Simple, broadband relative phase measurement of intermodulation products

Single tone and two-tone tests are used to characterize the nonlinear response of RF and microwave systems. One-tone testing is relatively straightforward. In contrast, two-tone testing results in the generation of intermodulation frequencies and generally only the magnitudes of these are measured. However full characterization requires that phase be extracted as well as magnitude. Measurement of the phase of intermodulation frequencies has historically been difficult. In this paper we present a broadband technique for performing the relative phase measurement of the intermodulation frequency components generated in a two-tone test. The method uses three phase-locked sources and common equipment found in a microwave laboratory.

[1]  Bumman Kim,et al.  Measurement of two-tone transfer characteristics of high-power amplifiers , 2001 .

[2]  Timo Rahkonen,et al.  Measurement technique for characterizing memory effects in RF power amplifiers , 2001 .

[3]  U. Lott.  A method for measuring magnitude and phase of harmonics generated in nonlinear microwave two-ports , 1988, 1988., IEEE MTT-S International Microwave Symposium Digest.

[4]  M.B. Steer,et al.  Modeling distortion in multichannel communication systems , 2005, IEEE Transactions on Microwave Theory and Techniques.

[5]  P.J. Tasker,et al.  A study of the effect of envelope impedance on intermodulation asymmetry using a two-tone time domain measurement system , 2002, 2002 IEEE MTT-S International Microwave Symposium Digest (Cat. No.02CH37278).

[6]  Ralf Dörner,et al.  Multiharmonic generators for relative phase calibration of nonlinear network analyzers , 2001, IEEE Trans. Instrum. Meas..

[7]  Joel Dunsmore,et al.  Novel Two-Tone Intermodulation Phase Measurement for Evaluating Amplifier Memory Effects , 2003, 2003 33rd European Microwave Conference, 2003.

[8]  K.A. Remley,et al.  Simplifying and interpreting two-tone measurements , 2004, IEEE Transactions on Microwave Theory and Techniques.

[9]  N. Suematsu,et al.  Transfer characteristic of IM/sub 3/ relative phase for a GaAs FET amplifier , 1997, 1997 IEEE MTT-S International Microwave Symposium Digest.

[10]  J. Verspecht,et al.  Calibrated vectorial nonlinear-network analyzers , 1994, 1994 IEEE MTT-S International Microwave Symposium Digest (Cat. No.94CH3389-4).