Common-aperture phased-array antenna based on slot structure

Abstract

The invention discloses a common-aperture phased-array antenna based on slot structures, which relates to the field of wireless communication technology and radar, and comprises a low-frequency slot antenna and a high-frequency slot antenna, the slot structures of the low-frequency slot antenna and the high-frequency slot antenna are back cavity slots, and the slot structures of the low-frequency slot antenna and the high-frequency slot antenna are back cavity slots. And the feed structures of the low-frequency slot antenna and the high-frequency slot antenna adopt micro-strip feeder lines to feed above the back cavity slots. The antenna has the characteristics of simple structure, good structural stability, low cost, wide band and wide-angle scanning, and can be used in a wireless communication system and a radar system working at multiple frequency bands.

Description

Technical Field

[0001] The present invention relates to the fields of wireless communication technology and radar, and in particular to a co-aperture phased array antenna based on a slot structure. Background Art

[0002] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

[0003] With the rapid development of communication and radar systems, the system is often required to cover multiple frequency bands to work. This will increase the space occupied by the communication system, and the contradiction between the limited space of the carrier platform is becoming increasingly prominent. The co-aperture phased array antenna is an antenna that can work in two or more frequency bands. It has the advantages of high spatial reuse rate, small size and high integration, which can well solve the contradiction between the space occupied by the communication system and the limited space of the carrier platform. At present, the co-aperture phased array antenna has become a research hotspot for wireless communication and radar systems.

[0004] The slot antenna unit is a traditional antenna unit form. Due to its advantages such as simple structure, low processing difficulty, broadband and wide scanning range, the slot antenna is often used in the design of phased array antennas.

[0005] In summary, the present invention is a design proposed for a co-aperture phased array antenna for broadband and wide-angle scanning. Summary of the invention

[0006] The purpose of the present invention is to provide a co-aperture phased array antenna based on a slot structure, which has the ability of two-dimensional beam scanning in two frequency bands, in order to solve the problems existing in the prior art.

[0007] The technical solution of the present invention is as follows:

[0008] A slot-structured co-aperture phased array antenna comprises: a low-frequency slot antenna and a high-frequency slot antenna, wherein the slot structures of the low-frequency slot antenna and the high-frequency slot antenna are cavity-backed slots, and the feeding structures of the low-frequency slot antenna and the high-frequency slot antenna use microstrip feed lines to feed above the cavity-backed slots.

[0009] Furthermore, the back cavity slots of the low-frequency slot antenna and the high-frequency slot antenna both adopt: a metal back cavity slot structure based on metal parts machining, a slot structure in a metal mechanical part filled with a dielectric, or an equivalent back cavity slot structure designed in a dielectric plate.

[0010] Furthermore, the microstrip feed lines of the low-frequency slot antenna and the high-frequency slot antenna are both located above the cavity-backed slot.

[0011] Furthermore, the microstrip feed line is Y-shaped or straight-line.

[0012] Furthermore, the microstrip feed lines of the low-frequency slot antenna and the high-frequency slot antenna are designed on the upper surface of the same dielectric layer or on the upper surfaces of different dielectric layers.

[0013] Furthermore, in order to achieve impedance matching in different frequency bands, a dielectric matching layer is designed above the feeder of the slot antenna.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] The present invention adopts a low-frequency slot antenna and a high-frequency slot antenna based on a back cavity slot structure, designs the high-frequency back cavity slot into an H-shape, and mirrors the high-frequency feeding structure in one dimension, thereby leaving enough space for the design of the low-frequency antenna, realizing the co-aperture operation of the high-frequency and low-frequency antennas, and realizing two-dimensional beam scanning performance in two frequency bands. The proposed co-aperture antenna has the characteristics of low cost, easy processing and assembly, broadband and wide-angle scanning. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the overall structure of a slot-structured co-aperture phased array antenna in Embodiment 2;

[0017] Figure 2 It is an exploded schematic diagram of the overall detailed structure of a co-aperture phased array antenna based on a slot structure in Example 2;

[0018] Figure 3 Schematic diagram of the slot structure cross section of a common-aperture phased array antenna based on a slot structure in Embodiment 2;

[0019] Figure 4 This is a schematic diagram of a feeder structure of a common-aperture phased array antenna based on a slot structure in Example 2;

[0020] Figure 5 It is a standing wave diagram of different planes scanned in low frequency band of a common aperture phased array antenna based on slot structure in embodiment 2;

[0021] Figure 6 It is a standing wave diagram of different planes scanned in high frequency band of a common aperture phased array antenna based on slot structure in embodiment 2;

[0022] Figure numerals: 1-metal mechanical parts, 2-low-frequency back cavity slot, 3-high-frequency back cavity slot, 4-RF connector, 5-feeding dielectric layer, 6-low-frequency feed line, 7-high-frequency feed line, 8-dielectric matching layer. DETAILED DESCRIPTION

[0023] It should be noted that relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0024] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0025] Embodiment 1

[0026] A slot-structured co-aperture phased array antenna comprises: a low-frequency slot antenna and a high-frequency slot antenna, wherein the slot structures of the low-frequency slot antenna and the high-frequency slot antenna are cavity-backed slots, and the feeding structures of the low-frequency slot antenna and the high-frequency slot antenna use microstrip feed lines to feed above the cavity-backed slots.

[0027] In the present embodiment, specifically, the back cavity slots of the low-frequency slot antenna and the high-frequency slot antenna both adopt: a metal back cavity slot structure based on mechanical processing of metal parts, a slot structure in a metal mechanical part filled with a medium, or an equivalent back cavity slot structure designed in a dielectric plate; it should be noted that in order to achieve impedance matching in different frequency bands, slots in different frequency bands are processed with different depths in the metal mechanical parts.

[0028] In this embodiment, specifically, the microstrip feed lines of the low-frequency slot antenna and the high-frequency slot antenna are both located above the back cavity slot. It should be noted that the microstrip feed lines of the low-frequency slot antenna and the high-frequency slot antenna can be designed on the upper surface of the same dielectric layer; at the same time, in order to achieve impedance matching in different frequency bands, the microstrip feed lines of the low-frequency slot antenna and the high-frequency slot antenna can also be designed on the upper surfaces of different dielectric layers.

[0029] In this embodiment, specifically, in order to achieve impedance matching in different frequency bands, the feed lines of the two frequency bands include but are not limited to the linear microstrip feed lines and the Y-shaped microstrip feed lines.

[0030] In this embodiment, specifically, in order to achieve impedance matching in different frequency bands, a dielectric matching layer is designed above the feeder of the slot antenna.

[0031] Embodiment 2

[0032] Embodiment 2 is a co-aperture phased array antenna based on a slot structure proposed in Embodiment 1, and is obtained after specific design.

[0033] A common aperture phased array antenna in this embodiment operates in the X / K frequency band, f X / f K =1.6(f X is the high frequency point when working in X-band, f K is the high frequency point when working in K band), the common aperture phased array antenna unit is as follows Figure 1 As shown, the cell size is 0.51λ X ×0.51λ X (λ X f X The free space wavelength corresponding to the frequency point); Figure 2 A detailed unit structure diagram is given to more clearly show the detailed structure of the co-aperture phased array antenna unit; it should be noted that the low-frequency antenna and the high-frequency antenna operate in different polarization modes, so that the co-aperture designed antenna has two polarization modes.

[0034] like Figure 2 As shown, the overall structure of a co-aperture phased array antenna unit based on a slot structure in this embodiment includes from bottom to top:

[0035] Metal mechanical parts 1, low-frequency back cavity slot 2, high-frequency back cavity slot 3, radio frequency connector 4, feeding dielectric layer 5, low-frequency feed line 6, high-frequency feed line 7 and dielectric matching layer 8;

[0036] Specifically, the low-frequency back cavity slot 2 and the high-frequency back cavity slot 3 are designed in the metal mechanical part 1;

[0037] The RF connector 4 passes through the metal mechanical part 1 to connect the low-frequency feed line 6 and the high-frequency feed line 7 located on the upper surface of the feeding dielectric layer 5, thereby realizing the feeding of the high-frequency antenna and the low-frequency antenna unit;

[0038] The dielectric matching layer 8 is located above the low-frequency feed line 6 and the high-frequency feed line 7; wherein the feed dielectric layer 5 is a dielectric plate with a thickness of 2 mm and a dielectric constant of 2.94;

[0039] The dielectric matching layer 8 is a dielectric plate with a thickness of 0.635 mm and a dielectric constant of 2.94.

[0040] In this embodiment, each X-band low-frequency antenna unit radiation aperture corresponds to 2×2 K-band high-frequency antenna units working in the same aperture. In more detail, the low-frequency back cavity slot 2 is designed on the metal mechanical part 1, and high-frequency back cavity slots 3 are designed around the low-frequency back cavity slot 2. CNC machine tool processing technology can be used to process back cavity slots of different frequency bands on the metal mechanical part 1.

[0041] In order to achieve impedance matching in different frequency bands, the depth of the back cavity groove in different frequency bands is designed differently. Figure 3 As shown in the cross-sectional view, the structural depth of the high-frequency back cavity groove 3 is smaller than the structural depth of the low-frequency back cavity groove 2.

[0042] In order to achieve the co-aperture design of the two frequency band antennas, the high-frequency back cavity slot 3 structure adopts an H-shaped slot to reduce the length of the high-frequency back cavity slot 3 structure, thereby reducing the occupied space of the high-frequency back cavity slot 3 structure and leaving enough space for the design of the low-frequency back cavity slot 2 structure.

[0043] Similarly, in order to leave enough space for the low-frequency RF connector 4 , the structure of the high-frequency feeder 7 is mirror-designed in one dimension, and space for arranging the low-frequency RF connector 4 is left between the two high-frequency feeder 7 structures.

[0044] like Figure 4 As shown, the high frequency feed line 7 is designed to be mirror-symmetrical about the X axis. In addition, the low frequency feed line 6 and the high frequency feed line 7 are structurally designed to be on the same plane, that is, the upper surface of the feeding dielectric layer 5 .

[0045] In order to achieve impedance matching between the two frequency bands during scanning, a dielectric matching layer 8 is designed at the top of the antenna to improve the scanning performance of the co-aperture phased array antenna in different frequency bands.

[0046] Figure 5 The simulation results of the active standing wave ratio of the designed co-aperture phased array antenna unit working in the X-band when scanning in the horizontal and elevation planes are given. Figure 5 As shown, within the scanning range of 45° in the horizontal plane and the elevation plane, the X-band antenna can achieve an active standing wave ratio of less than 3 and an impedance bandwidth of 15%.

[0047] Figure 6 The simulation results of the active standing wave ratio of the designed co-aperture phased array antenna unit working in the K-band when scanning in the horizontal and elevation planes are given. Figure 6 As shown, within the range of 45° scanning in the horizontal plane and the elevation plane, the K-band antenna can achieve an active standing wave ratio of less than 3 and an impedance bandwidth of 22%.

[0048] The above-mentioned embodiments only express the specific implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the protection scope of the present application. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the technical solution concept of the present application, and these all belong to the protection scope of the present application.

[0049] This background section is provided to generally present the context of the invention, and the work of the presently named inventors, the work to the extent described in this background section, and aspects of this section that did not constitute prior art at the time of application are neither explicitly nor implicitly admitted to be prior art to the present invention.

Claims

1. A common aperture phased array antenna based on a slot structure, characterized in that: include: The low-frequency slot antenna and the high-frequency slot antenna have slot structures that are cavity-backed slots, and the feeding structures of the low-frequency slot antenna and the high-frequency slot antenna use microstrip feed lines to feed above the cavity-backed slots.

2. The slot-structured co-aperture phased array antenna according to claim 1, characterized in that: The back cavity slots of the low-frequency slot antenna and the high-frequency slot antenna both adopt: a metal back cavity slot structure based on metal parts machining, a slot structure in a metal mechanical part filled with a medium, or an equivalent back cavity slot structure designed in a dielectric plate.

3. The slot-structured co-aperture phased array antenna according to claim 1, characterized in that: The microstrip feed lines of the low-frequency slot antenna and the high-frequency slot antenna are both located above the back cavity slot.

4. The slot-structured co-aperture phased array antenna according to claim 1, characterized in that: The microstrip feed line is Y-shaped or straight-line.

5. The slot-structured co-aperture phased array antenna according to claim 3, characterized in that: The microstrip feed lines of the low-frequency slot antenna and the high-frequency slot antenna are designed on the upper surface of the same dielectric layer or on the upper surfaces of different dielectric layers.

6. The slot-structured co-aperture phased array antenna according to claim 1, characterized in that: In order to achieve impedance matching in different frequency bands, a dielectric matching layer is designed above the feeder of the slot antenna.

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