A substrate integrated waveguide coupled feeding low sidelobe filtering antenna array

Abstract

The present invention relates to a substrate integrated waveguide coupled feeding low sidelobe filtering antenna array, TE 401 The module-substrate integrated waveguide cavity is used as the first stage of the filter power divider to achieve both filter response and power division; three TM 10 The microstrip patch resonator is the second-stage resonator of the filter power divider and also serves as the radiator of the filter antenna array. 401 The mode divides the energy into four equal parts along its long side, TE 401 The magnetic field amplitude at the junction of the substrate-mode integrated waveguide cavity is twice that of the outer side and the magnetic field direction is consistent, so that the filtering antenna array obtains a binomial power distribution (1:2:1). 10 The mode microstrip patches are arranged one by one directly above the three coupling slots. The coupling slots connect the TE 401 The energy in the mode-substrate integrated waveguide resonant cavity is coupled to the corresponding microstrip patch antenna and radiated outward, thereby achieving a lower sidelobe level.

Description

Technical Field

[0001] The invention belongs to the technical field of radio frequency communication and relates to a substrate integrated waveguide coupled feeding low sidelobe filtering antenna array. Background Art

[0002] Fusion design can effectively reduce the loss, volume and cost of the entire circuit or device, and is an ideal choice to meet the high integration and multi-functional development trend of modern wireless communication systems. Therefore, filter antennas, that is, fusion designs that combine the functions of filters and antennas into one module, have been widely studied and reported.

[0003] Unlike the filtering antenna unit, the filtering antenna array needs to integrate the function of the power divider to further reduce the connection loss and circuit complexity. The traditional implementation method of the filtering antenna array is that the source signal needs to pass through the filter and the power divider before reaching the radiator. The obvious disadvantage of this method is the inevitable insertion loss, especially for multiple cascaded resonators. In order to solve this problem, a filtering antenna array design method without adding additional filtering circuits has attracted widespread attention. This method introduces parasitic elements into the radiator or feeding network to produce radiation zero points. However, the filtering response design of this method lacks intuitiveness and flexibility, and it takes a lot of time to optimize during the design process. Based on the filter fitting theory, the fusion design method using the radiator instead of the final resonator has a detailed working principle, parameter study and complete design guide. However, when the number of radiating elements is large, the required feeding network is large and complex. Using high-order mode cavities to simplify the feeding network of the filtering antenna array is a practical solution. There are literatures that have well verified the feasibility of this method by studying a series of slot filtering antenna arrays fed by high-order mode resonant cavities.

[0004] Sidelobe level is another important issue of filter antenna array. When the sidelobe level is high, it is easy to be interfered by clutter and other directions, thus reducing the radiation performance of the filter antenna array. In the past, many designs of filter antenna arrays showed good filtering response, but their sidelobe levels were not satisfactory. The main reason for this phenomenon is that they are all excited by a feed network with uniform power distribution. Therefore, a filter antenna array with a conical power distribution is designed in some literature to solve the problem of high sidelobe level. This method can obtain a lower sidelobe level without changing the stopband roll-off. However, some designs in which the feed network with unequal power distribution ratio is directly cascaded with the antenna will not only bring inevitable connection loss, but also make the whole system bulky. In addition, a 2×4 waveguide filter antenna array with low sidelobe level is obtained on the E plane by using a feed network with unequal power distribution ratio. Although it adopts a fusion design method in which the last-stage resonator is both a resonant element and a radiating element to improve efficiency, its disadvantage is that the three-dimensional structure is bulky and difficult to integrate with planar circuits. In summary, it is still a challenging task to simultaneously obtain the desired low sidelobe level, simple power distribution network and good out-of-band suppression in a filter antenna array. Summary of the invention

[0005] The purpose of the present invention is to solve the above-mentioned deficiencies in the prior art and to provide a substrate integrated waveguide coupled feed low sidelobe filter antenna array. 401 Taking advantage of the inherent magnetic field distribution characteristics of the substrate integrated waveguide cavity, coupling grooves are reasonably etched on the upper surface of the substrate integrated waveguide to enable the final microstrip patch resonator (also serving as a radiator) to achieve a binomial power distribution (1:2:1) to reduce the sidelobe level.

[0006] In order to achieve the purpose of the present invention, the present invention provides a substrate integrated waveguide coupled feeding low sidelobe filtering antenna array, comprising a TE stacked from bottom to top. 401 The module substrate integrates the waveguide resonant cavity, the upper dielectric substrate and three TM 10 mode microstrip patch; the TE 401 The TM substrate integrated waveguide filter cavity is composed of an upper metal floor, a lower dielectric substrate, a lower metal floor and a metal through hole; the three TM 10 The microstrip patch and the upper dielectric substrate form three TM 10 The upper metal floor is provided with three coupling slots arranged along the x direction, the projections of the three coupling slots in the substrate integrated waveguide filter cavity are respectively located at the center and both sides thereof, and the three microstrip patches are arranged one by one directly above the three coupling slots.

[0007] TE 401The module-substrate integrated waveguide cavity is used as the first stage of the filter power divider to achieve both filter response and power division. 401 Four 1 / 4-TE channels are uniformly formed along the long side of the integrated waveguide cavity. 401 mode, so that the energy is evenly divided into 4 equal parts along its long side. The central coupling slot is located in the middle of the two 1 / 4-TE 401 The coupling slots on both sides are located at the end 1 / 4-TE 401 The outer side of the mold, TE 401 The magnetic field amplitude at the junction of the mode-substrate integrated waveguide cavity is twice that of the outer side and the magnetic field direction is consistent; the three TM 10 The microstrip patch resonator is the second-stage resonator of the filter power divider and also serves as the radiator of the filter antenna array. 401 The energy in the resonant cavity of the module-substrate integrated waveguide is coupled to the corresponding microstrip patch antenna and radiated outward.

[0008] The substrate integrated waveguide coupled feeding low sidelobe filtering antenna array of the present invention adopts high-order resonant mode technology in its feeding network, and only one TE 401 The substrate integrated waveguide resonant cavity can excite three patch antennas at the same time. 401 The power distribution characteristics of the substrate integrated waveguide cavity are rationally etched on the upper surface of the substrate integrated waveguide to achieve a binomial power distribution (1:2:1) for the final microstrip patch resonator (also as a radiator) to reduce the sidelobe level. Therefore, the proposed low sidelobe filter antenna array has a compact structure and an efficient design process, which is very attractive for current and future large planar arrays.

[0009] In addition, the present invention also proposes a design method for a substrate integrated waveguide coupled-fed low sidelobe filter antenna array, which is characterized by comprising the following steps:

[0010] Step 1: Calculate the low-pass prototype lumped parameters according to the performance indicators required by the filtering antenna unit, and calculate the coupling coefficient K and the input port external quality factor Q accordingly. es , radiation quality factor Q r ;

[0011] Step 2: Establish a model of the substrate integrated waveguide coupled feed low sidelobe filter antenna array according to the parameters determined in step 1, and adjust the first level TE according to the set binomial distribution power allocation. 401 Mode-Substrate Integrated Waveguide Resonator with 2nd Stage TM 10 The width w2 of the central coupling slot between the mode microstrip patch resonators, the length l2 of the central coupling slot, the width w1 of the coupling slots on both sides, and the length l1 of the coupling slots on both sides make the first-order TE 401 Mode-Substrate Integrated Waveguide Resonator with 2nd Stage TM10 The coupling between the mode microstrip patch resonators meets the design requirements: K1:K2:K3;

[0012] Step 3: Adjust the load on the first level TE 401 The width w of the corner slots on both sides of the input feed line of the substrate integrated waveguide resonator g2 and length l g2 , so that it satisfies the external quality factor Q of the input port calculated in step 1 es ;

[0013] Step 4: Adjust the side length l of the microstrip patch resonator c The relative dielectric constant of the upper dielectric substrate makes the radiation quality factor Q of the three microstrip patch resonators r1 , Q r2 and Q r3 Equal to the external quality factor Q of the input port es .

[0014] Among them, the lumped elements of the low-pass prototype include g0, g1 and g2; the coupling coefficient External quality factor BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention will be further described below in conjunction with the accompanying drawings;

[0016] Figure 1 It is a stereoscopic diagram of the substrate integrated waveguide coupled fed low sidelobe filtering antenna array of the present invention.

[0017] Figure 2 It is a plan view of the substrate integrated waveguide coupled fed low sidelobe filtering antenna array of the present invention.

[0018] Figure 3 TE in the present invention 401 Magnetic field distribution diagram of the mode-substrate integrated waveguide cavity.

[0019] Figure 4 It is the coupling coefficient curve under different coupling slot sizes.

[0020] Figure 5 (a) is a simulation of the low sidelobe patch filter antenna array of the present invention. 11 |And the achieved gain curve.

[0021] Figure 5 (b) is the efficiency of the low sidelobe filtering antenna array of the present invention.

[0022] Figure 6 It is the simulated radiation pattern (E plane, H plane) of the low sidelobe filter antenna array of the present invention at 13.06 GHz and 13.32 GHz. DETAILED DESCRIPTION

[0023] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0024] Figure 1 and Figure 2 The three-dimensional image and the plan view of the substrate integrated waveguide coupled feeding low sidelobe filter antenna array are respectively shown. The substrate integrated waveguide coupled feeding low sidelobe filter antenna array includes: a one-to-three unequal power division filter power divider and three microstrip patch antennas as the second stage of the filter power divider.

[0025] The filter antenna array used is composed of two layers of the same dielectric substrate, the first layer is TE 401 The second stage of the substrate integrated waveguide (a form of microwave transmission line, usually composed of an upper metal floor 2, a lower metal floor 4, a lower dielectric substrate 3 and a metal through hole 7, which uses the metal through hole to realize the field propagation mode of the waveguide on the dielectric substrate) filter power divider is composed of an upper dielectric substrate 1 and three microstrip patches 5. The upper metal floor 2 is provided with three coupling slots 6 arranged along the x direction, and the projections of the three coupling slots in the substrate integrated waveguide filter cavity are respectively located at the center and both sides thereof, and the three microstrip patches 5 are arranged one by one directly above the three coupling slots 6.

[0026] Specifically, if Figure 1 As shown, the substrate integrated waveguide filter power divider comprises an input port (S1) and three output coupling slots 6. 401 Four 1 / 4-TE channels are uniformly formed along the long side of the resonant cavity of the substrate integrated waveguide. 401 mode, so that the energy is evenly divided into 4 equal parts along its long side, TE 401 The magnetic field amplitude at the junction of the substrate-mode integrated waveguide cavity is twice that of the outer side and the magnetic field direction is consistent. 401 Two 1 / 4-TE in the center of the substrate integrated waveguide cavity 401 The magnetic field amplitude at the mode junction is a single 1 / 4-TE 401 The power distribution of the filter power divider is twice that of the mode, which enables the filter power divider to achieve binomial power distribution (1:2:1). The three microstrip metal patches are set on the upper layer of the filter power divider as the second stage of the filter power divider and are connected by the first stage TE 401 The mode substrate integrated waveguide resonant cavity is coupled and fed. The coupling slot connects the TE 401 The energy in the resonant cavity of the integrated waveguide of the mode substrate is coupled to the corresponding microstrip patch 5 and radiates outward. The length and width of the coupling slot of the microstrip patches on both sides are w1 and l1 respectively, and the length and width of the coupling slot of the middle microstrip patch are w2 and l2 respectively.

[0027] The low sidelobe filter antenna array includes a one-to-three unequal power division feeding network and a microstrip patch antenna. The unequally divided signals of the filter power divider are coupled and fed to the microstrip patch antenna through three substantially equal coupling slots.

[0028] In this embodiment, the input port S1 excites the TE of the substrate integrated waveguide resonant cavity through a 50Ω input feed line. 401 The two substrates of the proposed filtering antenna are made of Rogers 5880, with a relative dielectric constant of 2.2 and a loss tangent of 0.0009.

[0029] In this design, the microstrip patch size (l c × c ) and the relative dielectric constant of the dielectric substrate 1 can be determined by the classical formula. The distance d between adjacent antennas n is determined by balancing the antenna gain and sidelobe level. After the positions of the three microstrip patch antennas are fixed, TE 401 The size of the integrated waveguide cavity on the substrate (l s × s ) can be determined accordingly. Figure 3 The two 1 / 4-TE 401 The junction and outer side of the mold are single 1 / 4-TE 401 The double magnetic field relationship between the modes can easily achieve binomial power distribution (1:2:1). After determining the initial dimensions of the microstrip patch antenna and the substrate integrated waveguide cavity, the filter antenna unit is designed using the traditional bandpass filter fitting method and extended to the filter antenna array according to the formula. Next, extract the important parameters and input the external quality factor Q es , Radiation quality factor Q ri , coupling coefficients K1, K2 and K3, determine the corresponding critical dimensions in the proposed filtering antenna array. The coupling between the two-stage resonant cavity is achieved through three coupling slots, namely w1, l1, w2, l2. Input external quality factor Q es Mainly determined by the feed length of the feed line and the gap between the feed line and the cavity, loaded on the first level. TE 401 The width w of the corner slots on both sides of the input feed line of the substrate integrated waveguide resonator g2 and length l g2 Finally, the final size of the proposed filtering antenna array can be determined after fine-tuning.

[0030] Specifically, the design method of the substrate integrated waveguide coupled feeding low sidelobe filter antenna array of the present invention is characterized by comprising the following steps:

[0031] Step 1: Calculate the low-pass prototype lumped parameters according to the performance indicators required by the filtering antenna unit. The lumped elements of the low-pass prototype include g0, g1 and g2, and calculate the coupling coefficient K and the input port external quality factor Q accordingly. es , radiation quality factor Q r In this example, g0 = 1, g1 = 0.9873 and g2 = 0.6638, so the important parameters are coupling coefficient K, external quality factor Q es and radiation quality factor Q r It can be calculated by the following formula:

[0032]

[0033] Step 2: Establish a model of the substrate integrated waveguide coupled feed low sidelobe filter antenna array of this embodiment according to the parameters determined in step 1, and adjust the first level TE according to the set binomial distribution power allocation. 401 Mode-Substrate Integrated Waveguide Resonator with 2nd Stage TM 10 The width w2 of the central coupling slot between the mode microstrip patch resonators, the length l2 of the central coupling slot, the width w1 of the coupling slots on both sides, and the length l1 of the coupling slots on both sides make the first-order TE 401 Mode-Substrate Integrated Waveguide Resonator with 2nd Stage TM 10 The coupling between the mode microstrip patch resonators meets the design requirements:

[0034] The filter antenna array not only has filtering and radiation functions, but also integrates the power distribution function in the circuit. The second step of the fusion design is to fit the filter antenna array based on the filter antenna unit. Set TE 401 The module-substrate integrated waveguide cavity is used as the first stage of the filter power divider, which can achieve both filter response and power division. 10 The microstrip patch resonator is the second-order resonator of the filter and also the radiator of the array. The middle microstrip patch antenna and the two microstrip patch antennas on both sides are composed of two 1 / 4-TE 401 and 1 / 4-TE 401 Assuming that the substrate integrated waveguide resonator and the microstrip patch resonator are lossless, P s and P ri (i=1,2 or 3) represents the input power and output power respectively. In order to achieve the effect of low sidelobe level of antenna array, the power allocation ratio is set to P r1 :P r2 :P r3 =α1:α2:α3=1:2:1. The coupling coefficient should satisfy the formula

[0035]

[0036] The radiation quality factor of the three microstrip patch resonators is expressed as Q ri (i = 1, 2 or 3) means that the input external quality factor of the filtering antenna array is still Q es According to Q es , they satisfy the following relationship:

[0037]

[0038] Q r =Q r1 =Q r2 =Q r3 =29

[0039] Where ω0 is the resonant frequency of the filter antenna array, W as and W ri (i=1, 2 or 3) represents the stored energy of the substrate integrated waveguide cavity and the three microstrip patch resonant cavities respectively.

[0040] Through the above analysis, the important parameters K1, K2, K3, Q es and Q ri . The coupling between the two-stage resonant cavity is achieved through three coupling slots. The values ​​of K1, K2 and K3 can generally be extracted using the eigenmode method or weak coupling method. This design uses the eigenmode method. At the same time, since Slot 1 and Slot 3 are completely symmetrical along A-A' and B-B' in the substrate integrated waveguide cavity, the size of the two coupling slots can be determined by extracting the coupling coefficient of any slot. Here, Slot 1 is selected for extraction. K1 and K2 are determined by the size of Slot 1 and Slot 2. The curves are shown in Figure 2. Figure 4 As shown in Figure 2, K1 or K2 increases with the increase of w1(l1) or w2(l2), respectively. As expected, when the coupling coefficients K1 and K2 satisfy When , the sizes of the three coupling slots are almost the same. This result also further verifies that Figure 3 As shown, the two 1 / 4-TE 401 The energy of the adjacent region of the mode is a single 1 / 4-TE on both sides 401 Twice the mode energy.

[0041] Step 3: Adjust the load on the first level TE 401 The width w of the corner slots on both sides of the input feed line of the substrate integrated waveguide resonator g2 and length l g2 , so that it satisfies the external quality factor Q of the input port calculated in step 1 es When other parameters are fixed, increasing the width w of the slit between the feed line and the substrate integrated waveguide cavity g2and length l g2 can effectively reduce the external quality factor. ri It can be calculated by equations (7) and (8).

[0042]

[0043] Where S 11min and S 11 f0 and f a (f b ). M is the coupling coefficient between the waveguide port and the microstrip patch resonator. The calculation and parameter extraction results show that the Q es and the Q of the three microstrip patch resonators ri Still the same as expected is equal.

[0044] Step 4: Adjust the side length l of the microstrip patch resonator c The relative dielectric constant of the upper dielectric substrate makes the radiation quality factor Q of the three microstrip patch resonators r1 , Q r2 and Q r3 Equal to the external quality factor Q of the input port es .

[0045] Based on the above analysis, the design steps of the low sidelobe filter antenna array are summarized as follows.

[0046] (1) According to the required center frequency f0, the microstrip patch size (l c × c ) and relative dielectric constant (ε r ) can be determined by the classical formula. The distance dn between adjacent antennas is determined by balancing the antenna gain and the sidelobe level.

[0047] (2) After the positions of the three microstrip patch antennas are fixed, TE 401 The size of the integrated waveguide cavity on the substrate (l s × s ) can be determined. Figure 3 The two 1 / 4-TE 401 Adjacent areas of the mold and single 1 / 4-TE on both sides 401 The double magnetic field relationship between the modes can easily achieve binomial power distribution.

[0048] (3) After determining the initial dimensions of the microstrip patch antenna and substrate integrated waveguide cavity, the filter antenna unit is designed using the traditional bandpass filter fitting method, and can be extended to the filter antenna array according to formulas (1)-(8).

[0049] (4) Next, extract the important parameter Qes , Q ri , K1, K2 and K3, determine the corresponding critical dimensions in the proposed filtering antenna array.

[0050] (5) Finally, the final size of the proposed filtering antenna array is determined through fine-tuning.

[0051] For demonstration purposes, a Figure 1 The low sidelobe filter antenna array shown. The specific dimensions are as follows:

[0052] parameter d p h w l <![CDATA[w s ]]> <![CDATA[l s ]]> <![CDATA[w0]]> <![CDATA[w g1 ]]> <![CDATA[w g2 ]]> Value(mm) 0.4 0.6 0.508 40 46.5 12.18 38.4 1.5 0.8 0.5 parameter <![CDATA[l g1 ]]> <![CDATA[l g2 ]]> <![CDATA[w1]]> <![CDATA[w2]]> <![CDATA[l1]]> <![CDATA[l2]]> <![CDATA[l c ]]> <![CDATA[d r ]]> <![CDATA[d n ]]> - Value(mm) 0.9 3.8 1.0 0.9 2.2 2.2 6.8 6.09 16.4 -

[0053] Figure 5 (a) shows the simulation of the proposed low sidelobe filter antenna array |S 11 | and gain. It can be found that the simulated impedance bandwidth is about 3.4%, and the peak gain in the band is 11.9dBi. Figure 5 (b) shows the efficiency of the proposed low sidelobe filter antenna array, with a simulated peak efficiency of 89%. Figure 6 The radiation patterns of the proposed patch filter antenna array at 13.06 GHz and 13.32 GHz are shown. It can be seen that the sidelobe levels of the E-plane radiation pattern at the two resonance points are less than -19.1 dB. In addition, the cross-polarization levels of the E-plane and H-plane are both less than -20 dB.

[0054] The low sidelobe level filter patch antenna array of the present invention is fed by a substrate integrated waveguide filter power divider with unequal power division ratio. Since the feeding network adopts high-order resonant mode technology, only one substrate integrated waveguide resonant cavity can simultaneously excite three patch antennas. At the same time, according to TE 401 The magnetic field distribution of the substrate integrated waveguide cavity can easily obtain a three-way filter power divider with a power distribution of 1:2:1 to reduce the sidelobe level. Finally, using the filter fitting method based on the coupling coefficient and the external quality factor, a good filter response can be easily obtained.

[0055] In addition to the above embodiments, the present invention may also have other implementation modes. Any technical solution formed by equivalent replacement or equivalent transformation falls within the protection scope required by the present invention.

Claims

1. A substrate integrated waveguide coupled feed low sidelobe filter antenna array, characterized in that: Including TE stacking from bottom to top 401 The module substrate integrates a waveguide resonant cavity, an upper dielectric substrate (1) and three TM 10 Mode microstrip patch (5); the TE 401 The module substrate integrated waveguide resonant cavity is composed of an upper metal floor (2), a lower dielectric substrate (3), a lower metal floor (4) and a metal through hole (7); the three TM 10 The microstrip patch (5) and the upper dielectric substrate (1) form three TM 10 The upper metal floor (2) is provided with three coupling slots (6) arranged along the x direction, and the projections of the three coupling slots in the substrate integrated waveguide filter cavity are respectively located at the center and two sides thereof, and the three TM 10 The mode microstrip patches (5) are arranged one by one just above the three coupling slots (6); The TE 401 Four 1 / 4-TE channels are uniformly formed along the long side of the resonant cavity of the substrate integrated waveguide. 401 mode, so that the energy is evenly divided into 4 equal parts along its long side direction, and the central coupling slot is located in the middle of the two 1 / 4-TE 401 The coupling slots on both sides are located at the end 1 / 4-TE 401 The outer side of the mold, TE 401 The magnetic field amplitude at the junction of the mode-substrate integrated waveguide resonant cavity is twice that of the outer side and the magnetic field direction is consistent; The coupling slot will TE 401 The energy in the mode-substrate integrated waveguide resonator is coupled to the corresponding TM 10 The mode microstrip patch (5) radiates outwards, and the output power ratio of the antenna array is 1:2:

1.

2. The substrate integrated waveguide coupled fed low sidelobe filter antenna array according to claim 1, characterized in that: A device for inputting energy into TE is also provided. 401 Antenna input port (S1) of the substrate integrated waveguide resonator.

3. The substrate integrated waveguide coupled fed low sidelobe filter antenna array according to claim 1, characterized in that: TE 401 The module-substrate integrated waveguide resonator is used as the first stage of the filter power divider to achieve both filter response and power division; three TM 10 The microstrip patch resonator is the second-stage resonator of the filter power divider and also serves as the radiator of the filter antenna array.

4. A design method for a substrate integrated waveguide coupled feed low sidelobe filter antenna array, characterized in that The following steps are involved: Step 1: Calculate the low-pass prototype lumped parameters according to the performance indicators required by the filtering antenna unit, and calculate the coupling coefficient K and the input port external quality factor Q accordingly. es , radiation quality factor Q r ; Step 2: Establish a model of the substrate integrated waveguide coupled feed low sidelobe filter antenna array as claimed in claim 1 according to the parameters determined in step 1, and adjust the first stage TE according to the set binomial distribution power allocation. 401 Mode-Substrate Integrated Waveguide Resonator with 2nd Level TM 10 The width w2 of the central coupling slot between the mode microstrip patch resonators, the length l2 of the central coupling slot, the width w1 of the coupling slots on both sides, and the length l1 of the coupling slots on both sides make the first-order TE 401 Mode-Substrate Integrated Waveguide Resonator with 2nd Level TM 10 The coupling between the mode microstrip patch resonators meets the design requirements: K1:K2:K3; Step 3: Adjust the load on the first level TE 401 The width w of the corner slots on both sides of the input feed line of the substrate integrated waveguide resonator g2 and length l g2 , so that it satisfies the external quality factor Q of the input port (S1) calculated in step 1 es ; Step 4: Adjust the side length l of the microstrip patch resonator c The relative dielectric constant of the upper dielectric substrate (1) makes the radiation quality factor Q of the three microstrip patch resonators r1 , Q r2 and Q r3 Equal to the external quality factor Q at the input port (S1) es .

5. The design method of substrate integrated waveguide coupled feed low sidelobe filter antenna array according to claim 4, characterized in that: The lumped elements of the low-pass prototype include g0, g1 and g2; external quality factor Coupling coefficient 6. The design method of the substrate integrated waveguide coupled feed low sidelobe filter antenna array according to claim 5, characterized in that:

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