Self-adaptive Resonator Research Articles

Self-Adaptive Resonance Technology for Wireless Power Transfer Systems to Eliminate Impedance Mismatches

Impedance mismatching can severely decrease the power transmission capacity or even invalid the control logic of wireless power transfer (WPT) systems. To eliminate the impedance mismatch caused by various factors, such as resonant parameter drift, coupling structure misalignment and control strategy, a self-adaptive mistuning correction circuit and corresponding parameter design rules are proposed to ensure the WPT system consistently operates under resonant state, accompanying the optimal power transfer ability. Moreover, a reactive compensation circuit that can create an auxiliary voltage source by the absorbed reactive power that is introduced by impedance mismatching is designed. This source can generate a new current on the coil to bring the mismatched input current back to the resonant state, according to the current superposition principle. Unlike passive impedance network that require high parameter precision and active impedance matching strategies equipped with detection and control circuits, the proposed approach can self-adaptively eliminate either undesired capacitive or inductive reactance with two additional switches and an energy-storage capacitor, improving impedance adjusting rate and providing better system robustness. The simulations and experiments are in good agreement with the theoretical analysis. This study has potential applications in harsh environments where the system impedance and coupling strength are continuously disturbed.

Resonance-Activated Spin-Flipping for Efficient Organic Ultralong Room-Temperature Phosphorescence.

Triplet-excited-state-involved photonic and electronic properties have attracted tremendous attention for next-generation technologies. To populate triplet states, facile intersystem crossing (ISC) for efficient exciton spin-flipping is crucial, but it remains challenging in organic molecules free of heavy atoms. Here, a new strategy is proposed to enhance the ISC of purely organic optoelectronic molecules using heteroatom-mediated resonance structures capable of promoting spin-flipping at large singlet-triplet splitting energies with the aid of the fluctuation of the state energy and n-orbital component upon self-adaptive resonance variation. Combined experimental and theoretical investigations confirm the key contributions of the resonance variation to the profoundly promoted spin-flipping with ISC rate up to ≈107 s-1 in the rationally designed NPX (X = O or S) resonance molecules. Importantly, efficient organic ultralong room-temperature phosphorescence (OURTP) with simultaneously elongated lifetime and improved efficiency results overcoming the intrinsic competition between the OURTP lifetime and efficiency. With the spectacular resonance-activated OURTP molecules, time-resolved and color-coded quick response code devices with multiple information encryptions are realized, demonstrating the fundamental significance of this approach in boosting ISC dynamically for advanced optoelectronic applications.

PLL-Based Self-Adaptive Resonance Tuning for a Wireless-Powered Potentiometer

In this brief, we present for the first time a wireless through-the-obstacle use of a traditional potentiometer. The importance of phase-locked-loop (PLL)-based self-adaptive resonance tuning for a wireless potentiometer is emphasized. The wireless potentiometer integrates near-field communication and wireless power transfer. In order to maintain an optimal operation when severe system detuning occurs, self-adaptive resonance tuning is employed using a wideband quadrature PLL. An experimental example is demonstrated, implying a wide range of through-the-obstacle applications.

Diode-pumped Nd:YAG self-adaptive resonator with a high-gain amplifier operating at 100 Hz

A small gain-length product as high as 5.5 is demonstrated in a diode-pumped core-doped ceramic Nd:YAG amplifier. This module allows one to realize a self-adaptive laser resonator operating at 100 Hz and delivering single longitudinal mode, 20 ns and 100 mJ laser pulses.