A Grid Aplifier Improved Model

Grid amplifiers have been demonstrated to be very attractive solution for medium and high power generation at high frequencies. A grid amplifier is made by an active loaded grid cascaded with input and output polarisers. The models employed for this configuration are usually based on transmission line equivalent circuits where the grid cell and the polarisers are evaluated considering their equivalent reactances. In this paper an improved technique for grid amplifier modelling will be introduced. In particular an S-matrix representation derived from a full wave analysis has been considered for the polarisers and for the grid leads. Based on the proposed model, a 4.5 GHz 16-element grid amplifier has been designed and manufactured.