Wireless power transmission based on directional coupler or directional filter

Awai, Ikuo; Hori, Kunihito; Yakuno, Shigeo; Kazuki, Namikoshi

doi:10.1109/mwsym.2010.5515625

Cited by 3 publications

(2 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Another 1D power transmission system using a microstrip line (MSL) as the waveguide has been proposed by Awai et al [5]. In our system, the electromagnetic (EM) field leakage outside the waveguide is reduced significantly less than that of MSL.…”

Section: Introductionmentioning

confidence: 96%

One-dimensional proximity power transmission using ribbon-like waveguide and bar-type high-Q resonant receiver coupler

Noda

Shinoda

2011

2011 IEEE MTT-S International Microwave Workshop Series on Innovative Wireless Power Transmission: Technologies, Systems, and A

View full text Add to dashboard Cite

In this paper we propose a proximity power transmission system using one-dimensional (1D) thin waveguide. In the system the receiver device can extract microwave power from the ribbon waveguide through a bar-type coupler that resonate with high quality factor (high-Q). Due to the high-Q requirement, the system enables selective power transmission to the special receiver and prevents other objects from absorbing power. Due to the narrow geometry, the receiver coupler can be embedded onto the edge of electronic device where embedding a conventional planar coil receiver is difficult. Besides, the node position of the standing wave inside the 1D waveguide can be easily controlled. We demonstrate the power transmission to the thin receiver (8 × 3 × 60 mm 3 ) on the 10-mm wide waveguide can be stabilized regardless to the receiver position by using a reflection phase shifter. The measured transmittance is −10.9 dB. We also fabricated smaller coupler (5 × 2 × 60 mm 3 ) and its rectified output lighted up an LED under 500-mW input into the waveguide.

show abstract

Section: Introductionmentioning

confidence: 96%

One-dimensional proximity power transmission using ribbon-like waveguide and bar-type high-Q resonant receiver coupler

Noda

Shinoda

2011

2011 IEEE MTT-S International Microwave Workshop Series on Innovative Wireless Power Transmission: Technologies, Systems, and A

View full text Add to dashboard Cite

show abstract

“…Non-contact power transfer is desirable for safety and maintenance. A hybrid coupler approach [13] and overlay microstrip resonators [14] have been proposed for this application. This paper presents a power rail application and its principle for contactless power transfer.…”

Section: ⅰ Introductionmentioning

confidence: 99%

Wireless Power Transfer System

Arai¹

2011

Journal of electromagnetic engineering and science

View full text Add to dashboard Cite

This paper presents a survey of recent wireless power transfer systems. The issue of wireless power transfer is to achieve a highly efficient system with small positioning errors of the facilities setting. Several theories have been presented to obtain precise system design. This paper presents a summary of design theory for short range power transfer systems and detailed formulations based on a circuit model and an array of infinitesimal dipoles. In addition to these theories, this paper introduces a coil array scheme for improving the efficiency for off axis coils. In the microwave range, tightly coupled resonators provide a highly efficient power transfer system. This paper present sanoverlay resonator array consisting of half wavelength microstrip line resonators on the substrate with electromagnetically coupled parasitic elements placed above the bottom resonators. The tight couplings between the waveguide and the load resonator give strong power transmission and achieve a highly efficient system, and enables a contact-less power transfer railroad. Its basic theory and a demonstration of a toy vehicle operating with this system are presented. In the last topic of this paper, harmonic suppression from the rectenna is discussed with respect to acircular microstrip antenna with slits and stubs. Ⅰ. IntroductionSeveral solutions have been proposed for wireless power transfer using electromagnetic (EM) waves. For example, Felica utilizes electromagnetically inductive coils [1] over a very short distance. One of the hottest issues is non-radiative mid-range energy transfer [2]. This has weak tolerance for positioning and the coverage area is limited near the coil, however, it is a good candidate for high power transfer for fixed to fixed point applications. After its demonstration by the MIT group, many researchers carried out further studies and presented design methods. This is sometimes referred toas "magnetic field resonance"; however, it is simply understood as the strong coupling between two resonators. Its transfer efficiencydepends heavily on the distance between coils and is around 90 % at 1 m and 40 % at 2 m [2]. Although substantial electric power transmission is expected to charge an electric vehicle, a standard of small power less than 5 W was provided by the consortium [3]. In order to charge mobile devices, the detection of the device position is a key issue. The movement of coupling coils and the coil array are major schemes for free positioning of the device to be charged. Several applications using these methods are already on the market as cell phone chargers.A basic theory for coil coupling is given by circuit theory [2], [4], and is also explained by a filter theory [5] and others. This paper presents a simple circuit theory based one lectromagnetism to find the coupling efficiency between coils. In practical power transfer applications, the efficiency is a very important factor. To improve the transfer efficiency, an parameter optimization of the coil [6] and a coil array approach ha...

show abstract