Announcing the Development of the Field-Coupled Wireless Power Transmission System

The cellular phone jacket and the charge stand are not approved by the MFI Product plan (Be applying).


Murata Manufacturing Co., Ltd. has developed a field-coupled type* of power transmission system capable of supplying power to devices wirelessly. Use of this system makes it possible for the devices to be charged simply by placing them on the charger without the aid of power cords or other physical connections. The system is highly efficient and features a high level of positional freedom, making it extremely useful and convenient.


As mobile devices have continued to proliferate, wireless power transmission systems have been the focus of many development projects of late. However, one issue with the electromagnetic induction system that is the subject of many such projects is the fact that charging is not possible unless the device concerned is placed exactly at the charging point. Murata Manufacturing teamed up with TMMS Co., Ltd. (Technology Marketing & Management Solutions), which has its own field-coupled wireless power transmission technology, and utilized this technology to jointly develop a wireless power transmission system. With the use of this system, devices can be charged without having to be concerned about the location of the charging point.

By providing a means of wireless power transmission whose demand will only increase in the future, Murata Manufacturing hopes to pave the way toward a world in which power cords will no longer be necessary.


*Field-coupled system The field-coupled system is a method that involves positioning electrodes at the power-sending and power-receiving ends and transmitting energy using the electrical fields generated between these electrodes. Since a capacitance is generated between the electrodes, it is also called a capacitive coupling system.


By adding Murata Manufacturings circuit design technology to the power transmission technology of TMMS, introducing some innovations into the electrode structure wireless power transmission with a high level of positional freedom and excellent efficiency was achieved.

  • Charging of multiple types of electronic devices using a single charging stand enabled
  • A highly reliable system achieved by Muratas unique safety control methods
  • Reduced impact on the devices since minimal heat is generated by the transmission part
  • Charging of devices on the move also possible owing to high level of positional freedom
  • Easy incorporation into devices is possible since the electrode parts serving as the interface of the power transmission can be formed extremely thin
  • Many different materials such as transparent and flexible resins can be used for the charging stands, , enabling creation of highly attractive designs


Cell phones, mobile music players, digital still cameras, notebook PCs and other mobile devices, lighting fixtures, decorations, housing equipment and other related products

  • By incorporating the chargers into an office desk, the desk will become a smart desk capable of charging notebook PCs, cell phones, digital still cameras and other such devices simply by placing them on the desk.
  • By incorporating the system throughout transportation and accommodation facilities, an environment will be created wherein devices can be charged anywhere and without AC adaptors.

Part Number


Electrical Characteristics

Transmitted power 1-10W
Transmitting efficiency More than 90% by wireless transmission part alone

External Size

Power-sending module: 50 x 25 x10 mm (target size for 3W models)
Power-receiving module: 10 x 10 x 1.5 mm (target size for 3W models)


Start of mass production targeted for 2011

Monthly production to start with 10,000 units

Sample Prices

To be determined for individual orders; mass production target price of 980 yen for power-sending module and power-receiving module together (for orders received when the monthly production runs to 100,000 units)


10 patents pending relating to the transmission method

Concerning TMMS

Company name: TMMS Co., Ltd.
Established: October 3, 2006
Head office: 22 Kamaza-cho, Nakagyo-ku, Kyoto
Director: Stephane Vogley
Main lines of business: Technical development and support, market development and support