X頻段背地共平面微帶線饋入洩漏波天線 與 Ku頻段非對稱饋入洩漏波天線 應用研究

Abstract

本論文將提出三種有關洩漏波平面天線的應用, 內容包括: X頻段由背地共平面波導 (CBCPW) 轉背地共平面微帶線 (CBCPS) 饋入之主動洩漏波微帶天線, X頻段近全方位頻率掃描天線, Ku頻段串聯式雙波束洩漏波微帶天線陣列. 第一部份將描述一個主動波源藉由洩漏波天線頻率掃描的特性成為一個頻率掃描波源. 由背地共平面波導組成的震盪器將保留共平面波導的優點,同時利用背地共平面微帶線可較共平面微帶線 (CPS) 有較佳激發第一高階模的能力. 第二部份為近全方位掃描天線. 此天線由共平面波導自微帶天線中央饋入激發第一高階模並產生四波束場形. 此天線工做在X頻段, 調整發射頻率自 8.7至11.3 GHz, 吾人可得將近220度的掃描波束. 第三部份為Ku頻段的串聯式洩漏波微帶天線陣列. 實驗的結果顯示兩單元與四單元的陣列其增益分別較單元陣列高出2.56dB及5.6dB. E平面遭饋入結構破壞的場型也可陣列因子在廣側方向的強化而消除. H平面的波束在單元數變為四時將較一單元時偏移5度.

In this report, we present a X-band Conductor-Backed Coplanar Waveguide-to Conductor-Backed Coplanar Strip-line HEMT Oscillator Frequency Scanning Leaky Wave Antenna (LWA), an X-band Quasi-Omni-Directional scanning Leaky Wave Antenna, and a Ku-band Dual-Beam array of LWAs. In the first part, the active source sweeps from 9.32 GHz to 9.67 GHz and the main beam scan 11 degrees in the H-plane. The LWA with a CBCPW-to-CBCPS feeding structure excites the first higher mode easily than the CPW-to-CPS feeding structure and retains the advantages of the CPW and the CPS. In the second topic, the CPW-Center fed LWA generates four beams in the H-plane so that forms a scanning range of about 220 degrees. Antenna from 8.7 to 11.3 GHz makes each beam scan 60 degrees in the H-plane. The CPW-Center fed LWA generates four beams in the H-plane so that forms a scanning range of about 220 degrees. In the 3rd part, a Ku-band Dualbeam array of LWA is demonstrated at 15.5 GHz. The measured antenna results indicate that the 2-element and 4-element array has a power gain of 2.56 dB and 5.06 dB are higher than the single element antenna, respectively. The E-plane radiation pattern is improved by increasing the number of array also. Changing the phase of the excitation current, we successfully eliminated the side lobe in the broadside of antenna. The main beam shifts 5 degrees when the number of array increased from 1 elements to 4 elements.