Microwave Systems Design by Zaiki Awang

Author:Zaiki Awang
Language: eng
Format: epub
Publisher: Springer Singapore, Singapore

GaAs however exhibits higher flicker (or 1/f) noise, which can hinder oscillator applications. Higher flicker noise also means that Si is more suitable for low noise operations at low frequencies.

Finally, it is important to note that GaAs is not used in MOS-based circuits. The MOSFET is one example of such circuit. CMOS technology, which is popular in microprocessor applications, is based on MOSFET. The MOS field effect transistor requires a native oxide layer to operate. The high density states which exist at the GaAs-oxide interface in a native GaAs oxide hinder useful MOSFET operation. Si, on the other hand, has native oxide which is useful for MOSFETs—this explains the popularity of Si for low frequency, digital IC applications.

Recently, SiGe-based devices are also making an impact. SiGe devices employ processing technologies that are compatible to the highly mature Si processes. These facilitate mass production, leading to devices that are both cheaper and more reliable.

The advantages of Si are matured technology, which leads to lower cost, higher thermal conductivity, and lower 1/f noise. Si technology is established and its processing characteristics are well understood due to the fact that the integrated circuit industry is mostly driven by Si-based computer memory and microprocessor applications. As such there is significant advantage to be reaped if better higher frequency performance is obtained from Si-based devices—this explains the huge interest shown in SiGe lately. It also makes sense, both economically and technologically, to explore Si technology with the increasing merger of analog and digital design techniques in wireless applications.

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.