Oki Electric Develops Low-Noise Amplifier IC for Millimeter-Wave Wireless Communication Systems

Employs new low-cost MMIC technology with coplanar waveguide

Sample shipment will start from March 2001 and commercial shipments will begin in October 2001.

Oki Electric's IC will help to lower the equipment costs of millimeter-wave wireless communication systems, such as fixed wireless access*3 systems, ultra-high-speed wireless local area network (LAN) and intelligent transport systems (ITS). Mr. Tamotsu Kimura, general manager of Oki Electric's III-V Devices Department, Components Division says, "As a compact, high-performance, low-cost IC, it is expected to become a key component for these systems, which are being used to meet growing demands for high-speed, broadband services that exceed the capabilities of microwave and quasi-microwave systems."

The use of MMIC technology with coplanar waveguide will enable Oki Electric to lower its IC volume-production costs by about 15%. The new technology places the signal line and ground plane on a common chip surface, which eliminates the need for via holes*4 and substrate thinning. As a result, production capacity is higher than that of conventional microstrip lines*5 and costs can be reduced accordingly.

The new IC offers low noise, just 2.5 dB and 3.5 dB in the 38 GHz and 60 GHz bands, respectively, making it well suited to broadband wireless access and wireless LAN systems in Japan, North America and Europe.

Superior performance is realized by using a P-HEMT*6 structure, which is formed on a GaAs substrate. The gate electrode dimensions were reduced to 0.1 micrometer, which greatly improves gain and noise in the millimeter wave band.

Founded more than a century ago in 1881, Oki Electric Industry Co., Ltd. is Japan's first telecommunications manufacturer headquartered in Tokyo, Japan. With more than 25,000 employees worldwide, Oki Electric provides customers with top-notch products and technologies for telecommunication systems, information systems and electronic devices through its corporate slogan "Oki, Network Solutions for a Global Society." Oki's all manufacturing facilities are ISO9001 and ISO14001 certified.

Notes:

1. MMIC: Monolithic Microwave Integrated Circuit

   A microwave integrated circuit produced by simultaneously forming components, such as semiconductor devices, passive circuit devices and transmission lines, on a semiconductor substrate, such as GaAs.

2. Coplanar waveguide

   A type of transmission line for high-frequency signals, which propagates EM waves between a signal line and ground plane on a common substrate surface.

3. Fixed wireless access system

   General term for systems that use wireless transmission for access between exchanges and subscribers.

4. Via holes

   Through-holes made in a substrate to ground semiconductor devices and passive devices.

5. Microstrip line

   A type of transmission line used for high-frequency signals, which propagates EM waves between the signal line formed on the substrate surface and the ground plane formed on the other side of the substrate. Use of GaAs leads to reduction of the substrate thickness to 50 - 100 micrometers.

6. P-HEMT (Pseudomorphic High Electron Mobility Transistor)

   A field-effect transistor employing high-mobility 2D electrons, accumulated in a pseudomorphic heterojunction, as the active layer.