Analog finite-impulse-response (AFIR) filtering is proposed to realize low-power channel selection filters for the Internet-of-Things receivers. High selectivity is achieved using an architecture based on only a single—time-varying—transconductance and integration capacitor. The transconductance is implemented as a digital-to-analog converter and is programmable by an on-chip memory. The AFIR operating principle is shown step by step, including its complete transfer function with aliasing. The filter bandwidth and transfer function are highly programmable through the transconductance coefficients and clock frequency. Moreover, the transconductance programmability allows an almost ideal filter response to be realized by careful analysis and compensation of the parasitic circuit impairments. The filter, manufactured in 22-nm FDSOI, has an active area of 0.09 mm ². Its bandwidth can be accurately tuned from 0.06 to 3.4 MHz. The filter consumes 92 $\mu \text{W}$ from a 700-mV supply. This low power consumption is combined with a high selectivity: $\text{f}_{-60\,\text {dB}}/\text{f}_{-3\,\text {dB}}\,\,=$ 3.8. The filter has 31.5-dB gain and 12-nV/ $\sqrt {\text {Hz}}$ input-referred noise for a 0.43-MHz bandwidth. The OIP3 is 28 dBm, independent of the frequency offset. The output-referred 1-dB-compression point is 3.7 dBm, and the in-band gain compresses by 1 dB for an −3.7-dBm out-of-band input signal while still providing >60 dB of filtering.

中文翻译：

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使用跨导电容器模拟 FIR 的低功耗高选择性通道滤波

提出模拟有限脉冲响应 (AFIR) 滤波来实现物联网接收器的低功率信道选择滤波器。使用仅基于单个时变跨导和集成电容器的架构可实现高选择性。跨导是作为数模转换器实现的，并且可以通过片上存储器进行编程。逐步展示了 AFIR 的工作原理，包括其完整的带混叠的传递函数。滤波器带宽和传递函数可通过跨导系数和时钟频率高度可编程。此外，跨导可编程性允许通过仔细分析和补偿寄生电路损伤来实现几乎理想的滤波器响应。该滤波器采用 22 纳米 FDSOI 制造，² . 其带宽可在 0.06 至 3.4 MHz 范围内精确调谐。过滤器消耗 92 $\mu \text{W}$ 来自 700 mV 电源。这种低功耗与高选择性相结合： $\text{f}_{-60\,\text {dB}}/\text{f}_{-3\,\text {dB}}\,\,=$ 3.8. 该滤波器具有 31.5-dB 增益和 12-nV/ $\sqrt {\text {Hz}}$ 0.43 MHz 带宽的输入参考噪声。OIP3 为 28 dBm，与频率偏移无关。以输出为参考的 1dB 压缩点为 3.7dBm，对于 -3.7dBm 带外输入信号，带内增益压缩 1dB，同时仍提供 >60dB 的滤波。