以單/雙折疊式基板合成波導共振器實現微小化帶通濾波器之設計

Abstract

本篇論文提出了數種利用單/雙折疊式基板合成波導共振器的微小化帶通濾波器。所有濾波器都被設計以及實現在低溫共燒陶瓷的技術上。 首先設計的是由單折疊式基板合成波導共振器所組成的濾波器。為了縮小面積，共振腔可以往介質厚度的方向堆疊。具柴比雪夫響應的濾波器可以藉由在同層的兩對連通柱跟不同層間的槽線來達成。除此之外，為了實現準橢圓函數濾波器，電耦合可以利用懸在介質當中的連通柱來達成。在多層結構中，適當的排列每個共振腔的位置，可以使得濾波器面積縮小到28%。 另一種設計是由雙折疊式基板合成波導共振器所組成的濾波器。為了進一步縮小濾波器面積，所有共振腔都作垂直堆疊。在雙折疊共振腔以及多層結構技術的幫助下，跟傳統平面耦合波導濾波器相比，電路面積可以縮小到12%。除此之外，我們也找到類似電耦合的機制去實現準橢圓函數濾波器。

This thesis presents several miniaturized bandpass filters composed of single and double-folded SIW resonators. All of them are designed and fabricated in a multilayer low-temerature co-fired ceramic (LTCC) technology. First, we design filters composed of single-folded SIW resonators. For size reduction, cavities can be stacked into their thickness direction. Filters with Chebyshev response can be achieved by two pairs of vias in the same layers and narrow slots between different ones. Besides, to realize the quasi-elliptic function filter, electric coupling is achieved by vias suspended in the substrate. Compared with planar waveguide filters, the circuit area can be reduced to 28% by an appropriate arrangement. Another type of filters composed of double-folded SIW resonators is designed and fabricated on multilayer structures also. To further reduce the filter size, all the cavities are stacked vertically. By the aid of the double-folded SIW resonators and the multilayer capability, the footprint of filter can be reduced to 12% as compared to a conventional planar direct-coupled waveguide filter. Besides, we also find the equivalent electric coupling to realize the quasi-elliptic filter.