Exploiting Two-Tone Excitations for Multipactor Mitigation and to Determine the SEY of Materials

We exploit the effect of two-tone excitations on two-surface multipactor to mitigate multipactor for a microstrip transmission line, and to determine the SEY of copper samples. Simulations predict that adding a second tone with a certain frequency and amplitude relative to the primary operating signal will shift the multipactor region to higher power, thereby suppressing multipactor for the primary operating tone and power level. Simulations also indicate that whether or not multipactor occurs under two-tone excitation is highly sensitive to the SEY of the surfaces, such that a modest reduction in the SEY may be sufficient to suppress multipactor for a specific two-tone combination. We experimentally investigate this by testing an oxidized copper sample, and a de-oxidized version of that oxidized copper sample. We are also investigating these effects further using controlled-porosity samples as a means of varying the effective SEY.