Design and Optimisation of Low Noise Amplifier in Superhetrodyne GPS Receiver Front End
Shafqat Hameed1, Umar F. Khan2
1National University of Sciences and Technology(NUST), Islamabad, Pakistan
2University of Bradford, Bradford, UK
Abstract: The Global Positioning System (GPS) as it was developed for military purposes originally by the USA has become the most valuable tool for military purposes today. GPS can be used for different applications such as military, science, sports, transportation and many more. Each particular application needs a specific performance from GPS receiver. In this report the architecture of the Superhetrodyne GPS receiver front end will be discussed. The receiver includes all analogue signal paths including Low Noise Amplifier, Radio Frequency Filter, Mixer, Local Oscillator and IF Filter. Specific attention will be paid to the Low Noise Amplifier (LNA). The design issues related to LNA will be discussed as well. These issues include gain, noise figure and linearity. The discussion also includes the technological constraints for design of LNA. What particular technology is going to be used for this design? Normally LNA is designed using discrete elements, but for this particular application enhancement mode (pHEMPT) technology is used.
[Shafqat Hameed, Umar F. Khan. Design and Optimisation of Low Noise Amplifier in Superhetrodyne GPS Receiver Front End. Life Sci J 2012;9(1):689-694] (ISSN:1097-8135). http://www.lifesciencesite.com. 99
Keywords: GPS, Signal, Satellites, applications, frequency, Technology Full Text 99