寬頻混成積體Ku頻帶場效電晶體電壓控制振盪器

Abstract

本篇論文提出二種寬頻使用場效電晶體和變容二極體之Ku-band電壓控制 振盪器的設計，製造及測量。我們以Libra軟體有系統的模擬分析各種電 路組態後，設計了共源極和共閘極兩個混成微波積體電路的技術加以製造 。測量兩者之輸出頻寬可涵蓋11.4-18.7 GHz的範圍內(輸出功率大於5 dBm)，離載波頻率100 kHz測得相位雜訊皆小於-70 dBc/Hz 共閘極電路 測得之諧波失真小於-25 dBc及直流對高頻轉換效率是14.3%。最後，我們 以共閘極組態電路，加上一級緩衝放大器，以改善負載推動效應及輸出功 率，其測得之最大輸出功率提高2.7 dBm，可調頻率範圍在13.7-17.9 GHz ，離載波頻率100 kHz測得相位雜訊小於-70 dBc/Hz，可調頻率線性度 是21.5%。 In this thesis, the broadband hybrid integrated Ku-band FET VCOs' designs, fabrication, and measurements are presented. Several kinds of VCO circuit configurations were simulated by a microwave CAD tool, Libra, to predict the oscillation frequency and power in an efficient manner. In our design, common-source (CS) and common-gate (CG) circuit configurations with capacitive and inductive, respectively, series feedback were fabricated using hybrid microwave integrated circuit technology. The measured tuning bandwidth of these two circuits measured from the spectrum analyzer result is less than -70 dBc/ Hz at 100 kHz off the carrier frequency. The harmonic distortion of the CG VCO is less than -25 dBc and its DC to RF conversion efficiency is 14.3%. Finally, we added a stage of buffer amplifier into CG VCO to improve the load pulling effect and boost output power. The measured maximum output power raises 2.7 dBm; tuning bandwidth is 13.7-17.9 GHz; phase noise is less than -70 dBc/Hz(100 kHz off-carrier);tuning linearity is 21.5%.