A millimeter wave rectangular waveguide-in-glass waveguide filter

Abstract

The application provides a millimeter wave rectangular waveguide embedded gap waveguide filter, which comprises, from top to bottom, an upper metal cover plate, an intermediate metal block and a lower metal cover plate; the upper metal cover plate is provided with a coaxial input port; the lower metal cover plate is provided with a coaxial output port; the upper surface and the lower surface of the intermediate metal block are provided with a first periodic metal pin array and a second periodic metal pin array; the first periodic metal pin array and the second periodic metal pin array are respectively provided with a gap between the upper metal cover plate and the lower metal cover plate; the first periodic metal pin array surrounds a first slot gap waveguide resonant cavity on the upper surface of the intermediate metal block; the second periodic metal pin array surrounds a second slot gap waveguide resonant cavity on the lower surface of the intermediate metal block; a rectangular waveguide resonant cavity formed by hollowing out the inside of the intermediate metal block is in communication with the first slot gap waveguide resonant cavity and the second slot gap waveguide resonant cavity respectively.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of gap waveguide filters, and particularly relates to a millimeter wave rectangular waveguide embedded gap waveguide filter. BACKGROUND

[0002] With the development of the fifth generation mobile communication and future millimeter wave wireless systems, the demand for high-performance and miniaturized filters is increasingly urgent. The millimeter wave frequency band has become the key to realizing high-speed data transmission due to its rich spectrum resources and large available bandwidth. However, the shortened wavelength also brings higher transmission loss and severe challenges to the performance and size of passive devices. Therefore, how to realize a low-loss, high-selectivity and compact structure filter in the millimeter wave frequency band has always been the focus and difficulty of the field. In recent years, gap waveguide technology, as a new platform, can effectively limit the propagation of electromagnetic waves in the preset groove or cavity without physical metal contact through the formation of artificial magnetic conductors by periodic structures. This characteristic to some extent overcomes the dependence of traditional rectangular waveguides on precise mechanical contact, showing good application prospects. However, the existing gap waveguide filter design usually consists of a periodic pin array and occupies an independent physical space. Although this structure solves the contact problem, in order to maintain the necessary electromagnetic bandgap, its lateral size is often limited and difficult to further reduce, resulting in an overall structure that is not compact enough and the integration needs to be improved.

[0003] In summary, the millimeter wave filter in the prior art is difficult to achieve an ideal balance between miniaturization, high integration and high performance. Therefore, there is an urgent need in the field for an innovative filter structure that can combine the low-loss advantage of rectangular waveguides and the ease of manufacturing of gap waveguides, while breaking through the limitations of existing structures in size and integration. The rectangular waveguide embedded structure solves the problem of high assembly difficulty and cost, realizes a more compact size, higher integration and better frequency selectivity. SUMMARY

[0004] The application aims to provide a millimeter wave rectangular waveguide embedded gap waveguide filter, which reduces the assembly difficulty and cost while realizing a more compact size, higher integration and better frequency selectivity.

[0005] Technical scheme, in order to realize the above object, the present application proposes a kind of millimeter wave rectangular waveguide embedded gap waveguide filter, the filter includes from top to bottom sequentially assembled upper metal cover plate 100, intermediate metal block 200 and lower metal cover plate 300;The upper metal cover plate 100 is provided with coaxial input port 101, the lower metal cover plate 300 is provided with coaxial output port 301, and, coaxial input port 101 and coaxial output port 301 vertical direction coaxial;The upper surface of the intermediate metal block 200 is provided with first periodic metal peg array 201, and the lower surface is provided with second periodic metal peg array 202;First air gap is formed between the first periodic metal peg array 201 and the upper metal cover plate 100;Second air gap is formed between the second periodic metal peg array 202 and the lower metal cover plate 300;The first periodic metal peg array 201 is enclosed in first slot gap waveguide resonant cavity 11 on the upper surface of the intermediate metal block 200;The second periodic metal peg array 202 is enclosed in second slot gap waveguide resonant cavity 13 on the lower surface of the intermediate metal block 200;

[0006] The inside of the intermediate metal block 200 is hollow to form rectangular waveguide resonant cavity 12;Rectangular waveguide resonant cavity 12 is communicated with first slot gap waveguide resonant cavity 11 by first coupling hole, and is communicated with second slot gap waveguide resonant cavity 13 by second coupling hole;The first slot gap waveguide resonant cavity 11, rectangular waveguide resonant cavity 12 and second slot gap waveguide resonant cavity 13 are sequentially coupled to form three-order band-pass filter structure.

[0007] Further, the first slot gap waveguide resonant cavity 11 is provided with first perturbation peg 203, and the second slot gap waveguide resonant cavity 13 is provided with second perturbation peg 204.

[0008] Further, the position of the first perturbation peg 203 and the second perturbation peg 204 is adjustable, and the resonant frequency of preset mode is adjusted by adjusting the position in resonant cavity.

[0009] Further, the first slot gap waveguide resonant cavity 11 and the second slot gap waveguide resonant cavity 13 are configured to work in TE102 mode and TE201 mode, and the rectangular waveguide resonant cavity 12 is configured to work in TE101 mode.

[0010] Further, the coaxial input port 101 and the coaxial output port 301 are communicated with the first slot gap waveguide resonant cavity 11 and the second slot gap waveguide resonant cavity 13 respectively, and impedance matching is realized with the first slot gap waveguide resonant cavity 11 and the second slot gap waveguide resonant cavity 13 respectively.

[0011] Further, the first air gap and the second air gap constitute an artificial magnetic conductor boundary for limiting electromagnetic field leakage.

[0012] Compared with the prior art, the technical scheme of the present application has the following beneficial technical effects:

[0013] (1) By embedding the rectangular waveguide resonator as an independent unit in the middle layer of the gap waveguide, three-dimensional integration and spatial multiplexing of the structure are achieved, which significantly reduces the horizontal plane size and overall volume of the filter, and is conducive to the miniaturization of the system device.

[0014] (2) The embedded structure constitutes a compact electromagnetic cavity, and each resonant unit is highly integrated in physics, forming a stable integrated mechanical structure, which not only improves the physical stability of the device, but also simplifies the overall assembly.

[0015] (3) Thanks to the role of the disturbance pin, the filter can produce two controllable transmission zeros, achieving high frequency selectivity and excellent out-of-band suppression characteristics.

[0016] (4) To some extent, this structure inherits the advantage of low physical contact requirement of the gap waveguide technology, reducing the dependence on extremely high precision machining, which is conducive to controlling the manufacturing cost. BRIEF DESCRIPTION OF DRAWINGS

[0017] The present application will be described in further detail below with reference to the accompanying drawings and specific embodiments, so that the technical solutions in the embodiments of the present application or the prior art, the advantages and implementation modes of the present application will be more apparent. The content of the accompanying drawings is only used to explain and illustrate the present application, but will not constitute any meaningful limitation on the present application. In the accompanying drawings:

[0018] Figure 1 is a structural diagram of the present application;

[0019] Figure 2 is a top and bottom layer display diagram of the present application;

[0020] Figure 3 is a side view of the present application;

[0021] Figure 4 is an S parameter diagram of the filter. DETAILED DESCRIPTION

[0022] The embodiments of the present application will be described below with reference to the accompanying drawings, and the embodiments shown in the drawings are only exemplary in nature and are intended to explain the principles of the present application, but are not intended to limit the scope of the present application.

[0023] As Figure 1As shown, the application provides a millimeter wave rectangular waveguide embedded gap waveguide filter, comprising an upper metal cover plate 100, an intermediate metal block 200, and a lower metal cover plate 300.

[0024] The upper metal cover plate is provided with a coaxial input port 101, and the lower metal cover plate is provided with a coaxial output port 301, and the coaxial input port 101 and the coaxial output port 301 are coaxial in the vertical direction to realize energy input and output from the device; the intermediate metal block 200 is connected with a periodic metal pin array 201 above and a periodic metal pin array 202 below.

[0025] The metal pin array 201 is spaced apart from the upper metal cover plate 100 by an air gap, and the metal pin array 202 is also spaced apart from the lower metal cover plate 300 by an air gap, and the two air gaps constitute the artificial magnetic conductor required by the gap waveguide, prevent energy leakage, and reduce device loss.

[0026] The metal pin array 201 surrounds a space in the center of the upper surface of the intermediate metal block 200, which is referred to as a first slot gap waveguide resonant cavity 11, which is used to excite a TE102 mode and produce a resonance point. The metal pin array 202 also surrounds a space in the center of the lower surface of the intermediate metal block 200, which is referred to as a second slot gap waveguide resonant cavity 13, which is also used to excite a TE102 mode and produce a resonance point.

[0027] Inside the intermediate metal block 200, three regions are hollowed out, which are a rectangular waveguide resonant cavity 12 and two coupling holes 205 connected above and below; the rectangular waveguide resonant cavity 12 is connected with the first slot gap waveguide resonant cavity 11 through the coupling hole 205, and is connected with the second slot gap waveguide resonant cavity 13 through the coupling hole 205; the rectangular waveguide resonant cavity 12 can excite a TE101 mode and produce a resonance point; the coupling hole 205 can form an energy coupling path for the first slot gap waveguide resonant cavity 11-center rectangular waveguide resonant cavity 12-second slot gap waveguide resonant cavity 13, and realize a three-resonance-point (i.e. three-order) bandpass filter response.

[0028] The above-described technical solution constructs a three-order rectangular waveguide embedded gap waveguide filter, which has the characteristics of low loss, high integration, and compact size, and due to the existence of the artificial magnetic conductor boundary, it has good non-electric contact and is suitable for working in the millimeter wave frequency band.

[0029] Furthermore, the first perturbation pin 203 and the second perturbation pin 204 are respectively added to the first slot gap waveguide resonator 11 and the second slot gap waveguide resonator 13, and they are used to independently perturb the resonant frequency of the TE201 mode in the slot gap waveguide resonator 11 and 12. The TE201 mode excited by the coaxial input port 101 and the coaxial output port 301 in the slot gap waveguide resonator 11 and 12 cannot be effectively coupled through the coupling hole 205, thus generating two transmission zeros. The frequency positions of these two transmission zeros are the frequency positions of the TE201 mode excited in the first slot gap waveguide resonator 11 and the central rectangular waveguide resonator 12. Therefore, the transmission zeros can be controlled by the first perturbation pin 203 and the second perturbation pin 204.

[0030] The achieved filter effect is as follows Figure 4 As shown, the filter has a center frequency of 25.5 GHz, a 3dB bandwidth of 3.37%, an insertion loss of 0.17 dB, and a return loss better than 20 dB. Furthermore, two transmission zeros located in the upper stopband can be clearly observed; the first zero is located at approximately 26.74 GHz, and the second at approximately 27.11 GHz. The stopband range is greater than 1.14 times the center frequency, and the stopband rejection exceeds -40 dB, which is beneficial for improving the filter's frequency selectivity and upper stopband rejection.

[0031] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, chip, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, chip, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, chip, article, or apparatus that includes said element. The above descriptions are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A millimeter-wave rectangular waveguide embedded gap waveguide filter, characterized in that, The filter includes an upper metal cover plate (100), a middle metal block (200) and a lower metal cover plate (300) assembled from top to bottom. The upper metal cover plate (100) is provided with a coaxial input port (101), and the lower metal cover plate (300) is provided with a coaxial output port (301). Furthermore, the coaxial input port (101) and the coaxial output port (301) are coaxial in the vertical direction. The upper surface of the intermediate metal block (200) is provided with a first periodic metal pin array (201), and the lower surface is provided with a second periodic metal pin array (202); a first air gap is formed between the first periodic metal pin array (201) and the upper metal cover plate (100); a second air gap is formed between the second periodic metal pin array (202) and the lower metal cover plate (300); the first periodic metal pin array (201) forms a first slot gap waveguide resonant cavity (11) on the upper surface of the intermediate metal block (200); the second periodic metal pin array (202) forms a second slot gap waveguide resonant cavity (13) on the lower surface of the intermediate metal block (200). The interior of the intermediate metal block (200) is hollowed out to form a rectangular waveguide resonant cavity (12); the rectangular waveguide resonant cavity (12) is connected to the first slot gap waveguide resonant cavity (11) through the first coupling hole, and is connected to the second slot gap waveguide resonant cavity (13) through the second coupling hole; The first slot gap waveguide resonator (11), the rectangular waveguide resonator (12), and the second slot gap waveguide resonator (13) are sequentially coupled to form a third-order bandpass filter structure.

2. The millimeter-wave rectangular waveguide embedded gap waveguide filter according to claim 1, characterized in that, The first slot gap waveguide resonator (11) is provided with a first disturbance pin (203), and the second slot gap waveguide resonator (13) is provided with a second disturbance pin (204).

3. A millimeter-wave rectangular waveguide embedded gap waveguide filter according to claim 2, characterized in that, The positions of the first disturbance pin (203) and the second disturbance pin (204) are adjustable, and the resonant frequency of the preset mode can be adjusted by adjusting their positions in the resonant cavity.

4. A millimeter-wave rectangular waveguide embedded gap waveguide filter according to claim 1, characterized in that, The first slot gap waveguide resonator (11) and the second slot gap waveguide resonator (13) are configured to operate in TE102 mode and TE201 mode, respectively, and the rectangular waveguide resonator (12) is configured to operate in TE101 mode.

5. A millimeter-wave rectangular waveguide embedded gap waveguide filter according to claim 1, characterized in that, The coaxial input port (101) and coaxial output port (301) are connected to the first slot gap waveguide resonator (11) and the second slot gap waveguide resonator (13) respectively, and impedance matching is achieved with the first slot gap waveguide resonator (11) and the second slot gap waveguide resonator (13) respectively.

6. The millimeter-wave rectangular waveguide embedded gap waveguide filter according to any one of claims 1 to 5, characterized in that, The first air gap and the second air gap constitute the boundary of the artificial magnetic conductor.

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