Pulse Compression - MATLAB Simulations for Radar Systems Design - page 232

Pulse Compression

Chapter 5

Range resolution for a given radar can be significantly improved by using
very short pulses. Unfortunately, utilizing short pulses decreases the average
transmitted power, which can hinder the radarÓs normal modes of operation,
particularly for multi-function and surveillance radars. Since the average trans-
mitted power is directly linked to the receiver SNR, it is often desirable to
increase the pulsewidth (i.e., increase the average transmitted power) while
simultaneously maintaining adequate range resolution. This can be made pos-
sible by using pulse compression techniques. Pulse compression allows us to
achieve the average transmitted power of a relatively long pulse, while obtain-
ing the range resolution corresponding to a short pulse. In this chapter, we will
analyze analog and digital pulse compression techniques.

Two LFM pulse compression techniques are discussed in this chapter. The
first technique is known as Ðcorrelation processingÑ which is predominantly
used for narrow band and some medium band radar operations. The second
technique is called Ðstretch processingÑ and is normally used for extremely
wide band radar operations.

5.1. Time-Bandwidth Product

Consider a radar system that employs a matched filter receiver. Let the
matched filter receiver bandwidth be denoted as . Then the noise power
available within the matched filter bandwidth is given by

B

N 0
2

N i = 2 ------ B

(5.1)