TI Develops SiGe Process

Texas Instrumentst to expand its presence in the wireless market, Dallas-based <%=company%> (TI) has unleashed a bipolar CMOS (Bi-CMOS) process incorporating silicon-germanium (SiGe) technology. According to the company, the new process, called RFSiGe1, will be used during the development of RF solutions for current and next-generation wireless applications.

TI's new SiGe process technology allows designers to easily accomplish their cellular, PCS and ISM band designs as the process achieves peak f_T, (maximum unity power gain frequency) greater than 50 GHz, by employing a TI proprietary SiGe bipolar device. However, in wireless applications, optimum f_T is just 25 GHz (ten times the highest operating frequency). At this level, TI's process requires less than 20 µA to achieve an f_T of 25 GHz.

Additionally, the TI SiGe process offers good sensitivity requirements, achieving a minimum noise figure below 0.5 dB at 2 GHz. By providing these noise figures, Sam Pritchett, RF strategic marketing manager, says the SiGe process is a good replacement for traditional GaAs approached, which have been often used in wireless applications.

Linearity is also a key to TI's new process. Pritchett says the new process allows TI to develop highly linear RF components. By doing this, he says TI can develop RF products that process complex radio signals, such as those employed in 3G systems, without creating spurious signals.

Passive integration provides yet another benefit to TI's new process. As wireless designers well know, passive components are a big obstacle in increasing integration in the RF front end of a system design. Through the new SiGe process, Pritchett says TI can develop RF solutions that integrate four times the resistors, three times the capacitors, and two times the inductors. This level of integration will allow TI to produce RF solutions that reduce the PCB space.

TI's initial SiGe process features a bipolar emitter width of 0.25 µm. It also achieves +3 VDC CMOS with 0.35 µm drawn transistor gate-lengths..

TI expects to develop transmit and receive synthesizers, small signal chips, Bluetooth products, and other RF solutions using its SiGe process. Products using the 0.35 µm process, are in development with volume shipments scheduled for the third quarter of 2000. For more information, contact TI at 800-477-8924, ext. 4500.

Edited by Robert Keenan