1. Radar reception noise

Noise plays a very important role in radar reception, as its presence limits the ability to detect the desired signal. The purpose of this chapter is to explain the basic concepts related to this topic that are useful for radar applications.

The sources of noise in a receiver are:

• resistors that generate thermal noise;

• the active components that produce their own sounds.

All these noise sources combine in power within the receiver to form the total received noise. In practice, within a radar’s operating band, naturally occurring noise is uniformly distributed across all frequencies. The average noise power at the receiver’s output will therefore, all other things being equal, be proportional to its bandwidth.