CN203826522U - Broadband substrate integrated waveguide filter adopting U-shaped slot line - Google Patents

Abstract

The utility model discloses a broadband substrate-integrated waveguide filter adopting U-shaped groove lines, which comprises a substrate-integrated waveguide, and the substrate-integrated waveguide includes a dielectric substrate and two layers of metal patches arranged on the front and back of the dielectric substrate. And the upper and lower rows of metal through holes, the two layers of metal patches constitute the upper and lower walls of the substrate integrated waveguide, the upper and lower rows of metal through holes constitute the left and right walls of the substrate integrated waveguide, the metal patch on the front of the dielectric substrate U-shaped groove lines are etched thereon, and the substrate integrated with the etched U-shaped groove lines forms a multi-mode resonator. The broadband substrate integrated waveguide filter of the utility model utilizes the etched U-shaped groove line to make the substrate integrated waveguide form a multimode resonator, which eliminates the complexity of etching the periodic EBG structure on the substrate integrated waveguide, and can It meets the requirements of miniaturized broadband communication systems, not only overcomes the defect of large loss of traditional micro-broadband filters, but also solves the problem of high cost of using metal waveguides, and has a good application prospect.

Description

A Broadband Substrate Integrated Waveguide Filter Using U-shaped Slot Lines

technical field

The utility model relates to a broadband substrate integrated waveguide filter, in particular to a broadband substrate integrated waveguide filter adopting U-shaped groove lines, which belongs to the field of wireless communication.

Background technique

Wireless communication technology is playing an increasingly important role in real social life. As an important component in the field of wireless communication, the demand for band-pass filters is also increasing. The earlier microstrip bandpass filter was widely used due to its convenience in plan drawing and board making, but this kind of filter has a large loss, especially at high frequencies, it will produce a lot of energy radiation. With the continuous development of communication technology, the requirements for filters are getting higher and higher. Although the millimeter-wave filter using metal waveguide can achieve better technical indicators, it is expensive and cannot be widely used; the millimeter-wave filter with EBG (Electromagnetic Band-Gap) structure can well meet the current technical requirements. Index requirements, but this filter volume is relatively large. Recently, millimeter-wave filters using Substrate Integrated Waveguide (SIW for short) have received high attention, which can realize high-performance bandpass filters with small size and low cost. It is a new type of waveguide, which has the characteristics of high quality factor and easy design of the traditional metal waveguide, and also has the characteristics that the traditional waveguide does not have, such as small size, low cost, and easy processing. Its advantages make the filter of this structure widely used in wireless communication systems.

According to investigation and understanding, the existing technologies that have been disclosed are as follows:

1) In 2005, Zhu Lei and others published an article titled "Ultra-wideband (UWB) bandpaSS filters using multiple-mode resonator" on IEEE Microwave and Wireless Components Letters. The author proposed a step impedance line Multi-mode resonator, the structure is shown in Figure 1a, several resonant modes of this structure are shifted to the required passband, and an ultra-wideband filter is realized; Figure 1b is its simulation result.

2) Based on the multimode resonator technology, in order to improve the out-of-band suppression level of the ultra-wideband passband filter, the researchers proposed a further improvement scheme. In 2009, Wong Sai Wai et al. published an article titled "Quadruple-mode UWB bandpass filter with improved out-of-band rejection" on IEEE Microwave and Wireless Components Letters, and proposed to introduce two short-circuit stub lines into the multimode resonator , so that the fourth resonant mode moves to the low frequency end, together with the first three resonant modes, it forms a four-mode UWB filter, and produces a transmission zero at the lower and higher cut-off frequencies respectively, thus outside the passband Produce higher out-of-band rejection, the four-mode ultra-wideband filter structure is shown in Figure 2a, and its measured and simulated frequency response results are shown in Figure 2b.

3) The above two broadband filters are designed on the microstrip line and have a relatively wide bandwidth, but they have a common defect that the loss is relatively large. In 2005, Hao Zhangcheng and others published the title "Compact Super-Wide Bandpass Substrate Integrated Waveguide (SIW) Filters" on IEEE Transaction on Microwave Theory and Techniques and proposed to etch an electromagnetic bandgap (EBG) structure on the substrate integrated waveguide, as shown in the figure 3a and 3b. The simulation result is shown in Figure 3c, the relative bandwidth is close to 65%, and the loss is small, but this structure is more complicated and not easy to design and process.

Utility model content

The purpose of this utility model is to solve the defects of the above-mentioned prior art, and provide a broadband substrate integrated waveguide filter with a multi-mode resonator that can meet the requirements of a miniaturized broadband communication system and adopts a U-shaped slot line.

The purpose of this utility model can be achieved by taking the following technical solutions:

A broadband substrate-integrated waveguide filter using a U-shaped groove line, including a substrate-integrated waveguide, the substrate-integrated waveguide includes a dielectric substrate, two layers of metal patches arranged on the front and back of the dielectric substrate, and two rows of metal patches up and down. Through holes, the two layers of metal patches constitute the upper and lower walls of the substrate integrated waveguide, and the upper and lower rows of metal through holes sequentially pass through the metal patch on the front of the dielectric substrate, the dielectric substrate and the metal patch on the back of the dielectric substrate, forming a base The left and right walls of the chip integrated waveguide are characterized in that: U-shaped groove lines are etched on the metal patch on the front of the dielectric substrate, and the substrate integrated waveguide etched with U-shaped groove lines forms a multi-mode resonator.

As a preferred solution, there is one U-shaped groove line, and the U-shaped groove line is arranged at the center of the metal patch on the front surface of the dielectric substrate.

As a preferred solution, there are two U-shaped groove lines, and the two U-shaped groove lines form a groove line unit symmetrically up and down, and the groove line unit is arranged at the center of the metal patch on the front side of the dielectric substrate. Both sides of the upper U-shaped groove line face downward, and both sides of the lower U-shaped groove line face upward.

As a preferred solution, a first metal through hole is further provided between the groove line unit and the upper row of metal through holes, and a second metal through hole is further provided between the groove line unit and the lower row of metal through holes; The first metal through hole is vertically symmetrical to the second metal through hole, and sequentially penetrates through the metal patch on the front side of the dielectric substrate, the dielectric substrate, and the metal patch on the back side of the dielectric substrate.

As a preferred solution, there are four U-shaped groove lines, and every two U-shaped groove lines form a groove line unit symmetrically up and down. Upward; the two slot line units are respectively a first slot line unit and a second slot line unit, and the first slot line unit and the second slot line unit are symmetrically arranged on the metal patch on the front surface of the dielectric substrate.

As a preferred solution, a first metal through hole is further provided between the first groove line unit and the upper row of metal through holes, and a second metal through hole is further provided between the first groove line unit and the lower row of metal through holes. Metal through holes; a third metal through hole is also provided between the second slot line unit and the upper row of metal through holes, and a fourth metal through hole is also provided between the second slot line unit and the lower row of metal through holes holes; the first metal through hole is vertically symmetrical to the second metal through hole, the third metal through hole is vertically symmetrical to the fourth metal through hole, and the first metal through hole is left-right symmetrical to the third metal through hole. The second metal through hole is left-right symmetrical to the fourth metal through hole, and the first metal through hole, the second metal through hole, the third metal through hole and the fourth metal through hole sequentially pass through the metal patch on the front side of the dielectric substrate , the dielectric substrate and the metal patch on the reverse side of the dielectric substrate.

As a preferred solution, the upper row of metal through holes is arranged close to the upper edges of the two-layer metal patches, and the lower row of metal through holes is arranged close to the lower edges of the two-layer metal patches.

As a preferred solution, the left and right ends of the metal patch on the front of the dielectric substrate are respectively provided with an output port and an input port.

Compared with the prior art, the utility model has the following beneficial effects:

1. The broadband substrate-integrated waveguide filter of the present invention uses etched U-shaped groove lines to make the substrate-integrated waveguide form a multi-mode resonator, eliminating the complexity of etching periodic EBG structures on the substrate-integrated waveguide , can be widely used in broadband communication systems.

2. The volume of the broadband substrate integrated waveguide filter of the present invention has a great advantage compared with the volume of the traditional dielectric integrated waveguide. For example, the circuit volume of the present invention is 2.5 times smaller than that of the same 5th-order filter.

3. The broadband substrate integrated waveguide filter of the present invention has the advantages of small size and simple manufacture, and can meet the requirements of miniaturized broadband communication systems. The cost of waveguide is expensive, and it has a good application prospect.

Description of drawings

Fig. 1a is a schematic structural diagram of the first prior art.

Fig. 1b is a simulation result diagram of the first prior art.

Fig. 2a is a schematic structural diagram of the second prior art.

Fig. 2b is a frequency response result diagram of measurement and simulation of the second prior art.

Fig. 3a is a schematic front view of the third prior art.

Fig. 3b is a schematic view of the reverse structure of the third prior art.

Fig. 3c is a simulation result diagram of the third prior art.

Fig. 4 is a schematic diagram of the front structure of the broadband substrate integrated waveguide filter according to Embodiment 1 of the present utility model.

Fig. 5 is a mode distribution diagram of a broadband substrate integrated waveguide filter according to Embodiment 1 of the present invention.

Fig. 6 is a simulation result diagram of the broadband substrate integrated waveguide filter in the case of strong coupling and weak coupling in Embodiment 1 of the present utility model.

Fig. 7 is a schematic diagram of the front structure of the broadband substrate integrated waveguide filter according to Embodiment 2 of the present utility model.

Fig. 8 is a mode distribution diagram of a wideband substrate integrated waveguide filter according to Embodiment 2 of the present invention.

Fig. 9 is a diagram of the simulation results of the broadband substrate integrated waveguide filter in the case of strong coupling and weak coupling according to Embodiment 2 of the present utility model.

Fig. 10 is a schematic diagram of the front structure of the broadband substrate integrated waveguide filter according to Embodiment 3 of the present invention.

Fig. 11 is a simulation result diagram of the wideband substrate integrated waveguide filter in Embodiment 3 of the present invention.

Fig. 12 is a schematic diagram of the front structure of the broadband substrate integrated waveguide filter according to Embodiment 4 of the present invention.

Fig. 13 is a mode distribution diagram of the wideband substrate integrated waveguide filter in Embodiment 4 of the present invention.

Fig. 14 is a diagram of the simulation results of the broadband substrate integrated waveguide filter in the case of strong coupling and weak coupling according to Embodiment 4 of the present utility model.

Fig. 15 is a graph of the simulation and measurement results of the wideband substrate integrated waveguide filter in Embodiment 4 of the present utility model.

Fig. 16 is a graph of group delay of the wideband substrate integrated waveguide filter in Embodiment 4 of the present invention.

Among them, 1-dielectric substrate, 2-front metal patch, 3-upper row of metal through holes, 4-lower row of metal through holes, 5-output port, 6-input port, 7-U-shaped slot line, 8- The first metal via, 9 - the second metal via, 10 - the first slot line unit, 11 - the second slot line unit, 12 - the third metal via, 13 - the fourth metal via.

Detailed ways

Example 1:

As shown in FIG. 4 , the broadband substrate-integrated waveguide filter of this embodiment includes a substrate-integrated waveguide, and the substrate-integrated waveguide includes a dielectric substrate 1 and two layers of metal patches (front and back) arranged on the front and back sides of the dielectric substrate 1. The metal patch on the back is marked 2, the metal patch on the reverse side is not shown in the figure, the same as in Embodiments 2 to 4) and two rows of metal through holes, the two layers of metal patches constitute the upper and lower walls of the substrate integrated waveguide; The upper and lower rows of metal through-holes run through the metal patch 2 on the front of the dielectric substrate 1, the dielectric substrate 1, and the metal patch on the back of the dielectric substrate 1 in sequence. The two rows of metal through-holes are equivalent to electric walls, forming the left and right walls of the substrate integrated waveguide. Wherein the upper row of metal through holes 3 is arranged near the upper edge of the two-layer metal patch 2, and the lower row of metal through-holes 4 is arranged near the lower edge of the two-layer metal patch 2; the dielectric substrate 1 The left and right ends of the front metal patch 2 are respectively provided with an output port 5 and an input port 6, and a U-shaped groove line 7 is etched in the center, and the substrate integrated waveguide (SIW waveguide) that etches the U-shaped groove line 7 forms In the multimode resonator, a in the figure is used to determine the cut-off frequency of the SIW waveguide, and h is used to determine the position of the zero point, as shown in the following equations (1) and (2) respectively:

${\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; cut\; off</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; c</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; a</span>}\sqrt{{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; re</span>}}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

${\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; zero</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; c</span>}}{\mathrm{<span\; class="notranslate">\; 4</span>}\mathrm{<span\; class="notranslate">\; h</span>}\sqrt{{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; re</span>}}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

Then analyze the resonant mode distribution diagram of the filter of this embodiment, as shown in FIG. 5 , where f ₁ to f ₅ are the frequencies of the first to fifth resonant modes respectively, and f _z is the zero point frequency. It can be seen from Figure 5 that the first to third resonance modes are relatively close together, which can form a passband, but as h increases, the zero point shifts to a frequency lower than the third resonance mode, resulting in a bandwidth and Fig. 6 is the simulation results of the filter in the case of strong and weak coupling when h=4.5mm (|S ₁₁ | is the return loss of the input port, |S ₂₁ | is the input port to the output port Forward transmission coefficient), where the solid line is the simulation result of strong coupling, and the dotted line is the simulation result of weak coupling. The first to third resonant modes are simulated to form a passband, and the fourth and fifth resonant modes are spurious modes. It leads to out-of-band deterioration and needs to be suppressed.

Example 2:

As shown in Figure 7, the main features of the broadband substrate integrated waveguide filter of this embodiment are: improving on the basis of the filter structure of Embodiment 1, adding a U-shaped groove line, that is, the metal on the front side of the dielectric substrate 1 Two U-shaped groove lines 7 are etched on the patch 2, and the two U-shaped groove lines 7 form a groove line unit symmetrically up and down, and the groove line unit is arranged at the center of the metal patch 2 on the front of the dielectric substrate 1, The two sides of the upper U-shaped slot line 7 face down (that is, an inverted U shape), and the two sides of the lower U-shaped slot line 7 face up. The substrate integrated waveguide of the slot line unit is also etched to form a multimode resonator. Its cut-off frequency is obtained by formula (1), and the transmission zero point is obtained by the following formula (3):

${\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; zero</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; c</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; h</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; )</span>\sqrt{{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; re</span>}}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$

The resonant mode distribution diagram of the filter of this embodiment is shown in FIG. 8 , wherein f ₁ to f ₄ are the frequencies of the first to fourth resonant modes respectively, and f _z is the zero point frequency. It can be seen from Figure 8 that the first to third resonance modes can form a passband, and there is only one spurious mode close to the passband, so it is easier to find a way to improve the out-of-band suppression characteristics; and Figure 9 is h=2.75 mm, the simulation results of the filter in the case of strong coupling and weak coupling respectively, the solid line is the simulation result of strong coupling, the dotted line is the simulation result of weak coupling, a passband can still be formed, and there is a transmission zero outside the band, close to There is only one spurious mode in the passband.

Example 3:

As shown in Figure 10, the main features of this embodiment are: improving on the filter structure of Embodiment 2, adding two metal through holes, that is, between the slot line unit and the upper row of metal through holes 3 A first metal through hole 8 is provided, and a second metal through hole 9 is also provided between the groove line unit and the lower row of metal through holes 4, and the first metal through hole 8 and the second metal through hole 9 are vertically symmetrical , and pass through the metal patch 2 on the front side of the dielectric substrate 1 , the dielectric substrate 1 , and the metal patch on the back side of the dielectric substrate 1 in sequence. As shown in the simulation results shown in Figure 11, both in-band return loss and out-of-band rejection have been improved to a certain extent.

Example 4:

As shown in Figure 12, the main features of this embodiment are: since the |S21| 3 is improved on the basis of the filter structure, adding two U-shaped slot lines and two metal through holes, that is, there are four U-shaped slot lines 7, and each two U-shaped slot lines 7 form a slot line unit symmetrically up and down , wherein both sides of the upper U-shaped slot line 7 face downward, and the lower U-shaped slot line 7 faces upward; the two slot line units are respectively the first slot line unit 10 and the second slot line unit 11, so The first slot line unit 10 and the second slot line unit 11 are symmetrically arranged on the metal patch 2; a first metal through hole 8 is also provided between the first slot line unit 10 and the upper row of metal through holes 3 A second metal through hole 9 is also provided between the first slot line unit 10 and the lower row of metal through holes 4; a third metal through hole 9 is also provided between the second slot line unit 11 and the upper row of metal through holes 3 A metal through hole 12, a fourth metal through hole 13 is also provided between the second slot line unit 11 and the lower row of metal through holes 4; the first metal through hole 8 and the second metal through hole 9 are vertically symmetrical, The third metal through hole 12 and the fourth metal through hole 13 are vertically symmetrical, the first metal through hole 8 and the third metal through hole 12 are left and right symmetrical, and the second metal through hole 9 and the fourth metal through hole 13 are left and right Symmetry; the first metal through hole 8, the second metal through hole 9, the third metal through hole 12 and the fourth metal through hole 13 pass through the metal patch 2 on the front of the dielectric substrate 1, the dielectric substrate 1 and the dielectric substrate 1 in sequence The metal patch on the reverse side; the substrate integrated waveguide by etching the first slot line unit 10 and the second slot line unit 11 also forms a multimode resonator.

Continue to use the resonant mode distribution diagram for analysis, as shown in Figure 13, where f ₁ to f ₅ are the frequencies of the first to sixth resonant modes respectively, and f _z is the zero point frequency. It can be seen from Figure 13 that the first to fifth modes can form a passband, and there is a transmission zero outside the band, while the spurious modes close to the passband are suppressed by the transmission zero, which greatly improves the out-of-band characteristics. The |S21| parameter of the device also becomes better; and the simulation results are shown in Figure 14, the solid line is the simulation result of strong coupling, the dotted line is the simulation result of weak coupling, the first to fifth modes form a passband, the second One spurious mode is suppressed to below -30dB.

In order to verify the correctness of the filter structure of Embodiment 4, the filter is designed according to the size of Table 1, and its simulation and measurement result curves are shown in Figure 15. The dotted line is the simulation result, and the solid line is the measurement result, which can be It can be seen that the measurement results of the in-band return loss are slightly worse than the simulation results, but they are all below 11dB, and the measurement results are in good agreement with the simulation results; as shown in Figure 16, it is the group delay of the filter ( Refers to the delay of the signal waveform envelope, which reflects the influence of a device on the signal phase of each frequency point in the band), and the group delay in the passband range (that is, 6.75GHz to 10.35GHz) has a good flatness Its relative bandwidth is 42% (center frequency 8.5GHz).

Table 1 Filter Dimensions

In summary, the filter of the present invention utilizes the etched U-shaped groove line to make the substrate integrated waveguide form a multimode resonator, which eliminates the complexity of etching the periodic EBG structure on the substrate integrated waveguide, and at the same time It has the advantages of small size and simple manufacture, and can meet the requirements of miniaturized broadband communication systems. It not only overcomes the defect of large loss in traditional micro-broadband filters, but also solves the problem of expensive metal waveguides, and has a good application prospect.

The above is only a preferred embodiment of the utility model patent, but the scope of protection of the utility model patent is not limited thereto, any skilled person familiar with the technical field within the disclosed scope of the utility model patent, according to The technical scheme of the utility model patent and the equivalent replacement or change of the utility model concept all belong to the protection scope of the utility model patent.

Claims (8)

1. A broadband substrate-integrated waveguide filter adopting a U-shaped groove line, comprising a substrate-integrated waveguide, the substrate-integrated waveguide comprising a dielectric substrate, two layers of metal patches arranged on the front and back sides of the dielectric substrate, and upper and lower two A row of metal through holes, the two layers of metal patches constitute the upper and lower walls of the substrate integrated waveguide, the upper and lower rows of metal through holes sequentially penetrate the metal patch on the front of the dielectric substrate, the dielectric substrate and the metal patch on the back of the dielectric substrate, The left and right walls of the substrate-integrated waveguide are characterized in that U-shaped groove lines are etched on the metal patch on the front of the dielectric substrate, and the substrate-integrated waveguide etched with U-shaped groove lines forms a multi-mode resonator. 2. A broadband substrate integrated waveguide filter using a U-shaped slot line according to claim 1, characterized in that: there is one U-shaped slot line, and the U-shaped slot line is arranged on the metal plate on the front side of the dielectric substrate. At the center of the patch. 3. A broadband substrate integrated waveguide filter using U-shaped slot lines according to claim 1, characterized in that: there are two U-shaped slot lines, and the two U-shaped slot lines are formed symmetrically up and down A groove line unit, the groove line unit is arranged at the center of the metal patch on the front of the dielectric substrate, wherein both sides of the upper U-shaped groove line face downward, and the lower U-shaped groove line faces upward. 4. A broadband substrate integrated waveguide filter using U-shaped slot lines according to claim 3, characterized in that: a first metal through hole is also provided between the slot line unit and the upper row of metal through holes A second metal through hole is also provided between the groove line unit and the lower row of metal through holes; the first metal through hole and the second metal through hole are symmetrical up and down, and successively pass through the metal patch on the front of the dielectric substrate, The dielectric substrate and the metal patch on the reverse side of the dielectric substrate. 5. A broadband substrate integrated waveguide filter using U-shaped slot lines according to claim 1, characterized in that: there are four U-shaped slot lines, and every two U-shaped slot lines form a slot symmetrically up and down Line unit, wherein both sides of the U-shaped groove line at the top face downward, and both sides of the U-shaped groove line at the bottom face upward; the two groove line units are respectively the first groove line unit and the second groove line unit, and the second groove line unit The first groove line unit and the second groove line unit are symmetrically arranged on the metal patch on the front surface of the dielectric substrate. 6. A broadband substrate integrated waveguide filter using U-shaped slot lines according to claim 5, characterized in that: there is a first metal plate between the first slot line unit and the upper row of metal through holes. Through holes, a second metal through hole is also provided between the first slot line unit and the lower row of metal through holes; a third metal through hole is also provided between the second slot line unit and the upper row of metal through holes , a fourth metal through hole is also provided between the second groove line unit and the lower row of metal through holes; the first metal through hole and the second metal through hole are symmetrical up and down, and the third metal through hole and the second metal through hole The four metal through holes are vertically symmetrical, the first metal through hole and the third metal through hole are left and right symmetrical, the second metal through hole is left and right symmetrical to the fourth metal through hole, the first metal through hole, the second metal through hole The through hole, the third metal through hole and the fourth metal through hole sequentially pass through the metal patch on the front side of the dielectric substrate, the dielectric substrate and the metal patch on the back side of the dielectric substrate. 7. A broadband substrate integrated waveguide filter using a U-shaped slot line according to any one of claims 2-6, characterized in that: the upper row of metal through holes are arranged near the two-layer metal patch At the upper edge, the lower row of metal through holes is arranged close to the lower edge of the two-layer metal patch. 8. A broadband substrate integrated waveguide filter using a U-shaped groove line according to any one of claims 2-6, characterized in that: the left and right ends of the metal patch on the front of the dielectric substrate are respectively provided with output ports and input ports.