應用於天文接收機之Q頻段鏡像抑制降頻混頻器、可變增益功率放大器及毫米波除頻器之研究

Abstract

本論文包含三個部分。第一部分是應用於28 GHz相位陣列收發系統的毫米波注入鎖定除頻器設計與量測結果，使用90奈米金氧半場效電晶體製程。第二部分為應用於天文接收機之Q頻段鏡像抑制混頻器之設計與結果，使用90奈米金氧半場效電晶體製程。第三部分是應用於天文接收機之Q頻段可變增益功率放大器設計與量測結果，使用90奈米金氧半場效電晶體製程。 第一部分為應用於28 GHz相位陣列收發系統的注入鎖定除頻器設計。該電路採用Class-C偏壓架構以有效降低功耗，並藉由雙混頻技術，在不額外增加功耗的情況下增加操作頻寬；此外，利用諧波抑制電容設計以縮小晶片核心面積。量測結果顯示，所提出的除頻器具備21–36 GHz的鎖定範圍，功耗僅0.7 毫瓦，且晶片核心面積僅為0.043 平方毫米。 第二部分為應用於天文接收機之Q頻段鏡像抑制混頻器。該電路採用被動式電晶體設計以實現超寬頻中頻響應，並透過雙平衡式混頻器架構以達成優異的隔離度表現。此外，利用威金森功率分配器與耦合器，有效抑制鏡像訊號。量測結果顯示，所提出電路的中頻頻寬範圍為4至40 GHz，轉換損耗介於–11.5 dB至–14 dB之間，且鏡像抑制比在整個操作頻寬內皆優於30 dB。值得一提的是，本電路無直流功耗。 第三部分提出一個應用於天文接收機之Q頻段可變增益功率放大器。該電路於輸出級採用三明治結構的變壓器，以降低插入損耗；此外，提出一種新型增益調控架構，使在增益變化時輸入與輸出阻抗維持不變，以提升電路穩定度。量測結果顯示，該放大器3-dB頻寬為36.8 GHz至52.6 GHz，增益調控範圍為5.5 dB，且飽和輸出功率（Psat）達17.2 dBm。值得一提的是，一分貝壓縮點輸出功率(OP1dB)在不同增益設定下變化極小。

This thesis is composed of three parts. The first part presents the design and measurement results of a millimeter-wave injection-locked frequency divider (ILFD) intended for 28GHz phased-array transceiver systems, implemented using a 90-nm CMOS process. The second part describes the design and measurement of a Q-band image-rejection mixer for astronomical receivers, fabricated using the 90-nm CMOS technology. The third part focuses on the design and measurement results of a Q-band variable-gain power amplifier (VGPA) targeted for astronomical receiver applications, likewise implemented in a 90-nm CMOS process. In the first part, an injection-locked frequency divider is proposed for a 28 GHz phased-array system. The circuit adopts a Class-C biasing technique to reduce power consumption significantly and employs a dual-mixing technique to extend the locking range without additional power consumption. Furthermore, harmonic suppression capacitors are utilized to minimize the core chip area. Measurement results show a locking range from 21 to 36 GHz, with a low power consumption of 0.7 mW and a compact core area of only 0.043 mm². The second part presents a Q-band image-rejection mixer designed for astronomical receivers. The mixer utilizes a cold-biasing technique to achieve a wide IF bandwidth and adopts a double-balanced architecture to enhance isolation. A Wilkinson power divider and a coupler are incorporated to suppress the image signal effectively. Measurement results demonstrate an IF bandwidth ranging from 4 to 40 GHz, with a conversion loss between –11.5 dB and –14 dB, and an image rejection ratio exceeding 30 dB across the operational bandwidth. Notably, this design operates with zero DC power consumption. The third part proposes a Q-band variable-gain power amplifier for astronomical receivers. A sandwiched transformer is employed at the output stage to reduce insertion loss, and a new gain-control architecture is introduced to maintain stable input and output impedances across different gain settings, thereby improving circuit stability. Measurement results indicate a 3-dB bandwidth from 36.8 GHz to 52.6 GHz, a gain control range of 5.5 dB, and a saturated output power (Psat) of 17.2 dBm. It is worth mentioning that the OP1dB exhibits minimal variation under different gain conditions.