21-03-2011, 11:40 AM
Sagar. Malu
Manohar. K. R
Nishanth Shetty.
Mahesh Dali
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PROJECT SYNOPSIS
Applications.
AIM AND OBJECTIVE OF PROJECT:
The main aim of the project is to design the ULTRA LOW NOISE AMLIFIER for the GSM applications. This LNA design is mainly obtained to reduce the noise figure and also used in GPS Systems.
TECHNICAL DETAILS:
TheGSM system is the most widely used cellular technology in use in the world today. It has been a particularly successful cellular phone technology for a variety of reasons including the ability to roam worldwide with the certainty of being able to be able to operate on GSM networks in exactly the same way - provided billing agreements are in place.
GSM frequency bands: GSM-900, GSM-1800 and EGSM/EGSM-900.
Pseudomorphic high electron mobility transistors (PHEMTs)are high-gain, low-noise transistors that work well with microwave signals. To understand how PHEMTs work, we have to understand how earlier types of transistors work. These include junction transistors, field effect transistors (FETs) and high electron mobility transistors (HEMTs).
In HMETs and all previous transistors, the crystal-like P-type and N-type semiconductors each have equal spacing between their atoms (which is what makes them crystal-like). The structure of PHEMTs is different, because one of the semiconductor slivers is thin enough that it stretches, "pseudomorphically", to fit the spacing of the adjacent material. This makes the transistor work even faster. All transistors work on the same principles, but their structural differences make them work faster or slower. PHEMTs are the fastest transistor, which makes them ideal for microwave applications.
FEATURES OF LNA:
*Extremely Low Noise and High Gain
*High Intercept Point
*WideDynamicRange
*Internal Regulator / Active Bias
*Reverse Voltage Protection
*Wide Operational VoltageRange
* Flange Mount Available
BENEFITS:
*Fully Characterized Assembly
*Ruggedized Assembly
*Low Cost
*Highly Reliable
*Multi-Octave Frequency Coverage
*Military Screening Available
*Superior Customer Support
APPLICATIONS:
i) Tower Mounted Amplifier and Low Noise Amplifier for GSM/TDMA/CDMA Base stations.
ii) LNA for Wireless LAN, WLL/RLL and MMDS Applications.
iii) General Purpose Discrete PHEMT for other ULTRA low noise applications.
GENRAL BLOCK DIAGRAM:
HARDWARE DESIGN SPECIFICATIONS:
0.5 dB Noise Figure
Frequency used 900MHz.
Associated gain of 20 dB.
SOFTWARE DESIGN TOOL USED:ANSOFT/ADS DESIGNER for the design of LNA.