主動孔隙耦合式洩漏波天線

Abstract

本論文是介紹主動孔隙耦合式洩漏波天線及多波束孔隙耦合式洩漏波天線，包含了設計方法、製造和量測。為了能有效的激發微帶線的第一高階模，我們利用孔隙饋入結構並在天線中央打入包覆的接地線來抑制微帶線基態模。其中，洩漏波天線提供了波束掃描的能力、高增益及窄主波束，而孔隙饋入結構能縮小電路體積並提供主動與幅射元件間良好的屏蔽。 在此，我們製作出兩種主動孔隙耦合式洩漏波天線：單一波束旁饋結構與雙重波束中饋結構。在8.97GHz到9.5GHz的頻率區間，旁饋結構可在磁場平面有16度的掃描角度，且最大有效幅射功率為21.98±1.59 dBm。而在同樣頻率區間內，中饋結構可在磁場平面掃描20度，其最大有效幅射功率對右邊波束為18.56±0.33 dBm，對左邊波束為18.9±0.13 dBm。這兩種天線均適合主動天線陣列應用或是其他微波收發系統。 另一方面，我們利用此種孔隙耦合式洩漏波天線發展出多波束天線.觀察其發射與接收的幅射場型，可得知掃描角度分別為22度和16到18度。此種多波束孔隙耦合式洩漏波天線在收發模組(如智慧型天線系統)中擁有很大的發展潛力，因為收發模組只需使用單一支天線。

This thesis will investigate the active aperture-coupled leaky-wave antennas and the multi-beam aperture-coupled leaky-wave antenna, including design, fabrication and measurement. To excite the microstrip first higher mode, the aperture-fed structure is utilized and a sequence of covered wire is added in the center of this antenna to suppress the dominant mode. The leaky-wave antenna offers beam-steering capability, high gain and narrow main beam. In addition, the aperture-fed structure reduces the circuit size and offers an excellent shielding between active and radiation elements. We produce two kinds of active aperture-coupled leaky-wave antennas-side-fed with a single main beam and center-fed with a dual-beam. The side-fed one provides a 16°scanning angle in H-plane from 8.97 GHz to 9.5 GHz and its maximum EIRPs are 21.98±1.59 dBm. The center-fed one provides a 20°scanning angle in H-plane from 8.97 GHz to 9.5 GHz and its maximum EIRPs are 18.56±0.33 dBm for the right beam and 18.9±0.13 dBm. Theses antennas are suitable for active phase antenna array applications or other microwave transceiver system. On the other hand, we utilized the aperture-fed leaky-wave antenna to develop a multi-beam antenna. Its transmitting and receiving radiation patterns are observed their scanning angles as 22°and 16°~18°respectively. This antenna has a developmental potential in transmit/receive modules such as smart antenna systems because both modules employ use only one antenna.