應用於毫米波頻段之二合一帶通濾波器與濾波天線設計

Design of 2-in-1 Bandpass Filter and Filtering Antennas for Millimeter-Wave Applications

10.6342/NTU.2015.01730

蘇怡文

基板合成波導 ； 低溫共燒陶瓷 ； 模態正交 ； 帶通濾波器 ； 濾波天線 ； substrate integrated waveguide ； low temperature co-fired ceramics ； modal orthogonality ； bandpass filter ； filtering antenna

臺灣大學電信工程學研究所學位論文

2015年

碩士

吳瑞北

繁體中文

本篇論文提出毫米波頻段之二合一濾波器及濾波天線的設計，並以基板合成波導的結構來實現，兩個設計皆使用低溫共燒陶瓷技術。首先研製一個可實現於毫米波頻段二合一帶通濾波器的整合電路，並延續濾波器設計，將最後一級共振腔及輸出埠以天線取代，使其兼具天線與濾波功能，完成二合一濾波天線設計。 二合一濾波器的設計概念，是將原本相同規格的兩個濾波器共振腔，用單一雙模態共振腔取代，以達到減少電路使用面積的目的。而利用各模態彼此之間場型的正交性，不止可以透過不同模態來控制不同路徑的濾波響應，也提供良好的隔離度。二合一帶通濾波器相較於一般的濾波器電路，能利用相同數量的共振腔多設計出一組獨立的濾波器響應，並達到在電路面積的微小化之效果。濾波器操作於中心頻率73.5GHz，比例頻寬6.8%，最終的電路面積約為1.15 λg × 1.16 λg，較原始面積縮小約 31.2 %。 延續二合一帶通濾波器設計，將輸出埠以天線取代，則成為二合一濾波天線。首分別設計使用〖TE〗_201 與〖TE〗_102模態之單埠濾波天線後再以共用雙模態共振腔來整合濾波天線電路，並利用模態的正交性來獨立控制不同的濾波響應。此設計將濾波器與天線整合，亦有電路微小化的優點。濾波天線設計在中心頻率73.5GHz，比例頻寬6.8%，最終的電路面積約為2.01 λg × 1.92 λg，較原始面積縮小約38.2%。

This thesis proposes new design concepts for millimeter-wave 2-in-1 filters and filtering antennas based on substrate integrated waveguide (SIW) cavities implemented on low temperature co-fired ceramic (LTCC) substrates. First 2-in-1 bandpass filter is designed at millimeter wave frequency. By replacing the final stage resonator and the output ports with antennas, a 2-in-1 filtering antenna can then be realized. For the design concept of the 2-in-1 bandpass filter, it combines two filters with common dual modes resonators in order to reduce the size of circuit. Due to the concept of modal orthogonality in the SIW cavities, it could not only control the filter responses in different paths by different modes, but also prove well isolation to different path. Different from general filters, the design of 2-in-1 bandpass flter reduces half of cavities and achieves circuit area miniaturization. The center frequency of this two-in-one bandpass filter is 73.5GHz, fractional bandwidth is 6.8%, and the final circuit area 1.15 λg × 1.16 λg and has 31.2% size reduction. Following the design of 2-in-1 bandpass filter, the design of 2-in-1 filtering antenna is also proposed. First, filtering antenna using 〖TE〗_201mode and 〖TE〗_102 mode are designed separately. The two filtering antenna circuits can be further combined using common dual mode cavity. The design concept also keeps the modal orthogonality so that the filter response could be controlled independently. The filtering antenna acts at 73.5GHz, for fractional bandwidth is 6.8%, and the final circuit area 2.01 λg × 1.92 λg and has 38.2% size reduction.