Example 4.7. An engineer is to design a receiver for space applications with no concern for interferers.The engineer constructs the heterodyne front end shown in Fig.4.15(a),avoiding band-select and image-select filters.Explain why this design suffers from a relatively high noise figure. Figure 4.15.(a)Receiver for space applications,(b)effect of noise in image band. Thermal Noise LNA 20in-(LO 0L0 ODin 0 ⊙n ①L0 (gF ① ( (b)