Side-fed waveguide 1x4 circularly polarized antenna array and applications thereof

Abstract

The present disclosure provides a side-fed waveguide 1x4 circularly polarized antenna array and its application, which comprises: a power division feeding network comprising a primary power division network and a secondary power division network connected with the primary power division network; wherein the primary power division network adopts a side feeding mode, is used for realizing mode conversion from a coaxial line mode to a waveguide mode, and performing power division conversion on a fed-in signal to output a 1:2 primary power division signal; the secondary power division network is used for converting the 1:2 primary power division signal into a 1:4 secondary power division signal; and a four-ridge metal cavity circular polarizer is coupled and connected with the power division feeding network through a coupling gap, and is used for realizing circularly polarized radiation of the 1:4 secondary power division signal.

Description

Technical Field

[0001] This disclosure relates to the field of wireless communication technology, specifically to a side-fed waveguide 1x4 circularly polarized antenna array and its application. Background Technology

[0002] Pure metal waveguide antennas offer advantages such as low loss and wide bandwidth, making them widely used in phased array radar systems. On one hand, to meet the communication requirements between real-time attitude control platforms, it is often necessary to design circularly polarized antennas with a wide axial ratio and wide beamwidth. On the other hand, certain applications often impose limitations on the size and volume of waveguide antennas. Due to the inherent large size and bulk of waveguide structures, traditional waveguide antennas are difficult to design within finite dimensions for array implementation. Therefore, developing compact waveguide circularly polarized antennas is a significant challenge in phased array design. Summary of the Invention

[0003] To address the aforementioned problems in the prior art, this disclosure provides a side-fed waveguide 1x4 circularly polarized antenna array and its application. This antenna array uses a side-fed method, which achieves power division of the primary and secondary signals while realizing mode conversion, greatly reducing the size of the antenna array.

[0004] The first aspect of this disclosure provides a side-fed waveguide 1x4 circularly polarized antenna array, comprising: a power divider feed network, including: a primary power divider network and a secondary power divider network connected to the primary power divider network; wherein, the primary power divider network adopts a side-fed method to realize mode conversion from coaxial line mode to waveguide mode, and to perform power division conversion on the input signal, outputting a 1x2 primary power divider signal; the secondary power divider network is used to convert the 1x2 primary power divider signal into a 1x4 secondary power divider signal; a four-ridged metal cavity circular polarizer is coupled to the power divider feed network through a coupling slot, and is used to realize circularly polarized radiation of the 1x4 secondary power divider signal.

[0005] Furthermore, the primary power divider network employs a stepped ridge waveguide matching structure, which is used to achieve broadband impedance transformation.

[0006] Furthermore, the primary power divider network also includes multiple lateral ridge structures, which are used to introduce parallel admittance to offset part of the imaginary impedance introduced by the antenna.

[0007] Furthermore, the antenna array also includes a coaxial connector, the outer core of which is connected to the lower wall of the primary power divider network via a thread, and the inner core of which is connected to the upper wall of the primary power divider network via a reserved hole in the stepped ridge waveguide matching structure.

[0008] Furthermore, the four-ridged metal cavity circular polarizer is an asymmetrical four-ridged metal cavity, which adjusts the phase of the two orthogonal modes by adjusting the dimensions of the major and minor axes.

[0009] Furthermore, the height of the antenna array is less than 24 mm.

[0010] Furthermore, the phase difference of the circularly polarized radiation signal output by the antenna array is 90°.

[0011] The second aspect of this disclosure provides an application of a side-fed waveguide 1x4 circularly polarized antenna array, as provided in the first aspect of this disclosure, in a wireless communication system.

[0012] This disclosure provides an embodiment of a side-fed waveguide 1x4 circularly polarized antenna array and its application. This antenna array employs a special side-feeding method, simultaneously achieving mode conversion and power distribution. Through a stepped ridge waveguide matching structure designed in the primary power divider network, matching is achieved while significantly reducing the antenna size. Better matching is achieved by reasonably introducing side convex ridges in the ridge waveguide to offset the imaginary part introduced by the antenna. A 1x4 circularly polarized antenna array design is realized with a total antenna array height of less than 1.6 wavelengths. Attached Figure Description

[0013] To gain a more complete understanding of this disclosure and its advantages, reference will now be made to the following description taken in conjunction with the accompanying drawings, wherein:

[0014] Figure 1 A perspective view of a side-fed waveguide 1x4 circularly polarized antenna array according to an embodiment of the present disclosure is shown schematically.

[0015] Figure 2 A layered diagram of a side-fed waveguide 1x4 circularly polarized antenna array according to an embodiment of the present disclosure is shown schematically.

[0016] Figure 3A A bottom view of a primary power distribution network according to an embodiment of the present disclosure is shown schematically.

[0017] Figure 3B A schematic front view of a primary power distribution network according to an embodiment of the present disclosure is shown;

[0018] Figure 3C A schematic top view of a four-ridged metal cavity circular polarizer according to an embodiment of the present disclosure is shown.

[0019] Figure 4A A schematic diagram illustrating port voltage standing wave ratio (VSWR) results according to an embodiment of the present disclosure is shown.

[0020] Figure 4BA schematic diagram illustrating the axial ratio result of an antenna array according to an embodiment of the present disclosure is shown.

[0021] Figure 5A This schematically illustrates the radiation pattern of an antenna array according to an embodiment of the present disclosure in the XZ plane at 20 GHz.

[0022] Figure 5B The diagram illustrates the radiation pattern of an antenna array according to an embodiment of the present disclosure in the XZ plane at 21.5 GHz.

[0023] Figure 5C This schematically illustrates the radiation pattern of an antenna array according to an embodiment of the present disclosure in the YZ plane at 20 GHz.

[0024] Figure 5D The diagram illustrates the radiation pattern of an antenna array according to an embodiment of the present disclosure in the YZ plane at 21.5 GHz. Detailed Implementation

[0025] The embodiments of the present disclosure will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the disclosure. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of the present disclosure for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concepts of the present disclosure.

[0026] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0027] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0028] Figure 1 A perspective view of a side-fed waveguide 1x4 circularly polarized antenna array according to an embodiment of the present disclosure is shown schematically. Figure 2 A layered diagram of a side-fed waveguide 1x4 circularly polarized antenna array according to an embodiment of the present disclosure is shown schematically.

[0029] like Figure 1 and 2As shown, the side-fed waveguide 1x4 circularly polarized antenna array 100 includes: a primary power divider network 10, a secondary power divider network 20, a coupling slot 30, and a four-ridged metal cavity circularly polarized antenna 40.

[0030] The primary power divider network 10 is side-fed and is used to achieve mode conversion from coaxial line mode to waveguide mode, as well as power division of the input signal, outputting a 1-to-2 primary power divider signal. The secondary power divider network 20 is disposed on the primary power divider network 10 and is used to convert the 1-to-2 primary power divider signal into a 1-to-4 secondary power divider signal. The four-ridged metal cavity circular polarizer 40 is coupled to the secondary power divider network 20 through a coupling slot 30, and is used to achieve circular polarization radiation of the 1-to-4 secondary power divider signal output by the secondary power divider network 20.

[0031] In the embodiments of this disclosure, the side-fed waveguide 1x4 circularly polarized antenna array 100 adopts a coaxial structure for side feeding. In conventional designs, coaxial feeding from the back is first required to achieve mode conversion from coaxial mode to waveguide mode, followed by unit feeding via two 1x2 waveguide power dividers. However, existing technologies require a large space for the antenna array, making it difficult to design a 1x4 circularly polarized antenna within a limited size. The embodiments of this disclosure combine mode conversion and power divider networks. By using side feeding, a 1x2 primary power divider is achieved simultaneously with mode conversion. Then, a 1x4 power divider feeding network is achieved through secondary power dividers in the waveguide cavity, significantly reducing the size of the antenna array.

[0032] Specifically, such as Figure 3A As shown, the primary power divider network 10 adopts a stepped ridge waveguide matching structure, specifically including: a first stepped ridge waveguide 110, a second ridge waveguide 120, and a reserved aperture 140. The first stepped ridge waveguide 110 adopts a stepped ridge waveguide structure, and the second ridge waveguide 120 is arranged relatively alternately with the first stepped ridge waveguide 110 and has a coaxial reserved aperture.

[0033] According to an embodiment of this disclosure, the antenna array further includes a coaxial connector 140. The outer core of the coaxial connector 140 is connected to the lower wall (i.e., the second ridge waveguide 120) of the primary power divider network 10 via a thread, and its inner core is connected to the upper wall (i.e., the first stepped ridge waveguide 110) of the primary power divider network 10 via a reserved hole 130 in the stepped ridge waveguide matching structure, thereby connecting the first stepped ridge waveguide 110 and the second ridge waveguide 120 to enable power feeding to the first stepped ridge waveguide 110 and the second ridge waveguide 120.

[0034] In the embodiments of this disclosure, in order to further reduce the height of the antenna array, its primary power divider network 10 adopts a ridge waveguide structure, and realizes broadband impedance transformation through a stepped ridge structure. Broadband impedance matching is achieved by optimizing the height and length of the ridges in the two end ridge waveguides.

[0035] Furthermore, since a large imaginary part appears in the impedance after the output is connected to the secondary power divider network 20 and the four-ridged metal cavity circular polarizer 40, leading to matching deterioration, embodiments of this disclosure provide multiple side-convex ridge structures 150 at the ridge waveguide end of the primary power divider network 10, such as... Figure 3B As shown. The multiple lateral ridge structures 150 are used to introduce parallel admittance, partially offsetting the imaginary part of the impedance introduced by the antenna, so as to achieve a better matching effect.

[0036] According to an embodiment of the present disclosure, the four-ribbed metal cavity circular polarizer 40 includes four metal cavities, each corresponding to a coupling slot in the coupling slot 30, so as to be connected to the output terminal of the secondary power divider signal 20 in a one-to-one correspondence.

[0037] like Figure 3C As shown, the four-ridged metal cavity circular polarizer 40 is an asymmetrical four-ridged metal cavity. Each metal cavity includes a long ridge 410 and a short ridge 420. The four-ridged metal cavity circular polarizer 40 adjusts the phase of the two orthogonal modes by adjusting the length and height of the long ridge 410 and the short ridge 420, and maintains the phase difference at approximately 90° in the designed frequency band (e.g., 19.7–21.6 GHz) to achieve a better circular polarization axial ratio and meet the necessary conditions for circular polarization.

[0038] In the embodiments of this disclosure, assuming the antenna array 100 operates in the frequency range of 19.7–21.6 GHz, within this frequency band, the length and height of the long ridge 410 and the short ridge 420 are adjusted. The length of the long ridge 410 is preferably 1.7–2.1 mm, and its height is preferably 3.6–4.6 mm; the length of the short ridge 420 is preferably 1–1.4 mm, and its height is preferably 3.6–4.6 mm; the height of each metal cavity is preferably 4.2–5.2 mm. Adjusting the length and height of the long ridge 410 and the short ridge 420 within this range adjusts the phase of the two orthogonal modes, achieving a better circular polarization axial ratio and satisfying the necessary conditions for circular polarization.

[0039] According to embodiments of this disclosure, the power divider feed network employs a metal waveguide structure. The primary power divider network uses a side-feeding method, and the secondary power divider network is coupled to a four-ridged metal cavity circular polarizer through coupling slots to achieve circular polarization radiation. Through structural design optimization, the antenna array 100 can achieve an overall height within 24mm, i.e., 1.6 wavelengths, exhibiting a low longitudinal dimension.

[0040] The embodiments of this disclosure have been theoretically simulated for the antenna array 100, and the corresponding voltage standing wave ratio and axial ratio results are shown in the schematic diagram below. Figure 4A and 4B As shown. From Figure 4A and 4B As can be seen, within the bandwidth range of 19.7–21.6 GHz, the antenna standing wave ratio is below 1.5, indicating that more than 95% of its energy is dissipated by the antenna, with a relative bandwidth of approximately 9%. Within the bandwidth range of 19.3–21.6 GHz, the axial ratio is less than 6 dB, and the circular polarization axial ratio bandwidth is greater than the impedance bandwidth, indicating good circular polarization throughout the entire impedance bandwidth.

[0041] like Figures 5A-5D The diagram shows the azimuth and elevation radiation patterns of the antenna array. As can be seen from the diagram, the antenna array 100 designed according to the above embodiment has a wide right-hand circularly polarized beam within the operating frequency band, which can meet the performance requirements of wireless communication systems for circularly polarized antennas.

[0042] This disclosure provides a side-fed waveguide 1x4 circularly polarized antenna array. This array employs a special side-feeding method, simultaneously achieving mode conversion and power distribution. Through a stepped ridge waveguide matching structure designed in the primary power divider network, matching is achieved while significantly reducing the antenna size. Better matching is achieved by reasonably introducing side convex ridges in the ridge waveguide to offset the imaginary part introduced by the antenna. A 1x4 circularly polarized antenna array design is realized with a total antenna array height less than 1.6 wavelengths.

[0043] Another aspect of this disclosure provides an application of the side-fed waveguide 1x4 circularly polarized antenna array shown in the above embodiments in a wireless communication system. It should be noted that the specific structure and working principle of this side-fed waveguide 1x4 circularly polarized antenna array 100 are as shown in the above embodiments, and will not be described in detail here.

[0044] Although the present disclosure has been illustrated and described in detail in the accompanying drawings and the foregoing description, such illustrations and descriptions should be considered illustrative or exemplary rather than limiting.

[0045] Those skilled in the art will understand that the features described in the various embodiments and / or claims of this disclosure can be combined and / or combined in various ways, even if such combinations or combinations are not explicitly described in this disclosure. In particular, the features described in the various embodiments and / or claims of this disclosure can be combined and / or combined in various ways without departing from the spirit and teachings of this disclosure. All such combinations and / or combinations fall within the scope of this disclosure.

[0046] Although this disclosure has been shown and described with reference to specific exemplary embodiments thereof, those skilled in the art will understand that various changes in form and detail may be made to this disclosure without departing from the spirit and scope of the disclosure as defined by the appended claims and their equivalents. Therefore, the scope of this disclosure should not be limited to the above embodiments, but should be defined not only by the appended claims, but also by their equivalents.

Claims

1. A side-fed waveguide 1x4 circularly polarized antenna array, characterized in that, The antenna array comprises: a power division feeding network comprising a primary power division network and a secondary power division network connected with the primary power division network; wherein the primary power division network adopts a side feeding mode, is used for realizing mode conversion from a coaxial mode to a waveguide mode, and performing power division conversion on a feeding signal to output a 1:2 primary power division signal; the secondary power division network is used for converting the 1:2 primary power division signal into a 1:4 secondary power division signal; a four-ridge metal cavity circular polarizer coupled with the power division feeding network through a coupling gap, and used for realizing circular polarization radiation of the 1:4 secondary power division signal. The primary power division network adopts a stepped ridge waveguide matching structure, which is used for realizing wideband impedance conversion; the primary power division network comprises a plurality of side convex ridge structures, which are used for introducing a parallel admittance to realize cancellation of a part of impedance introduced by an antenna.

2. The side-fed waveguide 1x4 circularly polarized antenna array of claim 1, wherein, The antenna array further comprises: a coaxial connector, an outer core of which is connected with a lower wall of the primary power division network through a thread, and an inner core of which is connected with an upper wall of the primary power division network through a reserved hole on the stepped ridge waveguide matching structure.

3. The side-fed waveguide 1x4 circularly polarized antenna array of claim 1, wherein, The four-ridge metal cavity circular polarizer is an asymmetric four-ridge metal cavity, and the size of a long axis and a short axis is adjusted to adjust the phase of two orthogonal modes.

4. The side-fed waveguide 1x4 circularly polarized antenna array of claim 1, wherein, The height of the antenna array is less than 24 mm.

5. The side-fed waveguide 1x4 circularly polarized antenna array of claim 1, wherein, The phase difference of circular polarization radiation signals output by the antenna array is 90°.

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