Wideband wide-angle scanning matching structure based on microstrip antenna

Abstract

The utility model belongs to the technical field of phased array radar antennas, and relates to a broadband wide-angle scanning matching structure based on a microstrip antenna, which comprises a metal floor, a feed layer dielectric substrate, a copper layer and a radiation layer dielectric substrate, the lower surface of the feed layer dielectric substrate is fixedly connected with the metal floor, copper layers are etched on the upper surface and the lower surface of the feed layer dielectric substrate, metal isolation electric walls are arranged on the edge and the interior of the feed layer dielectric substrate, and the metal isolation electric walls are connected with the copper layers; the radiation layer dielectric substrate is adhered to the upper surface of the feed layer dielectric substrate; a metal isolation electric wall is introduced into a feed medium substrate, and the metal isolation electric wall surrounding the edge of the feed medium substrate forms an integrated back cavity structure, so that high-Q-value resonance excited by a parallel plate mode is suppressed; therefore, in-band resonance of the microstrip antenna is effectively suppressed, and broadband wide-angle scanning of the microstrip antenna is realized.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of phased array radar antenna, and particularly relates to a wideband wide-angle scanning matching structure based on a microstrip antenna. BACKGROUND

[0002] With the continuous development of phased array radar technology, in order to improve the combat capability and range of radar and electronic countermeasure system, in addition to the requirement of wideband operation of radar antenna, large airspace coverage and wide-angle scanning are also required. Therefore, it is a key problem to be solved to improve the working bandwidth of the phased array antenna while taking into account the wide-angle scanning characteristics. However, due to the mutual coupling between the units of the phased array antenna, a sharp and deep notch appears at a certain specific scanning angle before the grating lobe, at this time the energy is totally reflected, the antenna cannot radiate or receive energy, forming a scanning blind spot. The scanning blind spot is one of the important factors restricting the wideband wide-angle scanning of the phased array antenna.

[0003] The traditional active phased array radiating unit adopts a Vivaldi end-fire antenna form. This type of antenna can obtain a wide working bandwidth and a large beam scanning angle, but has the following defects:

[0004] (1) Large volume and large weight restrict the large-area application of the antenna on the airborne platform;

[0005] (2) The high profile characteristic weakens the structural strength with the increase of the antenna height;

[0006] (3) The mounting structure of the antenna is complex, and the assembly workload is large.

[0007] The microstrip antenna conforms to the development trend of modern airborne radar system, such as miniaturization, light weight, high reliability and multi-functionality, has many advantages such as low profile, small volume, light weight, easy to conform to the surface of the carrier, easy to integrate with active devices, and can be used as a new type of phased array radar antenna form. However, the microstrip antenna is easy to excite the propagation of surface waves on the open microstrip substrate, resulting in more complex and strong mutual coupling effect between the units of the microstrip array than the traditional active phased array radiating unit, leading to performance deterioration such as array impedance mismatch and radiation pattern distortion. At a large angle of scanning, this mutual coupling effect is more intense, making the scanning blind spot phenomenon more serious. The blind spot effect is one of the serious problems affecting the wideband wide-angle scanning performance of the microstrip phased array antenna. Since it appears before the grating lobe, some even appear at an angle not far from the broadside direction, which will inevitably greatly reduce the scanning area of the microstrip phased array antenna, leading to the decline of the scanning performance of the whole array, making it difficult to realize wide-angle scanning while ensuring wideband operation of the microstrip antenna.

[0008] Therefore, how to weaken the influence of the scanning blind spot effect of the microstrip phased array antenna on the working frequency band and the scanning angle domain is a problem to be solved. Utility model content

[0009] The purpose of the present application is to provide a wideband wide-angle scanning matching structure based on a microstrip antenna, so as to solve the problem that the existing microstrip antenna is easy to excite the propagation of surface waves on an open microstrip substrate, and the scanning blind spot phenomenon is more serious.

[0010] The technical scheme of the present application is: a wideband wide-angle scanning matching structure based on a microstrip antenna, comprising a metal ground plate, a feed layer dielectric substrate and a copper layer, and a radiation layer dielectric substrate; the lower surface of the feed layer dielectric substrate is fixedly connected with the metal ground plate, the upper and lower surfaces of the feed layer dielectric substrate are etched with the copper layer, the edges and the inside of the feed layer dielectric substrate are provided with metal isolation electric walls, and the metal isolation electric walls are connected with the copper layer; the radiation layer dielectric substrate is attached to the upper surface of the feed layer dielectric substrate.

[0011] Preferably, the metal isolation electric walls are arranged around the feed layer dielectric substrate, and part of the metal isolation electric walls is inserted into the inside of the feed layer dielectric substrate and the inserted part is arranged around the feed end of the feed layer dielectric substrate.

[0012] Preferably, the inside of the radiation layer dielectric substrate is provided with a closed cavity, and the cavity in the radiation layer dielectric substrate is provided with foam, and the cross section of the foam is rectangular, circular or elliptical.

[0013] Preferably, the radiation layer dielectric substrate has two layers and is arranged in layers, an upper radiation patch is arranged between the two layers of radiation layer dielectric substrates, a protective layer dielectric substrate is arranged on the radiation layer dielectric substrate in the upper layer, and a protective layer annular patch is arranged between the protective layer dielectric substrate and the radiation layer dielectric substrate in the upper layer.

[0014] The wideband wide-angle scanning matching structure based on a microstrip antenna of the present application introduces a metal isolation electric wall in the feed dielectric substrate, and the metal isolation electric wall around the edge of the feed dielectric substrate forms an integrated back cavity structure, which suppresses the high Q value resonance excited by the parallel plate mode; thereby effectively suppressing the in-band resonance of the microstrip antenna, and realizing the wideband wide-angle scanning of the microstrip antenna. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions provided by the present application, the following will briefly introduce the drawings. Obviously, the drawings described below are only some embodiments of the present application.

[0016] Figure 1 It is a schematic diagram of the overall structure of the present application;

[0017] Figure 2An overall structural exploded view of the application;

[0018] Figure 3 An active standing wave curve diagram of the microstrip antenna of the application.

[0019] 1, metal floor; 2, feed layer dielectric substrate; 3, copper layer; 4, radiation layer dielectric substrate; 5, metal isolation electric wall; 6, protective layer ring patch; 7, upper layer radiation patch; 8, coupling slot; 9, feed line end; 10, feed coaxial; 11, protective layer dielectric substrate; 12, foam. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the utility model.

[0021] A wideband wide-angle scanning matching structure based on a microstrip antenna, as shown in Figures 1-2 , comprising a metal floor 1, a feed layer dielectric substrate 2 and a copper layer 3, and a radiation layer dielectric substrate 4; the lower surface of the feed layer dielectric substrate 2 is fixedly connected with the metal floor 1, the upper and lower surfaces of the feed layer dielectric substrate 2 are both etched with the copper layer 3, the edges and the interior of the feed layer dielectric substrate 2 are both provided with metal isolation electric walls 5, the metal isolation electric walls 5 are connected with the copper layer 3; and the radiation layer dielectric substrate 4 is pasted on the upper surface of the feed layer dielectric substrate 2.

[0022] By introducing the metal isolation electric walls 5 into the feed layer dielectric substrate 2, the metal isolation electric walls 5 around the edges of the feed dielectric substrate form an integrated back cavity structure, and the high Q value resonance excited by the parallel plate mode is suppressed; thereby effectively suppressing the in-band resonance of the microstrip antenna, and realizing the wideband wide-angle scanning of the microstrip antenna.

[0023] Preferably, the metal isolation electric walls 5 are arranged around the feed layer dielectric substrate 2, and part of the metal isolation electric walls 5 is inserted into the interior of the feed layer dielectric substrate 2 and the inserted part is arranged around the feed end of the feed layer dielectric substrate 2. By arranging the metal isolation electric walls 5 around the outside of the feed dielectric substrate, the impedance matching of the feed structure can be adjusted. The copper layer 3 is provided with a coupling slot 8, the metal floor 1 is provided with a feed coaxial 10 connected with the feed line end 9, and part of the metal isolation electric walls 5 is also arranged around the coupling slot 8, the feed line end 9 and the feed coaxial 10, for adjusting the impedance matching of the feed structure and eliminating electromagnetic resonance.

[0024] Preferably, the radiation layer medium substrate 4 is internally provided with a closed cavity, and the foam 12 is arranged in the cavity of the radiation layer medium substrate 4, and the cross section of the foam 12 is rectangular, circular or elliptical. The foam 12 introduced by the radiation layer medium substrate 4 can eliminate surface waves and improve the impedance matching in the band. By changing the shape of the foam 12, various working conditions can be adapted.

[0025] The foam 12 is embedded in the radiation layer medium substrate 4, which provides support for the foam 12 to prevent the multilayer medium substrate from being crushed during pressing, and the radiation layer medium substrate 4 seals the foam 12 inside to achieve the effect of three-proofing protection.

[0026] Preferably, the radiation layer medium substrate 4 has two layers and is arranged in an upper and lower manner, the upper radiation patch 7 is arranged between the two layers of the radiation layer medium substrate 4, the protective layer medium substrate 11 is arranged on the radiation layer medium substrate 4 in the upper layer, and the protective layer annular patch 6 is arranged between the protective layer medium substrate 11 and the radiation layer medium substrate 4 in the upper layer. The protective layer medium substrate 11 is located on the upper surface of the entire antenna unit, and can protect the metal annular patch and the upper radiation patch 7 from being eroded and damaged by the external environment.

[0027] The microstrip antenna designed according to the application can realize ±45° scanning of the E plane and the H plane in the working frequency band of 7-13 GHz (VSWR<2). Therefore, the design can effectively expand the bandwidth and scanning angle domain of the microstrip antenna.

[0028] In summary, the application has the following advantages:

[0029] 1. The microstrip phased array antenna is expanded to ±45° in the scanning angle domain on the basis of 60% working bandwidth, and the advantages of low profile, small volume, light weight, easy conformation with the surface of a carrier and easy integration with active devices are retained.

[0030] 2. The design and processing difficulty coefficient are low, easy to realize, contain three-proofing design, and have strong engineering practical significance.

[0031] 3. The microstrip antenna can be used to realize wide bandwidth and angle scanning, and can be used on various radars, electronic warfare and communication equipment on various shipborne, airborne and roadbed platforms.

[0032] Finally, it should be noted that: the utility model discloses the embodiment in the drawing, only relates to the structure involved in the embodiment of the present disclosure, and other structures can refer to the usual design, and under the condition of no conflict, the same embodiment and different embodiments of the utility model can be combined with each other.

[0033] Finally: the above described is only the preferred embodiment of the utility model, and does not limit the utility model, and any modification, equivalent replacement, improvement etc. that is made within the spirit and principle of the utility model should be included in the protection scope of the utility model.

Claims

1. A wide bandwidth wide angle scanning matching structure based on microstrip antenna, characterized in that: It includes metal floor (1), feed layer dielectric substrate (2) and copper layer (3), radiation layer dielectric substrate (4);The lower surface of the feed layer dielectric substrate (2) is fixedly connected with the metal floor (1), the upper and lower surfaces of the feed layer dielectric substrate (2) are etched with copper layer (3), the edge and the inside of the feed layer dielectric substrate (2) are provided with metal isolation electric wall (5), the metal isolation electric wall (5) is connected with the copper layer (3);The radiation layer dielectric substrate (4) is pasted on the upper surface of the feed layer dielectric substrate (2).

2. The microstrip antenna based wide bandwidth angle scanning matching structure of claim 1, wherein: The metal isolation electric wall (5) is arranged around the feed layer dielectric substrate (2), and part of the metal isolation electric wall (5) is inserted into the inside of the feed layer dielectric substrate (2), and the inserted part is arranged around the feed end of the feed layer dielectric substrate (2).

3. The microstrip antenna based wide bandwidth angle scanning matching structure of claim 1, wherein: The inside of the radiation layer dielectric substrate (4) is provided with a closed cavity, and the radiation layer dielectric substrate (4) is provided with foam (12) in the cavity, and the cross section of the foam (12) is rectangular, circular or elliptical.

4. The microstrip antenna based wide bandwidth angle scanning matching structure of claim 1, wherein: The radiation layer dielectric substrate (4) has two layers and is arranged in upper and lower positions, and an upper layer radiation patch (7) is arranged between the two layers of radiation layer dielectric substrates (4), a protective layer dielectric substrate (11) is arranged on the radiation layer dielectric substrate (4) in the upper layer, and a protective layer annular patch (6) is arranged between the protective layer dielectric substrate (11) and the radiation layer dielectric substrate (4) in the upper layer.

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