A wideband substrate integrated waveguide filter

Abstract

The application discloses a wide-band substrate integrated waveguide filter, which comprises a dielectric plate, a first metal plating layer arranged on the first surface of the dielectric plate, a second metal plating layer arranged on the second surface of the dielectric plate, a plurality of metal through holes, each of which penetrates the dielectric plate, all the metal through holes separating the first metal plating layer, the dielectric plate and the second metal plating layer into a first resonant cavity, a second resonant cavity, a third resonant cavity and a fourth resonant cavity, inductive windows arranged between the first resonant cavity and the second resonant cavity, between the second resonant cavity and the third resonant cavity, and between the third resonant cavity and the fourth resonant cavity, and two open U-shaped grooves arranged in each of the first resonant cavity, the second resonant cavity, the third resonant cavity and the fourth resonant cavity, the U-shaped grooves being arranged on the first metal plating layer to push away high-order harmonics of the corresponding resonant cavities. The application can realize the effects of wide-band and miniaturization.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of wireless communication technology, and more particularly to a wide stop-band substrate integrated waveguide filter. BACKGROUND

[0002] With the rapid development of wireless communication industry, the filter as a key device of the transceiver front end, its frequency selection characteristic directly affects the quality of the entire communication system signal. The substrate integrated waveguide filter combines the advantages of microstrip line and rectangular waveguide, such as planarization, low cost, low profile, easy integration, low loss, etc., and has important practical application value. In many applications, in order to enhance the anti-interference of the circuit, the band-pass filter is required to have a very wide stop-band, which can suppress the high-order harmonic. In addition, for mobile communication equipment, the size of the filter is also a very important indicator. Therefore, developing high-performance and miniaturized filter is one of the current research hotspots. SUMMARY

[0003] The purpose of the present application is to provide a wide stop-band substrate integrated waveguide filter, which can achieve the effects of wide stop-band and miniaturization by setting a U-shaped slot in the resonant cavity.

[0004] In order to achieve the above purpose, the present application realizes by the following technical scheme:

[0005] A wide stop-band substrate integrated waveguide filter, comprising:

[0006] A dielectric plate comprising opposite first and second surfaces;

[0007] A first metal plating layer disposed on the first surface of the dielectric plate;

[0008] A second metal plating layer disposed on the second surface of the dielectric plate;

[0009] A plurality of metal vias, each of the metal vias penetrating the dielectric plate; all the metal vias separating the first metal plating layer, the dielectric plate and the second metal plating layer into a first resonant cavity, a second resonant cavity, a third resonant cavity and a fourth resonant cavity;

[0010] Inductive windows are provided between the first resonant cavity and the second resonant cavity, between the second resonant cavity and the third resonant cavity, and between the third resonant cavity and the fourth resonant cavity; and two open U-shaped slots are provided in each of the first resonant cavity, the second resonant cavity, the third resonant cavity and the fourth resonant cavity; the U-shaped slots are located on the first metal plating layer and used to push away the high-order harmonic of the corresponding resonant cavity.

[0011] Optionally, the wide stop-band substrate integrated waveguide filter further comprises:

[0012] an input end arranged at a first end of the first metal plating layer and connected with the first resonant cavity;

[0013] an output end arranged at a second end of the first metal plating layer and connected with the fourth resonant cavity; and the second end and the first end of the first metal plating layer are arranged oppositely.

[0014] Optionally, the first resonant cavity, the second resonant cavity, the third resonant cavity and the fourth resonant cavity are arranged in a straight line along the length direction of the first metal plating layer.

[0015] Optionally, the dielectric constant of the dielectric plate is 1.5-2.5, and the thickness is 1-2 mm.

[0016] Optionally, the input end and the output end both adopt a microstrip line with a characteristic group pit of 50 ohms.

[0017] Compared with the prior art, the present application has at least one of the following advantages:

[0018] The present application provides a wide-bandwidth substrate integrated waveguide filter, a first surface of a dielectric plate is provided with a first metal plating layer, a second surface of the dielectric plate is provided with a second metal plating layer, and a metal through hole penetrating through the dielectric plate can separate the first metal plating layer, the dielectric plate and the second metal plating layer into a first resonant cavity, a second resonant cavity, a third resonant cavity and a fourth resonant cavity; two open U-shaped grooves are arranged in each of the first resonant cavity, the second resonant cavity, the third resonant cavity and the fourth resonant cavity, and the U-shaped grooves are located on the first metal plating layer, so as to push away and suppress high-order harmonics of the corresponding resonant cavity.

[0019] In the present application, the resonant cavity loaded with the U-shaped groove can reduce the resonant frequency of the TE 101 mode, the TE 102 mode, the TE 201 mode and other high-order mode resonant frequencies in the corresponding resonant cavity due to the capacitive effect, and has a significant effect of pushing away the high-order mode TE 102 and TE 201 mode resonant frequencies, so as to realize the wide-bandwidth characteristic. At the same time, since the fundamental mode TE 101 mode resonant frequency is reduced, the resonant frequency can be increased by reducing the size of the corresponding resonant cavity, so as to realize the miniaturization effect of the filter.

[0020] In the present application, the filter adopts a four-order substrate integrated waveguide resonant cavity, the center frequency of the filter can be changed by adjusting the size of the resonant cavity; at the same time, the first resonant cavity, the second resonant cavity, the third resonant cavity and the fourth resonant cavity are arranged in a straight line, so as to realize the simple, compact, miniaturized and easy-to-print structure of the filter.

[0021] The filter of the present application adopts the substrate integrated waveguide structure, is easy to integrate, has the characteristics of small size, low loss, high Q value and high applicable frequency, and is suitable for the design of microwave integrated circuit. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a perspective view of a wide-band substrate integrated waveguide filter according to an embodiment of the present application;

[0023] Figure 2 is a sectional view of a wide-band substrate integrated waveguide filter according to an embodiment of the present application;

[0024] Figure 3 is a size chart of a wide-band substrate integrated waveguide filter according to an embodiment of the present application;

[0025] Figure 4 is a simulation test result of a wide-band substrate integrated waveguide filter according to an embodiment of the present application. DETAILED DESCRIPTION

[0026] The wide-band substrate integrated waveguide filter according to the present application will be further described below in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present application will be more apparent according to the following description. It should be noted that the accompanying drawings are greatly simplified and all use non-precise proportions, only to facilitate, clear auxiliary purpose of explaining the embodiments of the present application. In order to make the purpose, features and advantages of the present application more apparent and easy to understand, please refer to the accompanying drawings. It should be noted that the structure, proportion, size and the like shown in the drawings attached to the present specification are only used to cooperate with the content disclosed in the specification, so as to be understood and read by those skilled in the art, and are not used to limit the limited conditions of the implementation of the present application, so they do not have the technical meaning, any modification of structure, change of proportion relationship or adjustment of size, without affecting the effect and purpose that can be produced by the present application, should still fall within the scope of the technical content disclosed by the present application.

[0027] It should be noted that in this paper, such as the first and second relationship terms are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations. Moreover, the term "includes", "contains" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment. Without more limitations, the element defined by the statement "includes a" does not exclude the presence of another identical element in the process, method, article or equipment including the element.

[0028] Combined with appendix Figures 1 to 4 As shown, this embodiment provides a wide stopband substrate integrated waveguide filter, including: a dielectric substrate 100, which includes opposing first and second surfaces; a first metal plating layer 101 disposed on the first surface of the dielectric substrate 100; a second metal plating layer 102 disposed on the second surface of the dielectric substrate 100; a plurality of metal vias 120, each of the metal vias 120 penetrating the dielectric substrate 100 and abutting against the first metal plating layer 101 and the second metal plating layer 102; all the metal vias 120 dividing the first metal plating layer 101, the dielectric substrate 100 and the second metal plating layer 102 into a first resonant cavity 141, a second resonant cavity 142 and a third resonant cavity 143. 43. Fourth resonant cavity 144; Inductive windows 150 are provided between the first resonant cavity 141 and the second resonant cavity 142, between the second resonant cavity 142 and the third resonant cavity 143, and between the third resonant cavity 143 and the fourth resonant cavity 144; and two U-shaped grooves 130 with opposite openings are provided in the first resonant cavity 141, the second resonant cavity 142, the third resonant cavity 143 and the fourth resonant cavity 144; The U-shaped grooves 130 are located on the first metal plating layer 101, penetrating or not penetrating the first metal plating layer 101, and are used to push away, i.e. suppress, the higher harmonics of the corresponding resonant cavity; wherein, harmonics with a frequency more than twice the fundamental frequency are all higher harmonics.

[0029] Specifically, in this embodiment, all the metal through holes 120 can be arranged in a plurality of connected I-shaped configurations, and the first resonant cavity 141, the second resonant cavity 142, the third resonant cavity 143, and the fourth resonant cavity 144 formed by the metal through holes 120 are arranged in a straight line along the length direction of the first metal plating layer 101; adjacent resonant cavities can be coupled together through the inductive window 150, and the inductive window between the first resonant cavity 141 and the second resonant cavity 142 can be referred to as the first inductive window, the inductive window between the second resonant cavity 142 and the third resonant cavity 143 can be referred to as the second inductive window, and the inductive window between the third resonant cavity 143 and the fourth resonant cavity 144 can be referred to as the third inductive window, but the present invention is not limited thereto.

[0030] Specifically, in this embodiment, the U-shaped groove 130 is etched onto the first metal plating layer 101, and the openings of the two U-shaped grooves 130 in each resonant cavity are opposite to each other, thus the two U-shaped grooves 130 in each resonant cavity roughly form a rectangular structure. Due to the capacitance effect, the resonant cavity loaded with the U-shaped groove 130 can reduce the TE (transient current) present inside the corresponding resonant cavity. 101 Model, TE 102 Model, TE201 the first resonant frequency and other high-order resonant frequencies, and has a significant push far high-order mode TE 102 and TE 201 the effect of the first resonant frequency, thereby achieving a wide band characteristic. Since the fundamental mode TE 101 resonant frequency is also reduced, the resonant frequency can be increased by reducing the size of the corresponding resonant cavity, thereby achieving a filter miniaturization effect. More specifically, the U-shaped slot in the first resonant cavity 141 can be referred to as the first U-shaped slot, the U-shaped slot in the second resonant cavity 142 can be referred to as the second U-shaped slot, the U-shaped slot in the third resonant cavity 143 can be referred to as the third U-shaped slot, and the U-shaped slot in the fourth resonant cavity 144 can be referred to as the fourth U-shaped slot, but the present application is not limited thereto.

[0031] Please refer to Figure 1 and Figure 2 , the wide-band substrate integrated waveguide filter further comprises: an input end 111 disposed at the first end of the first metal plating layer 101 and connected to the first resonant cavity 141; an output end 112 disposed at the second end of the first metal plating layer 101 and connected to the fourth resonant cavity 144; and the first metal plating layer 101 is disposed opposite to the second end and the first end.

[0032] Specifically, in this embodiment, the input end 111 is connected to the first end of the first metal plating layer 101, which can achieve connection with the first resonant cavity 141; the output end 112 is connected to the second end of the first metal plating layer 101, which can achieve connection with the fourth resonant cavity 144; and the input end 111 and the output end 112 can be directly coupled to the filter for feeding, so that the filter can work normally. Preferably, the input end 111 and the output end 112 both use microstrip lines with a characteristic impedance of 50 ohms, but the present application is not limited thereto.

[0033] Specifically, in this embodiment, the dielectric constant of the dielectric plate 100 is 1.5-2.5, and the thickness is 1-2 mm. Preferably, the dielectric constant ε r of the dielectric plate 100 is 2.2, and the thickness is 1.27 mm. More specifically, as Figure 3As shown, the length y_sub of the medium plate 100 is 62 mm, and the width x_sub is 20 mm; the length lp of the input end 111 and the output end 112 is 5 mm, and the width wp is 4 mm; the length l1 of the first resonant cavity 141 and the fourth resonant cavity 144 is 11.4 mm, the length l2 of the second resonant cavity 142 and the third resonant cavity 143 is 13 mm, and the width w1 of the first resonant cavity 141, the second resonant cavity 142, the third resonant cavity 143 and the fourth resonant cavity 144 is 12 mm; the width win12 of the first inductive window and the third inductive window is 3.4 mm, and the width win23 of the second inductive window is 2.6 mm; the length lg1 of the first U-shaped slot and the fourth U-shaped slot is 9.4 mm, and the width wg1 is 4.5 mm; the length lg2 of the second U-shaped slot and the third U-shaped slot is 11 mm, and the width wg2 is 4.5 mm; and the hole diameter r_tongkong of the metal through hole 120 is 0.6 mm. The center frequency of the filter is 5.2 GHz (passband 5.12 GHz-5.27 GHz), and the simulation and debugging are performed by using an electromagnetic simulation software Ansys. Figure 4 The simulation results of S11 and S21 of the filter are shown, and the simulation results show that the filter has good band-stop (out-of-band suppression ≥40 dB in the frequency range of 5.6 GHz-13.3 GHz) effect, the return loss is below 20 dB, and the insertion loss is below 1.6 dB.

[0034] In summary, the embodiment provides a wide-band substrate integrated waveguide filter. The first surface of the medium plate is provided with a first metal plating layer, the second surface of the medium plate is provided with a second metal plating layer, and the metal through hole penetrating through the medium plate can separate the first metal plating layer, the medium plate and the second metal plating layer into a first resonant cavity, a second resonant cavity, a third resonant cavity and a fourth resonant cavity. Two open U-shaped slots are arranged in each of the first resonant cavity, the second resonant cavity, the third resonant cavity and the fourth resonant cavity, and the U-shaped slots are arranged on the first metal plating layer, so as to push away the high-order harmonics of the corresponding resonant cavity. In the embodiment, the resonant cavity loaded with the U-shaped slot can reduce the resonant frequencies of the TE 101 mode, TE 102 mode, TE 201 mode and other high-order mode resonant frequencies due to the capacitive effect, and has the effect of significantly pushing away the resonant frequencies of the high-order TE 102 mode and TE 201 mode, so as to realize the wide-band characteristic. At the same time, the substrate mode TE 101The resonant frequency is reduced, the resonant frequency can be increased by reducing the size of the corresponding resonant cavity, so that the filter miniaturization effect can be realized. In addition, in the embodiment, the filter adopts a four-order substrate integrated waveguide resonant cavity, and the center frequency of the filter can be changed by adjusting the size of the resonant cavity; at the same time, the first resonant cavity, the second resonant cavity, the third resonant cavity and the fourth resonant cavity are arranged in a linear type, so that the filter has simple and compact structure, realizes miniaturization of size and is easy to print.

[0035] Although the content of the present application has been described in detail through the above preferred embodiments, it should be recognized that the above description should not be considered as a limitation of the present application. After reading the above content, various modifications and alternatives of the present application will be apparent to those skilled in the art. Therefore, the protection scope of the present application should be defined by the appended claims.

Claims

1. A wide-stopband substrate integrated waveguide filter, characterized in that, include: A dielectric plate (100) includes opposing first and second surfaces; A first metal plating layer (101) is disposed on the first surface of the dielectric plate (100); A second metal plating layer (102) is disposed on the second surface of the dielectric plate (100); A plurality of metal through holes (120) are provided, each of which penetrates the dielectric substrate (100); all the metal through holes (120) divide the first metal plating layer (101), the dielectric substrate (100) and the second metal plating layer (102) into a first resonant cavity (141), a second resonant cavity (142), a third resonant cavity (143) and a fourth resonant cavity (144); the first resonant cavity (141), the second resonant cavity (142), the third resonant cavity (143) and the fourth resonant cavity (144) are arranged in a straight line along the length direction of the first metal plating layer (101); Inductive windows (150) are provided between the first resonant cavity (141) and the second resonant cavity (142), between the second resonant cavity (142) and the third resonant cavity (143), and between the third resonant cavity (143) and the fourth resonant cavity (144); and two U-shaped grooves (130) with opposite openings are provided in the first resonant cavity (141), the second resonant cavity (142), the third resonant cavity (143) and the fourth resonant cavity (144); the U-shaped grooves (130) are located on the first metal plating layer (101) and are used to push away the higher harmonics of the corresponding resonant cavity.

2. The wide stopband substrate integrated waveguide filter as described in claim 1, characterized in that, Also includes: The input terminal (111) is located at the first end of the first metal plating layer (101) and is connected to the first resonant cavity (141); The output terminal (112) is located at the second end of the first metal plating layer (101) and is connected to the fourth resonant cavity (144); and the second end and the first end of the first metal plating layer (101) are arranged opposite to each other.

3. The wide stopband substrate integrated waveguide filter as described in claim 1, characterized in that, The dielectric constant of the dielectric substrate (100) is 1.5 to 2.5, and the thickness is 1 to 2 mm.

4. The wide stopband substrate integrated waveguide filter as described in claim 2, characterized in that, Both the input terminal (111) and the output terminal (112) are microstrip lines with a characteristic group of 50 ohms.

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