CN104659451A - Four-mode band-pass filter based on 1/3 equilateral triangular substrate integrated resonator - Google Patents

Abstract

The invention discloses a four-mode bandpass filter based on a 1/3 equilateral triangular substrate integrated resonator, which includes a resonator cavity, an elliptical metallized through hole and two microstrip lines. The resonator cavity consists of a top metal layer, a dielectric substrate and a bottom metal layer that are parallel to each other from top to bottom. Two microstrip lines are respectively connected to the resonator cavity to form a complete resonator, and the elliptical metallization Vias are provided on the resonator. The invention has the advantages of simple structure, easy processing, wide working bandwidth and good electrical performance, and solves the contradiction between the increase of the frequency range of the filter and the difficulty of industrial processing.

Description

Four-mode Bandpass Filter Based on 1/3 Equilateral Triangular Substrate Integrated Resonator

technical field

The invention belongs to the technical field of millimeter waves, and in particular relates to a four-mode bandpass filter based on a 1/3 equilateral triangular substrate integrated resonator.

Background technique

In modern wireless communication, the microwave frequency band communication system has a lot of services, and the frequency resources are extremely tight. Future communication technology is developing towards a higher frequency band—millimeter wave. As a part used to separate signals, a filter is one of the key parts in a wireless communication system. Triangular substrate integrated resonators have the characteristics of high quality factor, low insertion loss, compact structure, high power capacity, etc., and are widely used in modern communications. As the frequency range continues to increase, the size of millimeter wave devices will continue to shrink. When the design size of millimeter-wave devices is reduced to a certain extent, due to the limitations of industrial processing technology, it will not be able to be precisely processed. How to improve the frequency range of the filter, and now the industrial processing technology can be precisely processed, has become a problem that needs to be solved increasingly in this field.

Contents of the invention

In order to solve the technical problems raised by the above-mentioned background technology, the present invention aims to provide a four-mode bandpass filter based on a 1/3 equilateral triangular substrate integrated resonator, which solves the problem between the increase of the frequency range of the filter and the difficulty of industrial processing. contradiction.

In order to realize above-mentioned technical purpose, technical scheme of the present invention is:

A four-mode bandpass filter based on a 1/3 equilateral triangular substrate integrated resonator, including a resonator cavity, an elliptical metallized through hole and 2 microstrip lines; the resonator cavity is sequentially arranged from top to bottom Comprising a top metal layer, a dielectric substrate and a bottom metal layer parallel to each other, the top metal layer, the dielectric substrate and the bottom metal layer are mutually congruent planar quadrilaterals, and the planar quadrilateral includes a first side, a second side, The third side and the fourth side, the angle between the first side and the second side is 60°, the third side is perpendicular to the second side, the fourth side is perpendicular to the first side, the angle between the third side and the fourth side is 120°, and the first side is equal to the second side, and the third side is equal to the fourth side. On the dielectric substrate, two rows of circular metallized vias are uniformly arranged along the first side and the second side. hole; two sides of the circular metallized through hole in the four sides of the resonator cavity are used as electric walls, and the other two sides are used as magnetic walls, and the two microstrip lines are respectively arranged along the edges of the two magnetic walls and Intersecting at the junction of two magnetic walls, the elliptical metallized through hole is provided on the aforementioned dielectric substrate.

Wherein, the impedances of the above two microstrip lines are both 50 ohms.

Wherein, the above-mentioned four-mode bandpass filter is a mirror symmetrical structure.

Wherein, a group of defect structures are etched on the underlying metal layer.

Wherein, the defective ground structure includes three slotting lines parallel to each other, and the two ends of each slotting line are arrow-shaped.

The beneficial effect brought by adopting the above-mentioned technical scheme:

(1) The present invention utilizes 1/3 equilateral triangular substrate to integrate the coupling of the four modes of the resonator, and adds an elliptical metallized through hole on the resonator to change the main mode frequency of the resonator, so that the resonator becomes a filter The filter improves the filtering range and has a large passband bandwidth;

(2) The main structure of the present invention is a 1/3 equilateral triangular substrate integrated resonator, which has a simple and compact structure and is easy for industrial processing.

Description of drawings

Fig. 1 is a schematic structural diagram of a resonator cavity in the present invention.

Fig. 2 is a schematic three-dimensional dissection diagram of the cavity of the resonator in the present invention.

Fig. 3 is a schematic structural diagram of a resonator in the present invention.

FIG. 4 is a schematic structural diagram of a four-mode bandpass filter of the present invention.

Fig. 5 is a simulation waveform diagram of S parameters of the resonator in the present invention.

Fig. 6 is an S-parameter simulation waveform diagram of the four-mode bandpass filter of the present invention.

FIG. 7 is a structural schematic diagram of defects in the present invention.

FIG. 8 is a schematic structural diagram of a four-mode bandpass filter with a defective structure according to the present invention.

FIG. 9 is an S-parameter simulation waveform diagram of a four-mode band-pass filter with a defective structure according to the present invention.

Reference numerals: 1. Top metal layer; 2. Dielectric substrate; 3. Circular metallized through hole; 4. Bottom metal layer.

Detailed ways

The technical solutions of the present invention will be described in detail below in conjunction with the accompanying drawings.

The basic unit of the present invention is a 1/3 equilateral triangular substrate integrated resonator. The vertical segment of the can be divided.

A four-mode bandpass filter based on a 1/3 equilateral triangular substrate integrated resonator, including a resonator cavity, an elliptical metallized through hole and two microstrip lines. As shown in Figures 1 and 2, the cavity of the resonator comprises a top metal layer 1, a dielectric substrate 2 and a bottom metal layer 4 parallel to each other from top to bottom, the top metal layer 1, the dielectric substrate 2 and the underlying metal layer 4 are mutually congruent planar quadrilaterals, which include a first side, a second side, a third side and a fourth side, the angle between the first side and the second side is 60°, and the third side The side is perpendicular to the second side, the fourth side is perpendicular to the first side, the angle between the third side and the fourth side is 120°, and the first side is equal to the second side, and the third side is equal to the fourth side , two rows of circular metallized through holes 3 are evenly arranged on the dielectric substrate 2 along the first side and the second side thereof. Among the four sides of the resonator cavity, two sides of the circular metallized through hole 3 are used as electric walls, and the other two sides are used as magnetic walls. The two microstrip lines are respectively arranged along the edges of the two magnetic walls and intersect At the intersection of the two magnetic walls, the two microstrip lines and the resonator cavity together form a complete resonator. In this embodiment, the impedance of the two microstrip lines is 50 ohms, and the two microstrip lines Respectively as the input and output of the resonator, its structure is shown in Figure 3.

Above-mentioned resonator comprises four modes TM ₁₀₁ mode, TM ₂₀₁ mode, TM ₁₀₂ mode and TM ₃₀₃ mode, as shown in Figure 4, on the dielectric substrate of resonator, be provided with ellipse metallized through hole, its effect is to improve the original The resonant frequency of the TM101 mode in the resonator makes the TM ₁₀₁ mode and TM ₂₀₁ mode, TM ₁₀₂ mode, and TM ₃₀₃ mode generate coupling respectively, thereby forming a bandpass filter. Figures 5 and 6 are the S-parameter simulation waveform diagrams of the resonator and the four-mode bandpass filter respectively. S21) and the dotted line (Simulated S11) respectively represent the relationship between the electromagnetic wave reflection coefficient and frequency, and the electromagnetic wave transmission coefficient and frequency. Comparing Figure 5 and Figure 6, it can be seen that the resonant frequency of TM ₁₀₁ mode has been greatly improved, and TM ₂₀₁ mode, TM ₁₀₂ mode and TM ₃₀₃ mode are coupled. In this embodiment, the entire four-mode bandpass filter is a mirror symmetrical structure.

Fig. 7 is a schematic diagram of the defective structure in the present invention, the defective structure includes three slotted lines parallel to each other in the shape of double arrows, the purpose of using the defective structure is to suppress higher-order modes in the filter, Thereby, the effect of improving the out-of-band characteristic is achieved. Figure 8 is a structural schematic diagram of a four-mode bandpass filter with a defective ground structure, and Figure 9 is its S-parameter simulation waveform diagram, which can be obtained from the figure, the center frequency of the bandpass filter is 20.01GHz, and the -5dB bandwidth is 14.55GHz~27.52GHz, the in-band insertion loss is about 2.2dB, and the return loss is greater than 13dB, indicating that the filter has good performance.

The above embodiments are only to illustrate the technical ideas of the present invention, and can not limit the protection scope of the present invention with this. All technical ideas proposed in accordance with the present invention, any changes made on the basis of technical solutions, all fall within the protection scope of the present invention. Inside.

Claims (5)

1. The four-mode bandpass filter based on 1/3 equilateral triangular substrate integrated resonator, is characterized in that: comprise resonator cavity body, elliptic metallization through-hole and 2 microstrip lines; Described resonator cavity The body includes a top metal layer, a dielectric substrate and a bottom metal layer in sequence from top to bottom, the top metal layer, the dielectric substrate and the bottom metal layer are mutually congruent planar quadrilaterals, and the planar quadrilateral includes the first side, the second side, the third side and the fourth side, the angle between the first side and the second side is 60°, the third side is perpendicular to the second side, the fourth side is perpendicular to the first side, the third side and The included angle of the fourth side is 120°, and the first side is equal to the second side, and the third side is equal to the fourth side. On the dielectric substrate, two A row of circular metallized through holes; two sides of the circular metallized through holes in the four sides of the resonator cavity are used as electric walls, and the other two sides are used as magnetic walls. The two microstrip lines are respectively along the two sides. The edges of the two magnetic walls are arranged and intersect at the joint of the two magnetic walls, and the elliptical metallized through hole is arranged on the aforementioned dielectric substrate. 2. The four-mode bandpass filter based on a 1/3 equilateral triangular substrate integrated resonator according to claim 1, wherein the impedances of the two microstrip lines are both 50 ohms. 3 . The four-mode bandpass filter based on a 1/3 equilateral triangular substrate integrated resonator according to claim 1 , wherein the four-mode bandpass filter is a mirror symmetrical structure. 4 . 4. The four-mode bandpass filter based on a 1/3 equilateral triangular substrate integrated resonator according to claim 1, wherein a group of defective structures are etched on the underlying metal layer. 5. The four-mode bandpass filter based on a 1/3 equilateral triangular substrate integrated resonator according to claim 4, wherein the defective ground structure includes 3 slotted lines parallel to each other, and each Both ends of the slotted line are arrow-shaped.