Circularly polarized antenna and phased array antenna system

Abstract

The embodiment of the invention provides a circularly polarized antenna and a phased-array antenna system, and relates to the technical field of circularly polarized antennae, the circularly polarized antenna comprises a dielectric substrate, the dielectric substrate is provided with an antenna radiation patch, a grounding metal column and an antenna feed probe; an antenna slot is formed in the antenna radiation patch; the antenna radiation patch is respectively connected with the grounding metal column and the antenna feed probe; and a certain included angle is formed between the connecting line of the antenna feed probe and the grounding metal column and the middle line of the antenna slot. The technical scheme of the invention has the advantages of low profile, wide impedance bandwidth and axial ratio bandwidth, simple structure, easiness in large-scale processing and the like.

Description

Technical Field

[0001] The present application relates to the technical field of circularly polarized antennas, and in particular to a circularly polarized antenna and a phased array antenna system. Background Art

[0002] Circularly polarized antennas are widely used in satellites, aircraft and other communication systems because they are insensitive to the polarization of electromagnetic waves. Phased array antennas have the ability of spatial power synthesis, fast inertia-free beam scanning, beam shaping and sidelobe control. Therefore, phased array antenna technology is one of the most promising technologies in the future. At present, more and more communication systems adopt circularly polarized phased array antenna systems, and at the same time, higher requirements are put forward for antennas in phased array antenna systems used for communication. Mobile platforms such as aircraft and satellites have limited space, and antennas used in these platforms should have a low profile; the communication capacity of the communication system is proportional to the working bandwidth, so the antenna should have a wide bandwidth and a good axial ratio characteristic within the working bandwidth; the phased array antenna contains multiple antenna units, and a large system even contains thousands of antenna units. The processing cost, consistency and installation convenience of the antenna directly affect the system cost and performance, so the antenna should be easy to process and install, and can ensure the consistency of multiple antenna units. However, these requirements are contradictory and often difficult to meet at the same time.

[0003] There are many solutions for circularly polarized antennas, but the existing solutions often have problems such as large antenna size, high profile, narrow impedance bandwidth and axial ratio bandwidth, complex structure, difficult processing and high cost. It is difficult to meet all requirements and then be used in large-scale phased array antenna systems. Summary of the invention

[0004] The embodiments of the present application provide a circularly polarized antenna and a phased array antenna system to solve the technical problems existing in the prior art.

[0005] Other features and advantages of the present application will become apparent from the following detailed description, or may be learned in part by the practice of the present application.

[0006] According to a first aspect of an embodiment of the present application, a circularly polarized antenna is provided, including:

[0007] A dielectric substrate, on which an antenna radiation patch, a grounding metal column and an antenna feeding probe are arranged;

[0008] An antenna gap is provided inside the antenna radiation patch;

[0009] The antenna radiation patch is connected to the grounded metal post and the antenna feeding probe respectively;

[0010] Wherein, a connection line between the antenna feeding probe and the grounded metal column and a center line of the antenna slot form a certain angle.

[0011] In some embodiments of the present application, based on the aforementioned solution, the antenna radiation patch includes a first L-shaped metal patch and a second L-shaped metal patch;

[0012] The head of the first L-shaped metal patch is connected to the grounded metal column, and the head of the second L-shaped metal patch is connected to the antenna feeding probe;

[0013] A groove is formed on each of the first L-shaped metal patch and the second L-shaped metal patch. The first L-shaped metal patch and the second L-shaped metal patch are arranged end to end so that the grooves on the first L-shaped metal patch and the second L-shaped metal patch constitute the antenna gap.

[0014] In some embodiments of the present application, based on the aforementioned solution, the overall structure of the antenna radiation patch is square.

[0015] In some embodiments of the present application, based on the aforementioned solution, the antenna feeding probe is located at the center of the dielectric substrate.

[0016] In some embodiments of the present application, based on the aforementioned solution, an antenna floor is provided on the back side of the dielectric substrate, and the grounding metal column is connected to the antenna floor.

[0017] According to a second aspect of an embodiment of the present application, there is provided a phased array antenna system, comprising: a plurality of array units;

[0018] Each array unit includes a circularly polarized antenna as described in any one of claims 1 to 5, and three other circularly polarized antennas obtained by angularly rotating the circularly polarized antenna as described in the first aspect.

[0019] The technical solution of the present application has the advantages of low profile, wide impedance bandwidth and axial ratio bandwidth, simple structure and easy large-scale processing.

[0020] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings herein are incorporated into the specification and constitute a part of the specification, showing embodiments consistent with the present application, and together with the specification, are used to explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0022] Figure 1 A top view of a circularly polarized antenna according to an embodiment of the present application is shown;

[0023] Figure 2 A side view of a circularly polarized antenna according to an embodiment of the present application is shown;

[0024] Figure 3 A schematic diagram of magnetic dipole current distribution according to an embodiment of the present application is shown;

[0025] Figure 4 A schematic diagram of electric dipole current distribution according to an embodiment of the present application is shown;

[0026] Figure 5 A schematic diagram of the reflection coefficient of a circularly polarized antenna according to an embodiment of the present application is shown;

[0027] Figure 6 A schematic diagram of the center frequency antenna axial ratio of a circularly polarized antenna according to an embodiment of the present application is shown;

[0028] Figure 7 A schematic diagram showing a change in the antenna axial ratio of a circularly polarized antenna with frequency according to an embodiment of the present application is shown;

[0029] Figure 8 A schematic diagram of an array arrangement of a phased array antenna system according to an embodiment of the present application is shown;

[0030] Fig. 9 A schematic diagram of the XOZ scanning pattern and axial ratio distribution of a phased array antenna system according to an embodiment of the present application is shown;

[0031] Fig.10 A schematic diagram of the YOZ plane scanning pattern and axial ratio distribution of a phased array antenna system according to an embodiment of the present application is shown.

[0032] Description of Reference Numerals

[0033] 1- dielectric substrate, 2- antenna radiation patch, 3- ground metal post, 4- antenna feed probe, 5- antenna slot, 6- antenna floor. DETAILED DESCRIPTION

[0034] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this application will be more comprehensive and complete and fully convey the concept of the example embodiments to those skilled in the art.

[0035] In addition, described feature, structure or characteristic can be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present application. However, those skilled in the art will appreciate that the technical scheme of the present application can be put into practice without one or more of the specific details, or other methods, components, devices, steps, etc. can be adopted. In other cases, known methods, devices, realizations or operations are not shown or described in detail to avoid blurring the various aspects of the application.

[0036] It should be noted that the “plurality” mentioned in this article refers to two or more.

[0037] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the objects used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those shown or described.

[0038] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is only a part of the embodiment of the present invention, not all the embodiments. Based on the embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] Some embodiments of the present application will be described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments may be combined with each other.

[0040] In order to solve the technical problems existing in the prior art, an embodiment of the present application provides a circularly polarized antenna, which is applied to a phased array antenna system. The antenna has the advantages of broadband, low cost, low ground profile, high performance, etc.

[0041] Specifically, an embodiment of the present application provides a circularly polarized antenna, including:

[0042] A dielectric substrate, on which an antenna radiation patch, a grounding metal column and an antenna feeding probe are arranged;

[0043] An antenna gap is provided inside the antenna radiation patch;

[0044] The antenna radiation patch is connected to the grounded metal post and the antenna feeding probe respectively;

[0045] Wherein, a connection line between the antenna feeding probe and the grounded metal column and a center line of the antenna slot form a certain angle.

[0046] It should be noted that this antenna can be considered as an organic combination of two sets of antennas. Among them, the antenna radiation patch works as an electric dipole antenna. The antenna radiation patch, the grounded metal column, and the floor together form a current loop, which is equivalent to a magnetic dipole radiation. The realization of circular polarization is mainly due to the current located at the upper edge of the antenna radiation patch. The connection line between the feed probe and the metal grounding hole forms a certain angle with the gap, which leads to a certain angle between the electric dipole and the magnetic dipole antenna. The existence of the magnetic dipole and the positional relationship between the magnetic dipole and the electric dipole further improve the impedance bandwidth and axial ratio bandwidth of the antenna.

[0047] In some feasible embodiments, based on the above solution, the antenna radiation patch includes a first L-shaped metal patch and a second L-shaped metal patch;

[0048] The head of the first L-shaped metal patch is connected to the grounded metal column, and the head of the second L-shaped metal patch is connected to the antenna feeding probe;

[0049] A groove is formed on each of the first L-shaped metal patch and the second L-shaped metal patch. The first L-shaped metal patch and the second L-shaped metal patch are arranged end to end so that the grooves on the first L-shaped metal patch and the second L-shaped metal patch constitute the antenna gap.

[0050] It should be noted that the first L-shaped metal patch and the second L-shaped metal patch are arranged close to each other end to end, which means that the head of the first L-shaped metal patch is close to the tail of the second L-shaped metal patch, and the head of the second L-shaped metal patch is close to the tail of the first L-shaped metal patch. The overall structure is ring-shaped and connected end to end, but the head and tail of the two are not directly connected.

[0051] It should be noted that, when the first L-shaped metal patch and the second L-shaped metal patch are arranged end to end, the groove of the first L-shaped metal patch and the groove of the second L-shaped metal patch are symmetrically arranged, and the two symmetrically arranged grooves are connected together to form the antenna gap.

[0052] For example, see Figure 1 , showing a top view of a circularly polarized antenna according to an embodiment of the present application.

[0053] See also Figure 2 , showing a side view of a circularly polarized antenna according to an embodiment of the present application.

[0054] like Figure 1 and Figure 2As shown, a circularly polarized antenna is shown, which includes a dielectric substrate 1, on which an antenna radiation patch 2 (including: a first L-shaped metal patch and a second L-shaped metal patch), a grounded metal column 3 and an antenna feeding probe 4 are arranged.

[0055] Among them, the first L-shaped metal patch and the second L-shaped metal patch both have a groove, and the first L-shaped metal patch and the second L-shaped metal patch are arranged on the dielectric substrate 1 in a form close to each other, so that the overall structure of the antenna radiation patch 2 is a square. Under this arrangement, the grooves opened on the first L-shaped metal patch and the second L-shaped metal patch are connected to each other to form an antenna gap 5.

[0056] In addition, the head of the first L-shaped metal patch is connected to the ground metal column 3 , and the head of the second L-shaped metal patch is connected to the antenna feeding probe 4 .

[0057] like Figure 1 As shown, the connection line between the antenna feeding probe 4 and the grounding metal column 3 forms a certain angle θ with the center line of the antenna slot 5, and the axial ratio characteristic of the antenna can be optimized by adjusting the size and position of the grounding metal column 3.

[0058] It should be noted that the overall shape of the antenna radiation patch is not limited to a square, but may also be other shapes, depending on the actual situation.

[0059] In some feasible embodiments, based on the above solution, the antenna feeding probe is located at the center of the dielectric substrate.

[0060] It should be noted that the antenna feeding probe is set at the center of the dielectric substrate because: when the circularly polarized antenna is used in an array, the axial ratio characteristics of the antenna array can be further improved by regularly rotating the antenna units. At the same time, the feeding point position of the antenna will not change during the rotation process, and the spacing between the antenna units will not change, which is beneficial to the connection between the antenna and the regularly arranged transceiver modules (T / R modules) in the phased array antenna system.

[0061] When a single antenna is used and the interface position is not a concern, the antenna feeding probe may not be located at the center of the antenna (ie, the center of the dielectric substrate).

[0062] In some feasible embodiments, based on the above solution, an antenna floor is provided on the back side of the dielectric substrate, and the grounding metal column is connected to the antenna floor.

[0063] For example, Figure 2 As shown, the antenna floor 6 is arranged on the back of the dielectric substrate 1 , and the grounding metal column 3 passes through the dielectric substrate 1 and is connected to the antenna floor 6 .

[0064] In this example, two L-shaped metal patches are used as the two arms of a dipole antenna, which is equivalent to the radiation of an electric dipole antenna. The antenna radiation patch, the grounded metal pole, and the antenna floor together form a current loop, which is equivalent to the radiation of a magnetic dipole. Figure 3 As shown, the current loop J E Equivalent to magnetic current J M radiation.

[0065] The realization of circular polarization is mainly due to the periodic current distribution changes on the two L-shaped metal patches, such as Figure 4 The figure shows the top view of the current distribution of the antenna radiation patch. At t = 0, the current is mainly distributed vertically upward along the inner and outer edges of the antenna radiation patch; at t = T / 4, the current is mainly distributed horizontally to the right at the center of the antenna radiation patch; at t = 3T / 4, the current is mainly distributed vertically downward along the inner and outer edges of the antenna radiation patch; at t = T, the current is mainly distributed horizontally to the left at the center of the antenna radiation patch. Along the antenna radiation direction (perpendicular to the screen and outward), the current periodically rotates counterclockwise, so the antenna realizes left-handed circularly polarized wave radiation.

[0066] The connection line between the antenna feed probe and the metal grounding post forms a certain angle with the antenna gap, which causes a certain angle between the electric dipole and the magnetic dipole antenna. The existence of the magnetic dipole and the positional relationship between the magnetic dipole and the electric dipole further improve the impedance bandwidth and axial ratio bandwidth of the antenna.

[0067] like Figure 5 As shown, the reflection coefficient change of the circularly polarized antenna is demonstrated.

[0068] like Figure 6 As shown, the center frequency antenna axial ratio of the circularly polarized antenna is shown.

[0069] like Figure 7 As shown, the antenna axial ratio of the circularly polarized antenna varies with frequency.

[0070] Based on the same inventive concept, an embodiment of the present application further provides a phased array antenna system, comprising: a plurality of array units;

[0071] Each array unit includes a circularly polarized antenna as described in any of the above embodiments, and another three circularly polarized antennas obtained by angularly rotating the circularly polarized antenna as described in any of the above embodiments.

[0072] For example, Figure 8 As shown, a phased array antenna system is shown, which is an 8×8 array unit, each array unit includes four circularly polarized antennas, one of which is the circularly polarized antenna described in any of the above embodiments, and the other three are obtained by rotating the circularly polarized antenna by 90°, 180° and 270° counterclockwise around its own center.

[0073] like Fig. 9 As shown in Figure 1, the XOZ scanning pattern and axial ratio distribution of the phased array antenna system are shown. Fig.10 As shown, the YOZ scanning pattern and axial ratio distribution of the phased array antenna system are displayed, and the axial ratio within the scanning range is better than 3dB.

[0074] In summary, the circularly polarized antenna and phased array antenna system provided in the embodiments of the present application have the following advantages:

[0075] 1. The antenna is easy to process. When used in phased array systems, multiple antennas can be processed in an integrated manner with high processing accuracy and low cost.

[0076] 2. The antenna profile is low. The thickness of the antenna working in the Ka band is only 1mm, which is only 0.09 times the wavelength corresponding to the lowest operating frequency;

[0077] 3. The spacing between unit antennas in the phased array antenna should meet certain requirements to avoid the appearance of grating lobes during beam scanning. For a regularly arranged rectangular array with a scanning range of ±60°, the unit spacing should be less than about 0.53 times the wavelength corresponding to the highest operating frequency. The antenna size of the present invention is only 5mm (less than 0.53 times the wavelength corresponding to the high frequency), and the radiation patch size is only 2.7mm (0.288 times the wavelength corresponding to the highest operating frequency);

[0078] 4. Working frequency bandwidth. -10dB impedance bandwidth is greater than 20% (28-34GHz), 3dB axial ratio bandwidth is 10.3% (28.3-31.4Ghz). Impedance bandwidth and axial ratio characteristics are as follows Figure 5 , Figure 6 and Figure 7 As shown, the antenna axial ratio is better than 3dB within the range of ±60° of the center frequency, and the axial ratio is small within the entire -10dB impedance bandwidth range of 28-34GHz. The antenna feed is located in the center of the antenna array, and the axial ratio characteristics can be further improved by periodically rotating the array without changing the antenna spacing and the relative position relationship of the feeding point.

[0079] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the embodiments disclosed herein. The present application is intended to cover any variations, uses or adaptations of the present application, which follow the general principles of the present application and include common knowledge or customary techniques in the art that are not disclosed in the present application. It should be understood that the present application is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A circularly polarized antenna, characterized in that: include: A dielectric substrate, on which an antenna radiation patch, a grounding metal column and an antenna feeding probe are arranged; An antenna gap is provided inside the antenna radiation patch; The antenna radiation patch is connected to the grounded metal post and the antenna feeding probe respectively; Wherein, a connection line between the antenna feeding probe and the grounded metal column and a center line of the antenna slot form a certain angle.

2. The circularly polarized antenna according to claim 1, characterized in that: The antenna radiation patch includes a first L-shaped metal patch and a second L-shaped metal patch; The head of the first L-shaped metal patch is connected to the grounded metal column, and the head of the second L-shaped metal patch is connected to the antenna feeding probe; A groove is formed on each of the first L-shaped metal patch and the second L-shaped metal patch. The first L-shaped metal patch and the second L-shaped metal patch are arranged end to end so that the grooves on the first L-shaped metal patch and the second L-shaped metal patch constitute the antenna gap.

3. The circularly polarized antenna according to claim 2, characterized in that: The overall structure of the antenna radiation patch is square.

4. The circularly polarized antenna according to claim 1, characterized in that: The antenna feeding probe is located at the center of the dielectric substrate.

5. The circularly polarized antenna according to claim 1, characterized in that: An antenna floor is arranged on the back of the dielectric substrate, and the grounding metal column is connected to the antenna floor.

6. A phased array antenna system, characterized in that: include: a plurality of array elements; Each array unit includes a circularly polarized antenna as claimed in any one of claims 1 to 5, and three other circularly polarized antennas obtained by angularly rotating the circularly polarized antenna as claimed in any one of claims 1 to 5.

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