01-01-2013, 03:46 PM
Low-Noise Amplifier
First gain stage in receiver
Amplify weak signal
Significant impact on noise performance
Dominate input-referred noise of front end
Impedance matching
Efficient power transfer
Better noise performance
Stable circuit
LNA Design Consideration
Noise performance
Power transfer
Impedance matching
Power consumption
Bandwidth
Stability
Linearity
Power Transfer and Impedance Matching
Impedance matching
Load and source impedances conjugate pair
Real part matched to 50 ohm
S-Parameters
Parameters for two-port system analysis
Suitable for distributive elements
Inputs and outputs expressed in powers
Transmission coefficients
Reflection coefficients