Filter and fly rod fastening structure thereof

Abstract

The invention provides a filter and its flying rod fastening structure. The filter includes a cavity and a cover plate. The cover plate covers the cavity to form a resonant cavity. The cavity is provided with ribs. The filter also includes a flying rod. A rod fastening structure, the flying rods of the flying rod fastening structure are installed on the ribs of the cavity. The fly rod fastening structure includes a fly rod seat and a fly rod. The lower end of the fly rod seat has an open slot extending along the length direction of the fly rod seat. The diameter of the positioning hole is larger than the width of the opening slit. At least one coupling hole is opened on the upper end of the fly rod seat, and the diameter of the coupling hole is larger than that of the coupling adjusting screw rod. The present invention performs rough adjustment of the coupling strength of the flying rod through the above-mentioned positioning hole, and then provides space for the fine adjustment of the coupling strength of the flying rod through the above-mentioned coupling hole, which is beneficial to the coupling of the flying rod after the installation of the flying rod or even after the cavity is installed. The strength is adjusted to a certain extent to compensate for the dimensional deviation of the fly rod due to assembly and manufacturing errors. The adjustment structure is simple, low in cost, convenient for assembly and debugging, can greatly reduce the probability of repair due to improper coupling of the fly rod, and improve the production pass rate.

Description

【Technical field】 [0001] The invention relates to a communication transmission component, in particular to a cavity filter and a fastening structure for a fly rod thereof. 【Background technique】 [0002] A filter is a frequency filtering device, which selects signals in the required frequency band and suppresses signals in the unnecessary frequency band. Filters are widely used in communication fields such as radio frequency and microwave. At present, the most widely used filter in the radio frequency and microwave frequency band is the coaxial cavity filter, which forms the desired working characteristics by adjusting the resonant frequency of multiple cavities and the coupling strength between the cavities. The adjustment of the resonant frequency of the cavity is generally accomplished by adjusting the depth of the tuning screw into the cavity, and the coupling between certain cavities is usually performed by controlling the size of the coupling fly rod. see figure 1 an...

AI Technical Summary

Problems solved by technology

see figure 1 and figure 2 , the fly rod 120 in the prior art is usually fastened in the filter cavity 130 by the fly rod seat 110, once the size of the fly rod 120 is determined, the coupling strength between the cavities 130 cannot be adjusted, because the coupling between the cavities 130 The strength is very sensitive to the size of the fly rod 120. In order to achieve a certain coupling strength, neither too weak nor too strong, the size of the fly rod 120 needs to be optimized repeatedly, but even if the appropriate size of the fly rod 120 is optimized, due to manufacturing and assembly The influence of the error will also affect the coupling strength. Since the structure cannot be adjusted after the fly rod 120 is installed and fixed, the coupling strength between the cavities 130 after assembly cannot meet the requirements, and it is difficult for the final filter to meet the required operating characteristics. In addition, Due to the lack of structural flexibility in the installation of the flying rod in the structure of the existing technical solution, it is difficult to install the flying rod on the flying rod seat, and the assembly is complicated and difficult

Images