Direct Digital RF Technology - Challenges for Beyond Nyquist Frequency Range
Direct Digital RF Technology - Challenges for Beyond Nyquist Frequency Range
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直接数字射频技术 - 超出奈奎斯特频率范围的挑战
DOI：
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
N. Suematsu
中科院分区：
文献类型：
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作者：
N. Suematsu
由于基于A/D和D/A的数字射频的最大工作频率是奈奎斯特频率，因此将数字射频的概念应用到更高的微波频段是很困难的。为了突破奈奎斯特的限制，本文引入了直接数字射频技术。该技术利用了更高阶奈奎斯特频段(超出奈奎斯特频段)，可以直接处理更高频率的微波信号。在接收机中引入了高阶直接射频欠采样结构，并给出了一个采用1 GHz采样时钟的28 GHz频段接收机的制作结果。发射机采用1比特带通$mathbf{Delta}mathbf{Sigma}$调制器，直接从8Gbps的1比特数字码流中产生26 GHz频段的射频信号。为了提高图像信号电平和信噪比，研究了RZ信令和曼彻斯特编码技术。这种直接数字射频技术为未来的CMOS时代带来了真正数字化的丰富的微波/毫米波收发信机。
Since the maximum operational frequency of digital RF based on A/D and D/A is Nyquist frequency, it has been difficult to apply digital RF concept to higher microwave frequency range. In this paper, direct digital RF technology is introduced to break this Nyquist limit. This technology utilizes the higher-order Nyquist Zones (beyond the Nyquist frequency range) and higher microwave frequency signal can be handled directly. Higher order direct RF undersampling architecture is introduced for receiver and a fabricated results of 28GHz-band receiver using 1GHz sampling clock will be shown. A 1-bit bandpass $mathbf{Delta}mathbf{Sigma}$ modulator is introduced for transmitter which generates a 26GHz-band RF signal directly from 8Gbps 1-bit digital stream. In order to enhance the image signal level and SNR, RZ signaling and Manchester coding techniques are examined. This direct digital RF technology brings really digital rich microwave/MMW transceivers in future CMOS era.