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International Journal of Scientific and Engineering Research
ISSN Online 2229-5518
ISSN Print: 2229-5518 7    
Website: http://www.ijser.org
scirp IJSER >> Volume 3,Issue 7,July 2012
Efficient Wideband High Gain Low Noise Amplifier in Modern Radars[
Full Text(PDF, )  PP.1-6  
Author(s)
Alaa El-Din Sayed Hafez, Mohamed Abd El-latif Mowad
KEYWORDS
Pseudomorphic High Electron Mobility Transistor (PHMET), Low Noise Amplifier (LNA), Cascaded Amplifiers, Noise figure (N.F).Radar receiver
ABSTRACT
In this paper a wideband single stage pseudomorphic high electron mobility transistor (PHMET) amplifier has been designed at 5.8 GHz, the input and output matching circuits have a pi form.Noise cancelling principle and sensitivity analysis are performed .Simulation results have been compared with their correspondence in [I0] give 2.71 dB improvement in amplifier gain at the same noise figure (N.F) and input, output returns loss. A new optimized low noise amplifier (LNA) using PHEMT at 3 GHZ have been designed to achieve an improvements of 3.3 dB in amplifier gain and 1.81 dB in noise figure.Also the two stages (common gate in cascaded with common source) LNA have been analyzed and optimized for (1-16) GHz full band application to achieve maximum gain over a wide frequency band. Simulation results carried out sever improvement in amplifier gain over the results obtained for the two structures in [16-17] respectively with no change in N.F value .The improvement in optimized gain for the first and second structures are (3.278, 2.82) dB. The comparative study between the traditional and optimized structures showing a superior performance of LNA making them sutiable to be used in modern radar systems.
References
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