應用於6G通訊中D-頻段之垂直極化一維端射天線陣列

Abstract

本論文目的在設計與比較三款應用於D-頻段的垂直極化端射天線陣列，第一部分首先使用IC載板BT製程設計操作頻率在140GHz的微帶線與GCPW。並從量測發現加入了金鈀金金屬表面處理製程的GCPW與未處理時相比增加了約20%的衰減係數。 在輻射場型量測時發現探針與襯墊存在不匹配，造成溢散輻射干擾，在θ=90°方向增益值嚴重下降，在θ=105°方向會產生較大增益。因此皆使用θ=75°方向來比較。 第二部分使用IC載板BT介質設計垂直極化一維基板集成波導號角天線陣列，透過加入印刷型過渡結構改善了阻抗匹配與輻射效率。其量測結果為垂直極化天線單元在140GHz的S11約為-12dB，頻寬範圍從110GHz-160GHz為大約50GHz，增益最大為9.1dBi，H平面HPBW為94°。1x4陣列天線在140GHz的匹配約為-23dB，頻寬涵蓋整個D-band約60GHz，增益最大為14.1dBi，H平面HPBW為28°。 第三部分採用EXG玻璃基板設計以垂直極化單極天線陣列，設計中引入了由玻璃通孔所構成的反射牆結構以提升指向性。1x4陣列模擬頻寬達48GHz，主波束增益為11.1dBi，輻射效率達80.6%，並可在-40°至+40°範圍內進行波束掃描。 第四部分則在無貫孔的石英玻璃IPD基板上實現垂直極化端射天線陣列，使用電磁帶隙架構與平行板的組合創造虛擬磁牆，將電磁場約束於平行板波導內，達成類似傳統波導的傳輸模式。電磁帶隙架構的量測結果顯示在126GHz以上頻段皆具有帶阻特性。以此結構設計的垂直極化天線單元量測結果為匹配皆大於-10dB，顯示其阻抗匹配不佳，輻射場型也與模擬有顯著差異。1x4天線陣列的量測結果為在140GHz匹配約-15dB，頻寬範圍從131GHz-151GHz為大約20GHz，增益最大為9.8dBi，H平面HPBW為20°。

This thesis aims to design and compare three vertically polarized end-fire antenna arrays for D-band applications. First, microstrip lines and GCPW operating at 140 GHz were fabricated on an IC carrier BT substrate. Measurements revealed that adding an IGEPIG surface finish to the GCPW increased the attenuation constant by about 16 % compared with the bare Cu version. For radiation-pattern measurements, the mismatch between the GSG probe and the GSG pad produced dispersive radiation that caused the gain to drop sharply at θ = 90° and to peak at θ = 105°, so gain at θ = 75° was adopted for all the follow comparisons. Next, a substrate-integrated-waveguide horn antenna array was designed on the IC carrier BT substrate. By introducing a printed transition, impedance matching and radiation efficiency were improved. In the measurement, the element antenna exhibits about –12 dB matching at 140 GHz, a 10 dB bandwidth of roughly 50 GHz from 110 to 160 GHz, maximum gain is 9.1 dBi, and an H-plane HPBW of 94°. The 1×4 array shows about –23 dB matching at 140 GHz, a bandwidth covering the entire D-band, a peak gain of 14.1 dBi, and an H-plane HPBW of 28°. The third part uses an EXG glass substrate to design a vertically polarized monopole antenna array in which a via-wall reflector enhances directivity. For the 1×4 array, simulation gives a bandwidth of 48 GHz, a main-beam gain of 11.1 dBi, a radiation efficiency of 80.6 %, and beam steering from –40° to +40°. Finally, a vertically polarized end-fire array was implemented on via-less quartz IPD glass. By combining an electromagnetic band-gap (EBG) structure with parallel plates to form a virtual magnetic wall, the electromagnetic field is confined in a parallel-plate waveguide that behaves like a conventional waveguide. Measurements show that the EBG structure presents a stopband above 126 GHz. For element antenna, the measured matching is worse than –10 dB, indicating poor matching, and the radiation pattern deviates markedly from simulation. For the 1 × 4 array, the measured matching is about –15 dB at 140 GHz, the bandwidth is about 20 GHz from 131 to 151 GHz, the peak gain is 9.8 dBi, and the H-plane HPBW is 20°.