A CMOS Passive LPTV Nonmagnetic Circulator and Its Application in a Full-Duplex Receiver
A CMOS Passive LPTV Nonmagnetic Circulator and Its Application in a Full-Duplex Receiver
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DOI：
10.1109/jssc.2017.2647924
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发表时间：
2017-03
影响因子：
5.4
通讯作者：
Negar Reiskarimian;Jin Zhou;H. Krishnaswamy
中科院分区：
文献类型：
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作者：
Negar Reiskarimian;Jin Zhou;H. Krishnaswamy
最近，我们展示了第一个CMOS非互易无源环行器的N通道滤波器的基础上，使用时间变化来打破互易性。在这里，性能指标的分析，如损耗，隔离度，线性度和调谐范围，提出的设计参数。该分析得到了65 nm CMOS环行器原型的实测性能的验证，该原型在发射机-天线（TX-ANT）和天线-接收机（ANT-RX）路径中具有1.7 dB的损耗，并具有高隔离度[TX-RX，通过调谐高达50 dB，20 dB带宽（BW）为32 MHz]和610-850 MHz的调谐范围。通过专为增强TX线性度而设计的架构特性，环行器实现了+27.5 dBm的带内TX-ANT输入参考三阶交调截点（IIP 3），比+8.7 dBm的ANT-RX IIP 3高出近两个数量级。该环行器还集成了一个自干扰消除全双工（FD）RX，具有模拟基带（BB）SI消除器。FD RX在12 MHz信号带宽范围内，在环行器和模拟BB域实现42 dB片内SI抑制。结合数字SI及其输入参考三阶互调（IM 3）消除，FD RX可实现85 dB的整体SI抑制，从而实现−7 dBm TX平均输出功率和−92 dBm本底噪声的FD链路预算。
Recently, we demonstrated the first CMOS nonmagnetic nonreciprocal passive circulator based on N-path filters that uses time variance to break reciprocity. Here, the analysis of performance metrics, such as loss, isolation, linearity, and tuning range, is presented in terms of the design parameters. The analysis is verified by the measured performance of a 65-nm CMOS circulator prototype that exhibits 1.7 dB of loss in the transmitter-antenna (TX-ANT) and antenna-receiver (ANT-RX) paths, and has high isolation [TX–RX, up to 50 dB through tuning and 20-dB bandwidth (BW) of 32 MHz] and a tuning range of 610–850 MHz. Through an architectural feature specifically designed to enhance TX linearity, the circulator achieves an in-band TX-ANT input-referred third-order intercept point (IIP3) of +27.5 dBm, nearly two orders of magnitude higher than the ANT-RX IIP3 of +8.7 dBm. The circulator is also integrated with a self-interference-canceling full-duplex (FD) RX featuring an analog baseband (BB) SI canceller. The FD RX achieves 42-dB on-chip SI suppression across the circulator and analog BB domains over a 12-MHz signal BW. In conjunction with digital SI and its input-referred third-order intermodulation (IM3) cancellation, the FD RX demonstrates 85-dB overall SI suppression, enabling an FD link budget of −7-dBm TX average output power and −92-dBm noise floor.