Impact of Noise Bandwidth on Noise Figure

Noise figures (NFs) are defined at each frequency of interest over a 1-Hz bandwidth. Their measurements are often performed over bandwidths of a few kilohertzs to a few megahertzs to accelerate the process and to reduce measurement jitter. These wider bandwidths introduce NF errors that can be substantial [>1 dB measured for a 0.4-dB NF low-noise amplifier] if the measurement equipment exhibits propagation delays as demonstrated in this paper. Similarly, propagation delays affect receiver noise and can cause inaccuracies in receiver sensitivity estimates.