| 摘要: | 相位偏移器經常用於通訊及雷達的相位陣列天線之中。在一個典型的相位陣列之中，通常會需要為數眾多的相位偏移器。使用單石微波積體電路來實現相位偏移器，有助於相位陣列之微小化。 首先我們使用TSMC 0.35-μm SiGe BiCMOS製程來實現一X頻段相移人工傳輸線。在頻率11 GHz下的量測結果顯示，偏壓於0至3.3 V間，此電路可提供46度的相位偏移量。其返回損耗皆大於12 dB，最差之插入損耗及P1dB點分別為6.3 dB、11.7 dBm。 接著我們採用WIN 0.15-μm GaAs pHEMT製程來實現一Ku頻段分佈式相位偏移器。在頻率13 GHz下的量測結果顯示，此相位偏移器在操作偏壓0 – 1.8 V下可提供60.5度的相位偏移，且返回損耗皆大於15 dB。最差的插入損耗及P1dB點分別為1.9 dB及10.7 dBm。 在分佈式類比相位偏移器中，可變電容是不可或缺的電路元件。雖然傳統的變容二極體被廣泛使用，但鐵電可變電容亦是一個具有潛力的可變電容技術，在微波頻段有低損耗以及高可調度的優點。在本論文中，我們製作以鐵電材料鈦酸鍶鋇薄膜為基礎的共平面波導傳輸線，並將之用於薄膜電性的萃取。我們量測共平面波導傳輸線的S參數量測並與全波電磁模擬結果比較，萃取出BST介電常數約為300，正切損耗約為0.1。 我們以兩種不同積體電路製程設計並實現了分佈式類比相位偏移器晶片，有助於相位陣列系統之微小化。我們並發展了鐵電薄膜製程，製作以鐵電薄膜為基礎的共平面波導傳輸線，將之用於薄膜高頻電性之萃取。這個工作是未來進行鐵電可調式微波電路設計的基礎。 Phase shifters are indispensable components in modern radar and communications phased-array antenna systems. A typical phased array employs a large number of phase shifters. Using MMIC technology to implement the phase shifters helps the miniaturization of phased-array systems. In this thesis, two distributed analog phase shifters implemented using two different IC processes are introduced. First, we design an X-band phase shifter based on artificial transmission lines using TSMC 0.35-μm SiGe BiCMOS process. The measurement results at 11 GHz show that, biased between 0 and 3.3 V, the circuit provides a phase shift of 46° and its return losses are greater than 12 dB. At 11 GHz, the measured maximum insertion loss and the minimum input P1dB of the phase shifter are 6.3 dB and 11.7 dBm, respectively. Next, a Ku-band distributed phase shifter is designed and implemented using WIN 0.15-μm GaAs pHEMT technology. The measurement results at 13 GHz show that, biased between 0 and 1.8 V, the circuit exhibits a phase shift of 60.5°, a maximum insertion loss of 1.9 dB, an input P1dB of 10.7 dBm, and a return loss greater than 15 dB. In distributed analog phase shifters, variable capacitors are indispensable circuit elements. Though conventional varactor diodes are most widely used for implementing the variable capacitors in phase shifter design, ferroelectric varactor technology offers a viable and potentially better alternative, having the advantages of low loss and high tunability in microwave regime. In this thesis, we fabricate coplanar waveguide (CPW) transmission lines based on ferroelectric barium strontium titanate (BST) thin films and use the CPW lines for extracting the electrical properties of the BST thin films. The S parameters of the CPW lines are measured and carefully compared with full-wave electromagnetic simulation results. The extracted dielectric constant and loss tangent of the BST thin films are approximately 300 and 0.1, respectively. In summary, we have designed and implemented distributed analog phase shifters using two different IC processes. Implementing phase shifters in MMIC forms helps to miniaturize phased-array systems. We have also developed a ferroelectric thin-film fabrication process. Based on the thin-film process, we have fabricated CPW lines and used them in the extraction of electrical properties of the films. This work provides a basis for ferroelectric-based tunable microwave circuit design in the future. |
