23 February 2012
SiGe:C heterojunction bipolar transistor
Renesas Electronics has announced the availability of a new SiGe:C heterojunction bipolar transistor, the NESG7030M04, for use as a low noise amplifier transistor for wireless LAN systems, satellite radios, and similar applications.
This device uses a process that adopts newly developed silicon germanium: carbon (SiGe:C) materials and is said to achieve industry leading low noise performance.
The new SiGe:C HBT is a transistor that amplifies a weak microwave signal received wirelessly to an appropriate level and achieves a noise figure of 0.75dB, which Renesas says is the industry's top level for the 5.8GHz band used by wireless LANs and other applications. The fact that it amplifies with such low noise means that it can increase communication sensitivity in end products. Since it can reduce signal transmission errors, it can achieve operating power consumption as low as one quarter of that of Renesas' existing products while maintaining equivalent performance.
By applying this newly developed SiGe:C process, Renesas' 5.8GHz band SiGe:C HBT and SiGe HBT devices are said to achieve the industry's lowest noise level of 0.75dB. This is an improvement of 0.35dB over earlier Renesas SiGe HBT devices. Also, this device achieves a gain at the minimum noise level of 14dB. This allows communication sensitivity to be increased and signal transmission errors to be reduced, and the new device can achieve equivalent performance to earlier Renesas products at 1/4 of the power consumption.
In earlier silicon based heterojunction bipolar transistors, it was not possible to avoid a reduction in the collector emitter withstand voltage in exchange for reducing noise and this limited the range of applications for which these devices could be used. In this new product, Renesas has optimised the collector base profile, making it possible to guarantee a withstand voltage rating of 4.3V. This increases the range of supply voltages that can be used and enables stable operation over a wide frequency range, from a few MHz to the 14GHz band. This makes it possible to use this device in a wider range of applications. For example, it can support all ISM band applications, including smart grid, smart meter, and home area network (HAN) applications.
Since this transistor was developed for microwave applications, Renesas provides it in an industry standard 4pin thin form mini-moulded package (for which the Renesas package name is M04). As a result, Renesas says the product can contribute to a reduction in manufacturing steps in end user products. Examples include simplifying the mounting evaluation process due to the track record of existing packages; and using an existing circuit board pattern and slightly modifying the surrounding circuits.
At the same time as expanding its product line of bipolar transistors with the industry's best low noise performance by taking advantage of this new process, Renesas is also committed to deploying this new process in the development of microwave ICs and providing further solutions in this area to respond to market needs.