CN103904391B - Multilayer hybrid guided mode hexagon substrate integral wave guide filter - Google Patents

Abstract

The invention discloses a multilayer mixed-mode hexagonal substrate integrated waveguide filter with high out-of-band selectivity, small volume and low loss. There is an included angle between the coplanar waveguide input end and the coplanar waveguide output end of the filter, and through the loading effect of the hexagonal coupling slot combination structure arranged on the first metal layer, it can effectively excite the resonance in the cavity The secondary mode, as well as the left-leaning and right-leaning non-resonant high-order modes, can also excite the electromagnetic coupling between the filter source and the load, effectively increasing the signal transmission path, thereby obtaining two additional transmissions on the basis of the original transmission zero. Zero point, the coupling between the first resonant cavity and the second resonant cavity can be realized through two symmetrically distributed V-shaped coupling grooves arranged on the second metal layer, and the fourth transmission zero point is generated to further broaden the stopband width And increase the attenuation of the stop band, and at the same time, the filter has low loss and small volume. It is suitable for promotion and application in the field of microwave and millimeter wave technology.

Description

Multilayer mixed-mode hexagonal substrate integrated waveguide filter

technical field

The invention relates to the field of microwave and millimeter wave technology, in particular to a multilayer mixed-mode hexagonal substrate integrated waveguide filter.

Background technique

Filter is one of the most commonly used components in communication systems, and its performance directly affects the quality of the circuit system. Traditional filters are generally divided into metal waveguide filters and planar microstrip or stripline structure filters. Traditional metal waveguide filters have the advantages of low loss, high Q value, and good selectivity, but have the disadvantages of large volume, complex processing, and difficulty in integrating with planar circuits. Although microstrip or stripline filters are easy to integrate with planar circuits, they have large losses and low Q values, especially in high-frequency bands, and there is large radiation, which affects circuit stability.

The filter based on the substrate integrated waveguide technology not only retains the characteristics of high Q value and good selectivity of the metal waveguide filter, but also has the advantages of easy integration, low cost and convenient processing of planar microstrip and stripline filters. advantage has received extensive attention in recent years. With the increasing scarcity of spectrum resources, the requirements for the transmission zero and selectivity of the filter are higher, and in the design of the traditional substrate integrated waveguide filter, the transmission zero obtained by the N-order resonator can only obtain N- 2. If more transmission zeros are needed, it can only be achieved by increasing the number of resonant cavities, but the area occupied by the substrate integrated waveguide resonant cavity unit is still relatively large. If the number of resonant cavities increases, the filter It will take up a lot of area in the circuit, which is very unfavorable to meet the stringent requirements of the modern communication system on the volume, selectivity and integration of the filter.

Contents of the invention

The technical problem to be solved by the invention is to provide a multilayer mixed-mode hexagonal substrate integrated waveguide filter with high out-of-band selectivity, small volume and low loss.

The technical solution adopted by the present invention to solve the above-mentioned technical problems is: the multilayer mixed-mode hexagonal substrate integrated waveguide filter includes a first metal layer, a first dielectric substrate, a second metal layer, a second dielectric substrate, and a third metal layer, the first metal layer is provided with a coplanar waveguide input end and a coplanar waveguide output end, and there is an angle between the coplanar waveguide input end and the coplanar waveguide output end , the first dielectric substrate is provided with an upper metallized through-hole array penetrating through the first dielectric substrate, and the upper metallized through-hole array together with the first metal layer and the second metal layer forms a hexagonal first A resonant cavity, the second dielectric substrate is provided with an array of lower metallized through holes penetrating through the second dielectric substrate, and the array of lower metallized through holes together with the second metal layer and the third metal layer forms a hexagonal The second resonant cavity, the second resonant cavity is located directly below the first resonant cavity, the first metal layer is provided with a hexagonal coupling groove combination structure, and the hexagonal coupling groove combination structure is located in the first resonant cavity In the cavity, the combined structure of the hexagonal coupling groove includes a metallized coupling through hole that runs through the first metal layer and the first dielectric substrate in sequence, a hexagonal coupling groove on the first metal layer, and two A bent groove, the metallized coupling through hole is located in the space surrounded by the hexagonal coupling groove, and the hexagonal coupling groove is located in the space surrounded by two bent grooves; the second metal Two symmetrically distributed V-shaped coupling grooves are arranged on the layer, and the two V-shaped coupling grooves are located in the second resonant cavity and arranged symmetrically around the center of the second resonant cavity.

Further, the angle between the input end of the coplanar waveguide and the output end of the coplanar waveguide is 115-125°.

Further, the gold first metal layer, the second metal layer and the third metal layer are made of gold or silver.

Further, the first dielectric substrate and the second dielectric substrate are made of microwave dielectric ceramics with a dielectric constant in the range of 1-20.

Beneficial effects of the present invention: there is an angle between the coplanar waveguide input end and the coplanar waveguide output end of the multilayer mixed-mode hexagonal substrate integrated waveguide filter of the present invention, and through the The loading effect of the combined structure of the hexagonal coupling groove can not only effectively excite the resonant secondary mode in the cavity of the resonant cavity, but also the two non-resonant high-order modes, left-dipping and right-dipping, and can also excite the electromagnetic wave between the filter source and the load. Coupling, which effectively increases the signal transmission path, thereby obtaining two additional transmission zero points on the basis of the original one transmission zero point. Since the second resonant cavity is located directly below the first resonant cavity, two symmetrical The distributed V-shaped coupling grooves can realize the coupling between the first resonant cavity and the second resonant cavity, and generate the fourth transmission zero point, which further widens the stop band width and improves the stop band attenuation, and the resonance described in the present invention The layout characteristics of the vertical cavity distribution do not need to occupy more circuit area, so that the volume of the multilayer mixed-mode hexagonal substrate integrated waveguide filter is smaller, and more resonant cavities can be vertically cascaded according to requirements. In addition, Only two resonant cavities can be used to achieve four poles and transmission zeros, while the traditional cross-coupled cavity filter requires six cavities to achieve similar performance, so the multilayer mixed-mode hexagonal base of the present invention The chip integrated waveguide filter has low loss. Furthermore, by controlling the position and angle of the coplanar waveguide input end, the coplanar waveguide output end, and the hexagonal coupling slot structure, the positions of the four zero points can be flexibly adjusted to meet the requirements of practical applications. need.

Description of drawings

Fig. 1 is the three-dimensional structure schematic diagram of multilayer mixed-mode hexagonal substrate integrated waveguide filter of the present invention;

Fig. 2 is the coupling topological diagram of the multilayer mixed-mode hexagonal substrate integrated waveguide filter of the present invention, wherein R1 and R2 represent the two resonant secondary modes of the first resonant cavity, R3 and R4 represent the two resonant secondary modes of the second resonant cavity Resonant secondary mode, R5 and R6 represent two non-resonant high-order modes, left-leaning and right-leaning in the first resonant cavity;

Fig. 3 is the electric field distribution diagram of the left-leaning non-resonant high-order mode of the multilayer mixed-mode hexagonal substrate integrated waveguide filter of the present invention;

Fig. 4 is the electric field distribution diagram of the right-leaning non-resonant high-order mode of the multilayer mixed-mode hexagonal substrate integrated waveguide filter of the present invention;

Figure 5 is a comparison diagram of transmission characteristics between the multilayer mixed-mode hexagonal substrate integrated waveguide filter of the present invention and the traditional dual-mode substrate integrated waveguide filter;

Explanation of symbols in the figure: first metal layer 1, first dielectric substrate 2, second metal layer 3, second dielectric substrate 4, third metal layer 5, upper metallized through-hole array 61, lower metallized through-hole array 62 , coplanar waveguide input end 7, coplanar waveguide output end 8, hexagonal coupling groove combination structure 9, metallized coupling through hole 91, hexagonal coupling groove 92, bent groove 93, V-shaped coupling groove 10; The first resonant cavity 11 and the second resonant cavity 12 .

detailed description

The specific embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

As shown in Figure 1, the multilayer mixed-mode hexagonal substrate integrated waveguide filter includes a first metal layer 1, a first dielectric substrate 2, a second metal layer 3, a second A dielectric substrate 4 and a third metal layer 5, the first metal layer 1 is provided with a coplanar waveguide input end 7 and a coplanar waveguide output end 8, between the coplanar waveguide input end 7 and the coplanar waveguide output end 8 There is an included angle, the first dielectric substrate 2 is provided with an upper metallized through hole array 61 penetrating through the first dielectric substrate 2, and the upper metallized through hole array 61 is connected to the first metal layer 1 and the second metal layer 3 A hexagonal first resonant cavity 11 is formed together. The second dielectric substrate 4 is provided with a lower metallized through-hole array 62 penetrating through the second dielectric substrate 4. The lower metallized through-hole array 62 and the second The metal layer 3 and the third metal layer 5 together form a hexagonal second resonant cavity 12, the second resonant cavity 12 is located directly below the first resonant cavity 11, and the first metal layer 1 is provided with six The hexagonal coupling groove combination structure 9, the hexagonal coupling groove combination structure 9 is located in the first resonant cavity 11, the hexagonal coupling groove combination structure 9 includes a first metal layer 1, a first dielectric The metallized coupling through hole 91 of the substrate 2, one hexagonal coupling groove 92 and two bent grooves 93 arranged on the first metal layer 1, the metallized coupling through hole 91 is located in the hexagonal coupling groove 92 In the enclosed space, the hexagonal coupling groove 92 is located in the space enclosed by two bent grooves 93; the second metal layer 3 is provided with two symmetrically distributed V-shaped coupling grooves 10, The two V-shaped coupling grooves 10 are located in the second resonant cavity 12 and arranged symmetrically around the center of the second resonant cavity 12 . The two bent grooves 93 form a discontinuous hexagonal groove, the ends of the two bent grooves 93 are not connected, and the V-shaped openings of the two V-shaped coupling grooves 10 are oppositely arranged. . There is an angle between the coplanar waveguide input end 7 and the coplanar waveguide output end 8 of the multi-layer mixed-mode hexagonal substrate integrated waveguide filter of the present invention, and through the hexagonal waveguide arranged on the first metal layer 1 The loading effect of the coupling slot combination structure 9 can not only effectively excite the resonant secondary mode in the resonant cavity cavity, but also the two non-resonant high-order modes, left-dipping and right-dipping, and can also stimulate the electromagnetic coupling between the filter source and the load, Effectively increase multiple signal transmission paths, as shown in Figures 3 and 4, so as to obtain two additional transmission zero points on the basis of the original one transmission zero point. Since the second resonant cavity 12 is located directly below the first resonant cavity 11, by setting Two symmetrically distributed V-shaped coupling grooves 10 on the second metal layer 3 can realize the coupling between the first resonant cavity 11 and the second resonant cavity 12, and generate a fourth transmission zero point, further widening the stopband width And improve the attenuation of the stop band, and the layout characteristics of the vertical distribution of the resonant cavity described in the present invention does not need to occupy more circuit area, so that the volume of the multilayer mixed-mode hexagonal substrate integrated waveguide filter is smaller, and it is also More resonant cavities can be vertically cascaded according to requirements. In addition, only two resonant cavities can be used to achieve four poles and transmission zeros, while traditional cross-coupled cavity filters require six cavities to achieve similar performance. Therefore, the loss of the multilayer mixed-mode hexagonal substrate integrated waveguide filter of the present invention is relatively low, moreover, by controlling the coplanar waveguide input end 7, the coplanar waveguide output end 8 and the hexagonal coupling slot 92 structure The positions and angles of the four zero points can be flexibly adjusted to meet the needs of practical applications.

Figure 3 and Figure 4 show the electric field distribution of the left-dipping and right-dipping non-resonant high-order modes of the multilayer mixed-mode hexagonal substrate integrated waveguide filter. In order to more effectively excite the left-dipping and right-dipping non-resonant high-order modes of the resonator, the included angle between the coplanar waveguide input end 7 and the coplanar waveguide output end 8 is preferably 115-125°.

In order to facilitate production and processing, the gold first metal layer 1, the second metal layer 3, and the third metal layer 5 are made of gold or silver; the first dielectric substrate 2 and the second dielectric substrate 4 are made of dielectric constant Made of microwave dielectric ceramics in the range of 1-20.

Fig. 5 is a comparison diagram of transmission characteristics between the multilayer mixed-mode hexagonal substrate integrated waveguide filter of the present invention and the traditional dual-mode substrate integrated waveguide filter, as can be seen from the figure, the multilayer mixed-mode hexagonal substrate of the present invention The shape SIWG filter can produce four transmission zeros, while the traditional dual-mode SIWG filter only produces one transmission zero, that is, to achieve better selectivity and more efficiency without increasing the filter transmission loss. wide stopband.

Claims (4)

1. The multi-layer mixed-mode hexagonal substrate integrated waveguide filter is characterized in that: it includes a first metal layer (1), a first dielectric substrate (2), and a second metal layer ( 3), the second dielectric substrate (4), the third metal layer (5), the first metal layer (1) is provided with a coplanar waveguide input end (7), a coplanar waveguide output end (8), so There is an included angle between the coplanar waveguide input end (7) and the coplanar waveguide output end (8), and the first dielectric substrate (2) is provided with an upper metallized through-hole array penetrating through the first dielectric substrate (2) (61), the upper metallized through-hole array (61) together with the first metal layer (1) and the second metal layer (3) form a hexagonal first resonant cavity (11), the second The dielectric substrate (4) is provided with a lower metallized through-hole array (62) penetrating through the second dielectric substrate (4), and the lower metallized through-hole array (62) is connected with the second metal layer (3), the third metal layer The layers (5) together form a hexagonal second resonant cavity (12), the second resonant cavity (12) is located directly below the first resonant cavity (11), and on the first metal layer (1) A hexagonal coupling groove combination structure (9) is provided, and the hexagonal coupling groove combination structure (9) is located in the first resonant cavity (11), and the hexagonal coupling groove combination structure (9) includes a sequential A metallized coupling through hole (91) penetrating through the first metal layer (1), the first dielectric substrate (2), a hexagonal coupling groove (92) and two bends arranged on the first metal layer (1) A bent groove (93), the metallized coupling through hole (91) is located in the space enclosed by the hexagonal coupling groove (92), and the hexagonal coupling groove (92) is located in the two bent grooves (93) in the enclosed space; the second metal layer (3) is provided with two symmetrically distributed V-shaped coupling grooves (10), and the two V-shaped coupling grooves (10) are located in the second resonant cavity (12) and arranged symmetrically around the center of the second resonant cavity (12). 2. The multilayer mixed-mode hexagonal substrate integrated waveguide filter as claimed in claim 1, characterized in that: the angle between the coplanar waveguide input end (7) and the coplanar waveguide output end (8) It is 115-125°. 3. The multilayer mixed-mode hexagonal substrate integrated waveguide filter as claimed in claim 1 or 2, characterized in that: the first metal layer (1), the second metal layer (3), the third metal layer Layer (5) is made of gold or silver. 4. The multilayer mixed-mode hexagonal substrate integrated waveguide filter as claimed in claim 3, characterized in that: the first dielectric substrate (2), the second dielectric substrate (4) adopt a dielectric constant of 1 It is made of microwave dielectric ceramics in the range of -20.