Enhanced-Selectivity High-Linearity Low-Noise Mixer-First Receiver With Complex Pole Pair Due to Capacitive Positive Feedback
Enhanced-Selectivity High-Linearity Low-Noise Mixer-First Receiver With Complex Pole Pair Due to Capacitive Positive Feedback
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DOI：
10.1109/jssc.2018.2791490
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发表时间：
2018-02
影响因子：
5.4
通讯作者：
Yuanching Lien;E. Klumperink;B. Tenbroek;J. Strange;B. Nauta
中科院分区：
文献类型：
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作者：
Yuanching Lien;E. Klumperink;B. Tenbroek;J. Strange;B. Nauta
提出了一种具有增强选择性和高动态范围的混频器优先接收器（RX），旨在消除移动电话中的表面声波滤波器，覆盖6ghz以内的所有频段。跨基带（BB）放大器的电容负反馈作为阻塞旁路路径，而额外的电容正反馈路径提供进一步的阻塞抑制。这种反馈路径的组合在BB放大器的输入处合成了一个复杂的极点对，该极点对上转换到RF端口，以获得更陡峭的RF带通滤波器滚降并降低失真。本文阐述了该电路的原理，并对RX的性能进行了分析。采用45 nm部分耗尽绝缘体上硅（SOI）技术制备的原型芯片实现了高带外线性度(输入参考三阶截距点（IIP3) = 39 dBm，输入参考二阶截距点(IIP2) = 88 dB）和低于3 dB的噪声系数。0-dBm阻滞剂引起的脱敏在1.4 GHz时仅为2.2 dB。
A mixer-first receiver (RX) with enhanced selectivity and high dynamic range is proposed, targeting to remove surface acoustic-wave-filters in mobile phones and cover all frequency bands up to 6 GHz. Capacitive negative feedback across the baseband (BB) amplifier serves as a blocker bypassing path, while an extra capacitive positive feedback path offers further blocker rejection. This combination of feedback paths synthesizes a complex pole pair at the input of the BB amplifier, which is upconverted to the RF port to obtain steeper RF bandpass filter roll-off and reduced distortion. This paper explains the circuit principle and analyzes RX performance. A prototype chip fabricated in 45-nm partially depleted silicon on insulator (SOI) technology achieves high out-of-band linearity (input-referred third-order intercept point (IIP3) = 39 dBm and input-referred second-order intercept point (IIP2) = 88 dB) combined with sub-3-dB noise figure. Desensitization due to a 0-dBm blocker is only 2.2 dB at 1.4 GHz.