Long-term multipactor discharge in multicarrier systems

Abstract

A new mechanism of long-term multipactor in multicarrier systems is studied employing both analytical and numerical methods. In particular, the investigation is focused on the impact that a realistic secondary emission yield at low energies produces on the development of long term multipactor. A novel analytical model for this interperiod charge accumulation is presented using the traditional multipactor theory for parallel plates, and approximating the multicarrier signal as a single-carrier signal modulated by a pulsed signal envelope. The analytical predictions are verified by numerical simulations for a typical rectangular waveguide. The analytical and numerical results demonstrate that the susceptibility of the system to develop a long-term multipactor discharge increases with higher values of low-energy secondary emission yield.

Prediction of Multipactor Breakdown for Multicarrier Applications: The Quasi-Stationary Method

“…The intervals in which V e (t) is above V SC are called "on" intervals, and those where it is below are known as "off" intervals [22]. Since the envelope is periodic, "on" and "off" intervals are intercalated indefinitely in time.…”

“…Hence, there will be a multipactor discharge in two cases: Either the "on" interval is long enough to make the electron population grow to a detectable level in the first period of the envelope, which is called a single-event discharge, or the electron growth during the "on" interval is higher than the electron absorption during the "off" interval. This makes the electron population grow slowly, period after period, culminating in a long-term multipactor discharge [22], [23]. Fig.…”

“…This scenario is valid for voltages above and below the multipactor threshold, which implies electron growth and absorption, respectively. In this scenario, the electron multiplication can be approximated by [22] …”

Determination of multiple roots of nonlinear equations and applications

“…Now, analyzing the relation between the second step in (1) and in (10), by using (15) and (16) we get:…”

“…Multipactor is an undesirable RF breakdown that may occur in the high power microwave devices working under the vacuum condition [15]. A particular scenario where the multipactor appears is inside a parallel plate waveguide.…”