95~105 GHz SiGe BiCMOS Wideband Digitally Controlled Attenuator for Metasurface Antenna Design
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摘要: 近年来,因对电磁波具备灵活的调控能力,超表面天线技术受到来自通信、雷达以及天线领域学者的广泛关注。其中,超表面天线单元中所使用的有源调控器件,是决定整个系统性能的最关键部件之一。基于0.13 μm SiGe BiCMOS工艺设计了一个95~105 GHz的五位宽带数控衰减器芯片。该衰减器采用了反射式和简化T型两种拓扑结构,其中4 dB与8 dB反射式衰减单元采用交叉耦合宽带耦合器代替传统的3 dB耦合器或定向耦合器,同时获得了高衰减精度和低插入损耗;而0.5 dB, 1 dB, 2 dB三个衰减单元均采用简化T型结构。此外,利用RC正斜率和负斜率校正网络分别应用于不同的衰减单元进行相位补偿,极大地改善了衰减器的附加相移。经过仿真验证,在95~105 GHz的感兴趣工作频率内,衰减器芯片在0.12 mm2的紧凑的尺寸下实现了0~15.5 dB的衰减范围,步进为0.5 dB,基态插入损耗小于2.5 dB,幅度均方根误差小于0.31 dB,附加相移均方根误差小于2.2º。所提出的W波段衰减器可作为一个关键部件赋能集成T/R的辐散一体化超表面天线系统的硬件实现。
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关键词:
- SiGe BiCMOS /
- W波段 /
- 衰减器 /
- 交叉耦合宽带耦合器 /
- 超表面
Abstract: Recently, metasurface antenna technology has raised meticulous attention from scholars in the communications, radar, and antenna communities, owing to its great capability in flexible control of electromagnetic waves. In particular, the active tunable device used in the metasurface antenna element is one of the most significant components that affect the performance of the entire system. In this paper, a 95 to 105 GHz digitally controlled attenuator with 5-bit resolution is designed in a 0.13 μm SiGe BiCMOS process. The attenuator employs two different topological structures, reflective and simplified T-type. The 4 dB and 8 dB reflective attenuation units utilize cross-coupled broadband couplers instead of traditional 3 dB couplers or directional couplers, achieving high attenuation precision and low insertion loss. On the other hand, the 0.5 dB, 1 dB, and 2 dB attenuation units adopt a simplified T-type structure. Furthermore, the utilization of RC positive and negative slope correction networks applied separately to different attenuation units enables phase compensation, significantly improving the additional phase shift of the attenuator. Within the desired frequency range of 95~105 GHz, the attenuator achieves an attenuation range of 0~15.5 dB with a step of 0.5 dB in a compact size of 0.12 mm2. It exhibits a simulated insertion loss below 2.5 dB, a simulated amplitude Root Mean Square (RMS) error less than 0.25 dB, and a simulated phase RMS error is better than 2.2°. The proposed W-band attenuator can serve as a key component empowering the hardware implementation of an integrated Transmit/Receive (T/R) metasurface antenna system with simultaneous radiation and scattering control.-
Key words:
- SiGe BiCMOS /
- W-band /
- Attenuator /
- Wideband coupler with cross-coupling /
- Metasurface
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表 1 等效电路模型元器件的参数值
器件 参数值 器件 参数值 L1 85.3 pH C1 0.5 fF L2 22.0 pH C2 2.7 fF L3
R1
k13.0 pH
1.9 ohm
0.7C3
C412.8 fF
0.7 fF表 2 关键器件参数
器件 参数值 器件 参数值 器件 参数值 器件 参数值 T1,2(W/L) 120 nm/630 nm C1,2,4 20 fF R4 1298 ohmR9 81 ohm T3(W/L) 120 nm/ 1050 nmC3 12 fF R5 57 ohm R10 223 ohm T4(W/L) 120 nm/850 nm R1 126 ohm R6 2273 ohmT5(W/L) 120 nm/900 nm R2 301 ohm R7 190 ohm T6,7(W/L) 120 nm/ 1200 nmR3 1433 ohmR8 100 ohm W:发射极宽度 L:发射极长度 表 3 性能总结和已报道的硅基毫米波衰减器芯片对比
文献 2014[6] 2016[18] 2021[19] 2022[22] #本文 工艺 65 nm
CMOS180 nm
SiGe BiCMOS65 nm
CMOS130 nm
SiGe BiCMOS130 nm
SiGe BiCMOS频率(GHz) 50~110 57-64 80~110 190~220 95~105 拓扑结构 Distributed Distributed Coupled Coupled lines Reflected+T type 位数(bit)/步进(dB) 14/0.75 4/1.0 6/NA 4/0.35 5/0.50 衰减范围(dB) 0~10.0 0~11.8 0~14.5 0~4.7 0~15.5 插入损耗(dB) 11.2 11.0 4.5* 2.0 2.5 幅度均方根误差(RMSA)(dB) NA <1.54 <0.31 <0.34 <0.31 相位变化(º) <5.0 12.0* <12.0 NA <4.8 相位均方根误差(RMSP)(º) <1.4 <3.6 NA NA <2.2 面积(mm2) 0.38 0.94 0.06 0.03 0.12 *:估算 #:仿真结果 -
[1] CUI Tiejun, LIU Shuo, and ZHANG Lei. Information metamaterials and metasurfaces[J]. Journal of Materials Chemistry C, 2017, 5(15): 3644–3668. doi: 10.1039/C7TC00548B. [2] CHENG Qiang, ZHANG Lei, DAI Junyan, et al. Reconfigurable intelligent surfaces: Simplified-architecture transmitters—from theory to implementations[J]. Proceedings of the IEEE, 2022, 110(9): 1266–1289. doi: 10.1109/JPROC.2022.3170498. [3] ZHAO Chenxi, GUO Jiawei, LIU Huihua, et al. A 33–41-GHz SiGe-BiCMOS digital step attenuator with minimized unit impedance variation[J]. IEEE Transactions on Very Large Scale Integration (VLSI) Systems, 2021, 29(3): 568–579. doi: 10.1109/TVLSI.2020.3046016. [4] CHEON C D, RAO S G, LIM W, et al. Design methodology for a wideband, low insertion loss, digital step attenuator in SiGe BiCMOS technology[J]. IEEE Transactions on Circuits and Systems II: Express Briefs, 2022, 69(3): 744–748. doi: 10.1109/TCSII.2021.3111177. [5] RAO S G, CHEON C D, and CRESSLER J D. A millimeter-wave, transformer-based, SiGe distributed attenuator[J]. IEEE Microwave and Wireless Components Letters, 2022, 32(2): 145–148. doi: 10.1109/LMWC.2021.3118291. [6] KIM K, LEE H S, and MIN B W. V-W band CMOS distributed step attenuator with low phase imbalance[J]. IEEE Microwave and Wireless Components Letters, 2014, 24(8): 548–550. doi: 10.1109/LMWC.2014.2322442. [7] BAE J and NGUYEN C. A novel concurrent 22–29/57–64-GHz dual-band CMOS step attenuator with low phase variations[J]. IEEE Transactions on Microwave Theory and Techniques, 2016, 64(6): 1867–1875. doi: 10.1109/TMTT.2016.2546256. [8] HE Yang, ZHANG Tiedi, TANG Yichen, et al. Wideband pHEMT digital attenuator with positive voltage control driver[J]. IEEE Microwave and Wireless Technology Letters, 2023, 33(2): 295–298. doi: 10.1109/LMWC.2022.3215495. [9] JEONG J C, UHM M, JANG D P, et al. A Ka-band GaAs multi-function chip with wide-band 6-bit phase shifters and attenuators for satellite applications[C]. 2019 13th European Conference on Antennas and Propagation (EuCAP), Krakow, Poland, 2019: 1–4. [10] ZHANG Qingfeng, ZHAO Chenxi, ZHANG Shuangmin, et al. Mechanism analysis and design of a switched T-type attenuator with capacitive phase compensation technique[J]. IEEE Microwave and Wireless Technology Letters, 2023, 33(10): 1438–1441. doi: 10.1109/LMWT.2023.3303181. [11] LI Nayu, ZHANG Zijiang, LI Min, et al. A DC–28-GHz 7-bit high-accuracy digital-step attenuator in 55-nm CMOS[J]. IEEE Microwave and Wireless Components Letters, 2022, 32(2): 157–160. doi: 10.1109/LMWC.2021.3120934. [12] YUAN Ye, MU Shanxiang, and GUO Yongxin. 6-bit step attenuators for phased-array system with temperature compensation technique[J]. IEEE Microwave and Wireless Components Letters, 2018, 28(8): 690–692. doi: 10.1109/LMWC.2018.2849224. [13] BAE J, LEE J, and NGUYEN C. A 10–67-GHz CMOS dual-function switching attenuator with improved flatness and large attenuation range[J]. IEEE Transactions on Microwave Theory and Techniques, 2013, 61(12): 4118–4129. doi: 10.1109/TMTT.2013.2288694. [14] KU B H and HONG S. 6-bit CMOS digital attenuators with low phase variations for X-band phased-array systems[J]. IEEE Transactions on Microwave Theory and Techniques, 2010, 58(7): 1651–1663. doi: 10.1109/TMTT.2010.2049691. [15] BULJA S and RULIKOWSKI P. High dynamic range reflection-type attenuator[C]. 2018 IEEE Radio and Antenna Days of the Indian Ocean (RADIO), Wolmar, Mauritius, 2018: 1–2. doi: 10.23919/RADIO.2018.8572448. [16] YISHAY R B and ELAD D. W-band SiGe attenuators based on compact low-VSWR topologies[C]. 2017 IEEE MTT-S International Microwave Symposium (IMS), Honololu, USA, 2017: 638–641. doi: 10.1109/MWSYM.2017.8058650. [17] PU Yuqian, SHEN Hongchang, TANG Feihong, et al. Design of millimeter-wave reflective attenuators with capacitive compensation technique[J]. Journal of Southeast University (English Edition), 2023, 39(2): 153–160. doi: 10.3969/j.issn.1003-7985.2023.02.006. [18] BULJA S and GREBENNIKOV A. Variable reflection-type attenuators based on varactor diodes[J]. IEEE Transactions on Microwave Theory and Techniques, 2012, 60(12): 3719–3727. doi: 10.1109/TMTT.2012.2216895. [19] 赵丽. 新一代宽带无线互联网射频收发机及关键芯片的研究与设计[D]. [博士论文], 东南大学, 2018.ZHAO Li. Investigations on RF transceivers and related integrated circuits for a new generation broadband wireless internet[D]. [Ph. D. dissertation], Southeast University, 2018. (in Chinese). [20] LUO Jiang, HE Jin, CHEN Pengwei, et al. Micro-strip line 90° phase shifter with double ground slots for D-band applications[J]. Journal of Circuits, Systems and Computers, 2018, 27(12): 1850192. doi: 10.1142/S021812661850192X. [21] ZHU Wei, WANG Jiawen, WANG Ruitao, et al. 14.5 A 1V W-band bidirectional transceiver front-end with <1dB T/R switch loss, <1°/dB phase/gain resolution and 12.3% TX PAE at 15.1dBm output power in 65nm CMOS technology[C]. 2021 IEEE International Solid-State Circuits Conference (ISSCC), San Francisco, USA, 2021: 226–228. doi: 10.1109/ISSCC42613.2021.9365944. [22] ZHU Nengxu and MENG Fanyi. A 190-to-220GHz 4-bit passive attenuator with 1.4dB insertion loss and sub-0.4dB RMS amplitude error using magnetically switchable coupled-lines in 0.13-µm CMOS technology[C]. 2022 IEEE/MTT-S International Microwave Symposium - IMS 2022, Denver, USA, 2022: 746–749. doi: 10.1109/IMS37962.2022.9865616.