Tunable band-stop filter of constant absolute bandwidth based on modular structure

A modular filter technology, applied in waveguide devices, electrical components, circuits, etc., can solve the problems of absolute bandwidth change of the stop band, high-order filter design can not be directly cascaded, etc., to achieve the effect of improving frequency selectivity
CN101916892AInactive Publication Date: 2010-12-15SOUTH CHINA UNIV OF TECH
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
SOUTH CHINA UNIV OF TECH
Publication Date
2010-12-15
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention discloses a tunable band-stop filter of constant absolute bandwidth based on a modular structure, which comprises a micro-band structure in the upper layer, a medium substrate in the middle layer and a grounded metal plate in the lower layer. The filter can consist of one module unit or a plurality of module units, each of which comprises two resonators and a main transmission line;the two resonators are both half-wavelength resonators which have the same structure, and the two resonators are symmetrical about a central vertical axis in the micro-band structure; the main transmission line comprises a coupling part and a non-coupling part; the coupling part consists of a seventh micro-band line, an eighth micro-band line and a ninth micro-band line, and the lines are sequentially connected to form an n-shaped structure which is arranged at the inside of an n-shaped structure of the coupling part of the resonators; variable capacitance diodes of the two resonators are setwith the same bias voltage; and the filter can be applied to various reconfigurable radio frequency front-end circuits and has the characteristics of constant absolute bandwidth when the frequency istuned. By cascading two or more module units, a tunable band-stop filter of constant absolute bandwidth can be obtained, the frequency selectivity of which is higher.
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Description

technical field

[0001] The invention relates to a band-stop filter with adjustable center frequency, in particular to an adjustable band-stop filter based on a modular structure, the absolute bandwidth is constant when the center frequency is tuned, and can be applied to a radio frequency front-end circuit. Background technique

[0002] The development of modern ultra-wideband radar and wireless communication requires high-performance reconfigurable RF subsystems. For example, the development of mobile communication requires miniaturized, multi-standard, multi-mode, multi-band transceivers. In order to meet this requirement, the RF front-end needs to be based on operating mode to adjust its operating frequency and bandwidth. This type of RF front-end requires a variety of RF tunable filters to select useful signals and suppress interfering signals, among which RF tunable band-stop filters are an important category of RF tunable filters. In the RF front-end circuits of multi...

Claims

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