© grzegorz kula Components | March 29, 2013

Direct current resonance method wireless power transmission system

Murata Manufacturing Co., Ltd. has developed a "direct current resonance" method as a new wireless power transmission system technology.
The direct current resonance method is a new technology that converts direct current electric energy into electromagnetic field energy and uses a newly discovered physical phenomenon called an electromagnetic resonance field to transmit power. The technology can enhance energy conversion efficiency because a resonance field is formed directly from the direct current power source. It can also reduce the number of times power is converted in the power transmission system and achieve greater simplicity and power efficiency. In addition, expanding resonance fields could extend applications to a variety of usage scenarios.

The direct current resonance method is an amalgamation of several technologies that Murata has fostered over the years, including power storage device technology, wireless transmission technology, power module technology to enhance power conversion efficiency, and EMI technology. Going forward, Murata aims to create new value in the electronics field by proposing solutions and developing products with value. These will be tailored to a variety of usage scenarios and applications and will be perfected by listening closely to the opinions of our customers and related industries.

Development background

Murata conducted pioneering research on the use of the "magnetic field resonance" method, which the company presented at an international academic conference in 1994. Based on this, Murata began further research in an industry/academic partnership with Doshisha University in 2009, using the newly discovered physical phenomenon of the "electromagnetic resonance field" to develop a direct current resonance method wireless power transmission system. Going forward, Murata will conduct full-fledged development to create practical uses and commercialize the results.

Major features (comparison with existing magnetic field resonance method)
  • This is a wireless power transmission system from a direct current power source: Most of the power that people use is direct current (DC). Even commercial alternating current (AC) is converted to direct current, and nearly every electronic device runs on direct current voltage. Therefore converting energy from a direct current power source can enhance efficiency.
  • The technology directly converts between electric energy and electromagnetic field energy: The goal is to require only one direct power conversion when transmitting power wirelessly, as opposed to the four to six repetitions required up to now. This allows overwhelming energy savings and creates a big advantage in terms of compactness and lightness.
  • The technology expands the resonance field to transmit power:Innovations in transmitting and receiving devices and resonance devices can expand the resonance field and create new possibilities, such as supplying power to multiple loads. This should lead to technical applications and product development for various usage scenarios.


Murata’s objective is to get the technology into use in fields where a wireless arrangement is of high value. These are not limited to supplying power to such mobile devices as smartphones and tablets. They could also include small battery-operated electronic devices and communications cards.

Murata will develop the technology primarily for applications requiring relatively small amounts of power. For applications requiring relatively large amounts of power, such as electric vehicle recharging, Murata will also consider the use of arrangements like open innovation as well as technical support and licensing.

Murata will continue its research and development and promote the results of these efforts as we seek to contribute to the development of wireless power transmission system science/technology and industry. In the field of energy, which is one of Murata’s key focus areas, we will endeavor to create new markets and expand into new products.
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December 13 2018 1:08 pm V11.10.14-2