CN2877052Y - Direct coupled substrate integrated waveguide spheric cavity filter - Google Patents

Abstract

The utility model discloses a direct-coupled substrate-integrated waveguide circular cavity filter, which comprises a dielectric substrate with metal patches on both sides, and a substrate-integrated waveguide circular cavity on the dielectric substrate. , through waveguide coupling between the substrate integrated waveguide circular cavities, microstrip lines are respectively connected to the substrate integrated waveguide circular cavities located at the edges of both sides, the above substrate integrated waveguide circular cavities are set in The metallized through holes arranged in a circle on the dielectric substrate are formed, and the waveguide is formed by two rows of metallized through holes. It has the advantages of small size, light weight, high quality factor, low loss, low cost, and easy integration.

Description

Directly Coupled Substrate Integrated Waveguide Circular Cavity Filter

technical field

The utility model relates to a key component of a microwave and millimeter radio frequency subsystem, in particular to a direct-coupled substrate integrated waveguide circular cavity filter for microwave and millimeter wave integrated circuits.

Background technique

The microwave and millimeter wave filter is a key component of the microwave and millimeter radio frequency subsystem, especially in the microwave and millimeter wave integrated circuits, the radio frequency front-end needs to use a filter with low insertion loss and good selectivity. Filters manufactured by traditional high-quality factor microwave and millimeter-wave filter technologies (such as traditional metal waveguides) have the advantages of high quality factor value and low loss, but at the same time have the disadvantages of bulkiness, high cost, and difficulty in integration.

Contents of the invention

The utility model provides a direct-coupled substrate-integrated waveguide circular cavity filter which is beneficial to the design of microwave and millimeter-wave integrated circuits and is small in size, light in weight, high in quality factor, low in loss, low in cost and easy to integrate.

The utility model adopts the following technical solutions:

A direct-coupled substrate-integrated waveguide circular cavity filter for filtering, including a dielectric substrate with metal patches on both sides, and a substrate-integrated waveguide circular cavity on the dielectric substrate. The substrate-integrated waveguide circular cavities are coupled through waveguides, and the substrate-integrated waveguide circular cavities located at the edges of both sides are respectively connected with microstrip lines. The metallized through-holes arranged on the chip and arranged in a circle are formed, and the waveguide is formed by 2 rows of metallized through-holes.

Compared with the prior art, the utility model has the following advantages:

The utility model utilizes the characteristics of high Q value and low loss of the SIW circular cavity, uses the SIW circular cavity as the basic unit, and adopts short SIW waveguides for mutual coupling between the cavities, so that the performance is excellent. The utility model is realized by slotting on the metal cladding plate and making a series of metal through holes on the dielectric substrate, which is beneficial to the integration in the microwave and millimeter wave circuit design; the utility model adopts short SIW between the cavities The direct coupling mode of the waveguide connection makes it have the advantage of no radiation; and the coplanar waveguide is used to feed the SIW cavity, so that it has the advantage of easy matching with the input and output microstrip lines. The utility model concrete advantage is as follows:

1) Its transmission parameters have good square coefficient and selectivity;

2) The direct coupling method can effectively suppress electromagnetic interference;

3) With the microstrip line as the input and output interface, it can be easily connected with the microstrip line and coaxial line;

4) It is easy to integrate in the design of microwave and millimeter wave circuits. Since this filter is completely implemented on the dielectric substrate, and the size of the filter can be easily adjusted by using the dielectric constant of the dielectric substrate, it can be better integrated with other microwave and millimeter wave circuits;

5) Compared with other achievable SIW cavities, the SIW circular cavity has the highest Q value and very low insertion loss. This is because this structure has characteristics similar to circular metal waveguides, so compared with microstrip circuits, its Q value is relatively high and its loss is relatively low.

6) The cost is low. The dielectric substrate can use various types of microwave dielectric boards such as polytetrafluoroethylene pressing plate, polytetrafluoroethylene ceramic composite dielectric substrate, low temperature co-sintered ceramics (LTCC), and does not require special processing, so the cost is low.

Description of drawings

Fig. 1 is the structural front view of the present utility model.

Fig. 2 is a structural top view of the utility model.

Fig. 3 is a bottom view of the structure of the utility model.

Fig. 4 is a schematic diagram of the structure of the metallized through hole of the present invention.

Fig. 5 is a diagram of the simulation and test results of the utility model.

Detailed ways

A direct-coupled substrate-integrated waveguide circular cavity filter for filtering, comprising a dielectric substrate 1 with metal patches 2 and 3 on both sides, and a substrate-integrated waveguide on the dielectric substrate 1 The circular cavities 4 are coupled through waveguides 5 between the substrate-integrated waveguide circular cavities, and the substrate-integrated waveguide circular cavities 4 on both sides are respectively connected with microstrip lines 6 and 7. The chip integrated waveguide circular cavity 4 is composed of metallized through-holes 8 arranged on the dielectric substrate 1 and arranged in a circle. The waveguide 5 is composed of two rows of metallized through-holes 9. Open a through hole on the substrate, set a metal sleeve 10 on the wall of the through hole and connect the metal sleeve with the metal patches covering both sides of the dielectric substrate. In this embodiment, the microstrip lines 6 and 7 pass through the coplanar The waveguide feeding structures 61 and 71 are connected to the substrate-integrated waveguide circular cavity 4 . The utility model is realized on a microwave dielectric substrate with a dielectric constant of 2.65 and a thickness of 1 mm. The simulation and test results of the scattering parameters are shown in Figure 5. Its center frequency is 5.93GHz, the minimum insertion loss is less than 2.2dB, the relative bandwidth is 2.9%, and the out-of-band suppression is below 44dB.

Claims (2)

1. A direct-coupled substrate integrated waveguide circular cavity filter for filtering, characterized in that it includes a dielectric substrate (1) that is provided with metal patches (2, 3) on the front and back sides. The chip (1) is provided with a substrate-integrated waveguide circular cavity (4), and the substrate-integrated waveguide circular cavity is coupled through a waveguide (5), and the substrate-integrated waveguide circular cavity located at the edge of both sides The body (4) is respectively connected with microstrip lines (6, 7), and the above-mentioned substrate integrated waveguide circular cavity (4) is composed of metallized through holes (8) arranged on the dielectric substrate (1) and arranged in a circle. ), the waveguide (5) is composed of two rows of metallized through holes (9). 2. The direct-coupled substrate-integrated waveguide circular cavity filter according to claim 1 or 2, characterized in that the microstrip lines (6, 7) pass through the coplanar waveguide feed structure (61, 71) and The substrate integrated waveguide circular cavity (4) is connected.

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