sqx
Member level 1
By defiltration, NF = (N_noise_due_to_input + N_added)/N_due_to_input
When we talk about the noise factor of a LNA under a 50 ohm system, is the input noise regarding the thermal noise of a 50 ohm source resistor? So that the output noise due to input source is K*T*B*Gain?
But let's say we have an antenna with 50 ohm impedance, and it has a equivalent noise temperature which is different from the environment, should the noise factor change?
When we talk about the noise factor of a LNA under a 50 ohm system, is the input noise regarding the thermal noise of a 50 ohm source resistor? So that the output noise due to input source is K*T*B*Gain?
But let's say we have an antenna with 50 ohm impedance, and it has a equivalent noise temperature which is different from the environment, should the noise factor change?