New insight in operating modes and optimum design of harmonic TED oscillators for W-band applications

In the present contribution, characteristics of harmonic Gunn oscillators for applications at W-band frequencies are determined by systematic large signal simulations. Based on Monte Carlo (MC) calculations of real active device structures, an accurate full hydrodynamic model has been developed in order to maximize computation speed. An efficient convolution method is used to take the load impedance characteristic of practical resonant mounting structures into account. Investigations of fundamental and harmonic operation with impressed voltages or currents reveal an exceptionally broad range of emitted powers which easily explains varying experimental observations. Numerical results obtained by consistent simulations including the passive load agree well with measurements and allow a deep insight into actual operation principles of the whole oscillator circuit. A preliminary result indicates that even simple Gunn device structures enable power generation at D-band frequencies.