Browse > Article
http://dx.doi.org/10.22895/jse.2020.0002

A Survey on RF Energy Harvesting System with High Efficiency RF-DC Converters  

Khan, Danial (Department of Electrical and Computer Engineering, Sungkyunkwan University)
Basim, Muhammad (Department of Electrical and Computer Engineering, Sungkyunkwan University)
Ali, Imran (Department of Electrical and Computer Engineering, Sungkyunkwan University)
Pu, YoungGun (Department of Electrical and Computer Engineering, Sungkyunkwan University)
Hwang, Keum Cheol (Department of Electrical and Computer Engineering, Sungkyunkwan University)
Yang, Youngoo (Department of Electrical and Computer Engineering, Sungkyunkwan University)
Kim, Dong In (Department of Electrical and Computer Engineering, Sungkyunkwan University)
Lee, Kang-Yoon (Department of Electrical and Computer Engineering, Sungkyunkwan University)
Publication Information
Journal of Semiconductor Engineering / v.1, no.1, 2020 , pp. 13-30 More about this Journal
Abstract
Radio frequency (RF) energy harvesting technology have become a reliable and promising alternative to extend the lifetime of power-constrained wireless networks by eliminating the need for batteries. This emerging technology enables the low-power wireless devices to be self-sustaining and eco-friendly by scavenging RF energy from ambient environment or dedicated energy sources. These attributes make RF energy harvesting technology feasible and attractive to an extended range of applications. However, despite being the most reliable energy harvesting technology, there are several challenges (especially power conversion efficiency, output DC voltage and sensitivity) poised for the implementation of RF energy harvesting systems. In this article, a detailed literature on RF energy harvesting technology has been surveyed to provide guidance for RF energy harvesters design. Since signal strength of the received RF power is limited and weak, high efficiency state-of-the-art RF energy harvesters are required to design for providing sufficient DC supply voltage to wireless networks. Therefore, various designs and their trade-offs with comprehensive analysis for RF energy harvesters have been discussed. This paper can serve as a good reference for the researchers to catch new research topics in the field of RF energy harvesting.
Keywords
Energy harvesting; power conversion efficiency; rectifier; RF energy harvesting; wireless networks;
Citations & Related Records
연도 인용수 순위
  • Reference
1 D. Yi, T. Arslan, and A. Hamilton, "Broadband antenna for RF energy scavenging system," in Proc. of IEEE Antennas and Propagation Conference (LAPC), pp. 1-4, Loughborough, UK, Nov. 2012.
2 S. Agrawal, S. Pandey, J. Singh, and P.N. Kondekar, "An efficient RF energy harvester with tuned matching circuit," VLSI Design and Test, Communications in Computer and Information Science, vol. 382, pp. 138-145, 2013.   DOI
3 M. T. Penella-Lpez and M. Gasulla-Forner, "Radiofrequency energy harvesting," Powering Autonomous Sensors, Springer Netherlands, pp. 125-147, 2011.
4 Hatay M (1980) Empirical formula for propagation loss in land mobile radio services. IEEE Trans Veh Technol 29:317-325.   DOI
5 J. Bito, R. Bahr, J. Hester, S. Nauroze, A. Georgiadis and M. Tentzeris, "A Novel Solar and Electromagnetic Energy Harvesting System With a 3-D Printed Package for Energy Efficient Internet-of-Things Wireless Sensors," IEEE Transactions on Microwave Theory and Techniques, vol. 65, no. 5, pp. 1831-1842, May 2017.   DOI
6 M. Dini, A. Romani, M. Filippi, V. Bottarel, G. Ricotti and M. Tartagni, "A Nanocurrent Power Management IC for Multiple Heterogeneous Energy Harvesting Sources," IEEE Transactions on Power Elecronics, vol. 30, no. 10, pp. 5665-5680, Oct. 2015.   DOI
7 F. Deng, X. Yue, X. Fan, S. Guan, Y. Xu and J. Cheon, "Multisource Energy Harvesting System for a Wireless Sensor Network Node in the Field Environment," IEEE Internet of Things Journal, vol. 6, no. 1, pp. 918-927, Feb. 2019.   DOI
8 A. Omairi, Z. H. Ismail, K. A. Danapalasingam, and M. I. Shapiai, "Power harvesting in wireless sensor networks and its adaptation with maximum power point tracking: Current technology and future directions," IEEE Internet Things J., vol. 4, no. 6, pp. 2104-2115, Dec. 2017.   DOI
9 W. K. G. Seah, Z. A. Eu, and H.-P. Tan, "Wireless sensor networks powered by ambient energy harvesting (WSN-HEAP)-Survey and challenges," in Proc. IEEE Int. Conf. Wireless VITAE, May 2009, pp. 1-5.
10 Carvalho, Carlos, and Nuno Paulino. "On the Feasibility of Indoor Light Energy Harvesting for Wireless Sensor Networks." Procedia Technology, vol. 17, pp. 343-350, 2014.   DOI
11 G. K. Ottman, H. F. Hofmann, and G. A. Lesieutre, "Optimized piezo- electric energy harvesting circuit using step-down converter in discon- tinuous conduction mode," IEEE Trans. Power Electron., vol. 18, no. 2, pp. 696-703, Mar. 2003.   DOI
12 M. T. Penella-Lpez and M. Gasulla-Forner, "Radiofrequency energy harvesting," Powering Autonomous Sensors, Springer Netherlands, pp. 125-147, 2011.
13 J. A. Hagerty, F. B. Helmbrecht, W. H. Mccalpin, R. Zane, and Z. B. Popovic, "Recycling ambient microwave energy with broad-band rectenna arrays," IEEE Trans. on Microwave Theory and Techniques, vol. 52, no. 3, pp. 1014-1024, March 2004.   DOI
14 M. Ghovanloo, and K. Najafi, "Fully integrated wideband high-current rectifiers for inductively powered devices," IEEE Journal of Solid-State Circuits, vol. 39, no. 11, pp. 1976-1984, Nov. 2004.   DOI
15 J.-P. Curty, M. Declercq, C. Dehollain, and N. Joehl, Design and optimization of passive UHF RFID systems, 1st edn., Springer Science Business Media, New York, 2007.
16 E. Y. Chow, A. L. Chlebowski, S. Chakraborty, W. J. Chappell, and P. P. Irazoqui, "Fully wireless implantable cardiovascular pressure monitor integrated with a medical stent," IEEE Transactions on Biomedical Engineering, vol. 57, no. 6, pp. 1487-1496, 2010.   DOI
17 D. Khan, H. Abbasizadeh, Z. Hayat, N. Khan, and K. Yoon, ''A 33.3% power efficiency RF energy harvester with -25 dBm sensitivity using threshold compensation scheme,'' IDEC J. Integr. Circuits Syst, vol. 3, no. 3, Jul. 2017.
18 Z. Wang, V. Leonov, P. Fiorini, and C. Van Hoof, "Realization of a wear- able miniaturized thermoelectric generator for human body applications," Sens. Actuators A, Phys., vol. 156, no. 1, pp. 95-102, Nov. 2009.   DOI
19 Y. Qiu, C. Van Liempd, P. G. Blanken, and C. Van Hoof, "$5 {\mu}W$-to-10 mW input power range inductive boost converter for indoor photovoltaic energy harvesting with integrated maximum power point tracking algorithm," in Proc. IEEE Int. Conf. Solid-State Circuits Conf. Dig. Tech. Papers, 2011, pp. 118-120.
20 S.-Y Kim et al., "A -20 to 30 dBm Input Power Range Wireless Power System with a MPPT-based Reconfigurable 48% Efficient RF Energy Harvester and 82% Efficient A4WP Wireless Power Receiver with Open Loop Delay Compensation" IEEE Trans. Power Electron, vol. 34, no. 7, pp. 6807-6817, July 2019.
21 D. Khan et al., "A Design of Ambient RF energy Harvester with Sensitivity of -21dBm and Power Efficiency of a 39.3% Using Internal Threshold Voltage Compensation," MDPI Energies, vol. 11, no. 5, May 2018.
22 D. Khan et al., "A CMOS RF Energy Harvester With 47% Peak Efficiency Using Internal Threhsold Voltage Compensation," IEEE Micro. Wireless Compon. Letter, vol. 29, no. 6, pp. 415-417, June 2019.   DOI
23 D. Khan et al., "An efficient Reconfigurable RF-DC Converter With Wide Input Power Range for RF Energy Harvesting," IEEE Access, vol. 8, pp. 79310-79318, April 2020.   DOI
24 S. Roundy, P. K. Wright, and J. Rabaey, "A study of low level vibration as a power source for wireless sensor nodes," Computer Communications, vol. 26, no. 11, pp. 1131-1144, 2003.   DOI
25 J. -P. Fleurial, G. Snyder, J. Herman, M. Smart, P. Shakkottai, P. Giauque, and M. Nicolet, "Miniaturized thermoelectric power sources," tech. rep., SAE Technical Paper, 1990.
26 S. Roundy and P. K. Wright, "A piezoelectric vibration based generator for wireless electronics," Smart Materials and Structures, vol. 13, no. 5, pp. 1131, 2004.   DOI
27 R. Venkatasubramanian, C. Watkins, D. Stokes, J. Posthill, and C. Caylor, "Energy harvesting for electronics with thermoelectric devices using nanoscale materials," in IEEE International Electron Devices Meeting, 2007, pp. 367-370, IEEE, 2007.
28 H. A. Sodano, G. E. Simmers, R. Dereux, and D. J. Inman, "Recharging batteries using energy harvested from thermal gradients," Journal of Intelligent Material Systems and Structures, vol. 18, no. 1, pp. 3-10, 2007.   DOI
29 B. A. Warneke, M. D. Scott, B. S. Leibowitz, L. Zhou, C. L. Bellew, J. A. Chediak, J. M. Kahn, B. E. Boser, and K. S. Pister, "An autonomous 16 mm3 solar-powered node for distributed wireless sensor networks," in Proceedings of IEEE Sensors, 2002, vol. 2, pp. 1510-1515, IEEE, 2002.
30 O. Schultz, R. Preu, S. Glunz, and A. Mette, "Silicon solar cell with screen-printed from side metallization exceeding 19% effiecieny," in Proceedings of the 22nd European Photovoltaic Solar Energy Conference (PVSEC), pp. 980-984, 2007.
31 Z. Harouni, L. Cirio, L. Osman, A. Gharsallah, and O. Picon, "A dual circularly polarized 2.45-GHz rectenna for wireless power transmis-sion," IEEE Antennas Wireless Propag. Lett., vol. 10, pp. 306-309, Apr. 2011.   DOI
32 J. Bito, J. G. Hester, and M. M. Tentzeris, "Ambient RF energy harvesting from a two-way talk radio for flexible wearable wireless sensor devices utilizing inkjet printing technologies," IEEE Trans. Microw. Theory Techn., vol. 63, no. 12, pp. 4533-4543, Dec. 2015.   DOI
33 Akhtar F, Rehmani MH (2015) Energy replenishment using renewable and traditional energy resources for sustainable wireless sensor networks: a review. Renew Sustain Energy Rev 45:769-784.   DOI
34 M. A. Abouzied and E. Sanchez-Sinencio, "Low-input power-level CMOS RF energy-harvesting front end," IEEE Trans. Microw. Theory Techn., vol. 63, no. 11, pp. 3794-3805, Nov. 2015.   DOI
35 Y.-J. Ren and K. Chang, "5.8-GHz circularly polarized dual-diode rectenna and rectenna array for microwave power transmission," IEEE Trans. Microw. Theory Techn., vol. 54, no. 4, pp. 1495-1502, Jun. 2006.   DOI
36 Vullers RJM, van Schaijk R, Doms I, Van Hoof C, Mertens R (2009) Micropower energy harvesting. Solid‑State Electron 53:684-693.   DOI
37 O. Jonah and S. V. Georgakopoulos, "Wireless power transfer in concrete via strongly coupled magnetic resonance,'" J. Chem. Inf. Model., vol. 53, no. 9, pp. 1689 -1699, 2013.   DOI
38 M. Xia and S. Aissa, "On the efficiency of far-field wireless power transfer,'' IEEE Trans. Signal Process., vol. 63, no. 11, pp. 2835-2847, Jun. 2015.   DOI
39 T. Salter, K. Choi, M. Peckerar, and G. Metze, "RF energy scavenging system utilising switched capacitor DC-DC converter," Electronics Letters, vol. 45, no. 7, pp. 374-376, March 2009.   DOI
40 J. P. Thomas, M. A. Qidwai, and J. C. Kellogg, "Energy scavenging for small-unmanned systems," Journal of Power Sources, vol. 159, no. 2, pp. 1494-1509, September 2006.   DOI
41 D. Y. Choi, "Comparative study of antenna designs for RF energy harvesting," Hindawi International Journal of Antennas and Propagation, February 2013.
42 M. Arrawatia, M. S. Baghini, and G. Kumar, "RF energy harvesting system from cell towers in 900MHz band," in Proc. of IEEE National Conference on Communications (NCC), pp. 1-5, Bangalore, Jan. 2011.
43 A. Aziz, A. Mutalib, and R. Othman, "Current developments of RF energy harvesting system for wireless sensor networks," Advances in information Sciences and Service Sciences (AISS), vol. 5, no. 11, pp. 328-338, June 2013.
44 X. Shao, B. Li, N. Shahshahan, N. Goldman, T. S. Salter, and G. M. Metze, "A planner dual-band antenna design for RF energy harvesting applications," in Proc. of IEEE International Semiconductor Device Research Symposium (ISDRS), College Park, MD, Dec. 2011.
45 J. M. Barcak, and H. P. Partal, "Efficient RF energy harvesting by using multiband microstrip antenna arrays with multistage rectifiers," in Proc. of IEEE Subthreshold Microelectronics Conference (SubVT), pp. 1-3, Waltham, MA, Oct. 2012.
46 S. B. Alam, M. S. Ullah, and S. Moury, "Design of a low power 2.45 GHz RF energy harvesting circuit for rectenna," in Proc. of IEEE International Conference on Informatics, Electronics & Vision (ICIEV), Dhaka, Bangladesh, May 2013.
47 M. Arsalan, M.H. Ouda, L. Marnat, T. J. Ahmad, A. Shamim, and K. N. Salama, "A 5.2GHz, 0.5mW RF powered wireless sensor with dual on-chip antennas for implantable intraocular pressure monitoring," in Proc. of IEEE International Microwave Symposium Digest (IMS), pp. 1-4, Seattle, WA, June 2013.
48 J. Bae, H. Koo, H. Lee, W. Lim, W. Lee, H. Kang, K.C Hwang, K.-Y. Lee, and Y. Yang, "High-efficiency rectrifier(5.2 GHz) using a Class-F Dickson charge pump". Microw. Opt. Tech. Lett. 2017, 54, 3018-3023.
49 J. Bae, S.-H. Yi, W. Choi, H. Koo, K.C Hwang, K.-Y. Lee, and Y. Yang, "5.8 GHz High-Efficiency RF-DC converter based on Common-Ground Multiple-Stack Structure". Sensors, MDPI, 2019.
50 C. Wang, N. Shinohara, and T. Mitani, "Study on 5.8-GHz Single-Stage Charge Pump Rectifier for Internal Wireless System of Satellite". IEEE Microw. Mag. 2017, 65, 1058-1065.
51 M. H. Ouda, W. Khalil, K. N. Salama, "Self-biased differential rectifier with enhanced dynamic range for wireless powering". IEEE Transactions on Circuits and Systems II: Express Briefs, 515-519, 2017.
52 M. A. Abouzied, K. Ravichandran, and E. Sanchez-Sinencio, "A fully integrated reconfigurable self-startup RF energy-harvesting system with storage capability," IEEE J. Solid-State Circuits, vol. 52, no. 3, pp. 704-719, Mar. 2017.   DOI
53 A. K. Moghaddam, J. H. Chuah, H. Ramiah, J. Ahmadian, P. I. Mak, and R. P. Martins, "A 73.9%-efficiency CMOS rectifier using a lower DC feeding (LDCF) self-body-biasing technique for far-field RF energy-harvesting systems". IEEE Transactions on Circuits and Systems I: Regular Papers, 64(4), 992-1002, 2017.   DOI
54 P.-A. Haddad, G. Gosset, J.-P. Raskin, and D. Flandre, "Automated design of a 13.56 MHz 19 $10 {\mu}W$ passive rectifier with 72% efficiency under $10 {\mu}A$ load," IEEE J. Solid-State Circuits, vol. 51, no. 5, pp. 1290-1301, May 2016.   DOI
55 C. Mikeka and H. Arai, "Design issues in radio frequency energy harvesting system," Sustainable Energy Harvesting Technologies-Past, Present and Future, December 2011.
56 S. Y. Hui, "Planar wireless charging technology for portable electronic products and Qi," Proc. IEEE, vol. 101, no. 6, pp. 1290-1301, Jun. 2013.   DOI
57 A. Kurs, A. Karalis, R. Moffatt, J. D. Joannopoulos, P. Fisher, and M. Soljacic, "Wireless power transfer via strongly coupled magnetic resonances," Science, vol. 317, no. 5834, pp. 83-86, June 2007.   DOI
58 Z. Zeng, X. Li, A. Bermak, C.-Y. Tsui, and W.-H. Ki, "A WLAN 2.4-GHz RF energy harvesting system with reconfigurable rectifier for wireless sensor network," in Proc. IEEE Int. Symp. Circuits Syst. (ISCAS), May 2016, pp. 2362-2365.
59 L. Xiao, P. Wang, D. Niyato, D. Kim, and Z. Han, "Wireless Networks with RF Energy Harvesting: A Contemporary Survey," 2014.
60 H. Liu, "Maximizing efficiency of wireless power transfer with resonant Inductive Coupling," 2011. (Available on-line at http://hxhl95.github.io/media/ib ee.pdf).
61 "FCC Codes of Regulation," http://transient.fcc.gov/oet/info/rules/.
62 H. R. Anderson, Fixed Broadband Wireless System Design, John Wiley & Sons, 2003.
63 H. T. Friis, "A note on a simple transmission formula," Proceedings IRE, vol. 34, no. 5, pp. 254-256, 1946.
64 L-G. Tran, H-K. Cha and W-T. Park, "RF power harvesting: a review on designing methodologies and applications," 2017.
65 Hemour S, Zhao Y, Lorenz CHP, Houssameddine D, Gui Y, Hu CM et al (2014) Towards low‑power high‑efficiency RF and microwave energy harvesting. IEEE Trans Microw Theory Tech 62:965-976.   DOI
66 Lorenz CHP, Hemour S, Wu K (2016) Physical mechanism and theoretical foundation of ambient RF power harvesting using zero‑bias diodes. IEEE Trans Microw Theory Tech 64:2146-2158.   DOI
67 P. Nintanavongsa, U. Muncuk, D. R. Lewis, and K. R. Chowdhury, "Design optimization and implementation for RF energy harvesting circuits," IEEE Journal on Emerging and Selected Topics in Circuits and Systems, vol. 2, no. 1, pp. 24-33, 2012.   DOI
68 J. F. Dickson, "On-chip high-voltage generation in MNOS integrated circuits using an improved voltage multiplier technique," IEEE journal of Solid-State Circuits, vol. 11, no. 3, pp. 374-378, 1976.   DOI
69 X. Shao, B. Li, N. Shahshahan, N. Goldman, T. S. Salter, and G. M. Metze, "A planner dual-band antenna design for RF energy harvesting applications," in Proc. of IEEE International Semiconductor Device Research Symposium (ISDRS), College Park, MD, Dec. 2011.
70 M. Arrawatia, M. S. Baghini, and G. Kumar, "RF energy harvesting system at 2.67 and 5.8GHz," in Proc. of IEEE Microwave Conference Proceedings (APMC), pp. 900-903, Yokohama, Dec. 2010.
71 Z. Zakaria, N. A. Zainuddin, M. Z. A. Abd Aziz, M. N. Husain, and M. A. Mutalib, "A parametric study on dual-band meander line monopole antenna for RF energy harvesting," in Proc. of IEEE International Conference on RFID-Technologies and Applications (RFID-TA), Johor Bahru, Malaysia, Sept. 2013.
72 B. Li, X. Shao, N. Shahshahan, and N. Goldsman, T. Salter, and G. M. Metze, "An antenna co-design dual band RF energy harvester," IEEE Transactions on Circuits and Systems I, vol. 60, no. 12, pp. 3256-3266, Dec. 2013.   DOI
73 Z. Zakaria, N. A. Zainuddin, M. Z. A. Abd Aziz, M. N. Husain, and M. A. Mutalib, "Dual-band monopole antenna for energy harvesting system," in Proc. of IEEE Symposium on Wireless Technology and Applications (ISWTA), Kuching, Malaysia, Sept. 2013.
74 D. Yi, and T. Arslan, "Broadband differential antenna for full-wave RF energy scavenging system," in Proc. of IEEE Antennas and Propagation Conference (LAPC), pp. 325-328, Loughborough, UK, Nov. 2013.
75 Kotani K, Sasaki A, Ito T (2009) High‑efficiency differential‑drive CMOS rectifier for UHF RFIDs. IEEE J Solid‑State Circuits 44:3011-3018.   DOI
76 J. F. Dickson, "Voltage multiplier employing clock gated transistor chain," July 22 1980. US Patent 4,214,174.
77 J. Yi, W.-H. Ki, and C.-Y. Tsui, Analysis and design strategy of UHF micropower CMOS rectifiers for micro-sensor and RFID applications," IEEE Transactions on Circuit and System I: Regular Papers, vol. 54, no. 1, pp. 153-166, 2007.   DOI
78 Facen A, Boni A (2007) CMOS power retriever for UHF RFID tags. Electron Lett 43:1424   DOI
79 Dehghani, S, Johnson, T., "A 2.4-GHz CMOS class-E synchronous rectifier". IEEE Trans. Microw. Theory Tech. 2016, 64, 1655-1666.   DOI
80 Fan, S, et al., "A 2.45 GHz Rectifier-Booster Regulator with Impedance Matching Converters for Wireless Energy Harvesting". IEEE Trans. Microw. Theory Tech. 2019, 67, 3833-3348.   DOI
81 P. Xu, D. Flandre, and D. Bol, "Analysis, Modeling, and Design of a 2.45-GHz RF Energy Harvester for SWIPT IoT Smart Sensors." IEEE J. Solid-State Circuits 2019, 54, 2717-2729.   DOI
82 C.-J. Li, and T.-C. Lee, "2.4-GHz high-efficiency adaptive power." IEEE Trans. Very Large Scale Integr. (VLSI) Syst. 2014, 22, 434-438.   DOI
83 M. Stoopman, S. Keyrouz, H. J. Visser, K. Philips, and W. A. Serdijn, "Co-design of a CMOS rectifier and small loop antenna for highly sensitive RF energy harvesters," IEEE Journal of Solid-State Circuits, vol. 49, no. 3, pp. 622-634, March 2014.   DOI
84 A. Buonanno, M. D'Urso, and D. Pavone, "An ultra wide-band system for RF Energy harvesting," in Proc. of IEEE European Conference on Antennas and Propagation (EUCAP), pp. 388-389, Rome, Italy, April 2011.
85 A. Nimo, D. Grgic, and L. M. Reindl, "Ambient electromagnetic wireless energy harvesting using multiband planar antenna," in Proc. of IEEE International Multi-Conference on Systems, Signals and Devices (SSD), Chemnitz, German, March 2012.
86 T. Umeda, H. Yoshida, S. Sekine, Y. Fujita, T. Suzuki, and S. Otaka, "A 950 MHz rectifier circuit for sensor networks with 10 m-distance," in IEEE International Solid-State Circuits Conference, 2005, Digest of Technical Papers (ISSCC), pp. 256-597, IEEE, 2005.
87 P. Saffari, A. Basaligheh, K. Moez, "An RF-to-DC recifier with high efficiency over wide input power range for RF energy harvesting applications," IEEE Trans. Circuits Syst. I, Reg. Papers, vol. 66, no. 12, pp. 4862-4875, Dec. 2019.   DOI
88 Y. Lu et al., "A wide input range dual-path CMOS rectifier for RF energy harvesting," IEEE Trans. Circuits Syst. II, Exp. Briefs, vol. 64, no. 2, pp. 166-170, Feb. 2017.   DOI
89 Z. Hameed and K. Moez, "A 3.2 V -15 dBm adaptive thresholdvoltage compensated RF energy harvester in 130 nm CMOS," IEEE Trans. Circuits Syst. I, Reg. Papers, vol. 62, no. 4, pp. 948-956, Apr. 2015.   DOI
90 Z. Hameed and K. Moez, "Hybrid forward and backward thresholdcompensated RF-DC power converter for RF energy harvesting," IEEE J. Emerg. Sel. Topics Circuit Syst., vol. 4, no. 3, pp. 335-343, Sep. 2014.   DOI
91 A. Nimo, D. Grgic, T. Ungan, and L. M. Reindl, "A new family of passive wireless RF harvesters based on R-C-Quartz oscillators," in Proc. of IEEE European Microwave Conference (EuMC), pp. 511-514, Nuremberg, German, Oct. 2013.
92 H. Lin, K.-H. Chang, and S.-C. Wong, Novel high positive and negative pumping circuits for low supply voltage," in Proceedings of the 1999 IEEE International Symposium on Circuits and Systems, vol. 1, pp. 238-241, IEEE 1999.
93 S. Agrawal, S.K. Pandey, J. Singh, and M. S. Parihar, "Realization of efficient RF energy harvesting circuits employing different matching technique," in Proc. of IEEE International Symposium on Quality Electronic Design (ISQED), pp. 754-761, Santa Clara, CA, March 2014.
94 S. B. Alam, M. S. Ullah, and S. Moury, "Design of a low power 2.45 GHz RF energy harvesting circuit for rectenna," in Proc. of IEEE International Conference on Informatics, Electronics & Vision (ICIEV), Dhaka, Bangladesh, May 2013.
95 P. Nintanavongsa, U. Muncuk, D. R. Lewis, and K. R. Chowdhury, "Design optimization and implementation for RF energy harvesting circuits," IEEE Journal on Emerging and Selected Topics in Circuits and Systems, vol. 2, no. 1, pp. 24-33, March 2012.   DOI
96 M. Roberg, T. Reveyrand, I. Ramos, E. A. Falkenstein, and Z. Popovic, "High-efficiency harmonically terminated diode and transistor rectifiers," IEEE Transactions on Microwave Theory and Techniques, vol. 60, no. 12, pp. 4043-4052, Dec. 2012.   DOI
97 T. Thierry, F. Ludivine, O. Laurent, and V. Valerie, "COTS-based modules for far-field radio frequency energy harvesting at 900MHz and 2.4GHz," in Proc. of IEEE International New Circuits and Systems Conference (NEWCAS), Paris, France, June 2013.
98 S. Scorcioni, L. Larcher, and A. Bertacchini, "Optimized CMOS RFDC converters for remote wireless powering of RFID applications," in Proc. of IEEE International Conference on RFID, pp. 47-53, Orlando, FL, April 2012.
99 M. Stoopman, S. Keyrouz, H. J. Visser, K. Philips, and W. A. Serdijn, "A self-calibrating RF energy harvester generating 1V at 26.3dBm," in Proc. of IEEE Symposium on VLSI Circuits (VLSIC), pp. 226-227, Kyoto, June 2013.
100 S. Scorcioni, L. Larcher, A. Bertacchini, L. Vincetti, and M. Maini, "An integrated RF energy harvester for UHF wireless powering applications," in Proc. of IEEE Wireless Power Transfer (WPT), pp. 92-95, Perugia, May 2013.
101 G. Papotto, F. Carrara, and G. Palmisano, "A 90-nm CMOS thresholdcompensated RF energy harvester," IEEE Journal of Solid-State Circuits, vol. 46, no. 9, pp. 1985-1997, Sept. 2011.   DOI