Filter based on substrate integrated waveguide in incomplete mode

Abstract

According to the invention, three technical characteristics are utilized for reducing the size of a resonance cavity. First, a substrate integrated waveguide in an incomplete mode is adopted. Second, a small-size CRME (Circular Ring Miniaturized Element) is loaded on the surface of the resonance cavity so as to excite resonant frequency of lower orders and thus the size of the resonance cavity can be reduced. Third, a feeding mode based on combination of a coplanar waveguide and the CRME is adopted. According to the invention, the ultra-small filter based on the substrate integrated waveguide in the incomplete mode is low in loss and good in frequency selection properties and the size of the filter can be reduced substantially. By the design of the novel CRME, the out-of-band suppression property of the filter is improved substantially. By the design of a single-layer PCB, processing, integration with other planar circuits and cost reduction are facilitated.

Description

Technical field [0001] The invention belongs to the technical field of a substrate integrated waveguide filter, and in particular relates to a filter based on a non-integral mode of the substrate integrated waveguide. Background technique [0002] With the rapid development of mobile communication systems, the radio frequency spectrum has become more and more crowded. At the same time, higher requirements are placed on microwave filters, especially higher out-of-band suppression characteristics and smaller volumes. [0003] At present, the substrate integrated waveguide structure commonly used for transmitting microwaves has the advantages of high quality factor and high power capacity, and is often widely used in wireless communication systems. There are also incomplete modes obtained by appropriately designing substrate integrated waveguides, such as one-eighth-mode substrate-integrated waveguide and one-sixteen-mode substrate-integrated waveguide. These incomplete modes can grea...

AI Technical Summary

Problems solved by technology

This kind of stacked filter has a complex structure and contains many layers, such as the first to third dielectric substrates, and the first to third intermediate metal layers, which is not conducive to the integration of filters and planar circuits; on the other hand, multilayer High difficulty in structural processing, corresponding to high cost of plate making

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