Extraction zero-point micro-strip filter

Abstract

The invention discloses an extraction zero-point micro-strip filter. One or more extraction zero-point units are arranged on input and output resonators of a parallel coupling line micro-strip filteror any one stage of resonator in the middle. Compared with the prior art, the extraction zero-point micro-strip filter has the beneficial effects that the parallel coupling micro-strip filter which can flexibly design transmission zero points through single coupling to improve out-of-band rejection, and can lower design and debugging difficulty is provided; by virtue of the extraction zero-point units, the transmission zero setting is quickly and flexibly achieved on the basis that the topological structure of the filter is not changed; and by adoption of the method provided by the invention,the out-of-band rejection of the micro-band filter is improved, and meanwhile, the design and debugging difficulty of the filter is simplified.

Description

technical field [0001] The invention belongs to the field of microwave circuits, and in particular relates to a microstrip filter for extracting zeros. Background technique [0002] Generalized Chebyshev filters are widely used in the field of microwave engineering because transmission zeros (TZ) can be generated in a limited frequency range to help improve out-of-band rejection of filters. The coupling matrix obtained through synthesis undergoes a series of matrix rotations and transformations to convert the ideal coupling matrix into a coupling matrix that can be realized in physical structure, and the generation of transmission zeros is mainly realized by cross-coupling. In general, a single negative coupling (or electrical coupling) produces a transmission zero at the low end of the passband, and a positive coupling (or magnetic coupling) produces a transmission zero at the high end of the passband. The generation of these two types of coupling mainly depends on two typ...

AI Technical Summary

Problems solved by technology

[0004] Although the CT or CQ structure can flexibly form different filter topologies to achieve a steep transition band and improve the out-of-band rejection near the passband, its structure is generally more complicated, and the zero point and in-band standing wave generated often affect the coupling The size of the quantity is extremely sensitive, and the control of the zero position is restricted

Reflected in the physical structure, the processing precision of the filter is high, and the structure itself has many types of coupling, which makes debugging difficult

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