Design considerations in lossy dielectric nonlinear transmission lines

Nowadays research on nonlinear transmission lines (NLTLs) is an area of intense study for replacing electronic tubes in compact high power microwave devices in military applications, surveillance and monitoring systems, ultra-wide band radars, etc. Although, great success was achieved using based-ferrite bead element lines up to 1 GHz, attempts to operate at higher frequencies above 100 MHz using dielectric element lines has been described as unpractical due to the capacitor dielectric losses that damp significantly the amplitudes of the RF output oscillations. In order to address that, in this paper by means of Spice and numerical simulations it will be shown the possibility of producing oscillations with lower damping using conventional dielectrics of higher losses at frequencies above 1 GHz using ceramic slabs such as the lead-manganese-niobate (PMN) piezoelectric with high equivalent series resistance (ESR) of about 2 Ω.