From frequency-domain, physics-based modeling to time-domain simulation of high data-rate performance II: non-linear gain with memory

Summary form only given. The explosive growth in telecommunications dictates the use of digital modulation techniques in wireless systems, and amplifiers for these systems must meet criteria that are usually specified in the time-domain. However, the physics-based nonlinear simulation of amplifiers such as traveling-wave tubes (TWTs) has been implemented traditionally in the frequency-domain, and traditional amplifier performance specifications usually relate to frequency domain properties. Thus, the impact of trade-offs of amplifier properties on digital signal performance is not directly obtainable. This is particularly true if the device under consideration has internal reflections that produce a frequency response with structure over the bandwidth of the digital signal, thus introducing significant memory effects. Here we present a new model that incorporates frequency dependence into the non-linear gain, i.e. a non-linear gain with memory.