PLL-Based Contactless Energy Transfer Analog FSK Demodulator Using High-Efficiency Rectifier

Abstract

This paper proposes a new phase-locked-loop (PLL)-based inductive coupled contactless energy transfer (CET) analog frequency-shift keying (FSK) demodulator using a high-efficiency RF-to-dc rectifier for biomedical implanted devices. The analog FSK demodulator is composed of a modified CMOS three-stage rectifier, a voltage regulator, an FSK signal generator, and a PLL. The proposed modified single-stage rectifier with both positive and negative output voltages using a PMOS and an NMOS pass transistor, an inverter, and two capacitors has a small active area and can enhance the power conversion efficiency. The proposed RF-to-dc rectifier achieves an efficiency of 64% at 8.4 dBm. The power consumption of the demodulator is as low as 0.76 mW, and the active area is 0.084 mm 2 . The analog FSK demodulator supports a data rate of 100 kb/s to 1 Mb/s. The chip was implemented in a Taiwan Semiconductor Manufacturing Company (TSMC) 0.35-μm double-poly quadruple-metal CMOS technology to verify the proposed CET circuit. Two figures of merit are provided to illustrate the advantages of the proposed architecture. Index Terms-Contactless energy transfer (CET), frequencyshift keying (FSK) demodulator, phase-locked loop (PLL), power conversion efficiency, rectifier.

New Resonant Inverter Tuning for Three-Phase Current Source Parallel Resonant Inverters

“…Regarding Figure 10 and Figure 11, the DC-link ripples are more affected by the voltage stress for a specific quality factor and frequency deviation. Forlow quality factors, the system approximately works like a balanced threephase system because the phase deviations are negligible, see Figure 8(b) and equation set (10). However, the switching frequency should be equal to the average value of the resonant frequencies to minimize the switching losses, negative sequences and DC-link current ripples.…”

“…Three-phase resonant inverters are widely used in industrial applications. Such applications include high power DC-DC converters, contact-less power transfer systems and multi-phase induction heating systems [1][2][3][4][5][6][7][8][9][10][11][12][13].…”

Three-Phase PLLs: A Review of Recent Advances

“…The advent of the phase-locked loop (PLL) dates back to 1930s when it was first designed and used for the synchronous reception of radio signals [1]. Since then, it has found widespread applications in different areas, such as the estimation of fundamental parameters (phase, frequency, and amplitude) of power signals [2]- [83], measurement of harmonics, interharmonics and power quality indices [84]- [90], implementing adaptive filters and robust controllers [91]- [93], control of AC and DC machines [94], [95], contactless energy transfer systems [96], [97], induction heating systems [98], [99], piezoelectric applications [100], [101], battery charge circuits [102], [103], magnetic encoders [104], islanding detection of microgrids [105]- [107], welding industry [108], grid fault and voltage sag detection [109], [110], synchronization of power quality instruments [111], [112], computation of synchrophasors [113], [114], etc. Fig.…”

RF‐DC converter for HF RFID sensing applications powered by a near‐field loop antenna

“…Several RF‐DC converters operating at 13.56 MHz were presented in literature. In Xiao et al [] and Hwang et al [], for instance, high‐efficiency RF‐DC converters are described, exhibiting −4 dBm and 1.2 dBm sensitivity, respectively. In Hwang et al [], a RF‐DC converter exploiting a reducing reverse loss current technique is proposed.…”