Global Sources
EE Times-India
Stay in touch with EE Times India
 
EE Times-India > RF/Microwave
 
 
RF/Microwave  

Reconfigurable analogue baseband LSI targets SDR

Posted: 08 Feb 2008     Print Version  Bookmark and Share

Keywords:analog baseband LSI  software defined radio 

reconfigurable LSI

NEC Corp. and NEC Electronics Corp. today announced the successful development of a reconfigurable analogue baseband LSI for software defined radio (SDR). The LSI is capable of filtering unnecessary signals in the frequency range of 400KHz to 30MHz, allowing it to simultaneously support multiple wireless standards for existing and future mobile system standards such as mobile phone, broadcasting and WLAN systems. Boasting a small chip area of 0.57mm², the LSI can also change the type of filter depending on the wireless standard.

Conventionally, it has been difficult to incorporate SDR into mobile equipment since the existing SDR technology relied upon selective switching of transceiver devices, which resulted in a large mounting area of existing chips for each wireless standard. One of the key building blocks for our novel SDR transceivers is an analogue baseband that includes tunable filters. NEC's slim, compact analogue baseband LSI has been achieved by development of a pulse-width controlled reconfigurable filter for changing filter type and/or bandwidth.

Features
The chip responds to tuned transmissions and rejects other signals within a broad bandwidth range of 400KHz to 30MHz, allowing support of mobile, WLAN, WPAN, broadcasting and GPS standards. It also realises reconfigurability to enable several filter types, including Butterworth, Chebyshev and Elliptic. All of the filter types are achieved by a simple change in the pulse-width of the control signal, realising a small chip area of 0.57mm².

In recent years, the need for mobile terminals to support several wireless functions has been rapidly increasing with the progressive integration of information and communication devices. However, these mobile terminals need to be able to support multiple wireless standards without increasing die and/or mounting area. This need can be met by SDR transceivers as they can change the RF building-block function and receive the appropriate wireless standard signal just by a simple change in software. One of the key building blocks for SDR transceivers is an analogue baseband that enables changes in filter characteristics, such as bandwidth, and selectivity—the ability to respond to tuned transmission and reject other signals—to meet specific application requirements. However, it is difficult to realise a wide tuning range (e.g. two orders of magnitude in bandwidth) or to reconfigure selectivity, such as filter type, with conventional filter technology. Therefore, it has conventionally been necessary to arrange filter circuits side by side and switch from one to the other to achieve several types of filter characteristics in a single chip, hence the current large chip size.

NEC and NEC Electronics have been actively carrying out research and development to solve the issues of circuit size and reconfigurability. The reconfigurable analogue baseband LSI is extremely small, making it fit for use in mobile equipment, says NEC.

This research result can also be applied to a single RF chip to support any wireless standard. NEC and NEC Electronics will continue to actively pursue research and development in this area toward early realisation of multi-standard mobile equipment, essential to a ubiquitous networked society.

The results of the research were presented at the International Solid-State Circuit Conference (ISSCC) 2008 held this week.




Comment on "Reconfigurable analogue baseband LSI..."
Comments:  
*  You can enter [0] more charecters.
*Verify code:
 
 
Webinars

Seminars

Visit Asia Webinars to learn about the latest in technology and get practical design tips.

 

Go to top             Connect on Facebook      Follow us on Twitter      Follow us on Orkut

 
Back to Top