一种消除直流失调的自动频率校准低通滤波器

doi:10.19665/j.issn1001-2400.2023.01.010

摘要/Abstract

摘要：

为了改善直接变频发射机中由于模拟基带信号直流失调引起的本振泄露问题,以及低通滤波器截止频率因工艺偏差、温度变化和芯片老化而漂移的问题,提出了一种具有直流失调消除功能的自动频率校准低通滤波器设计与实现方法。该滤波器在串行外设接口控制模式下,通过可调电容阵列,可以将截止频率区间配置为324~648 kHz;在自适应调谐模式下,提出了一种基于锁存比较器的数模混合校准结构,通过校准芯片的RC时间常数,在不同环境温度条件下得到的截止频率为373.8~393.3 kHz,相对于标称值383 kHz的调谐精度约为-2.4%~2.7%。采用0.18 μm CMOS工艺芯片进行流片生产验证,调谐电路面积为0.045 mm²,仅占主滤波器面积的约2.2%。在1.8 V电源电压下,整个滤波器的功耗约为6.08 mW,输入参考噪声约为38.49 nV/(Hz)^1/2。

关键词: 直接变频发射机, 低通滤波器, 直流失调消除, 自动校准

Abstract:

In order to improve the LO leakage caused by the DC offset of the analog baseband signal in the direct conversion transmitter,and the drift of the low-pass filter due to process deviation,temperature change,and chip aging,a method of design and implementation of an automatic frequency-calibrated low-pass filter with DC offset cancellation is proposed.In the SPI(Serial Peripheral Interface) control mode,the filter can configure the cut-off frequency from 324 kHz to 648 kHz through the adjustable capacitor array.In the adaptive tuning mode,a digital-analog hybrid calibration structure based on the latched comparator is proposed.By calibrating the RC time constant of the chip,the cut-off frequency is 373.8~393.3 kHz under different PVT conditions,and the tuning accuracy relative to the nominal value of 383 kHz is -2.4%~2.7%.The chip uses 0.18 CMOS technology for tape-out verification,and the tuning circuit area is 0.045 mm²,which is only 2.2% of the main filter area.Under the 1.8V supply voltage,the power consumption of the whole filter is 6.08 mW,and the input reference noise is 38.49 nV/(Hz)^1/2.

Key words: direct conversion transmitter, low-pass filters, DC offset cancellation, auto-calibration

中图分类号:

TN432

杨浩涵, 乔树山. 一种消除直流失调的自动频率校准低通滤波器[J]. 西安电子科技大学学报, 2023, 50(1): 85-92.

YANG Haohan, QIAO Shushan. Automatic frequency-calibrated low-pass filter with DC offset cancellation[J]. Journal of Xidian University, 2023, 50(1): 85-92.

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参考文献 15

[1]	SREESHNA P, RAJESWARI P. A 2GHz Carrier Leakage Calibrated Direct Conversion Transmitter[C]// 2018 3rd IEEE International Conference on Recent Trends in Electronics,Information & Communication Technology(RTEICT).Piscataway:IEEE, 2018:1206-1209.
[2]	KIELA K, JURGO M, MACAITIS V, et al. Design and Investigation of a Self-Tuning Circuit for Integrated Active-RC Filter[C]// 2021 44th International Conference on Telecommunications and Signal Processing(TSP).Piscataway:IEEE, 2021:120-125.
[3]	许彤通, 相征. 高性能双通带滤波器的快速设计方法[J]. 西安电子科技大学学报, 2020, 47(5):130-136.
	XU Tongtong, XIANG Zheng. Fast Design Method for the High-Performance Dual-Passband Filter[J]. Journal of Xidian University, 2020, 47(5):130-136.
[4]	DU D, LI Y, WANG Z, et al. An Active-RC Complex Filter with Mixed Signal Tuning System for Low-IF Receiver[C]// APCCAS2006 IEEE Asia Pacific Conference on Circuits and Systems.Piscataway:IEEE, 2006:1031-1034.
[5]	OSMAN H, LIFE E S S. A PVT-Resilient,Highly-Linear Fifth-Order Ring-Oscillator-Based Filter[J]. IEEE Transactions on Circuits and Systems I:Regular Papers, 2020, 67(12):4295-4308. doi: 10.1109/TCSI.8919
[6]	LI S T, LI J C, GU X C, et al. A 4-40 MHz Active-RC Chebyshev LPF with Digital-Assisted Calibration for Direct-Conversion DVB-S/S2 & ABS-S TV Tuners[C]// 2012 IEEE 11th International Conference on Solid-State and Integrated Circuit Technology.Piscataway:IEEE, 2012:1-3.
[7]	WANG H, LIN M, SUN S, et al. A Widely Tunable Active-RC Complex Filter for Multi-Mode Wireless Receivers with Automatic Frequency Tuning[J/OL].[2022-02-20].DOI:10.1587/elex.13.20160764. doi: 10.1587/elex.13.20160764
[8]	LAVALLE-AVILES F, Sánchez-Sinencio E. A 0.6-V Power-Efficient Active-RC Analog Low-Pass Filter with Cutoff Frequency Selection[J]. IEEE Transactions on Very Large Scale Integration Systems, 2020, 28(8):1757-1769. doi: 10.1109/TVLSI.92
[9]	JIANG C, XIE R, LI W, et al. Reconfigurable Low Pass Filter with Automatic Frequency Tuning for WCDMA and GSM Application[C]// 2011 9th IEEE International Conference on ASIC.Piscataway:IEEE, 2011:1066-1069.
[10]	张刚, 董江涛, 张天骐, 等. 改进型多用户高效DCSK通信方案的性能分析[J]. 西安电子科技大学学报, 2022, 49(3):36-47.
	ZHANG Gang, DONG Jiangtao, ZHANG Tianqi, et al. Performance Analysis for the Improved Multiuser High-Efficiency DCSK Communication Scheme[J]. Journal of Xidian University, 2022, 49(3):36-47.
[11]	LAOUEJ D, DAOUD H, LOULOU M. Design of Sixth Order Butterworth Gm-C Filter Using Particle Swarm Optimization Program for Biomedical Application[C/OL].[2022-02-22].DOI:10.1109/ICM.2017.8268842. doi: 10.1109/ICM.2017.8268842
[12]	CHEN W K. Passive,Active,and Digital Filters[M]. Boca Raton: Crc Press, 2018.
[13]	TRAN T, KUWAN A, KOBAYASHI H. Derivation of Loop Gain and Stability Test for Multiple Feedback Low-Pass Filter Using Deboo Integrator[C/OL].[2022-02-20].DOI:10.12792/iciae2020.039. doi: 10.12792/iciae2020.039
[14]	DELSHADPOUR S. A 5/10/20/40 MHz 5th Order Active-RC Chebychev LPF for 802.11 abg IF Receiver in 0.18 μm CMOS Technology[C]// 2019 IEEE 20th Wireless and Microwave Technology Conference(WAMICON).Piscataway:IEEE, 2019:1-4.
[15]	WU J, XIE Z, YU T, et al. A Wide Tuning Range Gm-C Complex Filter with Master-Slave Automatic Frequency Tuning Based Switched-Capacitor[J]. Microelectronics Journal, 2018, 81:200-207. doi: 10.1016/j.mejo.2018.04.009

工艺角	电压/V	温度/℃	截止频率/kHz	工艺角	电压/V	温度/℃	截止频率/kHz
Typical	1.62	-25	382.9	Slow	1.8	-25	386.5
Typical	1.62	27	378.7	Slow	1.8	27	384.6
Typical	1.62	95	375.9	Slow	1.8	95	376.7
Typical	1.98	-25	385.5	Fast	1.8	-25	373.8
Typical	1.98	27	380.8	Fast	1.8	27	380.5
Typical	1.98	95	377.6	Fast	1.8	95	393.3

文献	滤波器带宽/MHz	调谐范围/%	调谐精度/%	功耗/mW	电源电压/V	工艺节点/nm
[5]	1.5~22.5		3.5	6.20~8.90	1.0	130
[6]	4~40		6.0	29.96	2.8	130
[7]	0.06~14.00	30	2.0	19.50	1.3	130
[8]	20;40;80;160	35	5.0	14.28	0.6	130
[9]	0.2;2	20	2.5	1.60	1.5	130
[14]	5;10;20;40		2.0	6.84/8.1/9.36/10.926	1.8	180
[15]	0.09~1.96 0.15~1.95		3.0	2.88~3.78	1.8	180
文中	0.324~0.648	50	2.7	6.08	1.8	180