Measurement of intermodulation and a discussion of dynamic range in a ruby traveling-wave maser

This paper reports measurements of intermodulation in a ruby traveling-wave maser. The power level at frequency 2f2-f1was measured when strong signals at frequencies f1and f2were applied to the maser. In agreement with theoretical predictions, the intermodulation level was found to be extremely weak. Results of the measurement can be expressed as P(2f2- f1) = 2P(f2) - P(f1) - 95 where f1=4110 Mc, f2=4140 Mc and the powers are measured in dbm. The pertinent characteristics of traveling-wave masers are summarized in a concluding Section.