No abstract

In recent years, frequency control and impedance control systems have been studied to realize efficient wireless transmission systems using magnetic resonance coupling. However, the frequency control system has a problem that the usable frequency is bounded by the Industry-Science-Medical (ISM) band, and the impedance control system has a problem that the flexibly controllable impedance converting circuits are difficult to realize. Therefore, this paper proposes an efficient wireless power transmission system which operates at fixed frequency and impedance. In the proposed system, the relative position of the transmitter to the target antenna was measured and controlled to achieve high transmission efficiency. The relative position was measured based on a novel position sensing method also using magnetic resonance coupling. As a result, the transmission efficiency increases from 45.0% to 62.4% where the target value was 70.0%, and the effectiveness of the system on improving the transmission efficiency is experimentally verified.

No abstract

This paper investigates an auxiliary management and control channel (AMCC) signal extraction method using digital signal processing (DSP) blocks with 3-step moving averaging that allows a single coherent receiver to receive main signal and AMCC signal simultaneously. Receiver sensitivity characteristics versus the modulation index (MI) and average number of the proposed DSP blocks are elucidated. Based on the results, we discuss a policy for designing the parameters. Experiments apply the design policy to achieve receiver sensitivity of –41.8 dBm with both 25 Gbit/s QPSK main signal and 128 kbit/s AMCC signal; the main signal sensitivity penalty is just 0.2 dB.