| 摘要: | 近年來，相位陣列已逐漸導入日常生活中的無線通訊裝置。在諸多相位陣列技術中，由於切換式波束成型器具有低功率消耗、低成本的特性，以及較容易實現，因此更適合使用在商用無線通訊系統中。本論文以應用於行動通訊裝置中的智慧天線系統為開發目標，提出兩種使用IPD製程實現的2.4 GHz切換式波束成型模組，並達成低功耗、微型化的特性。
橋式T線圈是本論文中的核心技術，它被用來實現波束成型模組中的諸多組件，以達到微型化設計的目標。本論文首先以一個多模態共振器帶通濾波器設計來介紹如何以橋式T線圈縮小電路面積。此寬頻帶通濾波器是目前已發表的多模態共振器帶通濾波器中面積最小的。
其次，橋式T線圈被用以實現切換式波束成型器中的諸多組件，包含：單刀雙擲開關、收發切換開關、以及巴特勒矩陣。藉由以橋式T線圈替代傳輸線的方式，這些元件的電路尺寸皆大幅的縮小。本研究以異質整合的方法整合這些元件，實現兩種切換式波束成型模組。第一個模組整合了4 × 4巴特勒矩陣、收發切換開關、以及吸收式單刀四擲開關，其模組尺寸僅有4.9 mm × 5.0 mm × 0.9 mm。第二個模組整合了4 × 4巴特勒矩陣以及兩個吸收式單刀雙擲開關，其模組尺寸只有4.9 mm × 5.0 mm，更只有0.4 mm的厚度。
此外，本論文亦提出一個雙頻橋式T線圈的設計方式，以利微型化雙頻波束成型器的設計。首先，以此設計方式實現雙頻分枝耦合器於IPD晶片中，為目前已發表的雙頻分枝耦合器中最小的。並將之用於2.45 GHz以及5 GHz雙頻巴特勒矩陣的設計，以實現微型化雙頻波束成型器。本研究所提出之波束成型模組皆具低成本、微型化、及低功耗的特性，將有助於手持式裝置上實現智慧天線系統。;Phased arrays have been gradually applied to wireless communication systems in our daily life. Among various phased array technologies, the switched beamformers are relatively easy to realize, and they are more suitable for commercial wireless communication systems due to their low power consumption and low cost. In this study, two 2.4-GHz switched beamformer modules in IPD process with low power consumption and compact size are proposed, which are targeted for implementing smart antenna systems in mobile communication devices.
The Bridged-T coil is the core technology used in this study. Specifically, the bridged-T coil is adopted to realize the building blocks of the proposed switched beamformer such that very compact circuit size can be achieved. The use of the bridged-T coil to achieve circuit size reduction of microwave circuits is first demonstrated by an ultra-wideband multi-mode resonator bandpass filter design. The smallest multi-mode resonator bandpass filter ever reported is presented.
Next, the bridged-T coils are used to realize the key building blocks of a 2.4-GHz switched beamformer modules, i.e., an absorptive single-pole double-throw (SPDT) switch, a T/R switch, and a 4 × 4 Butler matrix. By replacing the transmission line sections with bridged-T coils, the chip sizes of these circuit elements are largely reduced. Two switched beamformer modules are then realized based on the heterogeneous integration of these building blocks. The first one integrates a 4 × 4 Butler matrix, an absorptive SP4T switch, and a T/R switch in a compact module size of 4.9 mm × 5.0 mm ×0.9 mm. The second one integrates a 4 × 4 Butler matrix and two absorptive SPDT switches, which features a module size of 4.9 mm × 5.0 mm with a very low profile of only 0.4 mm.
In additional, dual-band bridged-T coil is proposed to help achieve miniature dual-band beamformer designs. A dual-band branch-coupler is first implemented in IPD process, which is the smallest dual-band branch-line coupler ever reported. Then, a dual-band 4 × 4 Butler matrix is designed for 2.45/5.8-GHz dual-band switched beamformer applications. The proposed switched beamformer modules feature low-cost, compact size, low power consumption, and low-profile. They can help introduce smart antenna systems into modern mobile applications. |
