E頻段及W頻段天文觀測用降頻混頻器及V頻段低雜訊放大器之設計

Abstract

本論文包含三個部份。第一部分是應用於天文觀測的E頻段超寬中頻降頻混頻器，第二部分是應用於天文觀測的W頻段超寬中頻降頻混頻器，第三部分是應用於短距離無線通訊的V頻段低功耗寬頻低雜訊放大器，以上皆使用90奈米金氧半場效電晶體製程設計。 第一部分提出操作在E頻段62-92 GHz的降頻混頻器，此電路將被動式電晶體使用在單端混頻器，達到超寬中頻，並使用兩對電容-電感共振電路提升本地振盪端到射頻端的隔離度表現。量測結果顯示，在輸入8 dBm的60 GHz本地振盪訊號時，此電路中頻頻寬可達30 GHz，射頻頻寬可覆蓋整個E頻段，全頻轉換損耗介於9到12 dB之間，並在本地震盪端到射頻端有高達40.8 dB的隔離度。 第二部分提出操作在W頻段72-110 GHz的降頻混頻器，此電路將被動式電晶體使用在雙平衡式混頻器架構，達到超寬中頻。量測結果顯示，在輸入0 dBm的70 GHz本地振盪訊號時，此電路中頻頻寬可達38 GHz，射頻頻寬可覆蓋整個W頻段，全頻轉換損耗介於7到12 dB之間，並在本地震盪端到射頻端有高達37.5 dB的隔離度。 第三部分提出操作在V頻段60 GHz的低雜訊放大器，此電路採用三級共源共柵架構，運用源級衰退、雜訊抑制及增益放大技術提升雜訊及增益表現。量測結果顯示，此電路最佳增益為在60 GHz的 18.1 dB，並有5.8 dB的最低雜訊指數，3-dB頻寬達10 GHz，且僅需7.8 mW的功耗。

There are three parts to this thesis. The first part is an E-band down-conversion mix-er with wide IF bandwidth for astronomical observations. The second part is a W-band down-conversion mixer with wide IF bandwidth for astronomical observations. The third part is a V-band low-power broadband low-noise amplifier for short-distance wireless communication. The three circuits were fabricated in 90-nm CMOS. The first part of the paper proposes a modified cascode mixer in E-band. This circuit achieves wide bandwidth by applying cold-biased mixing transistors in a single-ended topology. Two pairs of LC resonators are embedded to improve isolation from the LO port to the RF port. According to the measurements, when pumped by a 60-GHz 8-dBm LO power, the mixer exhibits 30 GHz IF bandwidth. Over the full E-band, the measured conversion loss is between 9 and 12 dB. The LO-to-RF isolation reaches 40.8 dB. The second part of the paper proposes a modified Gilbert-cell mixer in W-band. This circuit achieves wide bandwidth by applying cold-biased mixing transistors in double-balanced topology. According to the measurement, when pumped by a 70-GHz 0-dBm LO power, the mixer exhibits 38 GHz IF bandwidth. Over the full W-band, the measured conversion loss is between 7 and 12 dB. And the LO-to-RF isolation reaches 37.5 dB. The third part of the paper proposes a low-noise amplifier operating in V-band. A three-stage cascode structure is adopted in this circuit. This circuit employs source degen-eration, noise reduction, and gain boosting techniques to improve noise and gain perfor-mance. According to the measurements, this circuit has a gain of 18.1 dB at 60 GHz, a lowest noise factor of 5.8 dB, and a 10 GHz 3-dB bandwidth, with only 7.8 mW power consumption.