應用於毫米波系統之放大器設計

Design for Millimeter-Wave System Power Amplifier

張碩軒(Shuo-Hsuang Chang)

指導教授 ： 王暉

國立臺灣大學/電機資訊學院/電信工程學研究所/碩士(2017年)

https://doi.org/10.6342/NTU201704388

摘要

本論文中，設計並實現三個毫米波放大器，包含一個Q頻段低雜訊中等功率放大器及Q頻段功率放大器，最後一個為Ka頻段切換功率模態放大器。
論文第一部份呈現一個應用於天文觀測Q頻段的低雜訊中等功率放大器的設計，以0.1微米砷化鎵假型高速電子場效電晶體製程製作。在ALMA接收機系統中,為了減少室溫系統的雜訊,需要具有低雜訊指數(Noise Figure)和高增益的放大器來抑制混頻器輸入端雜訊，此放大器3-dB頻寬為30 to 50 GHz並於50 GHz 有最高增益為21.1 dB，且在40.1 GHz具有最低值3.2 dB的雜訊指數，且具OP1dB大於7.6 dBm的特性。
論文第二部分呈現一個應用於天文觀測Q頻段的功率放大器的設計，以0.1微米砷化鎵假型高速電子場效電晶體製程製作。此功率放大器為三級架構，電晶體皆採用共源級架構，在輸出級接合兩路為達適度的增益以及功率輸出，並且採用補償式匹配結構來達到寬頻的效果，此功率放大器具高OP1dB可以增益ALMA接收機的校正準確度。此功率放大器於35 to 50 GHz 具有17.9 ~ 20.2 dB的增益，且具OP1dB 大於19.8 dBm的特性，飽和輸出功率大於20.1 dBm、功率增進效率在40 GHz時具有最大值27.2%。
論文最後一部分，呈現一個Ka頻段切換功率模態功率放大器的設計，採用65 奈米CMOS金氧化半場效電晶體製程實現。此功率放大器採用改良型切換式電容置於輸出級，轉換輸出級阻抗，以達到雙輸出功率模態的最佳附加增進效率，並利用電晶體基極浮接的技巧提升功率特性。此功率放大器於34 GHz之操作頻率下,在高功率模態/低功率模態具有13.8 /10.5 dB的增益，飽和輸出功率19.9/17 dBm、最大功率附加效率為25.8/22.8 %，在1dB增進壓縮點功率為14.5/17.4%，在功率輸出大小為17 dBm情況下，可藉由功率模態轉換將功率附加效率從高輸出功率模態14.5%改善至低輸出功率模態22.8%。

關鍵字

砷化鎵假型高速電子場效電晶體 ； 功率放大器 ； 互補式金氧化半場效電晶體 ； 切換模態功率放大器

並列摘要

In this thesis, three amplifiers designed at millimeter-wave are demonstrated. A Q-band amplifier with the low noise and a Q-band power amplifier with broadband performance are presented. At the end, a Ka-band dual-mode power amplifier is pre-sented.
The first part is an amplifier with low noise figure and medium output power ca-pability using 0.1-μm GaAs pHEMT. To minimize the noise attribution from the Warm Cartridge Assembly (WCA), the amplifier with high gain and low NF is required to suppress the noise at the input of the mixer. Measurements on the amplifier verify its OP1dB is better than 7.6 dBm from 35 GHz to 50 GHz, achieving minimum noise figure (NF) of 3.2 dB at 41GHz, with maximum power-added efficiency (PAE) of 17.9% at 35GHz.
The next is a Q-band power amplifier, which is fabricated in 0.1-μm GaAs pHEMT. The power amplifier utilizes the three-stage common source and compensated matching networks to achieve broadband performance. The power amplifier with flat gain and OP1dB is required for the calibration accuracy of the ALMA Band-1 Receiver. Measurements on the power amplifier verify its OP1dB is better than 19.6 dBm from 35 GHz to 50 GHz, achieving maximum power-added efficiency (PAE) of 27.2% at 40 GHz.
Lastly, a Ka-band dual-mode power amplifier in 65-nm CMOS is presented. The PA provides the capability of dual mode operation, higher-power (HP) and low-power (LP), and each mode is optimally matched by using the switched-capacitor. A switched-capacitor is fully considered to implement a tunable matching network in terms of power-handling capability, insertion loss. In the HP/LP mode, the presented PA achieves a measured small-signal gain of 13.8/10.5 dB, a saturated output power value of 19.9/17 dBm, a 1-dB output power value of 17/14 dBm, a peak power-added efficiency (PAE) value of 25.8/22.8 %, a power-added-efficiency at OP1dB value of 14.5/17.4 % at 34 GHz, respectively. The PAE at 17-dBm output power of the PA var-ies from 14.5% to 22.8% based on the LP mode of operation at 34 GHz.

並列關鍵字

GaAs pHEMT ； power amplifier ； ALMA ； CMOS ； dual-mode power amplifier

參考文獻

[6] Steve C. Cripps, RF Power Amplifier for Wireless Communications, 2nd, Artech House., 2006.

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