Integrated waveguide filter of medium loaded foldable substrate

Abstract

The invention provides an integrated waveguide filter of a medium loaded foldable substrate. The integrated waveguide filter comprises a first metal layer, a first medium layer, a second metal layer, a second medium layer and a third metal layer from top to bottom, wherein a high-dielectric-constant and high-Q-value medium block is embedded into the first medium layer; and a metalized through hole and a blind hole array, which respectively penetrate through the whole structure and the second medium layer, are additionally arranged. The whole body is formed by three main parts including resonant cavity structures, a feeder line structure and a coupling structure. The quantity of the resonant cavity structures is the same as that of the step quantity of the filter; and each resonant cavity structure is formed by a metalized through hole group embedded into the periphery of a medium block and covering parts of the first metal layer and the second metal layer. The feeder line structure can be used for realizing loading land coplanar waveguide on a groove at the edge of the first metal layer. The coupling structure is divided into an inter-digital electric coupling structure for realizing electric coupling and an induction window magnetic coupling structure for realizing magnetic coupling, and is specifically adopted between adjacent resonant cavities according to the design requirements of the filter. The integrated waveguide filter has the characteristics of miniaturization, low inserting loss, high-frequency selectivity, easiness for machining and the like.

Description

technical field [0001] The invention relates to a device in the field of radio frequency microwave technology, in particular to a dielectric-loaded folded substrate integrated waveguide filter. Background technique [0002] A microwave filter is one of the most basic components in a radio frequency system for gating or blocking signals or power in a specific frequency band, and its performance directly affects the performance of the entire system. The high performance and miniaturization of microwave filters have always been the main trend of its technical development. Substrate-integrated waveguide (SIW) is a microwave and millimeter-wave structure that simulates metal waveguides on a substrate by using printed circuit board (PCB) or low-temperature co-fired ceramics (LTCC). Its size and performance are between metal waveguides and planar circuits. Among them, it has the advantages of small planarization, high unloaded quality factor (Q value), large power capacity, and ea...

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Problems solved by technology

Patent document number CN201120042595.9 "Substrate-integrated waveguide filter with steep sideband characteristics" proposes a filter with defective ground structure (DGS) resonators carved on the surface of the substrate-integrated waveguide, which has a small area and is There are transmission zeros on the left and right of the strip; however, slots on the metal plane will increase the conductor and radiation losses of the resonator, thereby increasing the filter insertion loss

[0004] In addition, Wu, L.-S. et al published the article "Bandpass Filter Using Substrate Integrated Waveguide Cavity Loaded With Dielectric Rod" in IEEE Microw.Wireless Compon.Lett. By loading a dielectric rod short-circuited at both ends in the middle of the traditional substrate-integrated rectangular resonator, the size of the resonator and filter is greatly reduced, the unloaded Q value and insertion loss performance are improved, and the parasitic suppression characteristics of the component are improved; but The filter is difficult to achieve the transmission zero, the area is still larger than the microstrip circuit

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