| 摘要: | 本論文以被動電路微小化與積體化為目標，並以縮小尺寸且同時具備雙頻特性為設計主軸。相較於以傳統橋式T線圈取代傳輸線的設計方式，僅可作單頻之應用，本研究提出以雙頻橋式T線圈替代傳統橋式T線圈，而能將電路轉換為雙頻設計，且同時達到微小化目的，並應用於微小化雙頻直交分合波器、雙頻威爾京生功率分配器與三頻吸收式帶止濾波器之設計。於電路實現上，則使用電感與平行板電容，於氮化鎵(GaN)、砷化鎵(GaAs)與積體被動元件(IPD)製程中實現。
首先，以積體被動元件製程實現微小化雙頻直交分合波器與雙頻威爾京生功率分配器，中心頻率分別為2.45 GHz與5.5 GHz，其中雙頻直交分合波器於兩中心頻率下之電氣尺寸分別為0.0123〖 λ〗_0×0.0245〖 λ〗_0 及0.0275〖 λ〗_0×0.055〖 λ〗_0，而雙頻威爾京生功率分配器於兩中心頻率下之尺寸分別為0.0145〖 λ〗_0×0.0133〖 λ〗_0 及0.0333〖 λ〗_0×0.0305〖 λ〗_0，均較暨有設計大幅縮小。
其次，分別以兩種不同製程實現微小化三頻吸收式帶止濾波器。首先以傳統橋式T線圈設計單頻7.2 GHz吸收式帶止濾波器，再以雙頻橋式T線圈設計雙頻吸收式帶止濾波器，中心頻率分別為4.8 GHz與9.6 GHz，最後串接成一個三頻吸收式帶止濾波器，三個止帶頻率分別為4.8 GHz、7.2 GHz與9.6 GHz，其中以積體被動元件製程實現之電路於三個止帶頻率下之尺寸分別為0.038 λ_0×0.04〖 λ〗_0、0.058 λ_0×0.06 λ_0 及0.077〖 λ〗_0×0.08〖 λ〗_0，而以砷化鎵製程實現之電路於三個止帶頻率下之尺寸分別為0.0272〖 λ〗_0×0.0368〖 λ〗_0、0.0407〖 λ〗_0×0.0552〖 λ〗_0 及0.0543〖 λ〗_0×0.0736〖 λ〗_0，電路面積皆小於現有之設計。上述應用電路證實雙頻橋式T線圈架構的確能對被動電路面積有大幅度的尺寸縮減，且可簡單地實現雙頻操作之特性。
;In this thesis, very compact integrated passive circuits with high performance are presented. Today, the wireless communication system for multi-band demand is increasing. Therefore, more and more multi-band circuit of the basic components or subsystem design concept was presented in the recent year. However, the major bottleneck of the size reduction of active and passive microwave circuits is the requirement of multiple transmission lines with given electrical length. The traditional bridge T-coil will be equivalent to the transmission line, but only for single-frequency applications. In this work, the dual-band bridged T-coil is used to replace the conventional bridged T-coil, can be used in dual-band microwave passive circuit design, and While achieving the purpose of minimization. The dual-band bridged T-coil can be implemented using inductor and metal-insulator-metal (MIM) capacitor in GaN semiconductor and GaAs semiconductor IC process or Integrated Passive Device (IPD) process to achieve very compact size. It is then applied to the design of m Miniature dual-band branch-line coupler, dual-band Wilkinson power divider, and a triple-band absorptive band-stop filter (ABSF).
First of all, the proposed Miniature dual-band branch-line coupler and dual-band Wilkinson power divider are fabricated in IPD process. The center frequency of both are 2.45 GHz and 5.5 GHz. The circuit size of Miniature dual-band branch-line coupler is 0.0123〖 λ〗_0×0.0245〖 λ〗_0 at 2.45 GHz, 0.0275〖 λ〗_0×0.055〖 λ〗_0 at 5.5 GHz. And the circuit size of Miniature dual-band Wilkinson power divider is 0.0145〖 λ〗_0×0.0133〖 λ〗_0 at 2.45 GHz, 0.0333〖 λ〗_0×0.0305〖 λ〗_0 at 5.5 GHz.
Finally, the proposed Miniature triple-band ABSF is fabricated in two different process. At first, a single-band 7.2 GHz ABSF was designed with a conventional bridge T-coil, then a dual-band ABSF was designed with a dual-band bridge T-coil. The center frequency of dual-band ABSF was 4.8 GHz and 9.6 GHz. In the last, I cascade two filter which I described to a triple-band ABSF. The stop-band frequency of triple-band ABSF was 4.8 GHz, 7.2 GHz and 9.6 GHz. The circuit size of triple-band ABSF which is fabricated in IPD process is 0.038〖 λ〗_0×0.04〖 λ〗_0 at 4.8 GHz, 0.058〖 λ〗_0×0.06〖 λ〗_0 at 7.2 GHz and 0.077〖 λ〗_0×0.08〖 λ〗_0 at 9.6 GHz. And the circuit size of triple-band ABSF which is fabricated in GaAs semiconductor IC process is 0.0272〖 λ〗_0×0.0368〖 λ〗_0 at 4.8 GHz, 0.0407〖 λ〗_0×0.0552〖 λ〗_0 at 7.2 GHz and 0.0543〖 λ〗_0×0.0736〖 λ〗_0 at 9.6 GHz.
Compared with current designs, the above circuits are smaller in size. The effectiveness of dual-band bridged T-coil on the design of miniaturized on-chip passive microwave circuit is also validated through proposed design examples, and in a single circuit to achieve dual-frequency characteristics. |
