**Innovative Wireless Power Receiver for Inductive Coupling and Magnetic Resonance Applications**

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

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/63341

#### **Abstract**

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This chapter presents a wireless power receiver for inductive coupling and magnetic resonance applications. The active rectifier with shared delay-locked loop (DLL) is proposed to achieve the high efficiency for different operation frequencies. In the DC– DC converter, the phase-locked loop is adopted for the constant switching frequency in the process, voltage, and temperature variation to solve the efficiency reduction problem, which results in the heat problem. An automatic mode switching between pulse width modulation and pulse frequency modulation is also adopted for the high efficiency over the wide output power. This chip is implemented using 0.18 μm BCD technology with an active area of 5.0 mm × 3.5 mm. The maximum efficiency of the active rectifier is 92%, and the maximum efficiency of the DC–DC converter is 92% when the load current is 700 mA.

**Keywords:** wireless power receiver, high efficiency, active rectifier, DC–DC converter, inductive coupling, magnetic resonance

#### **1. Introduction**

In recent years, research on wireless charging system (WCS) has been actively carried out with the rapid development of smartphones and wearable devices. **Figure 1** shows the annual wireless power revenues by application. Since wireless charging techniques are applied not only for consumer electronics or mobile devices, but also for military applications and electric vehi‐ cles, the market is predicted to continue to keep expanding to over 11.8 billion dollars by 2020.

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Especially, for recent technology such as Internet of Things (IoT), The WCS is essential since sensor and communication functions need to be embedded in a single chip and energy need to be supplied simultaneously, while the user is communicating with other objects.

The remainder of this chapter is organized as follows. In **Section 2**, the WCS is described. **Section 3** provides a description of building blocks including the active rectifier, DC–DC converter, successive approximation register (SAR) ADC, and low drop out (LDO) regulator. **Section 4** shows the experimental results from the implementation of a 0.18 μm BCD, and **Section 5** concludes the chapter.

**Figure 1.** Annual wireless power revenues by application.
