Filter with adjustable capacitive transmission zeros

Abstract

The invention discloses a filter with adjustable capacitive transmission zeros. The filter comprises a filter cavity and a cover plate, multiple stages of resonant cavities are formed in the filter cavity, and harmonic oscillators are arranged inside the resonant cavities. The filter is characterized in that an adjusting threaded rod which is adjustable in height and is used for adjusting the capacitive transmission zeros is arranged on the cover plate, and arranged at a coupling window between the non-adjacent filter cavities. In combination with the using method of the adjustable transmission zeros in a microwave product are combined, the novel structure with the adjustable capacitive transmission zeros is provided and can be widely applied to the radio frequency product. The filter has the advantages that a few materials are used, the structure is simple, the adjustable range is wide, high and low temperature performance is reliable, and the inter-modulation level of the product can be increased to a certain degree.

Description

Technical field [0001] The invention belongs to the field of electronic communication, and particularly relates to a filter with an adjustable capacitive transmission zero point. Background technique [0002] In the design process of the bandpass filter, in order to improve the near-end rejection, an inductive or capacitive cross-coupling structure is usually used to generate zeros on the left and right of the transmission passband, such as figure 1 Shown. figure 1 There are four transmission zeros in total, of which 1 and 3 are the transmission zeros on the left side of the passband, which are produced by inductive cross-coupling; 2 and 4 are the transmission zeros on the right side of the passband, which are produced by the capacitive cross-coupling structure. [0003] figure 2 Shown in is the capacitive cross-coupling structure, which produces transmission zero 5 on the left side of the passband; image 3 Shown in is the inductive cross-coupling structure, which produces transmi...

AI Technical Summary

Problems solved by technology

[0004] The problems brought about by the structural parts are: first, the addition of additional materials brings additional costs; second, there are assembly errors in the installation project. When the size of the structural parts is relatively long and the distance from the harmonic oscillator is relatively close, the consistency is difficult Control, process requirements are relatively high

3. At high and low temperatures, structural parts may cause inconsistencies in capacitive zero-point accessory resonators with temperature changes

4. In intermodulation products, additional parts may affect the intermodulation value and bring the risk of intermodulation instability

Images