| 摘要: | 本文提出基於基板合成波導（SIW）三分之一模共振器的三通帶與六通帶帶通濾波器的設計，以實現多頻段高效濾波，滿足現代無線通信與雷達系統的需求。三通帶帶通濾波器採用 Mode 2、Mode 3 和 Mode 4 設計二階帶通濾波器，其中分為濾波器A與濾波器B，濾波器A饋入位置為非對稱，濾波器B饋入位置為對稱，並透過調整輸入與輸出端口的位置，以靈活控制通帶之間的傳輸零點，進一步提升選擇性與抑制非目標頻段。三個模式透過同一對耦合窗口進行能量耦合，使通帶頻率分別位4.93GHz、6.17 GHz 和 7.47 GHz。此外，透過在腔體內部引入擾動貫孔，可有效調整通帶外的雜散模態頻率，同時維持通帶內的穩定響應，而腔體中間額外加入微擾槽孔則能調整第一與第三通帶的頻率，而不影響第二通帶，使其具有更高的設計靈活性與可調性。六通帶帶通濾波器採用三層金屬與兩層介質的堆疊結構，這種結構相較於平面結構的耦合窗，增加了控制耦合量的靈活度，並在輸入與輸出端口增加錐形漸變的轉接結構，以降低外部品質因素，提高濾波器的性能表現。透過該物理結構，可以靈活控制耦合強度，而腔體中增加槽孔的設計可以微調通帶之間的頻率，此電路設計通帶頻率分別為 3.1 GHz、4.42 GHz、5.51 GHz、6.49 GHz、8.19 GHz 和 8.85 GHz。綜上所述，本文提出的三通帶與六通帶帶通濾波器，皆基於 SIW 三分之一模共振器的特性，透過適當的結構設計與耦合機制，實現多頻段濾波功能。以上設計不僅具備高選擇性、緊湊結構，亦提供較高的設計靈活性。;This paper proposes the design of Tri-band and Sext-band bandpass filters based on substrate integrated waveguide (SIW) one-third mode resonators to achieve efficient multi-band filtering, meeting the demands of modern wireless communication and radar systems. The Tri-band bandpass filter utilizes Mode 2, Mode 3, and Mode 4 to construct second-order bandpass filters, divided into Filter A and Filter B. Filter A features an asymmetric feed position, while Filter B adopts a symmetric configuration. By adjusting the positions of the input and output ports, the transmission zeros between the passbands can be flexibly controlled, thereby enhancing selectivity and suppressing undesired frequency bands. The three modes couple energy through the same pair of coupling windows, resulting in passband frequencies at 4.93 GHz, 6.17 GHz, and 7.47 GHz. Furthermore, introducing perturbation vias inside the cavity can effectively adjust the frequencies of spurious modes outside the passbands while maintaining stable responses within the passbands. Additional perturbation slots placed in the center of the cavity allow for tuning of the first and third passbands without affecting the second passband, offering greater design flexibility and tunability. The Sext-band bandpass filter employs a stacked structure composed of three metal layers and two dielectric layers. Compared to planar coupling window structures, this configuration offers increased flexibility in controlling the coupling strength. Taper transition are added to the input and output ports to reduce external quality factors and enhance filter performance. This physical structure allows for precise control of coupling strength, while the inclusion of slots in the cavity enables fine-tuning of the frequency spacing between passbands. The resulting passband frequencies are 3.1 GHz, 4.42 GHz, 5.51 GHz, 6.49 GHz, 8.19 GHz, and 8.85 GHz. In summary, the proposed Tri-band and Sext-band bandpass filters, based on the characteristics of SIW one-third mode resonators, achieve multi-band filtering through appropriate structural design and coupling mechanisms. These designs offer high selectivity, compact structures, and enhanced design flexibility. |
