**Author details**

When the output of the rectifier increases above 5.2 V, the active rectifier also begins to operate

As can be seen from the simulation results, with 7.5 W input and 13.83 Ω output load, a maximum power of 6.9 W and an efficiency of 92% were achieved at the maximum efficiency

**Figure 17b** shows the simulation waveform of WPR in WPC mode. WPR is supplied by VAC power, UVLO increases, detecting mode during mode select time. The frequency of VAC is 175 kHz, WPC mode is selected to send not only configuration packets but also error control

The measurement board for the WPR is illustrated in **Figure 18a**. The Tx coil and Rx coil were located at the bottom and top sides, respectively. The power was transferred from the WPT

**Figure 18b** shows the measured system efficiency of the proposed WPR. The maximum system

The comparison between the reported-related WPRs, and this work is summarized in **Table 2**. As can be seen from **Table 2**, the proposed WPR is the only chip that supports three different types of standards, namely A4WP, WPC, and PMA and shows the highest overall efficiency. Moreover, the results show that the proposed WPR has a wider input voltage range than the

This chapter presents a WPR for inductive coupling and magnetic resonance applications. Especially for the rectifier, which consumes the most significant portion of overall efficiency,

without any help from the passive diode [5].

82 Wireless Power Transfer - Fundamentals and Technologies

board to the WPR board through the Tx and Rx antenna.

efficiencies are 84 and 86% in A4WP and WPC/PMA modes, respectively.

**Figure 18.** (a) Measurement board and (b) measured system efficiency of the WPR.

other references [2, 9, 16, 17], which is from 3 to 20 V.

**5. Conclusion**

condition when DLL was locked.

packets.

Young-Jun Park, Hongjin Kim, Hyung-Gu Park and Kang-Yoon Lee\*

\*Address all correspondence to: klee@skku.edu

College of Information and Communication Engineering, Sungkyunkwan University, Suwon, South Korea

#### **References**


[13] Siamak Bastami, "Magnetic Induction or Magnetic Resonance for Wireless Charging?" Bodo's Power systems, pp. 22–26, January 2013.

**References**

[1] Wireless Power Consortium, "System Description Wireless Power Transfer", Volume

[2] Jun-Han Choi et al., "A Resonant Regulating Rectifier (3R) Operating at 6.78MHz for a 6 W Wireless Charger with 86% Efficiency", Solid-State Circuits Conference Digest

[3] Ryota Shinoda et al., "Voltage-boosting wireless power delivery system with fast load tracker by ΔΣ-modulated sub-harmonic resonant switching", Solid-State Circuits

[4] Ricky Tseng et al., "Introduction to the alliance for wireless power loosely-coupled wireless power transfer system specification version 1.0", Wireless Power Transfer

[5] Hyung-Gu Park et al. "A Design of a Wireless Power Receiving Unit With a High-Efficiency 6.78-MHz Active Rectifier Using Shared DLLs for Magnetic-Resonant A4 WP Applications", IEEE Transactions on Power Electronics, Vol. 31, No. 6, pp. 4484–

[6] Yeon-Kug Moon et al., "Wide input range, high-efficiency magnetic resonant wireless power receiver," International Journal of Electronics, Vol. 102, No. 2, pp. 326–344, 2015.

[7] Yat-Hei Lam et al., "Integrated Low-Loss CMOS Active Rectifier for Wirelessly Powered Devices", IEEE Transactions on Circuits and Systems II: Express Briefs, Vol.

[8] Ji-Hun Kang et al., "A design of wide input range, high efficiency rectifier for mobile wireless charging receiver", Wireless Power Transfer Conference (WPTC), 2014 IEEE,

[9] Young-Jin Moon et al., "A 3.0-W wireless power receiver circuit with 75-% overall efficiency", Solid State Circuits Conference (A-SSCC), 2012 IEEE Asian, pp. 97–100,

[10] Yan Lu et al., "A 13.56 MHz CMOS Active Rectifier With Switched-Offset and Com‐ pensated Biasing for Biomedical Wireless Power Transfer Systems", IEEE Transactions

[11] Christian Peters et al., "A CMOS integrated voltage and power efficient AC/DC converter for energy harvesting applications", Journal of Micromechanics and Micro

[12] Song Guo et al., "An Efficiency-Enhanced CMOS Rectifier With Unbalanced-Biased Comparators for Transcutaneous-Powered High-Current Implants", IEEE Journal of

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84 Wireless Power Transfer - Fundamentals and Technologies

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pp. 154–157, 2014.

2012.

4498, 2016.


**Section 2**

**New Technologies**
