Hitachi Cable, Ltd. has announced the successful development of a compact coupler designed for the new TransferJet*1 short range and high-speed wireless transfer system. The company will launch mass production in March 2010.

TransferJet is a short range and high-speed wireless transfer technology developed and promoted by Sony Corporation. Instead of an ordinary antenna using the radiated electromagnetic wave, this technology uses a coupler, a transmitting/receiving antenna based on inductive electric wave. This system has advanteges as mentioned below; high speeds comparable to the UWB*2 (Ultra-Wide Band) system, and the simplicity of the NFC*3 (Near-Field Communication) system adopted by "FeliCa",*4 which enable users to transfer data at rates of up to 560 Mbps simply by bringing two devices with mounted couplers within 3 cm of each other. Since this technology allows quick and easy transfers of large volume data without cables, such as image, audio, and video data, it is expected to be used in various applications/future digital products, including TVs, PCs, digital cameras, and mobile phones.

To broaden its lineup of antennas for mobile equipment and expand this business segment, Hitachi Cable has concluded a license agreement for TransferJet with Sony Corporation and developed a TransferJet-compatible compact coupler.

Since 2001, Hitachi Cable has produced internal wireless-communication antennas for notebook PCs and other mobile equipments. These products have received high marks for their antenna performance and quality. As of today, the company has delivered more than 150 million antenna units for notebook PCs.

The compact coupler recently developed by Hitachi Cable consists of a radiating element that transmits and receives radio waves and a thin coaxial cable that supplies power to the radiating element. Since the coupler is designed for installation in mobile equipment, the radiating element must be quite small. However, reducing the size of the radiating element tends to narrow the frequency band and reduce antenna sensitivity.

To overcome the above-mentioned issue, Hitachi Cable drew on proprietary design technologies to determine the ideal shape of the radiating element, achieving the performance at 4.20 to 4.76 GHz necessary for data transfers at up to 560 Mbps and realizing short range wireless data transfers within 3 cm while reducing coupler thickness to 1.6 mm.

The radiating element can be constructed from standard components (e.g., double-layer printed circuit boards), making the new coupler easy to mass-produce at low cost. Hitachi Cable will launch mass production in March 2010.

Hitachi Cable plans to continue developing smaller and thinner couplers and to expand its lineup, with the goal of increasing annual sales of compact couplers to 300 million yen by fiscal 2012.

*1	TransferJet is a registered trademark of Sony Corporation.
*2	UWB (Ultra-Wide Band) refers to a wireless communication method that transmits and receives a wide frequency band of approximately 1 GHz.
*3	NFC (Near-Field Communications) refers to a near-field wireless communications technology designed for bilateral communications at transfer rates of 100 to 400 kbps over very short distances (around 10 cm).
*4	FeliCa is a registered trademark of Sony Corporation.

Specifications of the compact coupler

Item	Specification
External dimensions	20×20×1.6(mm)
	20×20×2.4(mm)
	20×20×3.2(mm)
Frequency	4.20~4.76(GHz)
Coupling strength	|S21|>-25(dB)
Flatness (when coupled)	<3.0(dB)
Non-coupling strength	|S21|<-50(dB)
Sample price	1,000 yen/unit (Min. 5 units)

External view of compact coupler

• 

TransferJet Consortium website

• http://www.transferjet.org/en/index.html