Broadband Low Cross-Polarization Millimeter-Wave Antenna Array Fed by Printed Ridge Slot Waveguide

Abstract

The present invention relates to the technical field of millimeter-wave antennas, and provides a broadband low cross-polarization millimeter-wave antenna array fed by a printed ridge waveguide, which includes an antenna structure layer and a printed ridge waveguide feeding layer. The antenna structure layer includes a dielectric substrate A, an upper floor, two parasitic units, and four antenna units. The two parasitic units are symmetrically arranged on the dielectric substrate A; the four antenna units are symmetrically arranged in pairs on both sides of the two parasitic units, and the two antenna units on the same side are symmetrically arranged; the printed ridge waveguide feeding layer includes a dielectric substrate B, and a first rectangular slot and a second rectangular slot are respectively formed on the dielectric substrate B. By using the antenna units after miniaturization design, the miniaturization design of the antenna is realized. The symmetrically arranged antenna units and the loading of the parasitic units effectively reduce the cross-polarization level and improve the gain of the antenna in the high-frequency band at the same time.

Description

Technical Field

[0001] The present invention relates to the technical field of millimeter-wave antennas, and more particularly, to a broadband low cross-polarization millimeter-wave antenna array fed by a printed ridge slot waveguide. Background Art

[0002] In recent years, the characteristics of low latency and high transmission rate of 5G mobile communication systems have enabled them to be applied in various industrial fields. Due to the shortage of spectrum resources and severe interference in the microwave band, many current 5G systems operate in the millimeter-wave band. The millimeter-wave band not only has a wide bandwidth but also has advantages such as fast transmission speed, high communication security, and good transmission quality, greatly compensating for the disadvantages of microwave low-frequency transmission. However, electromagnetic waves have higher path loss and stronger phase noise during propagation in the millimeter-wave band. Therefore, designing a millimeter-wave antenna with broadband and high-gain performance has very important research significance.

[0003] In the past decade, the slot waveguide structure has received extensive research and attention because it can be used as a low-loss waveguide structure in the millimeter-wave band. Compared with the traditional microstrip line structure, the slot waveguide structure has lower transmission loss because it can suppress the transmission of unnecessary surface waves. Currently, the slot waveguide structure has been widely used in the design of antenna array feed networks. The literature "Wide-Band Slot Antenna Arrays With Single-Layer Corporate-Feed Network in Ridge Gap Waveguide Technology, (A.U. Zaman and P.-S. Kildal, IEEE Transactions on Antennas and Propagation, vol. 62, no. 6, pp. 2992-3001, 2014)" introduced a 2×2 broadband slot antenna array based on a metal ridge waveguide structure, and the antenna array achieved a gain higher than 12.1 dBi in the frequency band of 12 GHz to 15 GHz. However, due to the all-metal ridge waveguide structure used in the antenna array, it is heavy, difficult to process, and difficult to integrate and design.

[0004] To overcome these drawbacks, the printed ridge slot waveguide structure emerged. Compared with the traditional metal ridge waveguide structure, the printed ridge slot waveguide structure directly prints the microstrip ridge line on the PCB circuit board, which is easy to integrate and implement while retaining the advantage of low transmission loss of the ridge waveguide structure. The literature "Wideband Low-Loss Magnetoelectric Dipole Antenna for 5G Wireless Network With Gain Enhancement Using Meta Lens and Gap Waveguide Technology Feeding, (A. Dadgarpour, M. Sharifi Sorkherizi, and A. A. Kishk, IEEE Transactions on Antennas and Propagation, vol. 64, no. 12, pp. 5094-5101, 2016)" introduced a 1×4 broadband magnetoelectric dipole array loaded with split-ring resonator structures. This array uses a printed ridge slot waveguide as the feeding network of the array, reducing the transmission loss of the antenna. Moreover, the array element uses a magnetoelectric dipole antenna, which has broadband reflection performance. Furthermore, to further improve the array gain, multiple split-ring resonator structures are placed above the array. Finally, this array can achieve an impedance bandwidth of 34% in the 30 GHz frequency band, and the gain is higher than 16 dBi. However, due to the loading of multiple split-ring resonator structures in this array and the use of magnetoelectric dipole elements, the overall profile of the antenna is relatively high and the structure is complex.

[0005] As can be seen from the above literature, using a slot waveguide as the feeding structure of an antenna in the millimeter wave band is an effective way to reduce the antenna transmission loss, and using a printed ridge slot waveguide structure is more conducive to the integration and design of the antenna. The antennas that achieve broadband and high gain reported in the existing literature all have relatively complex multi-layer structures, with a high overall profile and large size. Therefore, it still has very important research significance to design a miniaturized broadband antenna with a lower profile and a simpler structure in the millimeter wave band. Summary of the Invention

[0006] The object of the present invention is to provide a broadband low cross-polarization millimeter wave antenna array fed by a printed ridge slot waveguide, which has a relatively wide bandwidth and a lower profile, and the designed center operating frequency is 28 GHz, so as to at least overcome the drawbacks existing in the existing millimeter wave antennas.

[0007] The object of the present invention is achieved by the following technical solutions:

[0008] A broadband low cross-polarization millimeter-wave antenna array fed by a printed ridged slot waveguide, comprising an antenna structure layer and a printed ridged slot waveguide feeding layer arranged in sequence from top to bottom;

[0009] The antenna structure layer includes a dielectric substrate A, an upper floor, two parasitic units, and four antenna units. The dielectric substrate A and the upper floor are tightly arranged in sequence from top to bottom;

[0010] The two parasitic units are symmetrically arranged on the dielectric substrate A; the four antenna units are symmetrically arranged in two groups on both sides of the two parasitic units, and the two antenna units on the same side are symmetrically arranged;

[0011] The printed ridged slot waveguide feeding layer includes a dielectric substrate B, and the dielectric substrate B is tightly arranged at the bottom of the upper floor;

[0012] A first rectangular slot and a second rectangular slot are respectively formed on the dielectric substrate B; the first rectangular slot corresponds to the parasitic unit, and there are two first rectangular slots corresponding to a single parasitic unit; the second rectangular slot corresponds to the antenna unit one by one; slots corresponding to the first rectangular slot and the second rectangular slot are formed on the upper floor.

[0013] In some possible embodiments, the parasitic unit includes a half-circular patch, the half-circular patch is printed on the dielectric substrate A, and the arc edges of the half-circular patches of the two parasitic units are opposite to each other. The two first rectangular slots corresponding to a single parasitic unit respectively correspond to both ends of the half-circular patch;

[0014] The antenna unit includes a quarter-circular patch and a quarter-circular arc patch. The quarter-circular patch is printed on the dielectric substrate A and located in the inner ring, and the quarter-circular arc patch is printed on the dielectric substrate A and located in the outer ring. The arc edge of the quarter-circular patch is opposite to the inner arc edge of the quarter-circular arc patch, and the second rectangular slot is aligned with the quarter-circular patch.

[0015] In some possible embodiments, metallized vias are formed on the straight edge of the half-circular patch, the outer arc edge of the quarter-circular arc patch, and the straight edges of the quarter-circular arc patches of the two antenna units on the same side of the parasitic unit. The metallized vias penetrate through the dielectric substrate A and are connected to the upper floor.

[0016] In some possible embodiments, the printed ridged slot waveguide feeding layer further includes a dielectric substrate C, a dielectric substrate D, and a lower floor. The dielectric substrate C, the dielectric substrate D, and the lower floor are tightly arranged in sequence from top to bottom at the bottom of the dielectric substrate B;

[0017] The top surface of the dielectric substrate C is provided with a feeding network structure, the feeding network structure is externally connected to an SMA connector, and the top surface of the dielectric substrate D is provided with an EBG structure.

[0018] In some possible embodiments, the feeding network structure includes a quarter-wavelength impedance transformer printed on the top surface of the dielectric substrate C, a 50Ω microstrip ridge line, and a 50Ω microstrip line. One end of the 50Ω microstrip ridge line is connected to the quarter-wavelength impedance transformer, the other end of the 50Ω microstrip ridge line is connected to one end of the 50Ω microstrip line, and the other end of the 50Ω microstrip line is connected to the SMA connector.

[0019] In some possible embodiments, the EBG structure includes a plurality of EBG unit patches printed on the top surface of the dielectric substrate D. The plurality of EBG unit patches are distributed in a rectangular array. EBG metallization vias corresponding to the EBG unit patches one by one are formed on the dielectric substrate D, and the EBG metallization vias penetrate through the dielectric substrate D and are connected to the lower floor.

[0020] In some possible embodiments, the number of EBG unit patches printed on the top surface of the dielectric substrate D is 12×12.

[0021] In some possible embodiments, a plurality of dielectric substrate vias A are formed along the circumferential direction of the edge of the dielectric substrate A, a plurality of dielectric substrate vias B are formed along the circumferential direction of the edge of the dielectric substrate B, a plurality of dielectric substrate vias C are formed along the circumferential direction of the edge of the dielectric substrate C, and a plurality of dielectric substrate vias D are formed along the circumferential direction of the edge of the dielectric substrate D;

[0022] The dielectric substrate vias A, dielectric substrate vias B, dielectric substrate vias C, and dielectric substrate vias D are coaxially arranged.

[0023] The millimeter-wave antenna array provided by the present invention is fed through SMA connectors. The excitation signal is transmitted from the SMA connectors to the quarter-wavelength impedance transformer through 50Ω microstrip lines, and then divided into four equal-amplitude signals and fed to the four antenna elements respectively through the second rectangular slots on the dielectric substrate B, thus forming array radiation. At the same time, the antenna elements adopted by the millimeter-wave antenna array are quarter-element structures after miniaturization design, mainly composed of a quarter-circular patch and a quarter-circular arc patch. In order to cancel the radiation of the antenna element in the y direction and improve the characteristic of the cross-polarization difference of the antenna element, the four antenna elements after array formation are symmetrically placed with respect to the x-axis and y-axis. At the same time, a 180° phase difference between the antenna elements that are symmetric with respect to the x-axis is provided by the feeding network structure in the x-axis direction. Secondly, the broadband characteristic of the millimeter-wave antenna array is mainly realized by the structural characteristics of the antenna element. The quarter-circular patch and the quarter-circular arc patch resonate at low frequency and high frequency respectively, and the dual-resonant characteristic of the antenna element realizes the broadband characteristic of the antenna, so that the -10dB impedance bandwidth of the millimeter-wave antenna array is 26.9GHz to 30.9GHz. In addition, the radiation performance of the millimeter-wave antenna array mainly comes from the energy radiation of the quarter-circular patch and the quarter-circular arc patch, and the parasitic element enhances the radiation performance of the antenna in the high-frequency band. At the same time, the printed ridged slot waveguide structure is mainly composed of periodically arranged EBG unit patches. The stopband provided by the EBG structure composed of periodically arranged EBG unit patches covers the working bandwidth of the antenna. In the stopband, the EBG structure confines the quasi-TEM wave above the 50Ω microstrip ridge line, and the electromagnetic wave only propagates along the 50Ω microstrip ridge line in the upper dielectric substrate, while suppressing the propagation of other surface waves. By this method, the transmission loss of the excitation signal on the feeding network structure is reduced.

[0024] The technical solutions of the embodiments of the present invention have at least the following advantages and beneficial effects:

[0025] 1. The broadband low cross-polarization millimeter-wave antenna array fed by the printed ridged slot waveguide provided by the present invention realizes the miniaturization design of the antenna by using the antenna element after miniaturization design. At the same time, the two patch unit structures of the antenna element excite the two resonant modes of the microstrip patch antenna, successfully enhancing the impedance matching of the antenna within the bandwidth, and the -10dB impedance bandwidth reaches 26.9GHz to 30.9GHz.

[0026] 2. The present invention uses the printed ridged slot waveguide as the feeding structure of the antenna, and uses the characteristic of the EBG structure to suppress the surface wave, confining the propagation of the electromagnetic wave above the 50Ω microstrip ridge line. Compared with the traditional microstrip line structure, this structure effectively reduces the transmission loss of the millimeter-wave antenna on the feeding network structure;

[0027] 3. By adopting a new array arrangement method, the present invention realizes the suppression of cross polarization by using the coupled loading technology. After forming an array, the antenna elements can significantly improve the cross polarization performance of the antenna. This arrangement method places four antenna elements symmetrically about the x-axis and y-axis respectively. At the same time, the feed network structure provides a 180° phase difference for the antenna elements placed symmetrically about the x-axis, cancels the spatial phase difference between the antenna elements in the x-axis direction, and realizes the suppression effect on the polarization in the y-axis direction. In addition, by adding parasitic elements between the antenna elements placed symmetrically about the y-axis, the radiation effect of the polarization in the y-axis direction is compensated, and the improvement of the antenna gain in the high-frequency band is realized. Description of the Drawings

[0028] Figure 1 It is a side view of the millimeter-wave antenna array provided by an embodiment of the present invention;

[0029] Figure 2 It is a top view of the millimeter-wave antenna array provided by an embodiment of the present invention;

[0030] Figure 3 It is a cross-sectional view of the top surface of the dielectric substrate B provided by an embodiment of the present invention;

[0031] Figure 4 It is a cross-sectional view of the top surface of the dielectric substrate C provided by an embodiment of the present invention;

[0032] Figure 5 It is a cross-sectional view of the top surface of the dielectric substrate D provided by an embodiment of the present invention;

[0033] Figure 6 It is a simulation curve graph of the -10dB impedance bandwidth and gain of the millimeter-wave antenna array provided by an embodiment of the present invention varying with frequency;

[0034] Figure 7 It is a simulation radiation pattern of the millimeter-wave antenna array provided by an embodiment of the present invention at a frequency of 27 GHz;

[0035] Figure 8 It is a simulation radiation pattern of the millimeter-wave antenna array provided by an embodiment of the present invention at a frequency of 28 GHz;

[0036] Figure 9 It is a simulation radiation pattern of the millimeter-wave antenna array provided by an embodiment of the present invention at a frequency of 29 GHz;

[0037] Figure 10 It is a simulation radiation pattern of the millimeter-wave antenna array provided by an embodiment of the present invention at a frequency of 30 GHz.

[0038] Icons: 10 - Antenna structure layer, 11 - Dielectric substrate A, 11a - Dielectric substrate via A, 12 - Upper floor, 13 - Parasitic unit, 14 - Antenna unit, 15 - Metallized via, 20 - Printed ridged slot waveguide feeding layer, 21 - Dielectric substrate B, 21a - First rectangular slot, 21b - Second rectangular slot, 21c - Dielectric substrate via B, 22 - Dielectric substrate C, 22a - Dielectric substrate via C, 23 - Dielectric substrate D, 23a - Dielectric substrate via D, 24 - Lower floor, 25 - Feeding network structure, 251 - Quarter - wavelength impedance transformer, 252 - 50Ω microstrip ridge line, 253 - 50Ω microstrip line, 26 - EBG structure, 261 - EBG unit patch, 262 - EBG metallized via. Detailed implementation

[0039] Embodiment

[0040] Please refer to Figures 1 to 5 , this embodiment provides a broadband low - cross - polarization millimeter - wave antenna array fed by a printed ridged slot waveguide, which can achieve broadband (26.9 GHz to 30.9 GHz) and relatively high gain (the maximum achievable gain is 10.2 dBi). Specifically, the millimeter - wave antenna array includes an antenna structure layer 10 and a printed ridged slot waveguide feeding layer 20 arranged successively from top to bottom.

[0041] In this embodiment, the antenna structure layer 10 includes a dielectric substrate A 11, an upper floor 12, two parasitic units 13, and four antenna units 14. Among them, the dielectric substrate A 11 and the upper floor 12 are closely arranged successively from top to bottom.

[0042] Combined with Figure 2 the content shown, the two parasitic units 13 are symmetrically arranged on the dielectric substrate A 11. Among them, the parasitic unit 13 includes a semi - circular patch, and the semi - circular patch is printed on the dielectric substrate A 11. At this time, the arc - shaped sides of the semi - circular patches of the two parasitic units 13 are opposite to each other.

[0043] Continue to refer to Figure 2 , the four antenna units 14 are symmetrically arranged in two - by - two groups on both sides of the two parasitic units 13, and the two antenna units 14 on the same side are also symmetrically arranged. That is to say, the four antenna units 14 are first symmetrically arranged in two - by - two groups about the x - axis, and then the two antenna units 14 in each group are symmetrically arranged about the y - axis, so as to realize that the four antenna units 14 are symmetrically arranged along the x - axis and the y - axis respectively.

[0044] Among them, the antenna element 14 includes a quarter-circular patch and a quarter-circular arc patch, and the centers of the quarter-circular patch and the quarter-circular arc patch coincide. At this time, the quarter-circular patch is printed on the dielectric substrate A11 and located in the inner ring, the quarter-circular arc patch is printed on the dielectric substrate A11 and located in the outer ring, and the arc edge of the quarter-circular patch is opposite to the inner arc edge of the quarter-circular arc patch. By adopting the antenna element 14 composed of a quarter-circular patch and a quarter-circular arc patch, two resonance modes can be excited in the antenna element 14 within the working bandwidth to achieve the broadband characteristics of the antenna. At the same time, by symmetrically arranging the four antenna elements 14 with respect to the x-axis and the y-axis respectively, the cross-polarization characteristics of the antenna can be effectively improved, and by adding the parasitic element 13, the gain of the antenna in the high-frequency band can be enhanced.

[0045] At the same time, a plurality of metallized vias 15 are opened on the straight edge of the above-mentioned half-circular patch, the outer arc edge of the quarter-circular arc patch, and the straight edge opposite to the quarter-circular arc patch of the two antenna elements 14 (that is, the two antenna elements 14 that are symmetric about the x-axis and on the same side) on the same side of the parasitic element 13, and the metallized vias 15 penetrate through the dielectric substrate A11 and are connected to the upper floor 12.

[0046] In this embodiment, the printed ridged waveguide feeding layer 20 includes a dielectric substrate B21, a dielectric substrate C22, a dielectric substrate D23, and a lower floor 24. Among them, the dielectric substrate B21 is closely arranged at the bottom of the upper floor 12, and the dielectric substrate C22, the dielectric substrate D23, and the lower floor 24 are sequentially and closely arranged at the bottom of the dielectric substrate B21 from top to bottom.

[0047] Combined with Figure 3 As shown in the figure, a first rectangular slot 21a and a second rectangular slot 21b are respectively opened on the dielectric substrate B21. For example, the first rectangular slot 21a and the second rectangular slot 21b opened on the dielectric substrate B21 in this embodiment are both rectangular grooves. Among them, the first rectangular slot 21a corresponds to the parasitic element 13, and there are two first rectangular slots 21a corresponding to a single parasitic element 13. At this time, the two first rectangular slots 21a corresponding to a single parasitic element 13 respectively correspond to both ends of the half-circular patch. The second rectangular slot 21b corresponds to the antenna element 14 one by one, that is, one antenna element 14 corresponds to one second rectangular slot 21b. At this time, the second rectangular slot 21b is aligned with the quarter-circular patch. Correspondingly, slots corresponding to the first rectangular slot 21a and the second rectangular slot 21b are opened on the upper floor 12 (not shown in the figure). It can be understood that the slots opened on the upper floor 12 have the same shape and size as the first rectangular slot 21a and the second rectangular slot 21b respectively to facilitate signal transmission.

[0048] It should be noted that the second rectangular slot 21b opened on the dielectric substrate B21 is the feeding slot of the antenna element 14, which is used to allow the energy transmitted by the feeding network structure 25 provided on the top surface of the dielectric substrate C22 to pass through, so as to excite the antenna element 14. The first rectangular slot 21a opened on the dielectric substrate B21 is a defected ground structure, which is used to disrupt the current distribution between the antenna element 14 and the parasitic element 13, so as to improve the impedance matching of the millimeter-wave antenna array within the operating bandwidth.

[0049] Combined with Figure 4 As shown in the figure, a feeding network structure 25 is provided on the top surface of the dielectric substrate C22. The feeding network structure 25 is externally connected to an SMA connector to transmit an excitation signal to the feeding network structure 25 through the SMA connector. Specifically, the feeding network structure 25 includes a quarter-wavelength impedance transformer 251, a 50Ω microstrip ridge line 252, and a 50Ω microstrip line 253 printed on the top surface of the dielectric substrate C22, so that the feeding network structure 25 can divide the excitation signal into four equal-amplitude signals and output them to the four antenna elements 14 respectively.

[0050] Among them, one end of the 50Ω microstrip ridge line 252 is connected to the quarter-wavelength impedance transformer 251, the other end of the 50Ω microstrip ridge line 252 is connected to one end of the 50Ω microstrip line 253, and the other end of the 50Ω microstrip line 253 extends to the edge of the dielectric substrate C22 and then is connected to the SMA connector. It should be noted that in order to cancel the spatial phase difference between the antenna elements 14 symmetrically arranged about the x-axis, the phases of the energy output by the feeding network structure 25 differ by 180° in the x-axis direction.

[0051] Combined with Figure 5 As shown in the figure, an EBG structure 26 is provided on the top surface of the dielectric substrate D23, so that within the stopband, the EBG structure 26 confines the quasi-TEM wave above the 50Ω microstrip ridge line 252, and the electromagnetic wave only propagates along the 50Ω microstrip ridge line 252 in the upper dielectric substrate, while suppressing the propagation of other surface waves.

[0052] Specifically, the EBG structure 26 includes a plurality of EBG unit patches 261 printed on the top surface of the dielectric substrate D23. The plurality of EBG unit patches 261 are distributed in a rectangular array. For example, in this embodiment, there are 12×12 EBG unit patches 261 printed on the top surface of the dielectric substrate D23. Of course, in actual implementation, the number of EBG unit patches 261 can also be adjusted according to needs. At the same time, EBG metallized vias 262 corresponding to the EBG unit patches 261 are formed on the dielectric substrate D23. The EBG metallized vias 262 penetrate through the dielectric substrate D23 and are connected to the lower floor 24, so as to jointly form the EBG structure 26 through the EBG unit patches 261 and the EBG metallized vias 262.

[0053] In addition, in combination with Figure 2 , Figure 3 , Figure 4 and Figure 5 as shown, a plurality of dielectric substrate vias A11a are formed along the circumferential direction of the edge of the dielectric substrate A11, a plurality of dielectric substrate vias B21c are formed along the circumferential direction of the edge of the dielectric substrate B21, a plurality of dielectric substrate vias C22a are formed along the circumferential direction of the edge of the dielectric substrate C22, and a plurality of dielectric substrate vias D23a are formed along the circumferential direction of the edge of the dielectric substrate D23. The dielectric substrate vias A11a, the dielectric substrate vias B21c, the dielectric substrate vias C22a, and the dielectric substrate vias D23a are coaxially arranged. By forming corresponding dielectric substrate vias on the dielectric substrates A11, B21, C22, and D23, it is beneficial to the fixation of the entire millimeter-wave antenna array structure.

[0054] Through the simulation test of the millimeter-wave antenna array, the simulation curve and a series of simulation radiation patterns of the millimeter-wave antenna array are obtained, as Figures 6 to 10 shown.

[0055] Combined with Figure 6 the simulation curve of the -10dB impedance bandwidth and the gain varying with frequency of the millimeter-wave antenna array shown, it can be seen that the millimeter-wave antenna array provided in this embodiment has a -10dB impedance bandwidth of 26.9 GHz to 30.9 GHz and a relative center bandwidth of 14.2%.

[0056] Combined with Figure 7 the simulation radiation pattern of the millimeter-wave antenna array at 27 GHz shown, it can be seen that the cross-polarization level of the millimeter-wave antenna array at this frequency is lower than 30 dB in the 0° direction, and the maximum gain is 10.1 dBi.

[0057] Combined with Figure 8It can be seen from the simulated radiation pattern of the millimeter-wave antenna array shown at a frequency of 28 GHz that the cross-polarization level of the millimeter-wave antenna array at this frequency is lower than 25 dB in the 0° direction, and the maximum gain is 9.9 dBi.

[0058] Combined with Figure 9 It can be seen from the simulated radiation pattern of the millimeter-wave antenna array shown at a frequency of 29 GHz that the cross-polarization level of the millimeter-wave antenna array at this frequency is lower than 25 dB in the 0° direction, and the maximum gain is 10.2 dBi.

[0059] Combined with Figure 10 It can be seen from the simulated radiation pattern of the millimeter-wave antenna array shown at a frequency of 30 GHz that the cross-polarization level of the millimeter-wave antenna array at this frequency is lower than 25 dB in the 0° direction, and the maximum gain is 9.4 dBi.

[0060] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A broadband low cross-polarization millimeter-wave antenna array fed by a printed ridge slot waveguide, comprising an antenna structure layer and a printed ridge slot waveguide feeding layer arranged successively from top to bottom, characterized in that, The antenna structure layer includes a dielectric substrate A, an upper floor, two parasitic units, and four antenna units. The dielectric substrate A and the upper floor are arranged in close contact with each other from top to bottom in sequence. The two parasitic units are symmetrically arranged on the dielectric substrate A. The four antenna units are symmetrically arranged in two groups on both sides of the two parasitic units, and the two antenna units on the same side are symmetrically arranged. The printed ridged slot waveguide feeding layer includes a dielectric substrate B, and the dielectric substrate B is arranged in close contact with the bottom of the upper floor. A first rectangular slot and a second rectangular slot are respectively formed on the dielectric substrate B. The first rectangular slot corresponds to the parasitic unit, and there are two first rectangular slots corresponding to a single parasitic unit. The second rectangular slot corresponds to the antenna unit one by one. Slots corresponding to the first rectangular slot and the second rectangular slot are formed on the upper floor. The parasitic unit includes a half-circular patch, and the half-circular patch is printed on the dielectric substrate A. The arc edges of the half-circular patches of the two parasitic units face each other, and the two first rectangular slots corresponding to a single parasitic unit respectively correspond to both ends of the half-circular patch. The antenna unit includes a quarter-circular patch and a quarter-circular arc patch. The quarter-circular patch is printed on the dielectric substrate A and is located in the inner ring. The quarter-circular arc patch is printed on the dielectric substrate A and is located in the outer ring. The arc edge of the quarter-circular patch faces the inner arc edge of the quarter-circular arc patch, and the second rectangular slot is aligned with the quarter-circular patch. Metallized vias are formed on the straight edge of the half-circular patch, the outer arc edge of the quarter-circular arc patch, and the straight edges of the quarter-circular arc patches of the two antenna units on the same side of the parasitic unit. The metallized vias penetrate through the dielectric substrate A and are connected to the upper floor.

2. The broadband low cross-polarization millimeter-wave antenna array fed by a printed ridge slot waveguide according to claim 1, characterized in that, The printed ridged slot waveguide feeding layer further includes a dielectric substrate C, a dielectric substrate D, and a lower floor. The dielectric substrate C, the dielectric substrate D, and the lower floor are arranged in close contact with each other from top to bottom in sequence at the bottom of the dielectric substrate B. A feeding network structure is arranged on the top surface of the dielectric substrate C, and the feeding network structure is externally connected to an SMA connector. An EBG structure is arranged on the top surface of the dielectric substrate D.

3. The broadband low cross-polarization millimeter-wave antenna array fed by a printed ridged waveguide according to claim 2, characterized in that, The feeding network structure includes a quarter-wavelength impedance transformer, a 50Ω microstrip ridge line, and a 50Ω microstrip line printed on the top surface of the dielectric substrate C. One end of the 50Ω microstrip ridge line is connected to the quarter-wavelength impedance transformer, the other end of the 50Ω microstrip ridge line is connected to one end of the 50Ω microstrip line, and the other end of the 50Ω microstrip line is connected to the SMA connector.

4. The broadband low cross-polarization millimeter-wave antenna array fed by a printed ridge slot waveguide according to claim 2, wherein The EBG structure includes a plurality of EBG unit patches printed on the top surface of the dielectric substrate D. The plurality of EBG unit patches are distributed in a rectangular array. EBG metallized vias corresponding to the EBG unit patches one by one are formed on the dielectric substrate D. The EBG metallized vias penetrate through the dielectric substrate D and are connected to the lower floor.

5. The broadband low cross-polarization millimeter-wave antenna array fed by a printed ridge slot waveguide according to claim 4, characterized in that, The number of EBG unit patches printed on the top surface of the dielectric substrate D is 12×12.

6. The broadband low cross-polarization millimeter-wave antenna array fed by a printed ridge slot waveguide according to claim 2, characterized in that, A plurality of dielectric substrate vias A are formed along the circumference of the edge of the dielectric substrate A, a plurality of dielectric substrate vias B are formed along the circumference of the edge of the dielectric substrate B, a plurality of dielectric substrate vias C are formed along the circumference of the edge of the dielectric substrate C, and a plurality of dielectric substrate vias D are formed along the circumference of the edge of the dielectric substrate D; The dielectric substrate via A, the dielectric substrate via B, the dielectric substrate via C, and the dielectric substrate via D are coaxially arranged.

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