High out-of-band rejection dual-passband SIW filtering antenna

Abstract

The invention discloses a high out-of-band rejection dual-passband SIW filtering antenna which comprises an upper dielectric substrate, a lower dielectric substrate, a first metal layer, a second metal layer, a third metal layer, a fourth metal layer, a plurality of metalized via holes in the upper dielectric substrate and the lower dielectric substrate, four M2 screw holes in the edges of the upper dielectric substrate and the lower dielectric substrate, and a 2.92 mm feed connector. A first metal layer is printed on the upper layer of the upper-layer dielectric substrate, a second metal layer is printed on the lower layer of the upper-layer dielectric substrate, and a plurality of metalized via holes are formed in the upper-layer dielectric substrate. A third metal layer is printed on the upper layer of the lower-layer dielectric substrate, a fourth metal layer is printed on the lower layer of the lower-layer dielectric substrate, and a plurality of metalized via holes are formed in the lower-layer dielectric substrate. The 2.92 mm feed connector is installed below the lower layer dielectric substrate, and a feed connector probe feeds power to the upper layer dielectric substrate. The first metal layer is provided with two radiation grooves. The second metal layer and the third metal layer are provided with four coupling grooves. The dual-passband SIW filtering antenna provided by the invention has a high out-of-band rejection level and good radiation performance.

Description

Technical Field

[0001] The present invention belongs to the field of communication technologies, and particularly relates to a high out-of-band rejection dual-band SIW filter antenna. Background Art

[0002] In traditional wireless communication systems, antennas and filters are usually designed as two independent devices and interconnected through a 50Ω transmission line. To eliminate the impedance mismatch generated during interconnection, a matching circuit often needs to be introduced between the two. This not only increases the design complexity but also enlarges the overall circuit size, which is not conducive to the miniaturization and high integration of the system. Therefore, in recent years, an integrated design of antennas and filters has been proposed to form filter antennas, aiming to simultaneously achieve the goals of size compression and system performance optimization.

[0003] Substrate Integrated Waveguide (SIW), hereinafter simply referred to as SIW, is a new type of transmission line structure with advantages such as high Q value, low loss, and easy integration with planar circuits. It has been widely used in microwave and millimeter-wave circuit designs. SIW simulates the transmission characteristics of traditional metal waveguides by constructing a metal via array in a dielectric substrate such as a printed circuit board (PCB) or low-temperature co-fired ceramic (LTCC), and combines the low loss and high power-carrying capacity of waveguides. Compared with traditional metal waveguides, SIW can effectively reduce the device size and weight, lower costs, improve integration and reliability, and is suitable for fields such as wireless communication, radar, and satellite communication.

[0004] Dual-band antennas need to operate simultaneously in two frequency bands. If the out-of-band rejection ability is insufficient, it is easy to introduce interference signals in adjacent frequency bands, resulting in crosstalk between systems. A dual-band SIW antenna with high out-of-band rejection helps to suppress spurious radiation and image responses in non-operating frequency bands, improves the spectral selectivity and anti-interference ability of the system, and thus enhances the overall performance of the dual-band communication system. Summary of the Invention

[0005] The object of the present invention is to design a high out-of-band rejection dual-band SIW filter antenna to solve the deficiency of low suppression levels between the two passbands and outside the passbands in dual-band communication.

[0006] The present invention is realized through the following technical solutions:

[0007] A high out-of-band rejection dual-band SIW filter antenna includes upper and lower dielectric substrates, a first metal layer, a second metal layer, a third metal layer, a fourth metal layer, a number of metallized vias in the upper and lower dielectric substrates, four M2 screw holes at the edges of the upper and lower dielectric substrates, and a 2.92mm feed connector.

[0008] The upper layer of the upper dielectric substrate is printed with a first metal layer, the lower layer of the upper dielectric substrate is printed with a second metal layer, and there are a number of metallized vias in the upper dielectric substrate. These metallized vias are in contact with the first metal layer above and the second metal layer below.

[0009] The upper layer of the lower dielectric substrate is printed with a third metal layer, the lower layer of the lower dielectric substrate is printed with a fourth metal layer, and there are a number of metallized vias in the lower dielectric substrate. These metallized vias are in contact with the third metal layer above and the fourth metal layer below.

[0010] The four M2 screw holes are used to fix the upper and lower dielectric substrates. Preferably, an insulating material nylon post is used for fixing, which can not only effectively ensure the mechanical stability between the multi-layer structures, but also avoid the electromagnetic interference or parasitic conduction problems caused by metal connectors.

[0011] The 2.92 mm feed connector is installed below the lower dielectric substrate and is in contact with the fourth metal layer. One end of the probe of the 2.92 mm feed connector is connected to the fourth metal layer, and the other end is connected to the first metal layer. When the probe of the 2.92 mm feed connector passes through the lower dielectric substrate, in order to achieve good transmission, a via with the same inner diameter as the outer conductor of the connector is dug out in the lower dielectric substrate and the inner wall is metallized. When the probe of the 2.92 mm feed connector passes through the upper dielectric substrate, in order to achieve good transmission, a via with the same diameter as the feed probe is dug out in the lower dielectric substrate.

[0012] Further, the metallized vias in the upper dielectric substrate and the first and second metal layers form a rectangular dual-mode cavity, a first rectangular single-mode cavity, and a second rectangular single-mode cavity. The rectangular dual-mode cavity is used to generate TE 102 and TE 201 two orthogonal modes, where the TE 102 mode is used to generate the first resonance point in the low-frequency passband, and the TE 201 mode is used to generate the first resonance point in the high-frequency passband. The first rectangular single-mode cavity is used to generate the TE 101 mode, which can generate the second resonance point of the low-frequency path. The second rectangular single-mode cavity is used to generate the TE 101 mode, which can generate the second resonance point of the high-frequency path.

[0013] Further, the TE 102 mode generated by the rectangular dual-mode cavity and the TE 101 mode generated by the first rectangular single-mode cavity achieve magnetic coupling through a first inductive coupling window. The TE 201 mode generated by the rectangular dual-mode cavity and the TE 101 mode generated by the second rectangular single-mode cavity achieve magnetic coupling through a second inductive coupling window.

[0014] Further, there is a high-order mode suppression metallized via hole in the upper dielectric substrate. This high-order mode suppression metallized via hole is used to suppress the TE 103 high-order mode and achieve good out-of-band suppression on the right side of the high-frequency passband.

[0015] Further, the first metal layer is etched with a first radiation slot and a second radiation slot. The first radiation slot is used to achieve the radiation of the low-frequency passband, and the second radiation slot is used to achieve the radiation of the high-frequency passband. Preferably, to achieve the same polarization performance for the high-frequency passband and the low-frequency passband, the radiation slot is tilted by 45°, realizing the 45° linear polarization radiation characteristic.

[0016] Further, the metallized via holes in the lower dielectric substrate and the third metal layer and the fourth metal layer form a third rectangular single-mode cavity and a special-shaped single-mode cavity. The third rectangular single-mode cavity is used to generate the TE 102 mode, and can generate the third resonance point within the low-frequency passband. The special-shaped single-mode cavity is used to generate the quasi-TE 102 mode, and can generate the third resonance point within the high-frequency passband.

[0017] Further, the second metal layer is etched with four coupling slots, namely a first coupling slot, a second coupling slot, a third coupling slot, and a fourth coupling slot. The first coupling slot is used to achieve magnetic coupling between the rectangular dual-mode cavity and the third rectangular single-mode cavity. The second coupling slot is used to achieve magnetic coupling between the rectangular dual-mode cavity and the special-shaped single-mode cavity. The third coupling slot is used to achieve electrical coupling between the second rectangular single-mode cavity and the special-shaped single-mode cavity. The fourth coupling slot is used to achieve electrical coupling between the first rectangular single-mode cavity and the third rectangular single-mode cavity.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. The high out-of-band suppression dual-band SIW filtering antenna proposed by the present invention generates multiple radiation null points by setting multiple path transmissions in the low-frequency path and the high-frequency path, which is used to enhance the out-of-band suppression effect.

[0020] 2. The high out-of-band suppression dual-band SIW filtering antenna proposed by the present invention generates three resonance points in each passband by setting multiple resonance cavities in the low-frequency path and the high-frequency path, which is used to broaden the bandwidth.

[0021] 3. The high out-of-band suppression dual-band SIW filtering antenna proposed by the present invention realizes the 45° linear polarization radiation characteristic by etching two 45°-tilted U-shaped slots on the surface of the first metal layer. Compared with horizontal polarization or vertical polarization, the 45° linear polarization radiation characteristic has stronger polarization compatibility and can reduce the polarization mismatch loss caused by the inconsistent polarization directions of the transmitting and receiving antennas to a certain extent.

[0022] 4. The high out-of-band rejection dual-band SIW filtering antenna proposed by the present invention operates in the Ku band and is applicable to application scenarios such as satellite communication, vehicle-mounted radar systems, aerospace communication, and meteorological detection radars. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The following further describes the present application in conjunction with the drawings and embodiments, where:

[0024] Figure 1 is the overall structure diagram of the high out-of-band rejection dual-band SIW filtering antenna in this embodiment;

[0025] Figure 2 is the planar structure diagram of the first metal layer of the high out-of-band rejection dual-band SIW filtering antenna in this embodiment;

[0026] Figure 3 is the partial dimension schematic diagram of the first metal layer of the high out-of-band rejection dual-band SIW filtering antenna in this embodiment;

[0027] Figure 4 is the planar structure diagram of the upper dielectric substrate of the high out-of-band rejection dual-band SIW filtering antenna in this embodiment;

[0028] Figure 5 is the partial dimension schematic diagram of the upper dielectric substrate of the high out-of-band rejection dual-band SIW filtering antenna in this embodiment;

[0029] Figure 6 is the planar structure diagram of the lower dielectric substrate of the high out-of-band rejection dual-band SIW filtering antenna in this embodiment;

[0030] Figure 7 is the partial dimension schematic diagram of the lower dielectric substrate of the high out-of-band rejection dual-band SIW filtering antenna in this embodiment;

[0031] Figure 8 is the planar structure diagram of the second metal layer of the high out-of-band rejection dual-band SIW filtering antenna in this embodiment;

[0032] Figure 9 is the partial dimension schematic diagram of the second metal layer of the high out-of-band rejection dual-band SIW filtering antenna in this embodiment;

[0033] Figure 10 is the planar structure diagram of the fourth metal layer of the high out-of-band rejection dual-band SIW filtering antenna in this embodiment;

[0034] Figure 11 is the |S 11 | and gain simulation result diagram of the high out-of-band rejection dual-band SIW filtering antenna in this embodiment;

[0035] Figure 12It is the radiation pattern at the center frequency of the low-frequency passband of the high out-of-band rejection dual-band SIW filtering antenna in this embodiment;

[0036] Figure 13 It is the radiation pattern at the center frequency of the high-frequency passband of the high out-of-band rejection dual-band SIW filtering antenna in this embodiment;

[0037] Reference numerals: 1 - first metal layer, 2 - upper dielectric substrate, 3 - second metal layer, 4 - third metal layer, 5 - lower dielectric substrate, 6 - fourth metal layer, 7 - 2.92 mm feed connector, 11 - first radiation slot, 12 - second radiation slot, 21 - rectangular dual-mode cavity, 22 - first rectangular single-mode cavity, 23 - second rectangular single-mode cavity, 24 - first inductive coupling window, 25 - second inductive coupling window, 26 - high-order mode suppression metallized vias, 27 - 4 M2 screw holes, 28 - first probe via, 29 - upper dielectric substrate metallized vias, 31 - first coupling slot, 32 - second coupling slot, 33 - third coupling slot, 34 - fourth coupling slot, 51 - third rectangular single-mode cavity, 52 - special-shaped single-mode cavity, 53 - first probe metallized vias, 54 - lower dielectric substrate metallized vias, 61 - feed probe interface. Detailed implementation manners

[0038] In order to make the objectives, technical solutions and advantages of this application clearer, the following further elaborates on this application in combination with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not used to limit this application.

[0039] In addition, the terms "first", "second", "third" and "fourth" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first", "second", "third" and "fourth" may explicitly or implicitly include one or more of such features.

[0040] In order to illustrate the technical solutions described in this application, the following elaborates in detail in combination with specific accompanying drawings and embodiments.

[0041] Figure 1 It is the three-dimensional hierarchical perspective view of the high out-of-band rejection dual-band SIW filtering antenna in this embodiment. The high out-of-band rejection dual-band SIW filtering antenna includes a first metal layer 1, an upper dielectric substrate 2, a second metal layer 3, a third metal layer 4, a lower dielectric substrate 5, a fourth metal layer 6 and a 2.92 mm feed connector 7.

[0042] The upper dielectric substrate 2 and the lower dielectric substrate 5 use dielectric substrates with a relative dielectric constant of 3.55 and a thickness of 0.813 mm. The size of the entire antenna is 25 mm × 30 mm × 1.626 mm.

[0043] The upper layer of the upper dielectric substrate 2 is printed with a first metal layer 1, and the lower layer of the upper dielectric substrate 2 is printed with a second metal layer 3. The upper layer of the lower dielectric substrate 5 is printed with a third metal layer 4, and the lower layer of the lower dielectric substrate 5 is printed with a fourth metal layer 6.

[0044] Figure 2 It is a schematic diagram of the planar structure of the first metal layer 1 of the high out-of-band rejection dual-band SIW filtering antenna in this embodiment. The figure includes a first radiation slot 11 and a second radiation slot 12.

[0045] The first radiation slot 11 is used to realize the radiation of the low-frequency passband, and the second radiation slot 12 is used to realize the radiation of the high-frequency passband. To achieve the same polarization performance for the high-frequency passband and the low-frequency passband, both the first radiation slot 11 and the second radiation slot 12 are inclined at 45 degrees to achieve the linear polarization radiation characteristic of 45°. The linear polarization radiation characteristic of 45° has stronger polarization compatibility, which can reduce the polarization mismatch loss caused by the inconsistent polarization directions of the transmitting and receiving antennas to a certain extent.

[0046] Figure 3 It is a schematic diagram of partial dimensions of the first metal layer 1 of the high out-of-band rejection dual-band SIW filtering antenna in this embodiment. The parameter l in the figure slot1 = 7 mm, w slot1 = 1.6 mm, l slot2 = 0.3 mm, θ1 = 45°, l slot1 = 5.2 mm, w slot1 = 1.2 mm, l slot2 = 0.2 mm, θ2 = 45°.

[0047] Figure 4 It is a schematic diagram of the planar structure of the upper dielectric substrate of the high out-of-band rejection dual-band SIW filtering antenna in this embodiment. The figure includes a rectangular dual-mode cavity 21, a first rectangular single-mode cavity 22, a second rectangular single-mode cavity 23, a first inductive coupling window 24, a second inductive coupling window 25, a high-order mode suppression metallization via 26, 4 M2 screw holes 27, a first probe via 28, and several upper dielectric substrate metallization vias 29.

[0048] Several upper dielectric substrate metallization vias 29 and the first metal layer 1 and the second metal layer 3 form a rectangular dual-mode cavity 21, a first rectangular single-mode cavity 22, and a second rectangular single-mode cavity 23. The rectangular dual-mode cavity is used to generate TE 102 and TE 201 two orthogonal modes, where the TE 102 mode is used to generate the first resonance point within the low-frequency passband, and the TE 201 mode is used to generate the first resonance point within the high-frequency passband. The first rectangular single-mode cavity 22 is used to generate TE101 mode, which can generate the second resonance point of the low-frequency path. The second rectangular single-mode cavity 23 is used to generate TE 101 mode, which can generate the second resonance point of the high-frequency path.

[0049] The TE generated by the rectangular dual-mode cavity 21 102 mode and the TE generated by the first rectangular single-mode cavity 22 101 mode are magnetically coupled through the first inductive coupling window 24. The TE generated by the rectangular dual-mode cavity 21 201 mode and the TE generated by the second rectangular single-mode cavity 23 101 mode are magnetically coupled through the second inductive coupling window 25.

[0050] The high-order mode suppression via-hole 26 is used to suppress TE 103 high-order modes, and is used to achieve good out-of-band suppression on the right side of the high-frequency passband.

[0051] Four M2 screw holes 27 are used to fix the upper dielectric substrate 2 and the lower dielectric substrate 5.

[0052] The first probe via-hole 28 is used to pass through the 2.92 mm feeding probe to feed the upper dielectric substrate 1.

[0053] Figure 5 is a schematic diagram of the partial dimensions of the upper dielectric substrate 2 of the high out-of-band suppression dual-band SIW filtering antenna in this embodiment. In the figure, the parameters are l1 = 9.1 mm, w1 = 14.3 mm, l2 = 7.8 mm, w2 = 7.3 mm, l3 = 5.2 mm, w3 = 7.8 mm, l 12 = 3.2 mm, l 13 = 3 mm, d = 0.8 mm, d1 = 0.4 mm, s = 1.3 mm.

[0054] Figure 6 is a schematic plan view of the lower dielectric substrate 5 of the high out-of-band suppression dual-band SIW filtering antenna in this embodiment. The figure mainly includes a third rectangular single-mode cavity 51, a special-shaped single-mode cavity 52, a first probe via-hole 53, and several lower dielectric substrate via-holes 54.

[0055] The lower dielectric substrate via-holes 54 and the third metal layer 4 and the fourth metal layer 6 form the third rectangular single-mode cavity 51 and the special-shaped single-mode cavity 52. The third rectangular single-mode cavity 51 is used to generate TE 102 mode, which can generate the third resonance point within the low-frequency passband. The special-shaped single-mode cavity 52 is used to generate quasi-TE 102 mode, which can generate the third resonance point within the high-frequency passband.

[0056] The first probe metallization via 53 is used to transmit the TEM electromagnetic wave of the 2.92 mm feed connector to the upper dielectric substrate, and the inner diameter of the metallization via is the same as the outer diameter of the outer conductor of the 2.92 mm feed connector.

[0057] Figure 7 It is a schematic diagram of partial dimensions of the lower dielectric substrate 5 of the high out-of-band rejection dual-band SIW filtering antenna in this embodiment. In the figure, the parameters are l4 = 8.4 mm, w4 = 4.9 mm, l5 = 5 mm, w5 = 2.5 mm, l6 = 6.5 mm, w6 = 6.5 mm, l7 = 7.8 mm, w7 = 14.3 mm.

[0058] Figure 8 It is a schematic diagram of the planar structure of the second metal layer 3 of the high out-of-band rejection dual-band SIW filtering antenna in this embodiment. The figure includes a first coupling slot 31, a second coupling slot 32, a third coupling slot 33, and a fourth coupling slot 34.

[0059] The first coupling slot 31 is used to achieve magnetic coupling between the rectangular dual-mode cavity 21 and the third rectangular single-mode cavity 51. The second coupling slot 32 is used to achieve magnetic coupling between the rectangular dual-mode cavity 21 and the shaped single-mode cavity 52. The third coupling slot 33 is used to achieve electrical coupling between the second rectangular single-mode cavity 23 and the shaped single-mode cavity 52. The fourth coupling slot 34 is used to achieve electrical coupling between the first rectangular single-mode cavity 22 and the third rectangular single-mode cavity 51.

[0060] Figure 9 It is a schematic diagram of partial dimensions of the second metal layer 3 of the high out-of-band rejection dual-band SIW filtering antenna in this embodiment. In the figure, the parameter l slot5 = 4 mm, w slot5 = 0.7 mm, l slot6 = 3.3 mm, w slot6 = 0.6 mm, l slot7 = 4.2 mm, w slot7 = 0.5 mm, l slot8 = 5 mm, w slot8 = 0.5 mm,

[0061] The third metal layer 4 has the same shape and size as the second metal layer 3

[0062] Figure 10 It is a schematic diagram of the planar structure of the fourth metal layer 3 of the high out-of-band rejection dual-band SIW filtering antenna in this embodiment. The figure includes a feed probe interface 61.

[0063] Figure 11 It is a simulation result diagram of |S 11 | and gain of the high out-of-band rejection dual-band SIW filtering antenna in this embodiment. Figure 11It is shown that the -10dB impedance bandwidth of the high out-of-band rejection dual-band SIW filtering antenna is 3.43% at the center frequency of 13.13GHz in the low-frequency band, and 2.42% at the center frequency of 16.5GHz in the high-frequency band. The peak gain of the low-frequency band reaches 4.95dBi, and the peak gain of the high-frequency band reaches 5.33dBi. A radiation null is generated on both sides of the low-frequency band and the high-frequency band. An out-of-band rejection of 35.5dB is generated on the left side of the low-frequency band, an out-of-band rejection of 25dB is generated on the right side of the high-frequency band, and an out-of-band rejection of 26dB is generated between the two bands. From the simulation results, the high out-of-band rejection dual-band SIW filtering antenna has a good out-of-band rejection effect.

[0064] Figure 12 It is the normalized radiation pattern of the phi = 45° main polarization and cross polarization at the center frequency of the low-frequency band of the high out-of-band rejection dual-band SIW filtering antenna in this embodiment. The cross polarization is greater than 20dBi.

[0065] Figure 13 It is the normalized radiation pattern of the phi = 45° main polarization and cross polarization at the center frequency of the high-frequency band of the high out-of-band rejection dual-band SIW filtering antenna in this embodiment. The cross polarization is greater than 20dBi.

[0066] The embodiments of the present application have been described in detail above with reference to the accompanying drawings. However, the present application is not limited to the above embodiments. Within the knowledge scope of those of ordinary skill in the art, various changes can be made without departing from the purpose of the present application. In addition, the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

Claims

1. A high out-of-band rejection dual-band SIW filter antenna, characterized in that, The antenna includes upper and lower dielectric substrates, a first metal layer, a second metal layer, a third metal layer, a fourth metal layer, several metallized vias in the upper and lower dielectric substrates, four M2 screw holes at the edges of the upper and lower dielectric substrates, and a 2.92 mm feed connector. The first metal layer is printed on the upper layer of the upper dielectric substrate, the second metal layer is printed on the lower layer of the upper dielectric substrate, and there are several metallized vias in the upper dielectric substrate. These metallized vias are in contact with the first metal layer above and the second metal layer below. The third metal layer is printed on the upper layer of the lower dielectric substrate, the fourth metal layer is printed on the lower layer of the lower dielectric substrate, and there are several metallized vias in the lower dielectric substrate. These metallized vias are in contact with the third metal layer above and the fourth metal layer below. The 2.92 mm feed connector is installed below the lower dielectric substrate and is in contact with the fourth metal layer. One end of the probe of the 2.92 mm feed connector is connected to the fourth metal layer, and the other end is connected to the first metal layer. When the probe of the feed connector passes through the lower dielectric substrate, in order to achieve good transmission, a via with the same inner diameter as the outer conductor of the connector is dug out in the lower dielectric substrate and the inner wall is metallized. When the probe of the feed connector passes through the upper dielectric substrate, in order to achieve good transmission, a via with the same diameter as the feed probe is dug out in the second dielectric substrate.

2. The high out-of-band rejection dual-band SIW filtering antenna according to claim 1, characterized in that, The first metal layer is etched with a first radiation slot and a second radiation slot. The first radiation slot is used to realize the radiation of the low-frequency passband, and the second radiation slot is used to realize the radiation of the high-frequency passband. In order to achieve the same polarization performance for the high-frequency and low-frequency passbands, the radiation slots are tilted by 45°, realizing the 45° linear polarization radiation characteristic.

3. The high out-of-band rejection dual-band SIW filtering antenna according to claim 1, characterized in that, The metallized vias in the upper dielectric substrate form a rectangular dual-mode cavity, a first rectangular single-mode cavity, and a second rectangular single-mode cavity with the first metal layer and the second metal layer. The rectangular dual-mode cavity is used to generate TE 102 and TE 201 two orthogonal modes, where the TE 102 mode is used to generate the first resonance point in the low-frequency passband, and the TE 201 mode is used to generate the first resonance point in the high-frequency passband. The first rectangular single-mode cavity is used to generate the TE 101 mode, which can generate the second resonance point of the low-frequency path. The second rectangular single-mode cavity is used to generate the TE 101 mode, which can generate the second resonance point of the high-frequency path.

4. The high out-of-band rejection dual-band SIW filtering antenna according to claim 3, characterized in that, The TE mode generated by the rectangular dual-mode cavity 102 mode and the TE mode generated by the first rectangular single-mode cavity 101 mode are magnetically coupled through a first inductive coupling window. The TE mode generated by the rectangular dual-mode cavity 201 mode and the TE mode generated by the second rectangular single-mode cavity 101 mode are magnetically coupled through a second inductive coupling window.

5. A high out-of-band rejection dual-band SIW filter antenna according to claim 3, characterized in that, The high-order mode suppression metallization vias in the upper dielectric substrate are used to suppress TE 103 high-order modes and achieve good out-of-band suppression on the right side of the high-frequency passband.

6. The high out-of-band rejection dual-band SIW filter antenna according to claim 1, characterized in that, The metallized vias in the lower dielectric substrate form a third rectangular single-mode cavity and a shaped single-mode cavity with the third metal layer and the fourth metal layer. The third rectangular single-mode cavity is used to generate TE 102 mode, which can generate the third resonance point in the low-frequency passband. The shaped single-mode cavity is used to generate quasi-TE 102 mode, which can generate the third resonance point in the high-frequency passband.

7. A high out-of-band rejection dual-band SIW filtering antenna according to claim 6, characterized in that, The second metal layer is etched with four coupling slots, namely the first coupling slot, the second coupling slot, the third coupling slot, and the fourth coupling slot.

8. A high out-of-band rejection dual-band SIW filter antenna according to claim 7, characterized in that, The first coupling slot is used to realize the magnetic coupling between the rectangular dual-mode cavity and the third rectangular single-mode cavity. The second coupling slot is used to realize the magnetic coupling between the rectangular dual-mode cavity and the non-standard single-mode cavity. The third coupling slot is used to realize the electrical coupling between the second rectangular single-mode cavity and the non-standard single-mode cavity. The fourth coupling slot is used to realize the electrical coupling between the first rectangular single-mode cavity and the third rectangular single-mode cavity.

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