Stability study of vortex amplifier (VA) distributed circuits

The stability analysis of distributed vortex amplifier (VA) circuits is considered, in particular with the analytical prediction of the phenomenon of transport delay surge. The analysis requires a dynamic VA model and a method for modelling and simulating the VA and the attached system. The transmission line modelling (TLM) method has been chosen for the analysis since it is particularly suited to distributed parameter systems. The method is briefly discussed. A lumped VA model previously developed is transformed into a distributed one to conform with the simulation method, and is then used in the stability analysis of several VA circuits. The analytical results show good agreement with experiment. Also, a new form of instability is identified which, as in the case of transport delay surge is the result of the interaction of a transport delay within the VA with the associated system dynamics.