NEC technologies as much as double communications speeds between wireless devices- Antenna reception sensitivity improved using metamaterial technologies -

*** For immediate use January 17, 2013


Tokyo, January 17, 2013 - NEC Corporation (NEC; TSE: 6701) has developed electromagnetic noise suppression technologies that improve the reception of antennas by as much as 10 times for high-speed wireless communications devices using internal printed circuit boards with NEC's independently developed artificial materials. These technologies improve the transmission performance of wireless devices and enable high-speed communications that are up to 2 times faster than that of devices without these technologies.

NEC's new electromagnetic noise suppression technology is an Electromagnetic Bandgap (EBG) structure that suppresses the electromagnetic wave transmission of particular frequencies using varieties of artificial materials (metamaterials, *1) that exhibit properties not found in nature. These properties are derived by periodically arranging certain metals.

 A newly developed   (micro) EBG structure achieves the world's smallest unit cell size, approximately 1/10 (*2) the size of existing cells, by introducing an open-stub resonator (*3) made up of spiral metal wire. As a result, EBG structure can be applied internally to circuit boards, which is difficult to accomplish with conventional technologies.

The communications performance of antennas for wireless communication devices is reduced by electromagnetic waves (electromagnetic noise) that are caused by devices on circuit boards then transmit within the circuit boards and radiate towards open space. These new technologies improve the reception sensitivity of antennas by up to 10 times more than conventional technologies by suppressing electromagnetic noise within circuit boards and preventing unnecessary emission of electromagnetic waves. As a result, transmission speeds are accelerated by as much as 2 times, enabling users to enjoy high quality video and content through high-speed wireless communications.

Key features of these new technologies include:

1. Original EBG structure with the world's smallest unit cell
   NEC developed a EBG structure featuring new unit cells that incorporate an open-stub resonator made up of spiral metal wire. As a result, the area of unit cells have been reduced by approximately 90% (2.1 x 2.1mm) to become the world's smallest of its kind when compared to existing LC resonators (*4) using unit cells with an EBG structure for suppressing electromagnetic noise in the 2.4GHz band used in WiFi. This enables the suppression of electromagnetic noise emissions through the implementation of unit cells within high density printed circuit boards, which has been difficult to perform through conventional technologies.




2. Unit cells placed near the source of electromagnetic noise and maximized transmission performance
   A high concentration of unit cells have been installed near the sources of electromagnetic noise, such as the small internal areas of printed circuit boards for devices, where it is difficult to install existing EBG structure cells. As a result, the electromagnetic noise of GHz bands that obstruct communications are reduced from within printed circuit boards, which improves the reception sensitivity of antennas by as much as 10 times and improves the transmission speed of wireless devices by as much as 2 times.




3. Reduces the electromagnetic noise of various frequency bands
   Multi-band operations are made possible by integrating multiple open-stub resonators with a unit cell in response to communication frequency bands. As a result, unit cells can flexibly support the frequencies in a variety of wireless communication standards by, for example, simultaneously reducing the electromagnetic noise in both 2.4 and 5GHz bands of WiFi.

Notes

(*1) Materials that exhibit properties not found in nature by periodically arranging artificial components. A unit cell consisting of a dielectric or a conductor features a structure with a large number of arrangements in a short period when compared to the wavelength of electromagnetic waves.

(*2) When compared to existing EBG structures using standard circuit board materials.

(*3) A resonator that is formed by the distributed constant line (stub) opened by the tip of the wire. It is possible to reduce the area of these resonators when compared to existing LC resonators because their resonance frequency can be changed in response to the length of the metal wire.

(*4) A resonator consisting of inductance and capacitance. EBG structure requires a large area since the frequency of resonance is determined in response to the area of the metal plate that forms capacitance.

NEC Press Contacts (Japan)

Takehiko Kato
NEC Corporation
+81-3-3798-6511
E-Mail:t-kato@cj.jp.nec.com

Joseph Jasper
NEC Corporation
+81-3-3798-6511
E-Mail:j-jasper@ax.jp.nec.com