PLANAR FILTERS FOR MICROWAVES AND MILLIMETRE WAVES WITH A CONTROLLABLE BANDWIDTH, WHICH ARE BASED ON CONCENTRATED RESONATORS

摘要

The invention relates to planar filters for microwaves and millimetre waves with a controllable bandwidth, which are based on concentrated resonators (6). According to the invention, the filters comprise a planar transmission means consisting of a conductor strip, a metallic ground plane and a dielectric substrate. The filters are characterised in that they comprise at least one stage consisting of a series LC resonator (11) which is disposed between the metallic ground plane and the conductor strip, a metallic junction (9) between the metallic ground plane and the conductor strip in the form of an inductive element and a coupling element between stages (7). In this way, it is possible to produce filters with reduced dimensions, to control the bandwidth, to control the transition band selectivity level effectively and to eliminate spurious bands.