A comparator offset immune and area-efficient In-phase and Quadrature (I/Q) mismatch calibration technique is proposed for direct conversion receivers in the letter. Theoretical analysis is provided to explain the independence between comparator offset and error detection accuracy. For verifying the proposed method, a receiver front-end prototype, along with the proposed I/Q mismatch calibration, is designed and fabricated in the 0.18- $\mu \text{m}$ technology. Experimental results show that Image Rejection Ratio (IRR) is 61.99 dB @15 MHz with a comparator offset ranging from 0 to 14 mV. And IRR for a wideband signal from 5 to 25 MHz is enhanced from 31.6 to 43.3 dB after calibration.

中文翻译：

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直接转换接收器的比较器偏移免疫I/Q校准技术

该信中针对直接转换接收器提出了一种比较器偏移免疫和面积高效的同相和正交 (I/Q) 失配校准技术。提供了理论分析来解释比较器偏移和错误检测精度之间的独立性。为了验证所提出的方法，在 0.18-$\mu\text{m}$ 技术中设计和制造了接收器前端原型以及所提出的 I/Q 失配校准。实验结果表明，图像抑制比 (IRR) 为 61.99 dB @15 MHz，比较器偏移范围为 0 到 14 mV。校准后，5 至 25 MHz 的宽带信号的 IRR 从 31.6 dB 增强至 43.3 dB。