4.2 Receiver Architecture Basic Heterodyne Receivers Motivation:Suppress the adjacent channel interferences at a lower Q Figure 4.7.(a)Downconversion by mixing,(b)resulting spectra,(c)use of LNA to reduce noise. [View full size image] RF Mixer Input LPF IF Output Aocos OLof Local Oscillator -0n-0Lo-n+00+0n-0Lo+0n+00 -0L00+0L0 (b) LNA RF LPF F Input Output Local Oscillator (c)4.2 Receiver Architecture Basic Heterodyne Receivers ◦ Motivation: Suppress the adjacent channel interferences at a lower Q