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For the first time, a wireless and chipless neuron stimulator was developed by utilizing a surface acoustic wave (SAW) delay line, a diode–capacitor interface, a sharp metal tip, and antennas for the stimulation of neurons in the brain. The SAW delay line supersedes presently existing complex wireless transmission systems composed of a few thousands of transistors, enabling the fabrication of wireless and chipless transceiver systems. The diode–capacitor interface was used to convert AC signals to DC signals and induce stimulus pulses at a sharp metal probe. A 400 MHz RF energy was wirelessly radiated from antennas and then stimulation pulses were observed at a sharp gold probe. A ∼5 m reading distance was obtained using a 1 mW power from a network analyzer. The cycles of electromagnetic (EM) radiation from an antenna were controlled by shielding the antenna with an EM absorber. Stimulation pulses with different amplitudes and durations were successfully observed at the probe. The obtained pulses were ∼0.08 mV in amplitude and 3–10 Hz in frequency. Coupling-of-mode (COM) and SPICE modeling simulations were also used to determine the optimal structural parameters for SAW delay line and the values of passive elements. On the basis of the extracted parameters, the entire system was experimentally implemented and characterized.

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In many countries, the use of the KTX high-speed rail has been generalized of late. Therefore, its customers who initially pursued only convenience and speed have begun pursuing quality services such as comfort and stability. Thus, the importance of reducing the noise in the high-speed rail is increasing. The active noise is best choice to reduce noise because of being able to actively reduce the ambient noise coming from the environmental-factor changes. But it’s too hard in a three-dimensional closed-space sound field such as the interior of a high-speed rail. In this study, we used multichannel(2x2) FXLMS algorithm for applying ANC system in KTX. In detail, after measuring the noise inside KTX during its runs in South Korea, multichannel active noise control was simulated to determine the extent to which it can reduce the noise inside KTX. Simulation was done using a multichannel FXLMS algorithm for reducing the actual noise inside KTX and the noise reduction in the open-space section of KTX was compared with that in the tunnel section, and the active-noise-control performances in the low-frequency (below 500 Hz) region were compared.

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