Application Note: Impedance Matching Techniques For Mixers And Detectors

The use of tables for designing impedance matching filters for real loads is well known. Simple complex loads can often be matched by this technique by incorporating the imaginary portion of the load into the first filter element. This technique is rarely useful for matching diodes because the equivalent circuit for the diode must include several real and imaginary elements. A methodical technique for matching such complex loads to a transmission line will be described. Previous references to similar procedures were empirical in nature. No tables are used, but it is necessary to know the admittance of the diode in the frequency band of interest.