Multilayer packaging dual‐band balanced bandpass filter based on dual‐mode substrate integrated waveguide cavities with split‐type topology

Abstract

A new design method of the dual‐band balanced bandpass filter (BPF) using multilayer packaging dual‐mode substrate integrated waveguide (SIW) cavities is proposed. Split‐type coupling topology based on dual‐mode resonators is developed for the design. Firstly, a single‐band balanced filter with perturbed metal vias is designed. The TE201 mode and the TE202 mode perturbed by the metal vias can form a passband. Secondly, an additional metal vias perturbed SIW cavity with the same dual‐mode is placed in the lower layer for the bandstop function. A dual‐band balanced BPF with split‐type coupling topology is successfully realised. Compared with the traditional cascaded single‐mode form, the proposed dual‐mode split‐type design has more compact size and can be more easily extended to multi‐passbands. To verify the proposed method, a dual‐band balanced filter operating at 13.3 and 14.2 GHz is designed, fabricated and measured. The designed dual‐band balanced filter has good filtering performance including differential mode passband transmission and common mode rejection. Measured results show good agreements with simulated ones.

Multilayer circular SIW cavity differential bandpass filter with wide‐stopband characteristics

“…To further reduce the size of the balanced filters, multilayer configurations are presented. 19,20 Most of the designs suffer from large footprint, high insertion loss caused by open side walls or open slots, and difficulty in integration with other microwave circuits due to the presence of the feeding structure in the middle layer. Some of the filters have smaller fractional bandwidths (FBWs).…”

“…In Shen et al, 18 a compact balanced SIW filter is reported by introducing transverse slots on the top metal plane. To further reduce the size of the balanced filters, multilayer configurations are presented 19,20 . Most of the designs suffer from large footprint, high insertion loss caused by open side walls or open slots, and difficulty in integration with other microwave circuits due to the presence of the feeding structure in the middle layer.…”

Miniaturised single‐layer bandpass filters using triple and quad‐mode patch resonators

“…Patch filters are widely researched and used due to their advantages of high‐power capacity and simple structure [1, 4–8]. Dual and triple‐mode filters can achieve compact sizes, which have gained more attention and research [9–27].…”