Tokyo, December 7, 2000---Fujitsu Laboratories Ltd. and Fujitsu Media Devices Limited announced today that they have successfully developed a compact SAW filter ideal for high-speed mobile and wireless access communications using the 5GHz band. This accomplishment paves the way for the commercial introduction of a 5GHz SAW filter. Fujitsu Media Devices plans to start sample shipments of the newly developed filter - which is expected to have a package size less than 2.5 x 2.0 x 1.0mm - in December 2001 and commence volume production in the spring of 2002.
Fujitsu will present details of its new SAW filter development at MWE 2000, being held in Yokohama December 12 - 14, 2000.
Background
SAW filters, small components that eliminate extraneous noise and ensure a clear signal, have played an important role in making possible dramatically smaller and lighter cellular phones. A mobile phone now contains four or five SAW filters on average. Today's mobile phones are getting even smaller and offering higher performance, and this requires SAW filters able to handle higher frequencies. The Fujitsu group already offers several highly regarded SAW filters for 800MHz and for 1.9GHz with CDMA/TDMA (*1) applications, as well as for 2.4GHz wireless LAN systems. They feature low insertion loss and greatly improve the quality of audio signals for small, lightweight cellular phones. Now, the use of high-speed wide-band 5GHz is being considered for fourth-generation mobile phone systems and future wireless LAN systems (*2), and this has triggered a global development competition.
Development Details
In order to handle higher frequencies, a SAW filter's inter-digital transducers (IDT) must have smaller periods. For 5GHz SAW filters, pattern width and gap width must each be 0.2 micron. Combining Electron Beam Lithography and Reactive Ion Etching techniques, Fujitsu developed a 0.2-micron rule fine pattern fabrication process. This, together with the use its proprietary ladder-type design, enabled Fujitsu to succeed in developing the world's first practical-level low-loss, wide-band 5GHz SAW filter.
Device Features
- Employs original design and process technologies: fabrication process for IDT patterning of 0.2-micron rule and ladder type design make device able to handle high frequencies.
- Small and lightweight: surface mount package is smaller than 2.5 x 2.0 x 1.0mm
- High frequency, low loss, wide band:
| Center frequency: | 5 - 5.8 GHz |
| Pass band width: | 100 - 200 MHz (fractional bandwidth 2 - 4 %) |
| Minimum insertion loss: | less than 3dB |
| Stop band attenuation: | over 25dB |
AI electrode pattern for 5GHz filter
Notes:
SAW: Surface Acoustic Wave
(1*) CDMA (Code Division Multiple Access): A format for digital communication that simultaneously sends and receives data. It allows multiple access and protects confidentiality by making signals into codes. TDMA (Time Division Multiple Access): A format for digital communication that alternately sends and receives data (time division). It can flexibly cope with changes in data volume.
(2*) 5GHz band for wireless LAN systems is going to a global standard, but the frequency band and bandwidth for fourth-generation mobile phone systems are not yet decided.
* All company/product names mentioned may be trademarks or registered trademarks of their respective holders and are used for identification purpose only.
Corporate Information
Fujitsu Limited
Fujitsu Limited (TSE: 6702) is a leading provider of Internet-based information technology solutions for the global marketplace. Comprising over 500 group companies and affiliates worldwide -- including ICL, Amdahl and DMR Consulting -- it had consolidated revenues of 5.26 trillion yen ($49.6 billion) in the fiscal year ended March 31, 2000. Fujitsu's pace-setting technologies, world-class computing and telecommunications platforms, and global corps of over 60,000 systems and services experts make it uniquely positioned to unleash the infinite possibilities of the Internet to help its customers succeed. Altogether, the Fujitsu Group has 188,000 employees and operations in over 100 countries.
Internet: http://www.fujitsu.com/
Fujitsu Laboratories Ltd.
Founded in 1968 as a wholly owned subsidiary of Fujitsu Limited, Fujitsu Laboratories Limited is one of the premier research centers in the world. With eight laboratories in Japan, one in China and one in the United States, the organization conducts a wide range of basic and applied research in the areas of Multimedia, Personal Systems, Networks, Peripherals, Advanced Materials and Electronic Devices.
Fujitsu Media Devices Limited
Fujitsu Media Devices Limited was established in 1998 to provide an array of multimedia solutions. The company resulted from the merger of Fujitsu's electronic components group, which specialized in SAW filters for multimedia equipment, PC card modules, and Fujitsu Towa Electron, which focused on high-frequency devices, capacitors, and advanced functional modules. The company's goal is to deliver the industry's most reliable and imaginative solutions by innovating state-of-the-art technologies, supported by superior service.