CN2243719Y - Small suspended microstrip duplex filter - Google Patents

Abstract

The utility model relates to a small-size duplex filter with a hanging microstrip line, which is a duplex filter used for transmitting and receiving microwaves. The utility model is mainly composed of a resonator (4) composed of a metallic shell (1), a dielectric layer (2) and an upper metallic strip line (3). A hanging microstrip line structure is used in the overall structure, and a transmitting filter and a receiving filter are integrated, wherein a baffle is arranged in the metallic shell and the space in the metallic shell is divided into two symmetrical cavities by the baffle. The transmitting filter and the receiving filter are respectively bridged on the side walls in the two cavities. The resonator is composed of the metallic microstrip line arranged on the dielectric layer.

Description

Small suspended microstrip duplex filter

The utility model relates to a duplex filter device used in microwave emission and reception, which belongs to the technical field of microwave filter manufacture.

The microwave duplexer is composed of microwave receiving and transmitting filters and a three-terminal circulator, among which the filter is the key component, which not only ensures the low in-band insertion loss of the duplex filter, but also ensures large out-of-band attenuation , to ensure that the receiving and sending channels are highly isolated. As microwave duplexers, interdigital filters made of metal rectangular rods (or round rods) or waveguide filters are mostly used at present. The main problems of this type of filter are large volume and heavy weight, especially in the microwave low frequency band, the increase in volume and weight is even greater, and the technical requirements are high, the precision of machining is high, and debugging is difficult, so the manufacturing cost is high. . In the technical field of aviation and aerospace, due to the large volume and heavy weight of this filter, it has always been a difficult problem for relevant technicians to overcome.

The purpose of the invention of the utility model is to provide a small suspended microstrip line duplex filter with small volume, light weight, low manufacturing cost and meeting the technical requirements of aviation and spaceflight.

The utility model relates to a small suspended microstrip line duplex filter. It is composed of a metal shell, a dielectric layer, and a resonator. In the overall structural design, a suspended microstrip line structure is used to integrate the transmitting and receiving filters into one. That is to say, the resonator composed of metal wire strips is placed in the cavity in the metal casing, and the transmitting and receiving filters share a metal casing. In this structure, the resonator is composed of an upper metal strip line bonded on a dielectric layer, and the dielectric layer is bridged on both sides of the metal shell, and a metal shell of appropriate height is left on the upper and lower sides of the dielectric layer cavity. A lower metal strip line is respectively provided on the lower side of the dielectric layer, that is, on the side where the resonator is provided and on the two sides where the shell is bridged. The metal casing includes an outer shell and a partition in the middle, which divides the cavity in the metal casing into two parts, and places the transmitting and receiving filters in the two separated cavities in the same metal casing Inside.

The utility model has the advantages of:

Because the suspended microstrip line has the advantage of small loss, the microwave filter is developed by using this microstrip line, which has low in-band insertion loss and high out-of-band rejection. Compared with the metal rectangular rod interdigitated filter and the waveguide waveguide, the duplex filter is small in size, light in weight, stable and reliable, and easy to process and manufacture. It can be completed only by general microstrip technology and simple shell machining. And debugging is convenient, suitable for mass production, so the cost is low. The application of this duplexer in aviation and aerospace equipment can show its unique advantages.

FIG. 1 is a schematic diagram of the structure of the suspended microstrip line adopted in the present invention.

Figure 2 is a schematic diagram of a metal stripline layout of a five-stage tap filter.

Fig. 3 is a schematic diagram of a transverse cross-sectional structure of the overall structure of the utility model.

Embodiments of the present utility model are as follows:

The upper metal strip line 3 of a certain width is fabricated on the dielectric layer 2 by the process of plate making and photolithography to form the resonator 4 of the multi-stage tap suspension microstrip filter, and the two sides below the dielectric layer are bridged with the metal shell 1 There is also a lower metal belt line 3-1 at the center, and a partition 1-2 is arranged in the center of the metal shell 1, and the inner cavity part of the metal shell 1 is divided into two identical cavities 1-1. A groove is provided on the inner side wall where it bridges with the dielectric layer 2, and the dielectric layer is inserted into the metal casing through the groove. The general microstrip connector is mounted on both ends of the metal shell at both ends of the resonator 4, and the core wires of the connector are welded on the outlet and inlet ports 4-1 at both ends of the resonator. In order to improve the stability and reliability of the filter, the cavities on the upper and lower sides of the dielectric layer can be filled with supporting materials with low dielectric constant. In order to fine-tune the performance index of the filter, an adjustment screw can be added to the housing at an appropriate position above the resonator. According to the above description, the small suspended microstrip line duplex filter of the present invention can be formed.

Claims (5)

1. A small suspended microstrip line duplex filter is characterized in that the filter is made up of a metal casing (1), a dielectric layer (2), and a resonator (4), and adopts a suspended microstrip line structure , combining the transmit and receive filters into one. 2. The small-sized suspended microstrip line duplex filter according to claim 1, characterized in that in the suspended microstrip line structure, the resonator (4) is made of an upper layer bonded on the dielectric layer (2) Composed of metal strip lines (3), the dielectric layer (2) is bridged on both sides of the metal casing (1), and there are cavities (1- 1). 3. The small suspended microstrip line duplex filter according to claim 2, characterized in that a lower metal strip line (3 -1). 4. according to claim 1 or 2 or 3 small suspended microstrip line duplex filters formed, it is characterized in that a dividing plate (1-2) is provided in the middle of the metal shell (1), the metal shell ( 1) The cavity inside is divided into two parts, and the transmitting and receiving filters are respectively placed in two separated cavities (1-1) in the same metal shell. 5. The small suspended microstrip line duplex filter according to claim 4, characterized in that the cavity (1-1) is filled with a support material with a low dielectric constant.

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