A theoretical analysis of superheterodyne design principles has been presented with emphasis on noise figure, selectivity trade-off, spurious response, and image phasing mixers. Magnetically tunable filters have been examined on a theoretical and practical basis. Problems associated with uhf micro-miniaturization have been discussed. Examination of varactor tuning techniques and a consideration of large signal effects are presented. Distributed and active inductors and their relative advantages and disadvantages are presented. Distortion and low-noise performance of field-effect transistor (FET) and switching mixers are presented with comparisons of dynamic range.
