Simplifying and Interpreting Two-Tone Measurements
Catherine A. Remley, Dylan F. Williams, Dominique Schreurs, John Wood
We develop a mathematical description of the response of systems to second-order memory mechanisms based on a time-varying gain modulation function. We show that intermodulation products arising from interactions at baseband have different phase symmetries from both interactions at second-harmonic frequencies and gain compression and thus, may be readily distinguished through measurement. We also use a technique for measuring and aligning the phase of intermodulation products outside the measurement bandwidth of our instrumentation to identify contributions to memory with broad frequency response.
IEEE Transactions on Microwave Theory and Techniques