Microwave Circuits Design Using Substrate Integrated Waveguide Cavity

• Main Authors: Li,Jen-Chih, 李仁智
• Other Authors: Ho, Min-Hua
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/t3v22v

碩士 === 國立彰化師範大學 === 電信工程研究所 === 105 === This thesis demonstrates microwave circuit designs of diplexer, duplexing antenna, band-pass filter (BPF), rat-race coupler, and reduced size BPF using the substrate integrated waveguide cavity (SIWC). The SIWC is composed of the microwave substrate possessing a via-hole perimeter to emulate the cavity’s side walls. Hence, it avoids the waveguide’s bulky mass and high cost, but still preserves the metal waveguide cavity’s advantages, such as low loss, low radiation emission, and high quality factor. The first chapter presents multiple SIWC diplexer circuit design which utilizes the orthogonal field distributions of the square cavity’s two degenerate modes, TE 102 and TE 201 , to achieve the required isolation between the duplexing ports. The design versatile is demonstrated in the diplexer’s I/O ports which can be either the single-ended or balanced form. The second chapter is devoted to the duplexing antenna circuit which integrates the SIWC diplexer with the radiating patch. The connection between the former and the latter is a copper rod. The third circuit presents a compact SIWC balanced diplexer design. Four SIWCs are vertically stacked and each duplexing band is form by two SIWC that are under single mode (TE¬102 or TE201) or dual-mode (both TE102 or TE201) resonance. The common-port is formed by CPW and the duplexing ones are built of SMA. The size-reduction filter of the SIWC structure is presented in the final of the thesis. To achieve the size reduction performance of the SIWC BPF, we use two substrates in a stacked form to build the resonant cavity with a circular patch deployed in the middle metallic layer and blind via-holes short the patch to the cavity’s bottom. Four size-reduction SIWCs are applied to build a sample BPF circuit. A 93% size-reduction in circuit area is achieved. The experiments are conducted to verify the design and performance of the above mentioned circuits and well agreements are observed between the measured and the simulated data. Keywords: substrate integrated waveguide cavity, balanced diplexer, filtering antenna, coupler, size-reduction filter