On the Equivalence in Performance of Several Phase-Locked Loop Configurations

A double-superheterodyne tracking loop using two frequency converters to provide coherent reference signals for demodulation is analyzed and compared to two other well-known configurations. It is shown that if the loop parameters are defined appropriately, then the dynamic noise performance of the loop is identically equivalent to that of a standard phase-locked loop or a double-superheterodyne tracking loop using a noise-free external reference generator.