CN1925211A - Half-modular substrate integral wave guide filter - Google Patents

Abstract

The half-mode substrate integrated waveguide filter can be used in the design of microwave and millimeter wave circuits, and can also be used in the design of microwave and millimeter wave integrated circuits. The filter includes a dielectric substrate (1), a metal patch (2), a metal through hole (3), and a slot (4); a metal patch (2) is arranged on the surface of the dielectric substrate (1), and the metal The middle part of the patch (2) is rectangular, and the two sides are strip-shaped and respectively connected to the input terminal (5) and the output terminal (6); in the middle part of the metal patch (2), a A row of metal through holes (3), and slots (6) are provided on the other side; a section of half-mode substrate integrated waveguide between the two slots constitutes a quarter-wavelength resonator. Compared with the microstrip structure, this half-mode substrate integrated waveguide filter has higher Q value and lower loss.

Description

Half-mode substrate integrated waveguide filter

technical field

The half-mode substrate integrated waveguide filter can be used in the design of microwave and millimeter wave circuits, and can also be used in the design of microwave and millimeter wave integrated circuits. It belongs to the technical field of microwave filters.

Background technique

Microwave and millimeter wave filters are at the center of many design issues in microwave and millimeter wave RF systems such as frequency converters, frequency multipliers, and multiplex communications. The electromagnetic spectrum is limited and must be allocated according to the application; and the filter can be used to limit the radiation of the high-power transmitter in the specified frequency band, and in turn can be used to prevent the receiver from being interfered with outside the working frequency band. Traditional microwave and millimeter wave metal waveguides can produce high-Q, low-loss, high-performance microwave filters, but this kind of filter is firstly difficult to process and requires high processing accuracy; secondly, the production cost is relatively expensive; thirdly, this kind of filter Filters are relatively bulky and difficult to apply to the design of microwave and millimeter wave integrated circuits. Therefore, there is an urgent need for microwave and millimeter wave filters with high performance, small size, light weight, high Q value, low loss, low cost, and easy integration, so as to facilitate the design of microwave and millimeter wave integrated circuits; The waveguide filter has good performance, small size, light weight and high Q value, and the half-mode substrate-integrated waveguide technology based on the substrate-integrated waveguide further reduces the size of the filter, and the half-mode substrate-integrated waveguide filter is smaller , while maintaining the advantages of high performance, high Q value, low loss, low cost, and easy integration.

Contents of the invention

Technical problem: The object of the present invention is to provide a half-mode substrate integrated waveguide filter for solving the integration problem of microwave and millimeter wave filters, which has a smaller volume than the original substrate integrated waveguide filter. The filter has the characteristics of easy integration, relatively low processing cost, and simple structure, and is suitable for the design of microwave and millimeter wave integrated circuits; this half-mode substrate integrated waveguide filter has a higher Q value compared with the microstrip structure. lower loss.

Technical solution: The half-mode substrate integrated waveguide filter of the present invention includes a dielectric substrate, a metal patch, a metal through hole, and a slot; a metal patch is provided on the surface of the dielectric substrate, and the middle part of the metal patch is rectangular. The two sides are strip-shaped, respectively connected to the input end and the output end; in the middle of the metal patch, a row of metal through holes is provided along one side of the middle of the metal patch, and a slot is provided on the other side; a section of half mold between the two slots The substrate-integrated waveguide forms a quarter-wavelength resonator.

The diameter d of the metal through hole is 0.2-0.8 mm, and the distance s is 0.4-1.6 mm.

Microstrip line width w=1~2mm, impedance transformer width tw=2~3mm, impedance transformer length tl=10~20mm, half-mode substrate integrated waveguide width a=7~7.6mm, first slot width w1 =0.1～0.14mm, second slot width w2=0.3～0.5mm, third slot width w3=0.1～0.14mm, first slot length l1=4.5～5.5mm, second slot length l2=5 ~5.6mm, the third slot width l3=4.5~5.5mm, the first resonator length d1=4.5~5.5mm, the second resonator length d2=4.5~5.5mm.

The half-mode substrate integrated waveguide filter utilizes the characteristics of high Q value and low loss of the rectangular metal waveguide. First, the half-mode substrate integrated waveguide is realized on the dielectric substrate. This waveguide has a transmission similar to that of the rectangular metal waveguide. characteristics; then, slots are formed on the metal surface of the half-mode substrate integrated waveguide, and a section of half-mode substrate integrated waveguide between the two slots constitutes a quarter-wavelength resonator, which is controlled by changing the size of the slot The strength of the coupling between the resonators makes the whole structure function as a filter. In addition, the high-pass characteristic of the half-mode substrate integrated waveguide improves the selectivity of the filter. In the structure of this half-mode substrate integrated waveguide filter, we mainly pay attention to the design of the following points:

1:) All structures are realized by punching a series of metal through-hole arrays on the dielectric substrate, which is conducive to the integration of this half-mode substrate integrated waveguide filter in microwave and millimeter wave circuit design;

2:) The filtering function of the half-mode substrate integrated waveguide filter is mainly realized by controlling the mutual coupling of the series half-mode substrate integrated waveguide resonators through the slots on the metal surface, so the slots on the half-mode substrate integrated waveguide The design plays a very important role in the whole half-mode substrate integrated waveguide filter;

Half-mode substrate-integrated waveguides have similar transmission characteristics to rectangular metal waveguides. The half-mode substrate-integrated waveguide filter we designed takes full advantage of this characteristic, and forms slots on the metal surface to control the coupling between substrate-integrated waveguide resonators, thereby realizing the half-mode substrate-integrated waveguide filter performance.

Beneficial effects: the invented half-mode substrate integrated waveguide filter has the following advantages:

1:) This half-mode substrate integrated waveguide filter is easy to integrate in the design of microwave and millimeter wave circuits. This is because the filter is completely realized on the dielectric substrate, and the size of the filter can be easily adjusted by using the dielectric constant of the dielectric substrate, so as to better realize the integration with other microwave and millimeter wave circuits;

2:) This half-mode substrate integrated waveguide filter has a higher Q value and lower loss. This is because this structure has similar characteristics to the rectangular metal waveguide, so compared with the microstrip circuit, its Q value is relatively high and the loss is relatively low;

3:) The center frequency of the second passband of this half-mode substrate integrated waveguide filter is about three times the center frequency of the first passband, while the center frequency of the second passband of the ordinary filter is about the first Twice the center frequency of the passband, so its operating frequency band is wider;

Description of drawings

Fig. 1 is a schematic diagram of the present invention,

Fig. 2 is the actual test result of the present invention.

In Figure 1, there are: dielectric substrate 1, metal patch 2, metal through hole 3, input end 4, output end 5, slot 6, microstrip line width W, aperture d, aperture s, impedance transformer width tw , Impedance transformer length tl, half-mode substrate integrated waveguide width a, first slot width w1, second slot width w2, third slot width w3, first slot length l1, second slot length l2 , the third slot width l3, the first resonator length d1, and the second resonator length d2.

Detailed ways

We have implemented the semi-mode substrate integrated waveguide filter described above with a printed circuit board (Printed Circuit Board) process, with a center frequency of 7.8GHz and a relative bandwidth of 22%. The diameter of the metal through hole used to form the dielectric integrated waveguide is 0.4m, the distance between the through holes is 0.8mm, and the relative dielectric constant of the dielectric substrate is 2.25. The structure of the filter includes a dielectric substrate 1, a metal patch 2. Metal through hole 3, slot 6); a metal patch 2 is provided on the surface of the dielectric substrate 1, the middle part of the metal patch 2 is rectangular, and both sides are strip-shaped, respectively connected to the input terminal 5 and the output terminal 6 ; In the middle of the metal patch 2, a row of metal through holes 3 are provided along one side of the middle of the metal patch 2, and a slot 6 is provided on the other side; a section of half-mode substrate integrated waveguide between the two slots constitutes a quarter One wavelength resonator.

The diameter d of the metal through hole (3) is 0.2-0.8 mm, and the distance s is 0.4-1.6 mm. Microstrip line width w=1~2mm, impedance transformer width tw=2~3mm, impedance transformer length tl=10~20mm, half-mode substrate integrated waveguide width a=7~7.6mm, first slot width w1 =0.1～0.14mm, second slot width w2=0.3～0.5mm, third slot width w3=0.1～0.14mm, first slot length l1=4.5～5.5mm, second slot length l2=5 ~5.6mm, the third slot width l3=4.5~5.5mm, the first resonator length d1=4.5~5.5mm, the second resonator length d2=4.5~5.5mm.

For example, its parameters are shown in the table below: w(mm) 1.5 w2(mm) 0.4 tw(mm) 2.5 w3(mm) 0.12 tl(mm) 14 l1(mm) 5 a(mm) 7.3 l2(mm) 5.3 d(mm) 0.4 l3(mm) 5 s(mm) 0.8 d1(mm) 5 w1(mm) 0.12 d2(mm) 5 .

Claims (3)

1. a half-modular substrate integral wave guide filter is characterized in that this filter comprises medium substrate (1), metal patch (2), metal throuth hole (3), the line of rabbet joint (4); Be provided with metal patch (2) on the surface of dielectric substrate (1), the middle part of this metal patch (2) is a rectangle, and both sides are banded input (5) and the output (6) of also connecting respectively; Middle part at metal patch (2) is provided with row's metal throuth hole (3) along the one side in the middle part of the metal patch (2), another side is provided with the line of rabbet joint (6); One section half module substrate integrated wave guide between two lines of rabbet joint constitutes a quarter-wave resonance device.

2. half-modular substrate integral wave guide filter according to claim 1 is characterized in that the aperture d=0.2～0.8mm of metal throuth hole (3), pitch-row s=0.4～1.6mm.

3. half-modular substrate integral wave guide filter according to claim 1 is characterized in that the micro belt line width w=1～2mm on the metal patch (2); impedance transformer width tw=2～3mm; impedance transformer length t1=10～20mm; half module substrate integrated wave guide width a=7～7.6mm; first slot width w1=0.1～0.14mm; second slot width w2=0.3～0.5mm; the 3rd line of rabbet joint width w3=0.1～0.14mm; first line of rabbet joint length 11=4.5～5.5mm; second line of rabbet joint length 12=5～5.6mm; the 3rd line of rabbet joint width 13=4.5～5.5mm; first resonator length d1=4.5～5.5mm; second resonator length d2=4.5～5.5mm.

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