晶圓級構裝可調T型線圈式濾波器之研製

Abstract

本論文提出以晶圓級構裝製程應用於5GHz到2.5GHz的可調T型線圈式濾波器電路設計。採用外接3組可變電容來達成可調範圍較寬的設計，此一設計擁有中心頻率可調、外部品質因子可補償、以及頻寬可調的特色。 設計一個模擬的程序，其模擬結果顯示，通帶頻率內最大損耗為3.48dB，濾波器尺寸為2.55mm × 1.42mm。由於晶片內的可變電容可調範圍有所限制，模擬結果可調範圍從5GHz到4GHz達20%，中心頻率損耗為3.55dB~3.98dB。 接著以實驗驗證，設計2.5GHz到1.25GHz的可調T型線圈式濾波器實驗，並利用20mil的Rogers Ro4003基板、表面黏著式陶瓷電容來進行實驗。反射損耗-15dB、比例頻寬5%下，可調範圍達50%，濾波器尺寸為16.4mm × 11.8mm，量測結果，中心損耗為1.7dB~2.66dB，此結果與模擬一致。

This thesis propose a tunable filter with T-coil circuit design whose tuning range is from 5GHz to 2.5GHz on InFO-WLP (Integrated Fan-Out Wafer-Level-Packaging). There are three sets of varactors to get wider tuning range so that the center frequency and external quality factor and bandwidth can be suitably tuned. A systematic design procedure has been set up and demonstrate the tunable filters of 3.48 dB in a compact size of 2.55mm×1.42mm. Due to the limited range of varactor value, simulated results show a tuning range of 20% from 5GHz to 4GHz, with insertion loss 3.55dB~3.98dB at center frequency . For experimental validation, a tunable T-coil filter with tuning range from 2.5GHz to 1.25GHz is designed and fabricated in 20mil Ro4003 board and SMD MLCC Capacitors. According to FBW=5% and return loss=-15dB, tuning range is 50%; size is 16.4mm×11.8mm; the measurement result shows loss at center frequency is 1.7dB~2.66dB and in good agreement with the simulation results.