本文介紹了一種頻率偏移調變(frequency-shift keying)訊號的接收器用於無限能量傳輸(wireless power transfer)。本文提出應用於植入式生醫系統的設計是由類比前端(analog front-end)、空佔比控制器(duty cycle controller)、資料檢測器(data detector)、偏壓再生(bias circuit) 以及數位區塊所組成。資料檢測器以及數位區塊可經由混和型訊號電路解調來自於感應電源鏈的頻率偏移調變訊號並從中提取出一個恆定的時脈。
所提出之完整架構可由仿真模擬達成且一個簡易架構已實現於0.18 um的互補式金屬氧化半導體製程。此兩種架構皆可在1伏特的電壓供應下接收13/16 MHz頻率偏移調變訊號且其數據傳輸速率最高可達到每秒百萬位元。簡易架構可提取出一個抖動幅度為1ms的恆定時脈且此抖動幅度已在所提出之架構中做修正。根據仿真模擬的結果，提出之架構的功率消耗為0.35 mW。相較於其他傳統架構，我們提出之架構使用較低的電壓供應及功率消耗下產生高數據傳輸速率。在未來的工作中，所提出的應用於生醫系統頻之率偏移調變訊號的接收器能於0.18 mm的互補式金屬氧化半導體製程實現並更進一步降低由類比低通電路中被動式元件所造成之面積損耗。

A frequency-shift keying (FSK) receiver for wireless power transfer(WPT) is presented in this work. The proposed design is composed of an analog front-end, duty cycle controller, data detector, bias circuit and a digital block which is design to apply to implantable biomedical system. The data detector and digital block can demodulate the FSK signal receives from the inductive power link and derive a constant clock through the mix-signal circuit operation.
The proposed full structure is presented in simulation and a simple structure is implemented in 0.18 mm CMOS process. Both structures work with 1V power supply and receive the 13/16 MHz FSK carrier signal with the highest data rate 1 Mbps. The simple structure derives a 1 MHz constant clock with jitter up to 1 ms which is revised in the proposed structure. The simulated power consumption of proposed structure is 0.35 mW. Compared to the conventional circuit, the proposed design consumes less power to reach the high data rate and uses the lower supply voltage. The future work is to implement the proposed FSK receiver in 0.18 um CMOS process in the implantable biomedical system and reduces the area that cause from the passive component of low pass filter in analog circuit.

1 Introduction 1
1.1 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.3 Thesis Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2 Frequency-Shift Keying Data Transfer System with WPT 6
2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.2 Prior Art of Frequency-Shift Keying Receivers . . . . . . . . . . 8
2.2.1 Injection Lock Oscillator Based FSK Receiver . . . . . . . 8
2.2.2 Fully Differential FSK Receiver . . . . . . . . . . . . . . . 10
2.2.3 Referenced Differential FSK Receiver . . . . . . . . . . . 12
3 Proposed Frequency-Shift Keying Receiver Architecture 14
3.1 Simple Version FSK Receiver . . . . . . . . . . . . . . . . . . . . 14
3.1.1 Analog Block of Simple Version FSK Receiver . . . . . . 15
3.1.2 Digital Block of Simple Version FSK Receiver . . . . . . 16
3.2 Full Version FSK Receiver . . . . . . . . . . . . . . . . . . . . . . 17
3.2.1 Analog Block of Full Version FSK Receiver . . . . . . . . 19
3.2.2 Digital Block of Full Version FSK Receiver . . . . . . . . 21
3.3 Designed Specification . . . . . . . . . . . . . . . . . . . . . . . . 22
4 Frequency-Shift Keying Receiver Circuit Implementation 24
4.1 Front-End . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
4.2 Duty Cycle Control . . . . . . . . . . . . . . . . . . . . . . . . . . 27
4.3 Data Detect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
4.4 Bias Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
4.5 Data Extraction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
4.6 Clock Extraction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
5 Measurement Results 63
5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
5.2 Measurement Results of FSK Receiver . . . . . . . . . . . . . . . 68
6 Conclusion 74
Bibliography 75

[1] Hossein Kassiri, Arezu Bagheri, Nima Soltani, Karim Abdelhalim, Hamed
Mazhab Jafari, M. Tariqus Salam, Jose Luis Perez Velazquez, and Roman
Genov, "Battery-less Tri-band-Radio Neuro-monitor and Responsive Neurostimulator
for Diagnostics and Treatment of Neurological Disorders,"
IEEE Journal of Solid-State Circuits, vol. 51, no. 5, pp. 1274-1289, May 2016.
[2] Maysam Ghovanloo and Khalil Najafi, "A wideband frequency-shift keying
wireless link for inductively powered biomedical implants," IEEE
Transactions on Circuits and Systems I: Regular Papers, vol. 51, no. 12, pp.
2374-2383, Dec. 2004.
[3] Fu-Wen Chang and Ping-Hsuan Hsieh, "A 13.56-MHz Wireless Power
Transfer Transmitter with Impedance Compression Network for Biomedical
Applications," 2020 IEEE International Symposium on Circuits and Systems
(ISCAS), pp. 1-5, Oct. 2020.
[4] Ting-Chung Lin, Tzu-MinWei, and Ping-Hsuan Hsieh, "A nonlinear wireless
power transfer receiver with adjustable interface impedance," 2017
IEEE Wireless Power Transfer Conference (WPTC), pp. 1-3, May. 2017.
[5] Cameron T. Charles, "Wireless Data Links for Biomedical Implants: Current
Research and Future Directions," 2007 IEEE Biomedical Circuits and
Systems Conference, pp. 13-16, Nov. 2007.
[6] Wentai Liu, Kasin Vichienchom, Mark Clements, Stephen C. DeMarco,
Chris Hughes, Elliot McGucken, Mark S. Humayun, Eugene de Juan,
James D. Weiland, and Robert Greenberg, "A neuro-stimulus chip with
telemetry unit for retinal prosthetic device," IEEE Journal of Solid-State Circuits,
vol. 35, no. 10, pp. 1487-1497, Oct. 2000.
[7] Jeffrey A Von Arx and Khalil Najafi, "A wireless single-chip telemetrypowered
neural stimulation system," 1999 IEEE International Solid-State
Circuits Conference. Digest of Technical Papers. ISSCC. First Edition, pp. 214-
215, Feb. 1999.
[8] Yamu Hu and Mohamad Sawan, "A fully integrated low-power BPSK demodulator
for implantable medical devices," IEEE Transactions on Circuits
and Systems I: Regular Papers, vol. 52, no. 12, pp. 2552-2562, Dec. 2005.
[9] Maysam Ghovanloo and Khalil Najafi, "A Modular 32-site wireless neural
stimulation microsystem," IEEE Journal of Solid-State Circuits, vol. 39, no.
20, pp. 2457-2466, Dec. 2004.
[10] Maysam Ghovanloo and Khalil Najafi, "A high-rate frequency shift keying
demodulator chip for wireless biomedical implants," Proc. 2003 International
Symposium on Circuits and Systems, pp. V-V, May. 2003.
[11] Mavsam Ghovanloo and Khalil Najafi, "A high data transfer rate frequency
shift keying demodulator chip for the wireless biomedical implants,"
The 2002 45th Midwest Symposium on Circuits and Systems, pp. IIIIII,
Aug. 2002.
[12] Maysam Ghovanloo and Khalil Najafi, "A fully digital frequency shift
keying demodulator chip for wireless biomedical implants," Southwest
Symposium on Mixed-Signal Design, pp. 223-227, Feb. 2003.
[13] Mohammad Salahshoor, Seyed Abdollah Mirbozorgi, Amir Arian, and
Sasan Naseh, "A new discriminator for a low-power capacitor-less FSK
demodulator for biomedical implants," 10th IEEE International NEWCAS
Conference, pp. 297-300, Jun. 2012.
[14] Ro-Min Weng, Shu-Ya Li, and Jing-Chyi Wang, "Low Power Frequency-
Shift Keying Demodulators for Biomedical Implants," 2007 IEEE Conference
on Electron Devices and Solid-State Circuits, pp. 1079-1082, Dec. 2007.
[15] J. Kim and K. Pedrotti, "Fully integrated low-power area-efficient FSK demodulator
for inductively powered biomedical implants," Electronics Letters,
vol. 49, no. 14, Jul. 2013.
[16] Mian Dong, Chun Zhang, Songping Mai, Zhihua Wang, and Dongmei
Li, "A wideband frequency-shift keying demodulator for wireless neural
stimulation microsystems," 19th International Conference on VLSI Design
held jointly with 5th International Conference on Embedded Systems Design (VLSID’
06), pp. 4-8, Jan. 2006.
[17] Chen-Hua Kao, Yu-Po Lin, and Kea-Tiong Tang, "Wireless data and
power transmission circuits in biomedical implantable applications," International
Symposium on Bioelectronics and Bioinformations, pp. 9-12, Nov.
2011.
[18] Ahmed I. AL-Kalbani, Mehmet R. Yuce, and Jean-Michel Redouté, "Performance
of a biomedical implant communication system using PWM
coded ASK," 2012 International Symposium on Communications and Information
Technologies (ISCIT), pp. 133-138, Oct. 2012.
[19] H. Zhang, X. Chen, M. Chen and G. Wang, "A wide-input-range lowpower
ASK demodulator for wireless data transmission in retinal prosthesis,"
2016 IEEE Biomedical Circuits and Systems Conference (BioCAS), pp.
492-495, Oct. 2016.
[20] Chao-Shiun Wang, Kun-Da Chu, and Chorng-Kuang Wang, "A 0.13um
CMOS 2.5Gb/s FSK Demodulator Using Injection-Locked Technique,"
2009 IEEE Radio Frequency Integrated Circuits Symposium, pp. 563-566, June.
2009.
[21] S. Delshadpour and M. Geng, "A PLL Based FSK Demodulator With
Auxiliary Path," 2020 IEEE 11th Latin American Symposium on Circuits and
Systems (LASCAS), pp. 1-4, Feb. 2020.
[22] A. Trigui, M. Ali, A. C. Ammari, Y. Savaria and M. Sawan, "A 1.5-pJ/bit,
9.04-Mbit/s Carrier-Width Demodulator for Data Transmission Over an
Inductive Link Supporting Power and Data Transfer," IEEE Transactions on
Circuits and Systems II: Express Briefs, vol. 65, no. 10, pp. 1420-1424, Oct.
2018.
[23] Alexander D. Rush and Philip R. Troyk, "A Power and Data Link for
a Wireless-Implanted Neural Recording System," IEEE Transactions on
Biomedical Engineering, vol. 59, no. 11, pp. 3255-3262, Nov. 2012.
[24] Alexander Rush and Philip R. Troyk, "Dual inductive link coil design for
a neural recording system," 2011 Annual International Conference of the IEEE
Engineering in Medicine and Biology Society,pp. 6397-6400, 30 Aug.-3 Sept.
2011.
[25] Behzad Razavi, "Design of Analog CMOS Integrated Circuits," McGraw-
Hill International edition, 16 Dec. 2000.
[26] Fu-Wen Chang, 2019. A 13.56MHz Wireless Power Transfer Transmitter
with Impedance Compression Network for Biotechnology Applications
(Unpublished doctoral dissertation). National Tsing Hua University, Taiwan,
Hsinchu City.
[27] Tzu-Min Wei, 2018. A 13.56MHz Wireless Power Transfer Receiver with
Resonant Frequency Tuning Mechanism (Unpublished doctoral dissertation).
National Tsing Hua University, Taiwan, Hsinchu City.