Strong resonant coupling for short-range wireless power transfer applications using defected ground structures

Abstract

This paper presents a new structure for highly efficient short-range wireless power transfer. The proposed structure is based on strongly coupled resonators using H-slot defected ground structures. An equivalent circuit model for Hslot coupled resonators is introduced. Measurement results for the new proposed structure show a power transfer efficiency of 70% at 15 mm distance between driver and load resonators. Experimental measurements have shown good agreement with electromagnetic and circuit simulations.

Asymmetric wireless power transfer systems using coupled DGS resonators

“…First, reasons for low power transfer distance was investigated and spiral strips DGS was proposed in this letter to mitigate the problems in H-shape DGS resonators that encountered in [1,2]. Fig.…”

“…1(a) illustrates the H-shape DGS and its modified versions (the semi H-shape, and the spiral-strips DGS) and EM simulated current elongated path, where there are two parallel current paths in H-shape DGS. This causes the low self-inductance of the resonator which results in the lower efficiency at a larger distance [1,2]. First, this problem is overcome by constructing a single current path only like in a semi H-shape DGS resonator and the value of inductance is further improved as in spiral-strips DGS resonator.…”

“…These parameters include the track width (W t,i ) and separation (s i ), and the number of turns (N i ) to realize a high unloaded Q-factor. To overcome these problems, the authors of this letter have proposed quasi-lumped elements based on defected ground structures (DGS) for wireless power transfer for the first time in [1,2]. Etching a DGS on the opposite side of a microstrip feeding line realizes a bandstop filter (BPF) characteristics [5,6,7,8].…”

“…Also, the DGSs exhibit a bandpass filter (BPF) characteristics by introducing a discontinuity in the feeding microstrip line above the DGS's slots and adding some stubs for matching [9,10]. In the same manner, when two DGS resonators are coupled back to back, it results in a bandpass characteristic, and power is transferred from the source to load through the DGS resonators [1,2]. In our proposed DGS-WPT system, we use electrical coupling for feeding.…”

“…The proposed spiral-strips DGS resonator overcome the problem of low self-inductance that encountered by H-shape DGS resonator in [1,2], so that the proposed WPT system that employs the proposed spiral-strips DGS resonators has better efficiency and higher power transmission distance. Design methodology of the proposed WPT system are formulated and fabricated.…”