Size Reduced UWB Bandpass Filter and Dual-Band Filtering Antenna Design with Duplexing Function Using SIW Cavity Integrated with Radiating Patch

• Main Authors: Geng-Gui Chang, 張耿貴
• Other Authors: Min-Hua Ho
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/59250114065537056879

碩士 === 國立彰化師範大學 === 電信工程研究所 === 103 === The substrate integrated waveguide cavity (SIW) cavity is an analogy to a dielectric-filled rectangular waveguide cavity structure. It is formed by a substrate with a surrounding via-hole fence synthesizing the metal waveguide cavity’s side walls. The quality factor, Q, of the SIWC, normally limited by the dielectric loss is typically ranged between 150 ~ 240, which is much larger than those of the planar structures such as microwave, CPW, stripline, and slot-line. It is also structural compatible to the mentioned planar ones. In a square form SIW cavity, two degenerate modes, TE102 and TE201, are created within the same space. This two mode resonance in one resonator doubles circuit order of the resonator. In such way, several degenerate-mode balanced bandpass filters is built by implying a single or multiple square SIWC structures that excite simultaneously the TE102 and TE201 modes. The filter possesses good signal selectivity and the unwanted common mode signals can be suppressed down to quite a large level. Hence, we propose a few research topics in this project. The first research topic is a reduce-size balanced bandpass filter using a meander slotline fed by balanced microstrip I/O. Second, the square SIW cavity is utilized in the designs of diplexer and diplexer antenna. The latter integrates diplexer, filter, and antenna in one and the former is a three-port device which diverts signals of two different frequency bands to two designated outputs. Although the aforementioned researches are subjected to a lower working frequency band for reducing the fabrication tolerance, the design methods proposed here can be applied to other designated high bands with only a little effort.