Combined filter employing ceramic resonator grooving and coupling mode

Abstract

The invention relates to the field of microwave communication, in particular to a combined filter. According to a combined filter employing a ceramic resonator grooving and coupling mode, each coaxial resonator comprises an open front-end surface of a non-conductive material and the other five surfaces are covered with a conductive material to form a conductive layer; two coaxial resonators at the outmost side comprise electrode surfaces of a signal input attenuator and a signal output attenuator; and coupling grooves are formed between cavity bodies of the coaxial resonators to form coupling of the filter. Adjustment on specific performance parameters of the filter is achieved through adjustment on the lengths of the coaxial resonators and the coupling grooves. The filter has the advantages of low loss and high inhibition; and second harmonics of a product are greatly improved.

Description

technical field [0001] The invention relates to the field of microwave communication, in particular to a combined filter. Background technique [0002] The dielectric filter will form a passband to pass the signal that needs to pass, and suppress the unwanted signal frequency band so that it will not pass. Due to the presence of capacitors and lead pins in the traditional combined filter, the loss will increase accordingly. At the same time, the traditional filter will form a second harmonic at the place where the frequency is doubled, so that it is very suppressed at the place where the center frequency is doubled. Poor, even form a secondary passband to prevent the signal from passing. [0003] The current ceramic dielectric filters are generally divided into two categories, single type and combined type. [0004] The monolithic type means that the filter is formed by a complete dielectric block. This type of filter has better near-end suppression performance, but poor s...

AI Technical Summary

Problems solved by technology

[0004] The monolithic filter is formed by a complete dielectric block. This type of filter has better near-end suppression performance, but poor second harmonic performance.

[0005] The combined filter is composed of multiple dielectric coaxial resonators, lead pins and capacitors. This type of filter has better second harmonic performance, but the insertion loss is too large and the near-end rejection is poor.

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