which significantly increases the actual weight of the antenna and limits the large-scale array formation capability of the antenna. At the same time, due to the dense arrangement of metal columns, the difficulty and complexity of processing are increased.

Contents of the invention

Aiming at the defects in the prior art, the object of the present invention is to provide a waveguide slot array anti-jamming antenna.

The waveguide slot array anti-jamming antenna provided according to the present invention includes a metal waveguide and a metal diaphragm, the metal waveguide is provided with a cavity, the inner space of the cavity forms a storage space, and the metal diaphragm is installed in the container. in space;

A plurality of metal diaphragms are arranged in sequence along the extending direction of the metal waveguide, the plurality of metal diaphragms include a first metal diaphragm and a second metal diaphragm, and the first metal diaphragm and the second metal diaphragm are arranged in sequence;

A radiation slot is arranged on the metal waveguide, and the internal space of the radiation slot communicates with the storage space.

Preferably, the end faces at both ends of the metal waveguide along the extending direction of the length respectively form a first end face and a second end face;

The cavity runs through the first end face, and the opening of the cavity on the first end face forms a signal input port; the second end face is provided with a metal wall.

Preferably, the cross-sectional shape of the metal diaphragm is rectangular, the metal diaphragm is fastened on the lower wall of the cavity, and the two ends of the metal diaphragm along the length extension direction are respectively connected to the two ends of the cavity along the width extension direction. connected.

Preferably, a plurality of first metal diaphragms are included, and the thickness and height of the plurality of first metal diaphragms are equal.

Preferably, the thickness of the first metal diaphragm is equal to that of the second metal diaphragm, and the height of the second metal diaphragm is not higher than the height of the first metal diaphragm;

The second metal diaphragm is located on the side where the signal input port is located.

Preferably, the plurality of metal diaphragms are arranged equidistantly along the extending direction of the metal waveguide.

Preferably, the metal waveguide is a tube with a rectangular section, and the radiation slot is opened on the upper end surface of the metal waveguide;

Preferably, a plurality of said radiation slots are arranged staggered in the extending direction of the length of the metal waveguide;

Along the width direction of the metal waveguide, the distances from the longitudinal centerlines of the plurality of radiation slots to the longitudinal centerline of the metal waveguide are equal.

Preferably, the cross-sectional shape of the cavity is rectangular, and the cavity with a rectangular cross-section is 19.05mm long and 9.525mm wide; the upper wall of the four walls of the cavity along the circumferential direction is 1.27mm thick, and the other three walls are 2mm thick ; Metal wall thickness 2mm.

Preferably, the thickness of the metal diaphragm is 0.5 mm, the center-to-center distance between two adjacent metal diaphragms is 9.7 mm, and the height of the metal diaphragm is 3.7 mm.

Compared with the prior art, the present invention has the following beneficial effects:

1. The present invention incorporates the filtering characteristics of the waveguide slow-wave structure into the waveguide slot array antenna through the fusion design of the traditional waveguide slot array antenna and the frequency-selective waveguide slow-wave structure loaded by the capacitive diaphragm, so that its space volume is almost unchanged On the basis of , it has good radiation characteristics in the working frequency band and adjacent high-frequency interference suppression characteristics, without additional equipment, which reduces the difficulty of system anti-interference design and reduces the amount of equipment required.

2. Compared with the traditional waveguide slot array antenna, the overall weight of the waveguide slot array anti-interference antenna designed by the present invention hardly increases, which is conducive to further array formation and large-scale use.

3. The waveguide slot array anti-interference antenna designed by the present invention adopts a complete metal structure, has low loss, and has high antenna efficiency in the working frequency band.

4. The waveguide slot array anti-interference antenna designed by the present invention integrates the antenna and the filter. Compared with the traditional waveguide slot array antenna plus a filter, there is no additional loss in the working frequency band.

5. Compared with the traditional waveguide slot array antenna, the present invention only adds a few capacitive metal diaphragms, so the processing difficulty is low and the process is simple.

6. The present invention is processed by pure metal materials, has high reliability and wide application range.

Description of drawings

Other characteristics, objects and advantages of the present invention will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

Fig. 1 is a schematic diagram of the three-dimensional structure of the waveguide slot array anti-jamming antenna loaded by the capacitive diaphragm of the present invention;

Fig. 2 is a cross-sectional view of the present invention;

Fig. 3 is a longitudinal sectional view of the present invention;

Fig. 4 is a top view of the present invention;

Fig. 5 is a longitudinal sectional view of a frequency selective waveguide slow wave structure loaded by a capacitive diaphragm for removing radiation gaps according to the present invention;

Fig. 6 is a transmission characteristic diagram of a frequency-selective waveguide slow-wave structure loaded by a capacitive diaphragm;

Fig. 7 is the voltage standing wave ratio curve of the waveguide slot array anti-jamming antenna working frequency band loaded by the capacitive diaphragm of the present invention;

Fig. 8 is the radiation pattern diagram of the waveguide slot array anti-jamming antenna loaded by the capacitive diaphragm of the present invention working at 12.25 GHz;

Fig. 9 is a radiation pattern diagram of the waveguide slot array anti-jamming antenna loaded by the capacitive diaphragm of the present invention working at 12.5 GHz;

Fig. 10 is a radiation pattern diagram of the waveguide slot array anti-jamming antenna loaded by the capacitive diaphragm of the present invention working at 12.75 GHz;

Fig. 11 is the gain curve and antenna efficiency diagram of the waveguide slot array anti-jamming antenna loaded by the capacitive diaphragm of the present invention in the working frequency band;

Figure 12 is a gain curve and antenna efficiency diagram of a traditional waveguide slot array antenna in the working frequency band;

Fig. 13 is a graph comparing the gain curves of the waveguide slot array anti-jamming antenna loaded by the capacitive diaphragm of the present invention and the traditional waveguide slot array antenna.

The figure shows:

Detailed ways

The present invention will be described in detail below in conjunction with specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

In describing the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", The orientation or positional relationship indicated by "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying the referred device Or elements must have a certain orientation, be constructed and operate in a certain orientation, and thus should not be construed as limiting the invention.

In the Ku-band terrestrial satellite communication system, such as mobile communication and static communication, the operating frequency of the receiving antenna is 12.25-12.75 GHz, and the operating frequency of the transmitting antenna is 14.0-14.5 GHz. The high-power transmitting antenna will cause serious interference to the receiving antenna, so it is necessary to design a receiving antenna with anti-interference ability. The waveguide slot array anti-interference antenna loaded by the capacitive diaphragm of this embodiment has a working frequency band of 12.25-12.75 GHz and an interference frequency band of 14.0-14.5 GHz

As shown in FIG. 1 , the waveguide slot array anti-jamming antenna provided by the present invention includes a metal waveguide 1 and a metal film. The metal waveguide 1 is a hollow metal tube with a rectangular cross-section, that is to say, a cavity is provided in the metal waveguide 1, and the end faces of the metal waveguide 1 along the extending direction of the length form a first end face and a second end face respectively, and the cavity Through the first end face, the opening of the cavity on the first end face forms a signal input port, and a metal wall 5 is provided on the second end face to form a closed structure. The upper wall of the metal waveguide 1 is provided with a plurality of radiation slots, and the radiation slots are equidistant and staggered relative to the central axis of the upper wall of the metal waveguide 1 . The inner space of the cavity forms a storage space, the metal diaphragm is installed in the storage space, the cross-sectional shape of the metal diaphragm is rectangular, the metal diaphragm is fastened on the lower wall of the cavity, and the metal diaphragm extends along the length The two ends in the direction are respectively connected with the wall surfaces at both ends of the cavity along the width extension direction. The plurality of metal diaphragms include a first metal diaphragm 2 and a second metal diaphragm 3 , the first metal diaphragm 2 is an ordinary metal diaphragm, and the second metal diaphragm 3 is a special metal diaphragm for optimizing impedance matching. The multiple first metal diaphragms 2 have the same thickness and the same height, and the number is adjusted according to needs, but it is necessary to ensure that the container space is filled; there is only one second metal diaphragm 3, and the second metal diaphragm 3 is the same as the first metal diaphragm 3. The metal diaphragm 2 has the same thickness, but the height is not higher than the first metal diaphragm 2, and is located at the end where the signal input port is located, and forms an impedance matching area with the front and rear small waveguides to optimize the antenna impedance matching. All metal diaphragms are arranged at equal intervals. In this embodiment, the more commonly used 8-element waveguide slot standing wave array is selected, that is, the number of radiation slots is 8 in total, the number of first metal diaphragms 2 is 11 in total, and the number of second metal diaphragms 3 for optimizing impedance matching is 1 in total. .

Preferred implementation mode:

Referring to FIG. 2 , the inner wall of the metal waveguide 1 has a wide side with length a and a narrow side with b. The metal waveguide 1 is preferably a standard waveguide. In this embodiment, the standard waveguide BJ120 is selected, working in the Ku band, and the inner wall size is a×b=19.05mm×9.525mm. The thickness of the four walls of the metal waveguide 1 and the thickness of the closed metal wall 5 are related to the processing level. In this design, the thickness of the upper wall of the metal waveguide 1 is 1.27mm, the thickness of the left, right and bottom walls is 2mm, and the thickness of the closed metal wall 5 is 2mm.

Referring to Fig. 3, the thickness of all metal diaphragms is t, the distance between the centers of the diaphragms is d, and the height of common metal diaphragms is h ₁ . with distribution. The method to determine the size of common metal diaphragm is as follows:

Referring to Fig. 5, a frequency-selective waveguide slow-wave structure model loaded by a capacitive diaphragm is established. The metal waveguide with openings at both ends also selects the standard waveguide BJ120 (the inner wall size is a×b=19.05mm×9.525mm). The metal diaphragms of the same size are evenly arranged on the bottom surface, the thickness is t, the distance between the centers of the diaphragms is d, and the height is h ₁ . Through three-dimensional electromagnetic simulation optimization, the parameters of the metal diaphragm are changed, so that the passband of the waveguide slow wave structure includes the working frequency range of 12.25-12.75GHz, and the stopband includes the interference frequency range of 14.0-14.5GHz. The thickness t of the metal diaphragm is preferably a smaller value according to the processing capacity, and 0.5mm is selected in this design; the center distance d of the diaphragm and the height h ₁ of the diaphragm are preferably 9.7mm and 3.7mm.

Figure 6 shows the transmission characteristic curve of the frequency-selective waveguide slow-wave structure of the above size, which belongs to the passband in the working frequency range of 12.25-12.75GHz, and belongs to the stopband in the interference frequency range of 14.0-14.5GHz, and the suppression degree exceeds 37dB.

Referring to Fig. 4 below, the radiating slot spacing is _λg /2, where _λg is the waveguide wavelength of the designed waveguide slot array anti-interference antenna at the working center frequency _f0 , which is related to the size and distribution of the metal diaphragm; The distance between the end-slit center and the closed metal wall 5 is λ _g /4. λ _g satisfies λ _g < λ _g0 , where λ _g0 represents the waveguide wavelength of a standard waveguide of the same specification (here, BJ120) at the working center frequency f ₀ . In this design, f ₀ takes 12.5GHz. The value of λ _g is optimized through three-dimensional electromagnetic simulation, so that the main lobe of the antenna radiation pattern points to the normal direction, and λ _g is the actual waveguide wavelength at this time. In this design, the value of λg is _25.9mm , which corresponds to a radiation gap spacing of 12.95mm.

Referring to Fig. 4 again, the width of the radiation slot is w _s ; the length of the radiation slot is l _s , and the slot offset is d _s (the distance between the longitudinal centerline of the elongated radiation slot and the longitudinal centerline of the broad side of the waveguide). The radiation slit width w _s is preferably w _s =λ ₀ /20, where λ ₀ is the vacuum wavelength of the center frequency of the working frequency band. The radiation slot length l _s and offset d _s are optimized through three-dimensional electromagnetic simulation, so that the input impedance of the antenna is in a resonant state in the working frequency band, that is, the real part curve of the impedance is relatively stable, and the imaginary part curve of the impedance is about zero. The optimization effect of this embodiment is: the radiation slot width, length, and offset are preferably 1.2 mm, 12 mm, and 3.1 mm, respectively. It should be noted that the slot resonance state at this time does not guarantee a good impedance matching of the antenna. Since the internal characteristic impedance of the capacitive diaphragm-loaded waveguide slot antenna is smaller than the characteristic impedance of the signal input waveguide port, the overall impedance after the radiation slot resonance is generally It is also smaller than the impedance of the signal input port, so it is still necessary to further optimize the impedance matching.

Finally, please refer to Fig. 3 again, the special metal diaphragm for optimizing impedance matching forms an impedance matching area with the front and rear small waveguides. The length of the impedance matching area is λ _g /4, and the distance from the center of the nearest radiation slot is λ _g /2. Through inversion transformation, the overall impedance of the lower resonance slot is raised to an impedance close to the signal input port, thereby optimizing the antenna impedance matching characteristics . The height of the special metal diaphragm is h ₂ , and the distance between it and the signal input port is preferably d/2, where d is the center-to-center distance of all diaphragms. The height h ₂ of the special metal diaphragm is not higher than the height h ₁ of the ordinary metal diaphragm, and as the height h ₂ decreases, the characteristic impedance of the impedance matching area increases. Adjusting the size of h ₂ can perform impedance matching for different antenna designs . In this design, h ₂ is preferably 3.5mm. What needs to be added is that, except for the special metal diaphragm, other common metal diaphragms can be arranged in the antenna in sequence with a distance d.

Figure 7 shows the voltage standing wave ratio (VSWR) curve of the waveguide slot anti-array interference antenna after the above-mentioned optimized impedance matching. The VSWR is less than 1.33 in the operating frequency range of 12.25-12.75 GHz and less than 1.5 in the range of 12.02-12.82 GHz. Has good impedance matching characteristics.

Figure 8, Figure 9 and Figure 10 show the radiation patterns of the waveguide slot array anti-jamming antenna loaded by the capacitive diaphragm at three frequencies of 12.25GHz, 12.5GHz and 12.75GHz, respectively, and have good uniformly distributed linear array radiation characteristics .

Fig. 11 and Fig. 12 respectively show the gain curve and efficiency comparison diagram of the waveguide slot array anti-jamming antenna loaded with capacitive diaphragm and the traditional waveguide slot array antenna at 11.75-13.25 GHz. For comparison, the traditional waveguide slot array antenna also adopts the 8-slot standing wave array design. At the working frequency of 12.25-12.75GHz, the two antennas have similar antenna efficiencies, indicating that the designed waveguide slot array anti-jamming antenna has the same good working performance as the traditional waveguide slot array antenna. The gain of the designed waveguide slot array anti-interference antenna is slightly lower than that of the traditional waveguide slot array antenna. The reason is that the aperture of the designed waveguide slot anti-jamming array antenna is slightly smaller than that of the traditional waveguide slot array antenna when the number of slots is the same. In addition, the antenna efficiency of the two antennas is slightly lower than that of a single waveguide slot linear array unit in a planar two-dimensional array, because both antennas adopt a single linear array design and have a wider beamwidth in the horizontal polarization direction. Thereby reducing the overall gain of the antenna; but this does not affect the comparison of the performance of the two antennas, and also does not affect the high efficiency characteristics of the waveguide slot array anti-jamming antenna designed in the array.

Fig. 13 is a comparison diagram of the overall gain of the waveguide slot array anti-jamming antenna loaded with the capacitive diaphragm and the traditional waveguide slot array antenna at 11.5-15 GHz. Both antennas can work normally in the working frequency band of 12.25-12.75GHz, and in the interference frequency band of 14.0-14.5GHz, the designed waveguide slot array anti-jamming antenna has an additional interference suppression higher than 17dB compared with the traditional waveguide slot array antenna, reflecting Good anti-interference characteristics.

Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art may make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. In the case of no conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims (6)

1. A waveguide slot array anti-interference antenna, characterized in that it comprises a metal waveguide (1) and a metal diaphragm, the metal waveguide (1) is provided with a cavity, and the inner space of the cavity forms a container space, the metal diaphragm is installed in the container space; Radiation slots are arranged on the metal waveguide (1), and the internal space of the radiation slots communicates with the storage space; The end faces at both ends of the metal waveguide (1) along the extending direction of the length respectively form a first end face and a second end face; The cavity runs through the first end face, and the opening of the cavity on the first end face forms a signal input port; the second end face is provided with a metal wall (5); The cross-sectional shape of the metal diaphragm is rectangular, the metal diaphragm is fastened on the lower wall of the cavity, and the two ends of the metal diaphragm along the length extension direction are respectively connected to the two ends of the cavity along the width extension direction; A plurality of metal diaphragms are sequentially arranged along the extending direction of the metal waveguide (1), and the plurality of metal diaphragms include a plurality of first metal diaphragms (2) and a second metal diaphragm (3), and the plurality of metal diaphragms The thickness and height of the first metal diaphragm (2) are equal; The thickness of the first metal diaphragm (2) is equal to that of the second metal diaphragm (3), and the height of the second metal diaphragm (3) is not higher than the height of the first metal diaphragm (2); The second metal diaphragm (3) is located on the side where the signal input port is located. 2. The waveguide slot array anti-jamming antenna according to claim 1, characterized in that a plurality of said metal diaphragms are arranged equidistantly along the extending direction of the metal waveguide (1). 3. The waveguide slot array anti-jamming antenna according to claim 1, characterized in that, the metal waveguide (1) is a tube with a rectangular cross-section, and the radiation slots are set on the upper end surface of the metal waveguide (1). 4. The waveguide slot array anti-jamming antenna according to claim 3, characterized in that a plurality of said radiation slots are staggered in the extending direction of the metal waveguide (1) length; Along the width direction of the metal waveguide (1), the distances from the longitudinal centerlines of the plurality of radiation slots to the longitudinal centerline of the metal waveguide (1) are equal. 5. The waveguide slot array anti-jamming antenna according to claim 1, characterized in that, the cross-sectional shape of the cavity is rectangular, and the cavity of the rectangular cross-section is 19.05mm long and 9.525mm wide; the cavity is along the circumferential direction The thickness of the upper wall among the four walls is 1.27mm, and the thickness of the remaining three walls is 2mm; the thickness of the metal wall (5) is 2mm. 6. The waveguide slot array anti-jamming antenna according to claim 2, characterized in that the thickness of the metal diaphragm is 0.5 mm, the center distance between two adjacent metal diaphragms is 9.7 mm, and the height of the metal diaphragm is 3.7 mm .